REPORT ON THE AMPHIPODA. 1029 



two halves apically a little dehiscent, together forming a broad oval, truncate at the base ; 

 on the outer sides, a little above each apex, the convex margin is interrupted and the 

 -angle carries a spine and a cilium. The difference between the telson of Elasmopus 

 subcarinata and that of Elasmopus delaplata corresponds pretty exactly with the 

 difference between the telson of Miera rubromacidata and that of Msera hruzdii. 



Length. — The specimen, in the position figured, measured, in a straight line from the 

 front of the head to the extremity of the third uropods, three-fifths of an inch. 



Locality. — Station 320, off Monte Video, February 14, 1876; lat. 37° 17' S., long. 

 53° 52' W.; depth, 600 fathoms; bottom, green sand; bottom temperature, 37°"2. One 

 specimen. 



Remark. — The specific name refers to the place of capture off the mouth of the Rio 

 de la Plata. 



Genus Par elasmopus, n. gen. 



Near Elasmopus, Costa. 



The mandibular palp with the second joint much shorter than either the first or 

 third. 



Upper Antennas with small accessory flagellum. 



The Uropods of moderate breadth. 



The sixth segment of the Pleon very small. 



It is perhaps doubtful whether this genus should be separated from Elasmopus, which 

 in general it so closely resembles, but the proportions of the mandibular palp appear to 

 be unique. 



Parelasmopus suluensis (Dana) (PI. C). 



1852. Gammarus Suluensis, Dana, Proc. Amer. Acad. Sci. and Arts, vol. ii. p. 210. 



1852. ,, suluensis, Dana, U.S. Explor. Exped., vol. xiii. pt. ii. p. 947, pi. lxv. fig. 3. 



1862. Megamoera Suluensis, Spence Bate, Brit. Mus. Catal. Amph. Crust., p. 230, pi. xl. fig. 6. 



No rostrum ; lateral lobes of the head rounded, lower angles produced in a sharp 

 point which does not project beyond the lateral lobes ; seventh segment of the perseon 

 and first two of the pleon distally produced into a small sharp tooth on either side of the 

 median fine, the third segment by dorsal emargination of the hind margin forming on 

 each side an angle of the hind margin rather than a tooth, the fourth segment with a 

 long sinuous dorsal line, which at the centre forms two branches, each ending in a sharp 

 upcurved tooth : the first and second segments of the pleon have the postero-lateral 

 angles produced in short sharp points, while the third segment has these angles sharply 



