SCHIZOPODA AND CUMACEA 



the place of the latéral denticle above a small incision in the lower margin, the submarginal 

 furrow from the insertion of the latéral denticle to the base of the antennse, and the deep 

 incision in the upper part of the hind margin, but the rostrum is still longer than in the 

 last-named species, reaching nearly to the end of the antennular lappet, thus longer than in anv 

 other species of the genus (or the order). 



The antennular peduncle has the characteristic lappet just described on the first joint, 

 second joint is provided with a long, spiniform, almost horizontal process from the middle 

 of its upper distal margin; the dorsal canna on the third joint is high. 



The abdomen has the third segment armed dorsally with a long, compressed, slightly 

 decumbent process; fourth and fifth segment each with a moderately short, spiniform unpaired 

 process ; ail three segments hâve the upper part of their posterior margin adorned with 

 incisions nearly as in E. spinifera, but the epimera of the fifth segment are less produced 

 posteriorly than in the latter species. 



A spécimen from the Swedish Expédition measures 28 mm. in length. 



Locality. — Lat. 56° 49' S., long. 64 3o' W.; depth of the sea 385o m., Jan. 16, 1898. 

 The fragment was captured bv the sounding apparatus. 



3. — Thysanoëssa macrura G. O. Sais (i883) 



(PI. I, figs. 2 a— 2 h 



iSS5. Thysanoëssa macrura G. O. Sars, Report Challenger Schizopoda. vol. XIII. p. 125, pi. XXIII, figs. 1-4. 

 1906. — — Holt & Tattersall, Ann. Mas. Nat. Hist., ser. 7, vol. XVII, p. 5. 



To this species I refer four immature spécimens; the largest spécimen measures 8 mm., 

 the smallest only 5.y mm. in length. Figures 2, a — 2/ represent parts of the large spécimen, 

 figs. 2 g — 2 h parts of the small one. 



The large spécimen agrées moderately well with the description and the figures given 

 by Sars, but the présence of a small spiniform process at the outer end of the distal edge of the 

 basai antennular joint — a feature being a remnant of a larval character — shows that the 

 animal has not quite finished the development. The upper section of the eyes is small (fig. 2a); 

 the rostrum (fig. 2 b) is a little shorter than in Sars' figure ; the céphalothorax possesses the 

 latéral denticle; the sixth abdominal segment is slightly shorter than the sum ofthe fourth 

 and the fifth (fig. 2e). Only one of the trunk-legs ofthe first pair is preserved, and it is 

 unusually short (fig. 2d), with the penultimate joint slightly longer than the last ; the last joint 

 is a little shorter than some of the setœ situated on its apex and its lower margin, and two of 

 the last-named setre are strong and sparingly ciliated. The terminal part of the telson has 

 acquired its final shape and armature (fig. 2/). 



The small spécimen (figs. 2 g — 2 h) shows some larval characters : it is in reality in the last 

 larval stage, but it is dealt with hère for the sake of comparison. The rostrum is a little shorter 

 than in the preceding spécimen, the process from the distal margin of first antennular joint is 

 long, the antennular flagella are short and unjointed, and the telson must be described separa- 

 tely. The most distal, tapering part of the telson is considerably shorter in proportion to its 

 breadth and the movable flat spines are much narrower (fig. 2 h) than in the large spécimen, but 

 the most essential différence is that a slender spine, ciliated along its inner margin and as long 



