218 THE GENERA OF NEMERTEANS. 



may moreover contribute to give it a moniliform appearance. 

 The fluid in this proboscidian cavity has a deep red tinge 

 which shines through the walls of the body and which is due to 

 haemoglobin contained in the corpuscles with which this 

 fluid is laden. The colour of the specimens may vary 

 fi'ora a vinous flesh colour to a dark bluish red. Three 

 short , dark , paralel , longitudinal stripes are present 

 on the top of the head towards the tip of the snout. 

 This species has a short caudal appendage. Urticating 

 elements in the proboscis of the most different dimensions 

 yet very regularly distributed over the surface , the largest 

 (0.132 mm. long with a thread of about twice that length) 

 being situated on two longitudinal ridges along the whole 

 length of the proboscis. Eyes seldom visible; in one spe- 

 cimen I noticed during compression and after having added 

 acetic acid six to eight very small pigment-specks close to 

 the margin of the body and the tip of the snout. 



22. Cerebratulus roseus (delle Chiaje) Hubr. 

 Synon. Polia rosea delle Ch. 



It is very probable that delle Chiaje's Polia rosea was 

 established on specimens of the species about to be des- 

 cribed. There is a general resemblance to C. urticans. The 

 colour is generally a light flesh colour or faint vermilion , 

 intermixed with yellow in the posterior pars of the body 

 where the intestine shines through the integuments. The 

 head is more or less flat and pointed and generally 

 yellowish too. Only once I met with an ohve green variety 

 which in a few days had changed its colour to a reddish 

 tinge. A caudal appendage is present in perfect indivi- 

 duals and was observed to attain a not inconsiderable length 

 in some cases. The portion of the trunk which forms the 

 oesophageal region is generally more cylindrical , posteriorly 

 the body becomes flattened. 



The principal difference from C. urticans is the greatly 

 diminished size of the urticating elements in the proboscis. 



Notes from, tlie Leyden Miuseiinri. 



