92 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 48. 



Endopod of sixth pair in the female one-jointed, not half as long as 

 the exopod. 



The abdominal segments (fig. lg) dorsally carinate, but the keel is 

 feebly developed on the sixth segment and wanting on about the an- 

 terior half of the first segment and on a smaller anterior part of the 

 second and third segments, while in the fourth and fifth segments the 

 keel is high and besides on each produced in a good-sized, compressed, 

 horizontal process, which generally is a fit tie longer on the fourth 

 than on the fifth segment; the sixth segment terminates above in a 

 process about as large as that of the fifth segment; the lower distal 

 spine on the sixth segment is simple in both sexes. Fourth and fifth 

 segments with the upper sublateral teeth rudimentary (they are well 

 developed in T. longipes), while the lateral plates of the segments are 

 nearly as in the preceding species. Sixth segment much shorter than 

 in T. longipes and only a little longer than the fifth. Telson as in 

 T. longipes; uropods about as long as or a little shorter than the 

 telson. 



(In one immature specimen measuring 16.2 mm. in length the 

 otherwise very acute angle at the outer end of the front upper margin 

 of the carapace is rounded; the abdomen has no keel on the first 

 and second segments, while the keel is very feeble on the third and 

 sixth segments; furthermore the fourth segment has no posterior 

 dorsal spine, while the spines on the fifth and sixth segments are well 

 developed. Some of these reductions may be due to the young age 

 of the specimen, others to variation.) 



Male copulatory organs of first pleopods (figs. lli-lJc) differ from 

 those in T. longipes in having the three large processes conspicuously 

 shorter and thicker and the setiferous lobe a little broader. The 

 spine-shaped process (p 1 ) is long and much curved. The terminal 

 process (p 2 ) has a little less than the proxi m al half rather thick and 

 then it is suddenly somewhat (fig. li) or considerably (Rg. Ik) curved, 

 with the distal half much narrower than the proximal part and the 

 end acute and turned outward. The proximal process (p 3 ) has the 

 proximal part considerably less thickened than in the terminal proc- 

 ess; it is straight (fig. li) or a little curved just before the middle 

 (fig. Ik) and its end shaped about as that of the terminal process. 

 The median lobe (Zm) not differing essentially from that in T. longipes, 

 but its lateral process (p 4 ) is inserted nearer the base and slightly or 

 scarcely beyond the base of the proximal process; the process, 

 which is far from reaching the end of the lobe, is somewhat curved 

 (fig. li) or straight (fig. Ik) with the end acute or subacute. Figs. 

 Ih and li represent the organ of a male which perhaps is not 

 quite adult, as the inner and the median lobes with their processes 

 are uncommonly short in proportion to the setiferous lobe, the 

 processes simple, solid at their acute ends and the auxiliary lobe 



