Xarhiiriirk verholen. 

 Ucbertetzungsrecht voihehalten. 



On Stichocotyle nephropis Cunningham, a Parasite of 

 the American Lobster. 



By 



W. S. Nlckerson. 



(Coutributions from the Zoological Laboratory of the Museum of Com- 

 parative Zoology at Harvard College, under the direction of E. L. Mabk, 



No. XLIX.) 



With Plate 29-31. 



Contents. 



1. Introduction. Literature, Material, Methods. Attempts at in- 

 fection. 



2. Description of live animal. 



3. Description of systems of organs. 



a) General form, size, arrangement of suckers &c. b) Cuticula. 

 c) Musculature, d) Suckers, e) Parenchyma, f) Digestive 

 system, g) Excretory system, h) Sexual organs, i) Nervous 

 system, j) Sense organs. 



4. Classification. 



5. Probable life-history. 



6. Literature cited. 



7. Explanation of figures. 



The parasite which is the subject of this paper was discovered 

 by chance in one of the lobsters used for dissection in the course on 

 the Morphology of Animals in Harvard College. In the specimen 

 upon which one of the students ^) was at work a considerable number of 

 small swellin{,'s were observed upon the wall of the posterior part of 

 the intestine and of the rectum in the vicinity of the rectal gland. 

 These appeared to be the cysts of some parasite, but as I could not 



1) Mr. W. T. Bush. 



