1903.] ENTO-PARASITES OF THE " SKEAT EXPEDITION." 149 



ACANTHOCEPHALA. 



Fam. ECHINORHYNCHID^. 



ECHINOBHYNCHUS PATANI, n. sp. (Plate XVI. figs. 9 & 10.) 



The encapsuled larvte of Echinorhynchidse are by no means 

 uncommon in snakes, and von Linstow * suggests that their corre- 

 sponding adult forms are to be looked for in the bodies of raptorial 

 birds. In the paper referred to, he enumerates species of these 

 parasites taken from snakes the names of which he gives. 

 Unfortunately many of the names are nomina nuda, and the hosts 

 cannot now be identified, and the same is the case with the new 

 species here described, as the name of the snake was not preserved. 



The cysts are at most 10 mm. long by 5 mm. broad. The worm 

 is bent twice, and the three limbs may lie in one plane or in two. 

 One of the specimens had escaped from its cyst, and had already 

 inserted its spiny head into some piece of tissue from which it was 

 well nigh impossible to free it. Another had freed its head and 

 straightened out its body, which, however, was still svirrounded by 

 a thin film-like sheath of tissue. The length of these specimens 

 was 25 mm., the breadth of the trunk was 2 mm., of the head 

 1 mm. The hooks were arranged in 12-14 longitudinal rows, the 

 hooks of one row being at the level of the space between two 

 neighbouring hooks of the row right and left (PI. XVI. fig. 10). 

 In this way the hooks in the horizontal rings also alternated with 

 one another. There were six of such rings, and the second and 

 third row consist of markedly large hooks, twice as large at least 

 as any of the others. Altogether there were six rings visible ; 

 there may have been one or more hidden by invagination, but I 

 do not think so. 



It is most unfortunate that the name of the snake which 

 harboured this parasite is unknown, but the parasite seems to be 

 a hitherto undescribed species. The names of those already known 

 to be encapsuled in snakes are recorded by von Linstow as 

 follows : — 



(i.) Ech. oligacanthoides Rud., with 4-5 rows of hooks, 

 (ii.) Uch. cinctics Rud., with 140 rows of hooks of similar size. 

 (iii.) Uch. ohligacanthus Rud., with 13 rows of hooks, 

 (iv.) Ech. megacephcdus Westrumb, with very numerous rows 

 of hooks and the proboscis swollen in the middle. 



(v.) Ech. dipsadis von Lins., with some 12-14 rows of large 

 hooks, followed by 20 rows of smaller hooks. 



(vi.) Ech. heterorhynchus Par. Proboscis anteriorly slender 

 with 1 1 rows of hooks, posteriorly enlarged with 1 6 rows of hooks. 



Wedl has mentioned other larval forms found in snakes, but 

 they are not in any case specifically identified. 



* Arch. Naturg. 54 Jahrsang, i. 1888. 



