108 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



aa. Ocelli fragmented or wanting . . . . d. 



d. With four groups of fragmented ocelli. 



1. Body usually less than 12 mm. in length; color pale 

 yellow ; 12 proboscidial nerves. T. aberrans, p. 29o. 

 dd. Ocelli wanting ; hermaphroditic. 



1. Body f) to 10 nun. in length; color whitish or very 

 pale yellowish ; probably parasitic, perhaps in 

 Tunicates. .... 7". caecum, p. 302. 



FF. Proboscis sheath provided with caecal appendages; proboscis 

 armed with central plate bearing a number of stylets, besides 

 several pouches of accessory stylets. Drepanophorus, p. 283. 

 1. Ocelli numei'ous, of very large size ; length of body 5 to 10 cm. ; 

 color of dorsal surface dull reddish or orange, thickly covered 

 with fine brownish dots ; ventral surface flesh color with tinge 

 of orange. ...... D. ritteri, p. 283. 



EE. Proboscis without stylet ; intestine dendrocoelous ; pelagic ; body 



without external appendages. . PLANKTOiSfEMERTf:.s, ]). 304. 



1. Body broad, much flattened, gelatinous and hyaline ; intestinal 



diverticula numerous ; median dorsal vessel present ; length 14 to 



47 mm.; color orange or pink . . . P. a^as,s«zu, p. 304. 



EEE. Proboscis withoiit stylets ; body pro^dded with a pair of cirriform 



appendages in nuchal region. . Nectonemertes, p. 30(). 



Bdellonemertea . 



Sucking disk present at posterior end of body ; intestine coiled, without 

 caecum or lateral diverticula ; i>arasitic in various species of Pelecypods. 



JMalacobdeli.a, \). 305. 



Systematic Account of the Genera and Species with 

 Descriptions of New Species. 



Carinella Johnston. 

 Mag. Nat. Hist. London, 6, p. 232, 1838. 



The 8j)ecies belonging to this genus are characterized h\ a slender, 

 soft, rounded l)ody, capable of extending and contracting to a 

 remarkable degree. Head distinctly marked off from body, usually 

 much broader than parts immediatelj^ following, often flattened 

 dorso-ventrally, and disk-like. 



On each side of body a transverse furrow separates the head from 



