409 



Vorliegende Untersuchungen wurden in Wien, im zoologischen 

 Institute des Herrn Prof. Dr. Hatschek angestellt. Herrn Professor 

 und den beiden Assistenten, Herrn Dr. K. C. Schneider und Herrn 

 Dr. H. Joseph spreche ich für die vielen Auskünfte, wodurch sie mir 

 das schwierige Schneiden und Präparieren dieser Thierchen erleich- 

 terten, meinen wärmsten Dank aus. 



Wien, 10. Februar 1902. 



2. The Genus Carcinonemertes. 



By Wesley R. C o e, New Haven, Connecticut. 

 (With 2 figs.) 



eingeg. 19. Februar 1902. 



On the coast of New England, both north and south of Cape Cod, 

 Mass., the lady-crab [Platyonychus ocellatus] is commonly infested with 

 a small, parasitic nemertean. Detailed study of both the young and 

 sexually mature worms indicates that the species is identical with the 

 European form, which was described by Koelliker in 1844, under the 

 name of Nemertes carcinophilos. 



The New England form is described in detail in the American 

 Naturalist for March, 1902 (Vol. XXXVI), and a brief account of its 

 life-history is there given. The anatomical structures are so decidedly 

 different from those of other species of Eunemertes, in which this form 

 is placed by Joubin and Bürger, that a new genus to include this 

 and a newly described, and closely related, species from the Pacific 

 Coast has been established. 



Carcinonemertes. 



Coe, American. Naturalist, Vol. XXXVI, March, 1902. 



Parasitic nemerteans living on various species of Crustacea. Body 

 small, slender, often filiform, rounded and of about the same diameter 

 throughout; head without distinct lateral grooves, not demarcated 

 from body. Body not usually coiled or much twisted, but often folded 

 sharply so that the anterior portion of body lies parallel and in con- 

 tact with the posterior portion. Mouth and proboscis open together; 

 oesophagus extremely short, opening broadly into the intestine through 

 a large muscular chamber, or pharynx, situated immediately behind 

 the brain ; intestine broad, with short lateral pouches which are but 

 little developed in posterior portion of body. 



Proboscis sheath without muscular walls, consisting merely of a 

 thin membrane closely applied to the small proboscis. Proboscis but 

 little developed, very small in size and extremely short, without la- 



