PLYMOUTH NEMEKTEANS. 417 



and wrinkled, much as in Cerebratulus corrvgatus. The anterior part 

 of my specimen got very thin by preservation (breadth 5 mm.) ; the 

 following region suddenly broadens till it has a breadth of 16 mm. The 

 living specimen had a brownish colour, with more whitish margins. 

 No markings were present. 



The sections revealed some features which decided my classification 

 of this species as a Euhorlasia ; I regard it, however, as a separate 

 species from both E. elisahcthac and immaculata. 



The proboscis sheath is very short, as already in the thinner portion 

 of the body it is devoid of its muscular coats. The intestinal caeca 

 are richly developed and branched. The gonads are placed in rows 

 between the caeca, alternating with their diverticula. They all open 

 dorsally. Muscular septa are entirely absent. The intestinum with 

 its diverticula and the gonads are surrounded by a thick layer of 

 connective tissue, in which a great number of very narrow blood-vessels 

 are imbedded. The structure of the epithelium agrees perfectly with 

 Burger's description ; the large gland cells are especially conspicuous 

 (Burger. Monograph Naples, T. 22, Fig. 39). 



Sub-family B. MICEUEINAE. 



Caudal cirrus present ; proboscis sheath usually extends nearly or 

 quite to the posterior end of the body. 



Genus Micrura. 



Small, thin, mostly flattened and soft nemertines ; head spathulate, 

 ending bluntly, not separated from the body. Lateral margins of the 

 body not remarkably thin ; incapable of swimming. Often with a 

 great many eyes. The mouth is circular. Proboscis sheath short, 



1. Micrura fasciolata {Ehrhg.). (Mcintosh. Monogr. PL VI, 

 Fig. 2.) 



Locality: Common in the dredgings from the Sound, Eddystone, 

 Mewstone, and from the Eame-Eddystone Grounds. 



General colour red or red-brown, head and ventral side white. 

 10-24 slender white transverse stripes across the dorsum. With 4-6 

 small eyes. Length 120-200 mm., breadth 1-2 mm. 



Geographical distribution : Sweden, Great Britain, Northern coast 

 of France, Mediterranean. 



2. Micrura aurantiaca {Grule). (Mcintosh. Monogr. PI. VII, 

 Fig. 4.) 



Among some tubes of preserved nemertines I found one containing 

 two nemertines from the Breakwater. They were supposed to belong 



