— i 9 — 



Seen from the side, ihe terminal part of first joint is suddenly 

 raised very considerably above the upper surface of the remain- 

 der of the joint; seen from above, the posterior margin of this 

 thickened portion is strongly convex. The lobe itself, which 

 proceeds from that thickened part, is a rather flat plate, at the 

 base a little narrower than the proximal part of second joint, 

 but its outer margin proceeds not only forwards but conside- 

 rably outwards, so that the distal part of the lobe covers nearty 

 or completely the total breadth of second joint; the front margin 

 of the lobe is obliquely and considerably concave, the outer 

 distal part of the lobe being produced as a triangular plate 

 directed forwards and somewhat outwards, with its terminal 

 angle very acute but not spiniform; the inner front angle of the 

 lobe measures about 8o° or 90 0 . The upper surface of the lobe 

 shows a scabrous appearance, being set with a number of gene- 

 rally short setae, which are much shorter than the curved setse on 

 the vaulted part of the joint. Second antennular joint without 

 any spine; its upper inner end is produced into a rather short 

 lobe covering a rather small part of third joint, as in T. vulgaris 

 and sorae other species. Abdomen without any dorsal spine. 

 The endopod of the uropods reaches about to the tip of telson, 

 and is a little shorter than the exopod. — Length of the largest 

 spécimen, an adult female, io/ 11 " 1 . 



Localities. — Stat. 171 5, 18 spécimens; stat. 1736, 4 spéci- 

 mens; stat. 1749, 2 spécimens; stat. 1760, 1 young spécimen; 

 stat. 1768, 1 spécimen; stat. 1781, 2 spécimens; stat. 1794, 

 6 spécimens; stat. 1797, 10 spécimens; stat. 1800, 4 spécimens; 

 stat. 1802, 2 spécimens; stat. i85i, 1 spécimen; stat. 1 856, 

 3 spécimens. 



Remarks. — This species resembles in gênerai aspect so clo- 

 sely T. vulgaris that it is absolutely necessary to examine the 

 shape of the lobe from first antennular joint in every spécimen. 

 But this lobe déviâtes so much in shape from that in any other 

 species hitherto described that T. œqualis must be considered a 

 sharply defined species. Even spécimens measuring only 6.5-7 mm 

 in length have that lobe so well devcloped that they can be 

 determined with certainty, but the lobe is yet proportionately 



(42) 



