Open Access

Alfonso Neri Garcia Aldrete

• Twenty two species of Lachesilla were found in the West Indies and Trinidad, 11 of which are here described. Twelve species inhabit the Greater Antilles (with two exclusive endemics), four species are found in the Lesser Antilles (with two exclusive endemics), and 11 species are found in Trinidad, four of which are exclusive endemics. Two species are shared between the Greater and the Lesser Antilles. Nine of the 12 species of the Greater Antilles also occur in Mexico and the US., eight species also occur in Central America and three species are also found in South America. One of the four species of the Lesser Antilles is also found in Mexico, the US., Central and South America. Four of the 11 species of Trinidad also occur in North America, four are also found in Central America, and four are also found in South America. There is a sharp drop in number of species from Trinidad to the islands north of it. The assemblages of Lachesilla species of the Greater Antilles, the Lesser Antilles and Trinidad are distinct. The genus has undergone little speciation in the Greater and in the Lesser Antilles; in Trinidad some speciation may have occurred by isolation from mainland populations. The greater diversity of Lachesilla on Trinidad may be due to more collecting and to greater proximity to the mainland.