12 THOS. H. MONTGOMERT, 



Space on the dorsal surface of the head. Pigment is also found along 

 the whole upper surface of the body, though it does not produce 

 large blotches or patches as in T. catenulatum, but is always finely 

 sprinkled or scattered along the body. 



Length never exceeding 10 mm. Proportionately more slender 

 than the preceding species of this genus. 



Abundant in Ludlam Bay, Sea Isle, on sea-weeds. 



The specific name "'flagellatunC\ which 1 have given to this form, 

 refers to the flagella, or vibratile hairs, which are found in its epi- 

 thelium. 



In conclusion, I would draw attention to the fact, that none of 

 the Metanemerteans which I found at Wood's Holl and Newport 

 possessed sensory (tactile ?) hairs in the body epithelium ; while three 

 of the five species collecting at Sea Isle possessed them — these 

 being Ämphiporus greenmani, Tetr. elegans and T. flagellatum. Is 

 this to be explained on the ground of there being some subtile dif- 

 ference of environment at Sea Isle, which should occasion their 

 presence? 



Postscript on the anatomyof Zygonemertes virescens. 



There is one pair of nephridia present, of the type characteristic 

 for Ämphiporus. Each nephridium extends from the head region, on 

 the other side of the corresponding ventral lobe of the brain, to the 

 posterior portion of the oesophageal region. The excretory pores, 

 one to each nephridium, lie at the anterior ends of the latter, and 

 open on the latero-ventral sides of the body. The main duct does 

 not form loops, but takes a nearly straight course from before back- 

 wards; it is situated on the dorsal side of the lateral nerve 

 chord, at the side of the intestinal coecum, though at occasional points 

 it passes to the ventral side of the chord. From it, at occasional 

 intervals, side branches (ductules) are given off; these are of short 

 length, and either pass upwards along the sides of the intestinal 

 coeca, or embrace the nerve chord ventrally. I have been unable to 

 determine the structure of the terminal bulbs ("Endkölbchen"). 



