86 Mr. B,. I. Pocock on the Genus Poecilotheria. 



pale bands and patches being far less clearly defined. They 

 also resemble the females in the development of the femoral 

 fringes on the legs ; but they differ strikingly from them in 

 the much smaller size of the body and the relatively much 

 greater length of the limbs, and also, as in the case of all 

 spiders, by the presence of the so-called palpal organ on the 

 tarsal segment of the palpus or short limbs of the first pair. 

 This is the intromittent organ of the male, and in Poecilo- 

 theria takes the form of a horny pear-shaped structure with 

 three sharp crests running spirally round its narrow apical 

 portion. 



The earliest known species of the genus Poecilotheria was 

 described by Latreille as My gale fasciata, and was based upon 

 the figure of a large spider named Aranea maxima ceilonica, 

 published in Seba's ' Thesaurus,' vol. i. pi. lxvii. The true 

 fasciata, therefore, is a Ceylonese species. 



C. Koch, who was practically the first to dismember the 

 old genus Mygale of Latreille and Walckenaer, in 1850 gave 

 to. this Ceylon spider the generic name Scurria. Unfortu- 

 nately this name had three years earlier been applied to a 

 mollusk, and since it is against the rules of zoological nomen- 

 clature for the same name to be used for two distinct animals, 

 Simon in 1885 proposed Poecilotheria to replace Scurria of 

 C. Koch. 



Up to 1885 the genus Poecilotheria, with its supposed 

 single species fasciata, was considered to be peculiar to the 

 island of Ceylon. In that year, however, Simon recorded 

 the occurrence of the species from Ramnad, in the Madura 

 district of S. India (Bull. Soc. Zool. France, 1885, p. 38). 

 Touching the accuracy of this determination, it is permissible 

 to have doubts ; nevertheless the discovery that the genus is 

 not confined to Ceylon was important. No one, however, 

 seems to have suspected the existence of more than one species 

 of Poecilotheria up to 1895. Early in that year I worked 

 out the material of this genus contained in the British 

 Museum, with the result that two well-marked, sharply 

 defined species of the genus were found to occur in Ceylon, 

 another in S. India, and a third in the island of Pinang *. 

 These species were briefly described in the February number 

 of the ' Annals.' The discovery of two species in Ceylon of 

 course raised the whole question as to which of the two was 

 the genuine fasciata. The two species seem to be equally 

 common in the island, and it was quite certain that specimens 



* For correction of this locality see note on p. 9(3. 



