LEIDY'S DESCRIPTIONS OF DISTOMA. 303 



DiSTOMA HORRiDUM. Corpus album, postice brunneo variegatutTi, spathifopme, splnulis minutissimis in annulis 

 transversis dispositis ; disco anteriore subtus et pone apicem sito, ore magno, rotundo, margine incrassato ; 

 intestini ramis rectis ; foramine genitali mox ante discum ventralem sito ; pene exserto, curvato, basi 

 vagina tecto; testiculis 4, epididymibus tenuibus conjunctis; ovariis 2, lateralibus, lobatis; oviducto, 

 iongissimo, plicato, valdeque contorto. 



Long. 2^ Jin.; iat. 1-27 unc. 



Parasiticum in Boa constrictore, in pelve et uretere renis. 



Body uhite, posteriorly variegated with brown arising from the ova along the 

 tortuous and folded oviduct, spathiform, narrowing from behind forwards, furnished 

 with minute spinous appendages arranged in circles around the body, of which 

 there are in the neighbourhood of 200 ; length of spines l-1142d in. Oral acetabulum 

 globular, placed just posterior to the anterior apex of the body, 1-1 07th in. in 

 diameter. Oral orifice large and round when expanded, l-160th in. across. Pharynx 

 broad, l-320th in. long. Oesophageal bulb oblong, I-12-3d in. broad. Oesophagus 

 1-1 14th in. long, dividing into two long straight intestinal branches,' which are dilated 

 or clavate posteriorly. Ventral acetabulum round, a very little larger than the 

 anterior, with the appearance of a transver.se opening, 1-lOOth in. in diameter. 

 Generative orifice just anterior to the ventral acetabulum. Penis exserted, curved, 

 cylindrical, l-63d in. long ; an apparent second portion, rather longer and with a 

 sigmoid curve, is contained in a sheath, at the posterior part of which the vas 

 deferens is connected. Testes four in number u.sually globular and distant : the first 

 or most posterior is l-80th in. in diameter, the second 1-9 7th in., the third is 

 .subreniforra, and is in contact with the last and is l-160tli in ; the fourth is l-89th in. 

 Ovaries two, lateral and anterior to the testes, white, about l-35th in. long, each 

 consisting of ten to thirteen oval or rounded lobes, connected together by a delicate 

 tube ; the two joined by a transverse duct which opens into a very long sinuous and 

 folded oviduct, occupying the posterior two-thirds of the body. Vagina opening at 

 the base of the exserted penis. Ova very numerous, brown, oval, l-727th in. long by 

 l-1333d in. broad. 



Dimensions. — Greatest length 2| lines; shortest li lines; greatest breadth 

 posteriorly l-20th in., anteriorly on a line with the penis l-33d in. 



Habitation and^Remarks. — Of this species of Dtstoma I found twenty-six specimens 

 in the ureters and pelves of the kidneys of a Boa constrictor, which died in the 

 menagerie in this city. They were not contained in cysts, but were loose, and were 

 enveloped in mucous, probably the result of irritation produced by the spinous 

 appendages of the entozoon. The spinous appendages exist from the oral acetabu- 

 lum to the posterior extremity of the body, and are arranged in transverse annuli 

 around the latter, which give the body itself the appearance of being annulated. It 



77 



