DE. T. S. COBBOLD Olf STEONGTLUS TETEACANTHTJS. 287 



of the head, there are two papillso, one on each side of the 

 mouth. These I have also seen. The fore gut has a complicated 

 structure, more strikingly so than has hitherto been stated. 

 The mouth leads to a strong buccal cup, supporting a circular 

 series of short bristles (described and figured by Schneider, but 

 only indicated by a dark line in my drawing), which separately 

 have an extreme length of y^^ of an inch. The cup rests upon a 

 muscular ring, which also supports a circular row of small chitinous 

 processes. The ring is succeeded by an anterior oosophageal bulb, 

 the lumen of which is bordered by chitin -plates. Then follows a 

 broad muscular pharynx, through which the narrow chitinous 

 cylinder of the lumen glimmers distinctly, leading down to the 

 somewhat broader posterior bulb, which also displays thick dental 

 plates. By these means an unusually powerful sucking action 

 must result. The fore gut is next succeeded by a broad chyle- 

 intestine marked at the upper part by regular constrictions, due 

 to the presence of muscle-fibres which are connected at their 

 periphery with nucleated muscle-cells that stretch across the 

 perivisceral cavity. The constrictions become less marked 

 towards the lower half of the mid gut, which latter finally ends 

 in a short and narrow rectum, opening in the female at the base 

 of a short conical tail. In some situations fine granules may be 

 seen fioating in the perivisceral fluid, and on one side of the 

 oesophagus a particularly well-marked, colossal unicellular gland 

 is visible. Concerning the sexual apparatus of the male I have 

 little to add, except by way of confirmation of the views of 

 Schneider as to the grouping of the rays of the hood. However, 

 it is worth remarking that in examples of Strongylus tetr acanthus, 

 examined in February 1876, I found the innermost branch of 

 the thrice-divided posterior ray supplied with an oiFshoofc, which, 

 in place of being quite rudimentary, was nearly as long as the 

 primary branch itself. The spicules are narrow, and when x'e- 

 tracted are closely applied to each other, so as to look like a 

 single straight rod of uniform thickness. As regards the female 

 sexual apparatus, the uterine horns and utero-vaginal passage 

 were well seen in the example figured, the cavity of the uterus 

 being crowded with ova near the fundus . 



Eespecting the skin and its appendages, I must explain that 

 the large bristles of the neck described by Schneider were neither 

 seen in the specimen here drawn, nor in any of the numerous 



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