6o CRUSTACEA MALACOSTRACA II. 



Antennulae (figs. 3 a and 3 b) somewhat shorter than the carapace. First joint only somewhat 

 longer than the two other joints combined -- thus proportionately a good deal shorter than in T. fin- 

 marchicus -- seen from the side about three times as long as deep and tapering considerably, seen 

 from above tapering nearly regularly from near the base to the end. Second joint somewhat longer 

 than deep, less than half as long as the third; longest terminal setae considerably shorter than third 

 joint. - Antennae with third joint slightly thickened (fig. 3 b); fourth joint not twice as long as the 

 penultimate; terminal setae almost longer than those of the antennulae. 



Chelipeds (fig. 3 b) moderately long. Basal joint moderately long; the posterior protuberance a 

 little longer than deep, and the distance between its hind margin and the front lower angle of second 

 thoracic segment is more than half as long as the joint; carpus rather slightly longer than the basal 

 joint, about three times as long as deep — thus less robust than in T. finmarchicus. Chela as long 

 as the carpus, a little more than three times as long as broad; movable finger somewhat or a little 

 longer than the anterior margin of the hand ; fixed finger distinctly broader than the movable, with 

 a couple of triangular teeth towards the end of the incisive margin. 



Thoracic segments (fig. 3 a) with their lateral margins subparallel excepting those of second seg- 

 ment which converge backwards. Second segment about half as long as the third, in females without mar- 

 supium generally with a moderately small or very small ventral process as in T. finmarchicus. Fifth 

 segment slightly longer than the fourth or the sixth and slightly shorter than broad. — Thoracic legs 

 somewhat short and robust. Second pair (fig. 3 b) with fifth joint a little longer than the fourth and not twice 

 as long as deep; sixth joint much longer than the fifth, about as long as or a little longer than seventh 

 joint with claw; setae moderately short. Third pair with fourth and fifth joints short in proportion to 

 thickness; seventh joint with claw considerably more than half as long as the sixth; distal anterior 

 seta on sixth joint moderately long. Three posterior pairs nearly as in T. finmarchicus ; second joint 

 about two and a half times as long as broad ; fourth and fifth joints somewhat broad, each with a 

 distal small spine; sixth joint about as long as fifth and half of the fourth combined; seventh joint 

 somewhat long, together with the fine claw nearly as long as the sixth joint. 



Abdomen slightly broader than seventh thoracic segment and about as long as seventh and 

 sixth segments combined. — Uropods (fig. 3 f) moderately short; endopod with the proximal joint some- 

 what longer than the distal; exopod scarcely reaching the middle of the distal joint of the endopod, 

 with the distal joint a little longer than the proximal. 



Length of a female with marsupium T.94 m "'. 



Subadult Male. The antennulae (fig. 3c) considerably thicker than in the female; first joint 

 about two and a half times as long as deep and tapering a little; second joint conspicuously deeper 

 than long; third joint a little thickened below towards the base. — Length 1.9 mm . 



Remarks. T.mixtus might perhaps be considered a variety of T. finmarchicus, but according 

 to my judgment it is a separate species; I have learned by experience that even small characters are 

 not infrequently of specific value. T. mixtus differs from T. finmarchicus in having the first joint af 

 the antennulae conspicuously shorter in proportion to the two other joints combined, in having the 

 carpus of the chelipeds less deep in proportion to its length and the movable finger of the chela longer 

 in proportion to the front margin of the hand. — I have been unable to find any difference between 



