ATI. ANT. DEEP-SEA EXPED. 191(1. VOL. III]. 



PELAGICA NEMERTEANS. 



13 



Joubin (1904): 

 "Princesse Alice", St. 1849 (Lat. 36" 17' N; long. 28" 53' W) 

 Plankton haul (vertical) 3000—0 metres 

 1 spec. 



Craven & Heath (1906): 

 "California" (Monterey Bay) On fishing lines, 400 — 500 

 fathoms depth, 3 spec. 



"Albatros", St. 4393 (south coast of California) bottom trawl, 

 2113—2259 metres depth, 2 spec. 



Foshay (1912): 

 Near Misaki, Japan, depth? net used? 6 spec. 



„Michael Sars (1910): •) 





Length 



Greatest breadth 



Greatest thickness 



c? 



12 mm. 



4 



2 



? 



14 „ 



4 



2 



St. 



53 



(Lat. 



34" 



59' 



N; long. 33° 



or 



W) 



' /6 



1 spec 



St. 



62 



( . 



36" 



52' 



N; 



, 39" 



55' 



W) 



20 ,6 



2 „ 



St. 



64 



( „ 



34" 



44' 



N; 



47" 



52' 



W) 



24 /6 



2 „ 



St. 



70 



( . 



42" 



59' 



N; 



, 51° 



15' 



W) 





3 „ 



St. 



80 



( >• 



47" 



34' 



N; 



43" 



11' 



W) 



ll/_ 



29 „ 



St. 



81 



( , 



48" 



02' 



N; 



39° 



55' 



W) 



12/. 



22 „ 



St. 



82 



( , 



48° 



24' 



N; 



, 36" 



53' 



W) 



13/ 



5 „ 



St. 



84 



( „ 



48" 



04' 



N; 



, 32° 



25' 



W) 



15/„ 



/ 1 



8 „ 



St. 



87 



( „ 



46° 



48' 



N; 



27° 



46' 



W) 



17,' 



1 „ 



St. 



88 



( „ 



45" 



26' 



N; 



, 25" 



45' 



W) 



18/ 7 



3 „ 



St. 



90 



( . 



46" 



58' 



N; 



19" 



06' 



W) 



- l h 



2 „ 



St. 



92 



( . 



48° 



29' 



N; 



, ' 13° 



55' 



W) 



23 /7 



3 „ 



St. 



101 



( „ 



57" 



41' 



N; 



, 11° 



48' 



W) 



6/„ 

 /8 



1 „ 



Nectonemertes primitiva nom. nov. 

 (Plate II, Figs. 11 — 13.) 



Syn. Nectonemertes mirabilis Burger (1907) 1912 (6). 



After having shown that N. mirabilis and H. atlantica 

 Verrill were male and female of one and the same species, 

 the tentacles on the sides of the head being a secondary 

 sexual character of the male, it appeared natural to 

 consider the specimens shown in Figs. 11 — 13 (PI. II), 

 — which are entirely identical in structure save for the 

 tentacles and genital organs, and differ characteristically 

 from N. mirabilis, - as male and female of another 

 species. 



Comparison shows, that the species is identical with 

 that represented by a single specimen described by Burger 

 as N. mirabilis. 



With regard to the appearance of the animal in a 

 living state, the reader may refer to Burger's description 

 and figure. The preserved specimens are, as will be seen 

 by comparison, shorter, relatively broader, and with the 

 tail flipper far more developed than N. mirabilis. The 

 species is considerably smaller than the foregoing. 



') Implement and depth not noted here, these being included in 

 the table p. 11. 



The tentacles were only 1.5 mm. long, which must 

 undoubtedly be ascribed both to considerable contraction 

 and also to the youth of the specimen, which was not 

 fully mature. 



Of specific points of difference when compared with 

 N. mirabilis, the following may be noted: 



The stomach is narrower and shorter than in the 

 mentioned form, and already in the cerebral region leads 

 into the pyloric tube, the length of which is only o.8 mm. 

 The caecum also is smaller, and has but four pairs of 

 diverticula, which are relatively small. 



The genital organs of the male exhibit a most striking 

 difference of species. The testicles of N. mirabilis are 

 numerous, and arranged in two oval groups ventrally in 

 the head, whereas in the present case, there are but 

 four pairs of testicles, arranged in a double row (PI. 11, 

 Fig. 12) their discharge ducts extending forward in the head. 



The ovaries also are considerably less numerous, 

 there being 10 pairs developed. And as there are 50 

 pairs of intestinal diverticula, the numbers by no means 

 permit of one pair of ovaries being placed between each 

 two pairs of diverticula. 



Habitat: 



Burger (1912): 

 "Valdivia", St. 66 (Lat. 3" 55' S; long. 7° 48' 5" E) 



vertical net 3000 — metres. 

 "Michael Sars", St. 51 (Lat. 31" 20' N; long. 35" 7' W) 

 s /e at 666 metres depth, (1000 metres 

 of wire). 



St. 53 (Lat. 34" 59' N; long. 33" 1' W) 

 8 / 6 , at 200 metres depth (300 metres 

 of wire). 

 The material from the „Michael Sars" shows that the 

 species lives at remarkably slight depths. 



Nectonemertes minima Brinkmann 1915. 

 (Plate II, Fig. 23). 



Syn. Hyalonemertes atlantica Burger (1907) 1912 (5). 

 Nectonemertes minima Brinkmann 1915 (2). 



I have recently given a preliminary description of 

 this species based upon material from another expedition, 

 in which it was shown that Burger had been dealing 

 with a female specimen, which he had erroneously ende- 

 avoured to identify with Verrill's H. atlantica (TV. mira- 

 bilis Verrill $ ). The male is easily distinguished from 

 the two foregoing species, partly by its small size, and 

 partly by the fact that the testicles, which are placed in 

 a single row on either side of the head, have laterally 



