426 



the genus Syngamus of Siebold from it (which, however, is not ad- 

 mitted by Diesing), there would remain only four, or perhaps five 

 species. Two of these have been observed in the Horse (Equus ca- 

 ballus) } the Ass (E. asinus), and in the Mule ; a third in the Pig (Sus 

 scrofa) and in the Peccaries {Bicotyles torquatus and albirostris) ; 

 a fourth in the American Tapir {Tajpirus americanus) ; and perhaps 

 a fifth in the Puma (Felis concolor). An addition to this small 

 number may not be uninteresting. 



The Sclerostome which I am now about to describe is a small 

 Nematoid worm, of from 1 0 lines to 1 inch in length ; of a light 

 flesh-colour when alive, but nearly white in spirits. The body is 

 cylindrical in shape, thicker in the middle, tapering towards each 

 extremity, and finely striated across, though the strise are rather 

 distant from each other. The head is rather large, cylindrical, about 

 1 line in length, truncated at the apex, thicker than the neck, and 

 separated from it by a distinct line or groove. The mouth is orbi- 

 cular, placed in the centre of the truncated part of the head, and 

 surrounded with two horny capsules or bullae, the limb or margins of 

 which are each armed with a row of numerous teeth. The limb of 

 the external capsule is the larger of the two ; and the teeth, though 

 numerous, are less so than in the internal limb, and are stronger and 

 pointed outwards. The limb of the inner capsule is much smaller, 

 the teeth very minute and exceedingly numerous. This portion of 

 the body does not differ in the two sexes. 



The tail of the male is in the form of a membranous expansion or 

 pouch surrounding this extremity of the body, and is divided into 

 three lobes. The central lobe is the largest, and is supported by 

 seven ribs or rays, three in the middle and two at each side. The 

 three central ribs are dichotomous, and the middle one of these has 

 its two branches sending off two or three short processes, like buds ; 

 the two others are simple. Of the lateral ribs (two on each side), 

 the innermost one is dichotomous, the two branches into which it is 

 divided sending off short processes or buds ; the outer rib is simple. 

 The two lateral lobes of this caudal expansion are smaller than the 

 central one, and are each supported by four simple ribs. 



The tail of the female terminates in a rather long and sharp point, 

 which is oblique in position to the body, owing to a sort of tubercle, 

 about half a line from its extremity, under which is situated the 

 anus. This aperture is very distinctly seen immediately underneath 

 the tubercle ; and the vulva, which is not very conspicuous, and is 

 in the form of a narrow slit across the body, is situated immediately 

 above the tubercle. 



The oesophagus is rather long, and terminates in a lobed stomach, 

 which extends for a short distance and then terminates in a straight 

 intestinal canal running through the whole length of the animal. 

 The uterus is peculiar in form, and presents a very pretty appearance 

 under the microscope ; it is two-branched, and has during its length 

 several expansions or swellings followed by contractions ; and the 

 ovaries are very long and twisted round the intestine. 



This species of Sclerostomy differs in many characters from any 



