CRUSTACEA MALACOSTRACA. II. 37 



terior margin; it is unusually large, slightly more than half as long as the carapace, somewhat or 

 a little less than twice as broad as long, a little or somewhat shorter than third segment and without 

 any process below. Third to seventh segments with their lateral margins strongly angular or, in the 

 three posterior segments, very convex, but the angles or the broadest place of the segment is on the 

 third segment situated not much behind the front margin, on the fourth a little more backwards, on 

 the fifth at the middle, on the sixth somewhat behind the middle and on the seventh a little before 

 the posterior margin. — The legs are rather long and slender; second pair have the sixth joint (fig. 5b) 

 almost as long as fifth and fourth joints combined and only a little longer than seventh joint with 

 claw; the few setae of the legs short. Third pair rather similar to second, but sixth joint is a little 

 shorter and seventh joint with claw only about two-thirds as long as sixth joint; setae short. Fourth 

 pair completely as the third. Seventh pair (fig. 5d) slender; second joint almost five times as long 

 as broad; fourth and fifth joints not expanded, with a tooth-shaped spine at the distal posterior angle; 

 sixth joint somewhat longer than the fifth; seventh joint with claw more than half as long as 

 sixth joint. 



Abdomen scarcely as long as the two preceding segments combined. — Uropods long and 

 slender (figs. 5 a and 5e); endopod two-jointed, with first joint somewhat or a little less than twice as 

 long as the second; the exopod reaches the middle of the distal joint of the endopod and seems to be 

 undivided. 



Length of a female with marsupium 1.6 ,nm , of a large female without marsupium 1.85 ram . 



Subadult Male. Differs from the female only in the antennulae, which have the distal part 

 of first joint and the whole second joint somewhat thicker than in the female, while the third joint 

 has the basal part distinctly thickened on the lower side. 



Remarks. T. irregularis is easily distinguished from all other forms of the genus excepting 

 T. macroccphala n. sp. and T. mucronatus n. sp. by the shape and relative length and breadth of the 

 thoracic segments; the rather short antennulae, the legs and the uropods afford further characters. It 

 bears some resemblance to T. macrocephala^ but the latter species is easily distinguished by its ex- 

 tremely large carapace, the enormous process on the lower side of second thoracic segment, etc. From 

 T. mucronatus it is easily separated by the widely different antennae, short setae on the legs, etc. 



Occurrence. The "Iugolf" has taken this fine species at twelve stations, all in the cold area. 



North of the Faeroes: St. 141 : Lat. 63° 22' N., Long. 6°58'W., 679 fm., temp. -=- 0.6° ; 22 spec. 



St. 139: Lat. 63°36' N., Long. 7°3o'W., 702 fm., temp. -=- 0.6°; ab. 50 spec. 



East of Iceland: St. 104: Lat. 66° 23' N., Long. 7°25'W., 957 fm., temp, -f- 1.1 ; 1 spec. 



— - St. 103: Lat. 66° 23' N., Long. 8°52'W., 579 fm., temp, -f- o.6° ; 1 spec. 



— - St. 102: Lat. 66° 23' N., Long. io°26' W., 750 fm., temp. -=-0.9°; 21 spec. 

 North of Iceland: St. 126: Lat. 67° 19' N., Long. 15° 52' W., 293 fm., temp. ^0.5°; 2 spec. 



St. 125: Lat. 68° 08' N., Long. i6°02 r W., 729 fm., temp. -f- 0.8°; 12 spec. 

 North-East of Iceland: St. 120: Lat. 67° 29' N., Long. n°32' W., 885 fm., temp. -^ i.o°; 2 spec. 



vSt. 119: Lat. 67° 53' N., Long. io°i9' W., ioiofm., temp. -=- 1.0° : 2 spec. 

 South of Jan Mayen: St. 118: Lat. 68° 27' N., Long. 8° 20' W., 1060 fm., temp, -f- i.o°; 6 spec. 



— - - St. 117: Lat. 69° 13' N., Long. 8° 23' W., 1003 fm., temp. -=- 1.0° ; ab. 40 spec. 



