36 HISTORY OF THE SUBJECT. 



Order.— NEMERTINEA. 



Sub-order I. — Nemertinea enopla, Max Schultze. 

 Proboscis furnished with a stylet-apparatus. 



Fam. 1. TflEMACEPHALIDiE. 



The fissures of the head short, of a transverse (linear) form, or funnel-shaped. Brain with 

 the superior ganglion less elongated than the inferior, and separated by an almost free border 

 from the latter; the lateral nerve springing from the posterior end of the inferior ganglion, or 

 almost a continuation thereof. 



(a) Fremacephalida without the lobe-shaped front of the head. 



Gen. 1. Folia, Delle Chiaje, 1825. Head easily distinguished from the body, narrowed 

 anteriorly, without eyes. Mouth near the anterior end. Body diminished posteriorly. 



Gen. 2. Forlasia, Oken (char, reform.). Head not distinguished from the body, mostly 

 with eyes. Mouth in some removed the breadth of the head from the anterior end. Body less 

 diminished posteriorly, and generally somewhat short. 



Gen. 3. (Erstedia, Quatref., 1846. Head not distinguished from the body; lateral nerves 

 coursing near the median line, not, as generally, entirely confined to the sides. 



(b) Tremaceplialidce with the lobe- shaped head anteriorly. 



Gen. 4. Micrura, Ehrenberg, 1831. Head not distinguished from the body; anteriorly 

 with a transverse fissure, so as to form an upper and under lip, between which the proboscis 

 emerges. With eyes. Mouth situated about the breadth of the head from the anterior end. 



Gen. 5. Frosorhochmus, gen. nov. Head not distinguished from the body, snout with 

 three lobes, the anterior border being heart-shaped, with the third lobe placed dorsally (over the 

 notch). The track of the proboscis separates the inferior lobes anteriorly. With eyes. Mouth 

 placed a pair of head-breadths from the anterior end. Body moderately long and contractile. 



Gen. 6. Lobilabrum, Blainville, 1828. Head not distinguished from the body, anterior end 

 with four lobes ; this anterior end is separated into an upper and a lower lip, between which the 

 proboscis passes ; and, again, the border is heart-shaped (emarginate), the upper more deeply 

 than the under, so that it seems to be provided with two ten taenia. 



Stib-order II. — Nemeuti^ea anopla, Max Schultze. 

 Proboscis not supplied with a stylet-apparatus. 



Fam. 2. — RHOCHMOCEPHALIDiE. 



The cephalic fissures are long, and occupy the entire side of the head. Brain with the 

 upper ganglion covering the inferior completely; the lateral nerve springing from the side of the 

 inferior ganglion in front of its posterior and pointed ending. 



