Oil the Development of the Pedipalpi. 419 



examination in life would show some silvery lines and longi- 

 tudinal brownish stripes. JMr. Cunningliam adds ihat the 

 resemblance of this spider to a caterpillar is very remarkable ; 

 and no doubt in life the caudal prolongation is mobile. 



The genus Ariamnes has a very wide range; but I have 

 not before seen an example of it nearer the East Indies than 

 Cevlon. 



EXPLANATION OF PLATE XXII. 



Fig. 1. Ariamnes simulnns, 5 , enlarged. 



Fig. 2. Ditto, in protile, less enlarged. 



Fig. 3. Fore part of the caput, showing the position of the eyes. 



Fig. 4. Genital aperture. 



LI I. — Ofi the Development of the Pedipalpi. By Dr. A. 

 Strubell, of the Zoological Institute of Bonn am Rheiu*. 



In view of our scanty knowledge of the natural history of the 

 Pedipalpi, I made it one of my principal tasks during a 

 lengthy sojourn in the Malay Archipelago to follow out in 

 greater detail the development and life-history of a represen- 

 tative of this group of Arachnida, which offers so many 

 points of interest. As the subject of my investigations I 

 selected Thelyphonus caudatus, which, while widely distri- 

 buted in these islands, is particularly common in Java, where 

 I spent several months. 



Guided by the erroneous statements of the text-books, 

 according to which the Pedipalpi are viviparous, I commenced 

 by sacrificing a considerable number of specimens without 

 ever discovering embryos in their genital ducts, until towards 

 the end of October I received a female, to the ventral surface 

 of which there was attached a fairly capacious egg-sac. 



I am indebted to my little Malay friends for the gradual 

 acquisition of a larger number of eggs, representing a develop- 

 mental series, which is not absolutely continuous, it is true, 

 but nevertheless embraces the most important stages. 



As regards all details of my results I must refer the reader 

 to a fuller account which I hope shortly to be able to lay 

 before those who are interested in the study of the group j I 

 now merely desire to give a brief outline of the development 

 of the external bodily form. 



* Translated from the * Zoologischer Anzeiger,' xv. Jalirg. (1892), 

 no8. 385 and 380, pp. 87 93. 



29* 



