411 



Brain and latterai nerves as in other metanemerteans. 

 Usually oviparous, although fertilization often takes place inter- 

 nally, and sometimes a portion of the ova of an individual may be re- 



hr-i- 



Fig. 2. Horizontal section of proboscis of Carcinon einer tes epialti; slightly dia' 



grammatic; g, gland cells surrounding basis of stylet; ct, connective tissue in which« 



rudimentary proboscis sheath is imbedded. Other reference letters as in Fig. 1. 



tained until the development of free-swimming embryos. Development 

 without complicated metamorphosis, although the layer of ciliated 

 cells originally covering the embryo is shed as development proceeds. 

 The principal synonomy of the type species is as follows: 



Carcinonemertes carcinophila (Koelliker) Coe. 

 American Naturalist, Vol. XXXVI, 1902. 

 Host: Platyonychus ocellatus; on the gills when young; mi- 

 grating to the egg-masses when sexually mature; coast of 

 New England. 

 Nemertes carcinophilos Koelliker. 



Verb. Schweiz. Nat. Ges. Chur, p. 89—93. 1845. 

 Host: »Small crab«; Messina. 

 Folia involuta van Beneden. 



Mém. Acad. Roy. de Belgique, Tome XXXII, p. 18 — 23, 



PI. Ill figs. 1—30. 1861. 

 Host: Egg masses of Carduus maenas\ 

 Coast of Belgium. 



