i;o THE NEMERTIN1 



CLASS NEMERTINI, SIEBOLD AND STANNIUS, 1848 



( = Nemertina, Ehrenb. ; = Nemertea, Quatref. ; = Nemertinea, Dies. ; 

 = Aplocoela, E. Blanchard ; = Rhynchocoeldj Max Schultze). 



BRANCH A. DIMYARIA. Nemertines in which the dermal muscula- 

 ture consists of an external coal, of circular muscles and an internal coat 

 of longitudinal muscles. 



SECTION 1. ANOPLA, Max Schultze ( = Palaeonem,ertini minus Eupo- 

 liidae, Hubr.). Dimyaric Nemertines in which the proboscis is not pro- 

 vided with a calcareous stylet ; the mouth is behind the brain, and there 

 is no anterior caecum to the intestine. 



ORDER 1. Protonemertini, Burger. 



Dimyaric anoplous Nemertines in which the brain and lateral nerve 

 cords lie outside the musculature. 



FAMILY 1. CARINELLIDAE, M'Intosh. The cerebral organ is in 

 the form of a shallow vertical furrow, without any relation to the lateral 

 blood-vessel ; there is no dorsal blood-vessel. The intestinal pouches are 

 short and ill-defined. Carinina, Hubr. ; Carinella, Johnst FAMILY 2, 

 HUBRECHTIIDAE, Burg. The cerebral organs are spherical and impinge 

 upon the lateral blood-vessel. A dorsal vessel is present ; the intestinal 

 pouches are deep. Hubrechtia, Burg. 



ORDER 2. Mesonemertini, Burger. 



Dimyaric anoplous Nemertines in which the lateral nerves have sunk 

 into the somatic musculature. 



FAMILY CEPHALOTHRICIDAE, M'Intosh. There is no cerebral organ 

 nor cephalic furrow. Carinoma, Oudem. ; Cephalothrix, Oersted. 



SECTION 2. ENOPLA, Max Schultze. Dimyaric Nemertines in which 

 the proboscis is armed with calcareous stylets, except in certain modified 

 genera. The mouth is in front of the brain, and may be coincident with 

 the rhynchostome. The stomodaeum is complex, and there is usually an 

 anterior, median, and ventral caecum to the midgut. 



ORDER 3. Metanemertini, Biirger ( = Hoplonemertini, Hubr.). 



The brain and lateral nerves have sunk through the somatic muscu- 

 lature and lie in the parenchyma. The mouth is in front of the brain. 



TRIBE A. PRORYNCHOCOELA. Metanemertines with a long, thin body 

 which can coil into a ball ; they creep with eel-like undulations and never 

 swim. The rhynchocoel- never extends into the hinder half of the body, 

 and the proboscis is much shorter than the worm. 



FAMILY 1. EUNEMERTIDAE, M'Intosh. Eyes present. Eunemertes, 

 Vaill. ( = Nemertes, M'Intosh nee Cuv.) ; Nerrwrtopsis, Burger. FAMILY 

 2. OTOTYPHLONEMERTIDAE, Burger. No eyes, a pair of otocysts. Oto- 

 typhlonemertes, Dies. 



TRIBE B. HOLORHYNCHOCOELA. Metanemertines with usually a short 

 body, which does not coil into a ball ; they creep without undulations. 



