AUGUST BRINKMANN. 



[REP. OF THE ..MICHAEL SARS" NORTH 



caudal region, ramifying out from a dorsal and a ventral 

 main branch. The intestinal caecum has three pairs of 

 diverticula. 



The proboscis resembles in structure that of the 

 Plotonemertes but is considerably thinner; 16 proboscideal 

 nerves are developed. The stylet apparatus is developed 

 as in the remaining members of the family. 



The proboscis sheath terminates at the limit between 

 the fore and hinder portion of the body, its muscular layers 

 are interwoven as in the forms previously described. 

 From this musculature a strong muscle extends on either 

 side, commencing in the cerebral region close behind the 

 ventral commissure of the brain and running close to 

 the lateral nerve of the respective side, following it to 

 the tail. 



The vascular system in this species exhibits the same 

 peculiarity as in the case of Plotonemertes, with a similar 

 blind vessel terminating in the extreme end of the tail 

 and running from the posterior surface of the caudal 

 commissure. 



The lateral nerve stems are situate far up in the 

 parenchyma. 



Both the specimens were female, with from 20- 24 

 pairs of ovaries situate between the diverticula of the 

 intestine and opening ventrally just outside the lateral 

 nerves. In each ovary, only two, or in exceptional cases 

 three, eggs are developed; these reach, however, a con- 

 siderable size. 



Habitat; St. 25 (Lat. 35" 46' N; long 8" 16' W.) s /s, 

 1000 metres depth (1500 metres of wire). 



St. 94 (Lat. 50° 13' N; long. 11° 23' W.) 2u / 7> 1000 

 metres depth (1500 metres of wire). 



Planktonemertidae nov. fain. 



Medium-sized pelagic nemerteans. Body very 

 broad and more or less flattened. The diverticula 

 of the intestine and intestinal caecum commonly 

 with ventral branch, in any case always highly 

 ramified. Circular and longitudinal musculature 

 in the proboscis sheath interwoven. Musculature 

 of the body wall highly reduced. 



The typical genus of the family is Planktonetnertes 

 Woodworth (21); is is not represented in the material. 



Crassonemertes nov. gen. 



Body very broad and thick. Tail short, some- 

 what flattened and sharphy distinct from the body. 

 Mouth and proboscis pore separate but situate 

 very close together. Vascular and nerve commis- 

 sure immediately in front of anus. The proboscis 

 sheath extends into the tail. 



Crassonemertes robusta nov. sp. 

 (Plate I, Fig. 8.) 



This species, with its remarkably heavy form, is 

 represented by a single female specimen. 



The animal in question, which had been preserved 

 in formalin, was yellowish white and entirely opaque. 



Length 25 mm. greatest breadth 10 mm. greatest thick- 

 ness 4.5 mm. 



Musculature of the body wall so reduced as to be 

 of probably but little importance for swimming. The 

 species should in all likelihood be considered as princi- 

 pally a floating organism. 



Stomach highly developed - - it had been forced 

 somewhat out of the mouth opening by process of fixation; 

 vide Fig. 8, PI. I. — passing over behind the brain into 

 the pyloric tube, the latter 6 mm. long. 



The intestine fairly broad at the fore end, but quite 

 narrow at the rear; it forms some 40 pairs of diverticula 

 which are ramified to a quite unusual degree and so 

 closely adjacent one to another that the ramifications 

 appear interwoven. The intestinal caecum is furnished 

 with at least five pairs of diverticula, likevise highly 

 ramified, the ramification throughout emanating from a 

 dorsal and a ventral main branch. 



Proboscis of about the same length as the body. 

 The stylet basis is bent almost to a right angle and 

 furnished with at least 10 stylets. Some 20 — 21 probos- 

 cideal nerves are developed. 



The proboscis sheath terminates 2 mm. in front of 

 the anus; the musculature in its wall consists of inter- 

 woven bundles of circular and longitudinal fibres. 



The rhynchodaeum is short, opening at the base of 

 a depression in the epithelium, this depression, however, 

 is not so large as to include the mouth, as is the case 

 with Bathynemertes and Planktonemertes. The vascular 

 system here exhibits the same original features as in 

 Bathynemertes, the caudal commissure being situate far 

 out at the tip of the tail. 



Ovaries to the number of 35 pairs are developed, 

 being still quite young and forming elongated sacs on the 

 outer side of the lateral nerves with the dorsal portion 

 curving in over the latter. Numerous young egg cells 

 were found in the ovaries, and a considerable number 

 of eggs are doubtless developed in each ovary. 



Habitat: St. 101 (Lat. 57" 41' N; long. 11° 48' W) 

 6 — 7 /k, abt. 1666 metres depth (2500 metres of wire). 



Burger/ell 7 dee nov. fam. 



Body broad but relatively slightly flattened. 

 The intestinal diverticula highly reduced in num- 

 ber, projecting from the intestine at considerable 



