186 Mr. F. F. Liiillaw on 



new 



Sly tlianks arc clue to j\Iajor Alcock for permission (o 

 examine tliese interesting specimens, and to Professor Hickson 

 for permission to work in the IJeyer Laboratories of the 

 University of Manchester. 



METANEMERTINI. 



H L R II Y N C n C (E L A. 



Pelagonemertidae. 

 DiNONEMERTES, gen. nov. 



Moutli and proboscis openings separate and distinct. 

 ]\Iedian dorsal vessel present. Gut-diverticala very nume- 

 rous, not branching dendritically. Body broad, flattened, 

 Ijyaline, sides parallel ; bluntly rounded at its anterior and 

 posterior extremities. 



This genus is somewhat closely allied to PlanktonemeriPff^ 

 "Woodworth ['99], and resembles it in appearance. It is 

 readily distinguished from Woodworth's genus by the separa- 

 tion of the mouth and proboscis openings. 



Dinonemertes invesfigaforit, sp. n. 

 (PI. VIII. fig. 1.) 



Station 319, lat. 12° 2' N., long. 73° 46' E., llo4 fath. 

 (Z. E. V. ip). Indian Marine Survey, 1903-1904, east of 

 Laccadives. 



Length 15 cm., breadth 4*8 cm., thickness 4 mm. 



There is no note as to colour; in the preserved specimen 

 this is whitish yellow. Bands of longitudinal muscle- fibres 

 can be distinguished without the aid of a lens. 



The specimen is a male. 



The epidermis has completely disappeared, leaving 

 exposed the basal membrane, which is about '02 mm. in 

 thickness and has stained deeply. Immediately below it 

 lies a very thin layer of circular fibres, and within these is 

 the layer of longitudinal fibres, which are grouped in fascicles 

 liaving a triangular outline in cross-section, the apex of the 

 triangle being directed inwards. These fascicles are embedded 

 in gelatinous parenchyma, which shows no cellular structure 

 and is quite without nuclei, but presents a finely fibrillar 

 structure. 



The parenchyma is very similar to that described by 

 Ilubrecht for Felagonemertes [^87], and, as in that genus, 

 it is traversed in all directions by nerve-fibres which have a 



