REPORT ON THE NEMERTEA. 15 



between the layer of ciliated cells immediately surrounding the lumen and the deeper 

 layer of granular gland- cells is very marked. 



There is no muscular layer in the oesophagus as in Eupolia giardii (PI. VI. fig. 9) 

 or in Cerebrahdus corrugatus (PI. XIII. fig. 6) ; the thick layer of glandular cells just 

 alluded to may here and there show a longitudinal fibre in addition to the radial ones 

 that serve to suspend it in the circum-oesophageal lacuna ; for the greater part these cells 

 project freely into this cavity and are bathed by the fluid it contains. 



B. HOPLONEMERTEA. 



Amongst the Hoplonemertea collected by the Challenger none are so difi"erent from 

 those that are at present known as to necessitate the establishment of a new genus. Still 

 several of them present certain notable points of interest by which our knowledge of 

 this order of worms is extended, and which at the same time ofier valuable material for 

 more general speculations. 



The three genera Drepanophorus, Amphip>orus and Tetrastemma, to which all the 

 Challenger Hoplonemertea belong (when we except Pelagonemertes) appear to be very 

 cosmopoHtan ; the same remark, however, applying to the Schizonemertean Cere- 

 hratulus, as wUl be shown in the sequel. 



Family AMPHiPORiDiE. 



Drepcmophorus, Hubrecht. 



TJie mouth and the aperture of the proboscis are separate openings. The exceedingly 

 muscular proboscidian sheath communicates with lateral spaces that are metamerically 

 placed, and have thin cellular or membranous walls. TJie armature of the proboscis 

 often conforms to an aberrant type. 



Drepanophorus ruhrostriatus, Hubrecht. 



This species, although not represented by complete specimens, was dredged by the 

 Challenger off St. Vincent, Cape Verde Islands, in July 1873. MTntosh identified the 

 fragments before they came into my hands, and remarks upon them in his preliminary 

 notes as follows : — 



" Two fragments of a form apparently closely related to Drepanophorus rubrostriatus, 

 the two measuring about 14 mm. by about .3 mm. in breadth. The colour of the animal 

 is reddish-brown on the dorsum, with longitudinal pale stripes 



"The ganglia and cephalic sacs are remarkably distinct and the nerve-cords have a 

 cellular investment. A very remarkable feature is the presence of large granular tubes 

 which communicate with the cavity of the proboscis 



