CRUSTACEA MALACOSTRACA. III. 15 



with reddish-brown dots, while in specimens from considerable depths such dots have disappeared. 

 But much more important differences are found in the shape of the head and the relative size of the 

 eyes. In specimens taken in comparatively shallow water, down to 70—100 fathoms, the eyes (fig. 1 a) 

 are proportionately very large, with black pigment, and situated close to the lateral margins of the 

 head; the head is not expanded laterally, and its surface is scarcely or slightly excavated along the 

 anterior or the lateral margins. Fig. 1 d exhibits the head of a specimen from my deepest station 

 enumerated below; it is seen that the yellowish-brown eyes are proportionately very much smaller 

 than in the preceding -specimen (fig. 1 a), and much removed from the lateral margins; the lateral parts 

 of the head are much expanded and their surface is considerably excavated, so that the margin turns 

 much upwards. Furthermore the surface is excavated transvervely along the front margin, and espe- 

 cially at its middle portion, which is turned much upwards. In all these particulars the two specimens 

 from the deepest station, 1010— 1140 fathoms, exceed all other specimens seen by me. Ever)' possible 

 transition between the two heads described and figured is found among my material. Fig. 1 c exhibits 

 as to size of the eyes, their distance from the lateral margins, and the degree of dorsal excavation a 

 specimen intermediate between those shown in fig. 1 a and fig. 1 d, and that specimen was taken in 

 295 fathoms. — Furthermore the surfaces of the three posterior thoracic segments have the elevations 

 higher and more pronounced in specimens from deep water than in those from shallow water. Finally the 

 shape of the abdomen varies a little, as is seen from a comparison of fig. 1 b, showing the abdomen 

 of the specimen whose head is exhibited in fig. 1 a, with fig. 1 e, which belongs to the same specimen as 

 fig. id; in fig. 1 e the postero-lateral parts of the abdomen are produced a little more backwards, are 

 more protruding, and less evenly rounded than in fig. 1 b, of the specimen with the eyes very large. 



Sars said that the female is 7 mm., the male 10 mm. long, but such large males I have not 

 seen. The ovigerous female shown in figs. 1 a— 1 b is only 3-9111111.; the female with marsupium from 

 295 fathoms (fig. 1 c) is 7-4 mm.; the female from the deepest station (figs. 1 d — 1 e) has no marsupium 

 and is 6-5 mm. long, while the male from the same station is 7 mm. My largest ovigerous female, 

 from off Seydis Fjord, 135 fath., is 8-i mm.; as to eyes and shape of the head this specimen is inter- 

 mediate between the animals from 295 and from about 1100 fathoms, which shows that the reduction 

 in the size of the eyes, their distance from the lateral margins, and the excavations are not always 

 quite proportional to the depths of their localities. 



Fig. 1 f shows the posterior part of the male first pleopods, and their posterior margin differs 

 materially from that in Ianira alta (fig. 2 d). 



Occurrence. Taken by the "Ingolf" at thirteen places. 



West Greenland: Stat. 27: Lat. 64°54' N., Long. 55°io' W., 393 fath., temp. 3-8°; 1 spec. 

 — — Mouth of Ameralik Fjord, Lat. 64°03' N., 5—70 fath., shells; 5 spec. 



Denmark Strait, off Angmagsalik: Stat. 94: Lat 64°56' N., Long. 36°i9' W., 204 fath., temp. 4-1°; 



1 spec. 



Between Angmagsalik and West Iceland: Stat. 95 : Lat. 65°i4' N., Long. 30°39' W., 752 fath., 



temp. 2-1°; 4 spec. 

 __ - _ Stat. 96: Lat. 65°24' N., Long. 29°oo' W., 735 fath., 



temp. 1-2°; 1 spec. 



