1888.] NATURAL SCIENCES OF PHILADELPHIA. 165 



PAKASITIC CRUSTACEA. 

 BY JOSEPH LEIDY, M. D. 



Attached to the Shark, Odontaspis littoralis, caught at Beesley's 

 Point, N. J., above indicated, on each side of the mouth, hanging 

 from the upper lip, were a number of lernean parasites, and these 

 were thickly covered with a hydroid parasite. The lernean appears 

 to be an undescribed species, and may therefore be distinguished by 

 the following name and characters. 



Lerneonema procera. 



Animal pale yellowish. Head horizontal, semi-oval, convex 

 above, with three, short, blunt occipital tubercles, fore part convex, 

 excavated beneath and enclosing the mouth, antennae and maxilli- 

 peds ; neck long, linear, cylindrical ; body short, fusiform, and trun- 

 cated behind ; tail longer than the body, linear, cylindrical. Egg 

 pouches, long, linear, cylindrical. Length 70 mm. ; including egg 

 pouches 90 mm. Head 3 mm. long ; neck 30 to 45 mm. long. 0"375 

 thick ; body 10 to 12 mm. long, I'TS thick ; tail 12 to 15 mm. long, 

 0'5 thick. Egg pouches 20 mm. long, 0"25 thick. 



The hydromedusarium appears to belong to Uucope parasitica, 

 found in the same manner, by A. Agassiz, on a lernean of Ortha- 

 goriscus mola. Some of the stems rise from the creeping root from 

 5 to 8 millimeters, with short branches, two or three ringed. The 

 polyp-cups are 0*375 mm. long by 0*25 wide. The stems are O'l 

 mm. thick, and the alternate lateral branches about 0'2 long. 



From the fin of a Shark, also caught at Beesley's Point., but the 

 name not ascertained, there was obtained a single specimen of a 

 lernean, which nearly resembles the Perrisopus dentatus, of Steen- 

 strup and Liitken. It is 5 mm. long. The cephalothorax is a little 

 smaller than the abdominal segment, and between them are three 

 pairs of dorsal lobes which completely cover the space. The egg 

 pouches are linear and 0*25 mm. thick. 



