226 



CRUSTACEA MALACOSTRACA. III. 



of the head and in the shape of the last abdominal segment, the major part of which is a narrow 

 triangle; the sides of the abdominal segments have some few setae. — Length nearly 6 mm. 



Occurrence. The "Ingolf" has secured this species twice. 



West of Iceland: Stat. 9: Lat. 64°i8' N., Long. 2foo' W., 295 fath., temp. 5-8°; 1 spec. (d). 



Without locality in a calcareous sponge; 4 spec. (1 d\ 2 ?, 1 larva). 



Furthermore it has been taken in Baffin Bay at Lat. 72°32' N, Long. 58°5' W., 116 fath., by 

 the Swedish expedition in 1871 (1 o* borrowed from the Riksmuseum in Stockholm). The Ryder Exp. 

 captured it twice, viz. off East Greenland at Lat. 69°25' N., Long. 20V W., 167 fath., 3 spec. (1 o*, 1 ?, 

 1 larva), and near Jan Mayen at Lat. 70°32' N., Long. 8°io' W., 470 fath., 1 spec. (<?). 



Distribution. Taken by the Norwegian North-Atl. Exp. at two stations, viz. midway be- 

 tween Finmark and Beeren Eiland, 191 fath., temp. 3-5°, and west of Spitzbergen, Lat. 78°2' N., 416 

 fath., temp. o-8°. Dollfus recorded it from a place a little north of the first-named Norwegian station 

 viz. from Lat 72°37' N, Long. i7°4o' E., 209 fath. 



160. Gnathia hirsuta G. O. Sars. 

 (PI. XVI, figs. 7 a-7 b). 



1877. Ancrus hirsutus G. O. Sars, Arch. Math, og Naturv. Vol. II, p. 349. 

 ! ^85. — — G. O. Sars, North-Atl. Exp., Crust. I, p. 92; PL 8, figs. 23—24. 



! 1888. cristatus H.J.Hansen, Vid. Medd. Nat. Forening i Kjobenhavn for 1887, p. 182; PI. VII, 



figs. 2— 2 a. 



In the paper quoted I established A. cristatus on a single male without abdomen from 

 Baffin Bay. The name was derived from the fact that the upper side of the proximal half of the 

 mandibles was raised as an irregularly incised and dentate crest. I wrote : "Anc. hirsuto G. O. Sars sat 

 affiuis, structura mandibularum a speciebus omnibus mihi cognitis diversa", and by these words I 

 referred to the dentate crest mentioned; on A. hirsutus Sars had said (p. 93) on the mandibles: "On 

 the outer margin, occurs, about in the middle, a distinct, though small, dentiform projection", and on 



the mandibles in A. robustus (p. 95) " the outer edge smooth, without any perceptible dentiform 



projection". The specimen of my A. cristatus belonged to the Riksmuseum in Stockholm, but according 

 to information from the Director of the Department it could not be found, which is unfortunate, as I 

 now think that the median part of the front margin of the head was somewhat incorrectly drawn 

 by me in 1887. The specimen measured without abdomen 3-1 mm., and according to the relative 

 length of abdomen as compared with head plus thorax in allied forms the abdomen has measured 1-2 

 or 13 mm., thus the whole animal must have been 4-3 or 4-4 mm. Consequently it cannot belong to 

 G. abyssornm G. O. S., which is only 2-5—3-5 mm - lon g> mit eitner to G - rob?/sta or to G. hirsuta, or be 

 distinct from both. It cannot belong to G. robusta, because its body is proportionately more narrow, 

 and the thoracic segments have, as shown in my figure in 1887, a good number of somewhat long 

 lateral setse, while G. robusta has only very few and short lateral setae. 



The Director of the Museum in Christiania kindly lent me in 1915 the types of G. hirsuta 

 G. O. S., and I found, what I now had expected, that the proximal half of the outer upper part of the 



