16 DR. G. S. GIGLIOLI ON THE 



the original specific denomination given by Diesing in 1835, so 

 that this tongue-worm is now known under the name of Raillie- 

 tiella furcocerca. 



Through the kindness of Dr. Khali], of the Department of 

 Helminthology of the London School of Tropical Medicine, I 

 have been able to examine two female specimens of this parasite, 

 collected from the lungs of an Amphishcena alba, which died in 

 the London Zoological Gardens, and I would now submit the 

 following as a more accurate description of the external mor- 

 phology of this species : — 



Length 26 mm. ; breadth 1 mm. (anteriorly). The cephalo- 

 thorax is the bulkiest ]3art of the body, and from it the abdomen 

 tapers gradually towards the caudal extremity. The body is 

 straight and delicate. The cephalothorax is roughly triangular 

 in shape, with the generic characters of RaillietieUa very well 

 marked. The mouth is terminal, but situated on the ventral 

 surface. The oral papilla is shield-shaped and large, with a well- 

 marked chitinous outline. It is surmounted by two small 

 rounded papillae, which are terminal. Laterally, and slightly dor- 

 sally to these, other two long finger-shaped papillae are situated, 

 which are directed laterally. These structures occupy the apex 

 of a large fleshy cone which forms the anterior part of the 

 cephalothorax, and is very slightly flexed ventrally. At its base 

 the anterior pair of hooks are situated. The whole chitinous 

 hook-apparatus is remarkably small, especially the root. They 

 are supported, or rather enclosed, by a voluminous fleshy struc- 

 ture, which protrudes laterally, so that when the hook is at ]'est 

 not even its tip is free. The hooks are, in fact, only visible by 

 transparenc}^. Their fleshy base presents a somewhat complicated 

 form, in which three parts can be distinguished : an exteiiial 

 rounded pad or mass situated laterally to the hook and slightly 

 behind it ; a similar but smaller structure symmetrically situated 

 on the internal aspect of the hook ; and a compressed, trans- 

 parent hood, situated over the two preceding organs, and which 

 shrouds the hook, both root and blade. The hood is open at its 

 lower end, so as to allow the extrusion of the hook-blades, but 

 these are so small that only a very little part of the blade can 

 ever be freed from its fleshy sheath. The hooks are smooth and 

 simple, the posterior pair slightly larger, and supported hy a 

 much larger and stronger base. As in other species of the genus 

 RaillietieUa, the large sensitory papillre, corresponding to the 

 anterior or medial pair of hooks, are finger-shaped and of unusual 

 sizo, and situated on the latero-dorsal sui'face of the cephalo- 

 thorax. Behind these and a little nearer to the median doi'sal 

 line two other smaller papillae are visible. These I have not 

 observed in other species {R. boulengeri, R. geckonis). 



The abdomen is fairly cylindroid in its anterior third, and then 

 tapers gradually to the posterior extremity, Avhich is acumiijated 

 and bifid. Tlie annulation, though present, is practically efiaced, 

 so that the number of rings cannot be given. On the first five 



