194 DK WALTER M. TATTERSALL ON 



Stimpsonii, Heller (1868). HELLER says of the latter that the hind margin of the 

 seventh segment of the thorax is produced into a conical process, and that the telsouic 

 segment has an acute apex. The adjective " acute," as applied to the telson, is, I take 

 it, meant relatively to the shape of that organ in such a species as E. gigas, and in no 

 way intended absolutely. I have accepted this implied emendation to the characters 

 of the genus Exosphseroma, and, as modified, include & tristense, Leach, within its limits. 

 I may, perhaps, be allowed to suggest the probability that E. tristense, Leach, and 

 E. Stimpsonii, Heller, are synonymous. I have already referred to the close similarity 

 between E. tnstense and E. gigas as regards their appendages and general structure. 

 The above remarks on E. Stimpsoni apply equally well to the male of the specimen I 

 refer to E. tristense, and I think it highly probable the two forms are one and the same 

 species. I have not the necessary material to pronounce a definite opinion here, but I 

 make the suggestion, for any future worker with more material at his disposal to decide. 

 If the suggestion is upheld by future research, LEACH'S name has priority. The females 

 of E. tristense agree very closely with WHITE'S types of S. leiicitra, which I have 

 examined at the British Museum. This species was named by WHITE (1847), but never 

 described. It is not unlikely that it will be found to be synonymous with S. integrum, 

 Heller, described from specimens taken off Chile, near the same locality as that from 

 which WHITE'S types came. HELLER'S name would have preference, since WHITE'S name 

 can only be regarded as a nomen nudum. HANSEN refers S. leucura to Exosphseroma, 

 and S. integrum to, possibly, Isocladus or Zuzara. I believe both should be referred 

 to the genus Exosphseroma, and suspect that the males will be found to have the same 

 form as those of E. tristense. It would not surprise me if Sphseroma Stimpsonii, 

 S. leucura, and S. integrum were all eventually found to be synonymous with S. tristense, 

 though females of allied species of Exosphssroma are notoriously difficult to separate. 



Exosphseroma Kraussii, sp. nov. (Plate, figs. 2 and 6.) 



1 Sphseroma tristense, Krauss, 1843. 

 1 Sphxroma tristense, Stebbing, 1910. 

 Scotia. 



Station 483, entrance to Saldanha Bay, Cape Colony, trawl. Three females, 

 8 mm. 



Specific Characters. Sexes similar ; body microscopically granular, especially on 

 the pleon and uropods ; segments of the thorax with four very obscure small tubercles 

 equidistantly placed, the tubercles most pronounced on the last thoracic segment, and 

 becoming almost obsolete on the anterior segments ; a pair of larger and more definite 

 rounded tubercles on the centre of the combined first three segments of the pleon ; last 

 segment of the latter triangular in shape with a pointed apex, having a pair of closely 

 approximating, conspicuous elongate tubercles at the centre of the anterior part, the 

 tubercles separated by a shallow groove, from the distal end of which a light carina runs 



(ROY. soc. KDIN. TRANS., VOL. XLIX., 884.) 



