The mating behavior of the nursery web spider Pisaurina mira is described for the first time. These spiders mate while suspended from draglines as in Oxyopes heterophthalmus (Latr.) and Peucetia viridans (Hentz). The unique feature of the mating in P mira, however, is the male's use of a veil of silk to wrap the female's legs I and II into a flexed position prior to copulation while her legs III and IV are held in a flexed position by the male's embrace. Mating is accomplished in a version of position II with body axes in a right angle as the female is cradled by the male's legs. The use of silk to tie the female is reported elsewhere only in Xysticus.

The Neotropical spider genus Thaumasia Perty, 1833 is revised. Seven of the known species are redescribed andillustrated: Thaumasia senilis Perty, 1833 (type-species); T. abrahami Mello-Leitão, 1948; T. annulipes F.O. Pickard-Cambridge, 1903; T. argenteonotata (Simon, 1898); T. heterogyna Chamberlin & Ivie, 1936; T. scoparia (Simon, 1888)and T. velox Simon, 1898. Ten new species from the neotropical region are described and illustrated: T. caxiuana sp.nov., T. onca sp. nov., T. diasi sp. nov., T. xingu sp. nov., T. acreana sp. nov., T. caracarai sp. nov., T. peruana sp.nov., T. hirsutochela sp. nov., T. lisei sp. nov. and T. oriximina sp. nov. The types of Thaumasia senilis are assumed tobe lost and neotypes are designated. The males of Thaumasia heterogyna, T. annulipes, T. abrahami and the female ofThaumasia senilis are described and illustrated for the first time. Thaumasia annecta Bryant, 1948 and T. decemguttataMello-Leitão, 1945 are synonyms of Thaumasia velox. Thaumasia argyrotypa Chamberlin & Ivie, 1936 issynonymized with Thaumasia heterogyna. Thaumasia argentinensis Mello-Leitão, 1941 is transferred to Lycosidaeand Thaumasia benoisti Caporiacco, 1954 is a junior synonym of Architis spinipes (Taczanowski, 1874). The types ofThaumasia argyrura Mello-Leitão, 1943, Thaumasia brunnea Caporiacco, 1947, Thaumasia strandi Caporiacco, 1947and Thaumasia rubrosignata (Mello-Leitão, 1943) are juvenile specimens, and those species are considered as speciesinquirendae. The type of Thaumasia niceforoi Mello-Leitão, 1941 was not found and is this is species is considered a nomen dubium.

The Neotropical spider genus Paradossenus is revised and currently comprises a total of 14 species. P. andinus (Simon 1898), P. protentus (Karsch 1879) and P. venezuelanus (Simon 1898) are new junior synonyms of P. longipes (Taczanowski 1874), the type species of the genus. Five known species, P. longipes, P. caricoi Sierwald 1993, P. pulcher Sierwald 1993, P. corumba Brescovit & Raizer 2000, and P. minimus (Mello-Leitão 1940), are redescribed and illustrated. New species: P. isthmus, P. benicito, P. amazonensis, P. acanthocymbium, P. tocantins and P. pozo are described from both male and female. The new species P. sabana is described only from the male while P. junin is described only from the female. The subfamily Trechaleinae is erected, diagnosed, and an illustrated key to all the included genera is presented.

The species currently known as Tetragonophthalma taeniata (Mello-Leitao, 1943) is transferred to the genus Hogna of the family Lycosidae after examination of the juvenile holotype, Birabenia taeniata Mello-Leitao.

A new species of Trechalea Thorell 1869, T. rothi from Colombia, South America, is described, illustrated and compared with the only other two species of the genus also known from Colombia, T longitaris (C.L. Koch 1848) and T. lomalinda Carico 1993. Additionally, it is compared with the similar species, T trinidadensis Carico 1993. A single female from Para, Brazil, is also described and illustrated as a new species, Enna xingu, based on features of the genitalia.

The male of the species, Trechalea trinidadensis Carico 1993, is described for the first time. The distributional range for this species is extended from Trinidad to Brazil.

The genus Dyrines, is revised for the first time since Simon provided the name in 1903 to replace the preoccupied Drances. A female lectotype is designated for the type species, Dyrines striatipes (Simon 1898), which is redescribed and illustrated. The holotype of D. taeniatus Mello-Leitao 1943 is a tiny spiderling and is considered a nomen dubium. Dyrines lineatipes Petrunkevitch 1925 is regarded as a junior synonym of D. striatipes. Dyrines rubriosignatus Mello-Leitao 1943 is transferred to the genus Thaumasia, resulting in Thaumasia rubrosignata (Mello-Leitao 1943b), new combination. Two new species are described and illustrated: D. huanuco from Huanuco, Peru, and D. ducke from Reserva Florestal Adolfo Ducke near Manaus, Brazil.

Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted until now to Pisauridae. Here, we describe this behavioral pattern found in two Trechaleidae species, Paratrechalea azul Carico 2005, and Paratrechalea ornata (Mello-Leitão 1943), mainly based on field observations. We observed the following steps of sexual behavior: sperm induction, nuptial gift construction, mate searching, pre-copulatory courtship, copulation, and copulatory ending. In this group, a nuptial gift consists of a prey wrapped in silk, which appears as a white rounded shape. The male carries his nuptial gift in his chelicerae while searching for a female. When he finds a female, he shows a stereotyped courting behavior consisting of a hyperflexed posture that is also assumed by the receptive female while they face each other. The copulatory position and pattern is similar to that found in other Lycosoidea: the male mounts the female and makes a total of four palpal insertions while alternating sides. However, after each palpal insertion the male dismounts and returns to a frontal position while biting the gift. Copulatory courtship is evidenced by palpal and leg movements. The copulation ends by female initiative and she almost always retains the nuptial gift. No case of pre-copulatory or post-copulatory cannibalism has been recorded. Descriptions of nuptial gift construction by males and copulation in these species, as well as hypotheses about the origin of nuptial gift construction among spiders, are presented. These descriptions are the first records of such nuptial gift offering for Neotropical spiders and for non-Pisauridae species as well.

A single male from Oaxaca, Mexico is described as the new species, Tinus oaxaca, based on distinct features of the palpus including the shape of the retrolateral apophysis, the position of components of the palpal bulb, and the color pattern of the dorsum. Notes on the current taxonomic status of the genus Tinus are included.

The spider genus Dossenus Simon, 1898, with six species, is revised. The types of Dossenus marginatus Simon, 1898 are redescribed. One new species, D. guapore from Mato Grosso, Brazil, is described and illustrated. The types of D. fluminensis (Mello-Leitao), D. marginellus Badcock, D. longipes Mello-Leitao and D. fidelis Mello-Leitao are juveniles and those names are therefore considered species inquirendae.

Two new genera in the spider family Trechaleidae, Trechaleoides and Paratrechalea, are described. The females of the two known species of Trechaleoides, T. keyserlingi (F.O.P.-Cambridge) (type species) and T. biocellata (Mello-Leit (a) over tildeo) are redescribed and their respective males are described for the first time; both are transferred from Trechalea. Two additional previously described species, also both transferred from Trechalea, are herein placed in the genus Paratrechalea are redescribed from their types, i.e., the female of P. ornata (Mello-Leit (a) over tildeo) (type species) and male of P. wygodzinskyi (Soares & Camargo). The male of P. ornata is described for the first time. Four new species of Paratrechalea, P. longigaster, P. galianoae, and P. azul from females, and P. saopaulo from males and females are described. The immature specimen historically regarded as the holotype of Trechalea longitarsis (C.L. Koch) and regarded as a mistaken identity, is an unidentified species of Trechaleoides. The female holotype of Trechalea limai Mello-Leit (a) over tildeo is confirmed to be lost but is considered to be a member of the genus Paratrechalea based on a study of the original description.

Hesydrus palustris Simon and H. habilis (O.P.-Cambridge) are redescribed. Four new species are described: H. caripito, H. yacuiba and H. chanchamayo are described only from females, and H. canar from both male and female specimens. Hesydrus monticola Chamberlin is a junior synonym of H. palustris. Hesydrus bucculentus Simon is a senior synonym of Trechalea cezariana Mello-Leit (a) over tildeo. Hesydrus estebanensis Simon is transferred to the genus Enna O.P.-Cambridge. Hesydrus ornatus Mello-Leit (a) over tildeo and H. bivittatus Mello-Leit (a) over tildeo, known only from unidentifiable spiderling holotypes, are regarded as nomina dubia. Coincidence of geographic distributions of Hesydrus and Trechalea are noted.

The spider family Trechaleidae, introduced by Simon in 1898 but abandoned immediately thereafter, is defined. Characters proposed for trechaleids by recent authors for this family and some characters used to separate it from the Pisauridae and Lycosidae are reviewed. Genera included in the family Trechaleidae, all of which were previously placed in the Pisauridae, are: Trechalea, Hesydrus, Syntrechalea, Dossenus, Paradossenus, Dyrines and Enna. Familial placement of all other genera of the western hemisphere previously placed in the Pisauridae are considered.The genus Trechalea, with eleven species, is revised. Redescriptions of eight known species are given: T. longitarsis (C. L. Koch), T. cezariana Mello-Leitao, T. macconnelli Pocock, T. paucispina di Caporiacco, T. connexa (0. Pickard-Cambridge), T. extensa (0. Pickard-Cambridge), T. gertschi Carico & Minch and T. amazonica F. Pickard-Cambridge. Descriptions of three new species: T. boliviensis, T. lomalinda and T. trinidadensis are presented. The holotype of the type species of Trechalea, T. longitarsis, is lost. The specimen which was previously regarded as the holotype is mislabelled and belongs actually to another, unnamed, trechaleid genus. All other relevant species names not synonymized with any of the above and not previously placed in Trechalea are removed to other known genera or will be later included in new genera.

A Mecynogea lemniscata (Walek.) female with egg sacs removes her orb web by breaking the peripheral anchoring threads and the upper and lower guying threads attached to the surrounding labyrinth. The collapsed web then loosely surrounds the egg sac string which hangs above the open hub of the formerly intact web. Repeated trips by the spider around this fluffy mass tightly wraps it around the egg sac string. The collapsed orb then becomes an additional layer of silk added to the covering of the egg sacs and thus contributes to the survival success of the eggs and young in their exposed position. This previously unknown secondary use of the destroyed orb is a third alternative to two well-known fates, i.e. whether it is ingested or discarded.