LYSIANASSIDAE 



73 



Orchomenella acanthurus (Schell.) (Figs. 27 a, 31). 

 Schellenberg, 193 1, p. 47, fig. 25. 



Occurrence: 1. St. 141. South Georgia. 1 ovig. $ 10 mm. 



2. St. 145. South Georgia. 1 ovig. $ 13 mm. 



3. St. WS 33. South Georgia. 1 juv. 7 mm. 



4. St. MS 62. South Georgia. 2 juv. 5-6 mm. 



Description. Body plump. Integument indurated. Head with antero-lateral angle 

 quadrate. Eyes oval, wider below, black. Side-plates deep, one parallel-sided, rounded 

 below, five nearly evenly bilobed, the posterior 

 lobe only a little deeper than anterior, peraeopod 3 

 therefore freely movable outside the side-plate. 

 Pleon segment 3 with dorsal profile less convex 

 than usual, posteriorly subcarinate, and ending 

 in a square, almost pointed, projection, postero- 

 inferior angle quadrate ; segment 4 with a high 

 acute triangular process following the inden- 

 tation. Telson ovate, scarcely half as long again a "■ 



as wide, cleft for a little over half its length, lobes Fi g- 3 1 - Orchomenella acanthurus (Schell.). 



tapering to acute apices with a spinule in a notch a ' ^ rofile of e P istome and u PP er U P" *• Gnatho " 

 .. - . , , 1.1 pod 1, with palmar denticles further enlarged, 



on outside or apex, and three lateral spinules. c jelson 



Antenna 1, 1st joint stout, 2nd and 3rd short, 

 flagellum 9-jointed, 1st joint long, accessory flagellum 6-jointed, 1st joint also long. 

 Antenna 2 a little longer than antenna 1, flagellum 13-jointed. 



Epistome produced in a broadly rounded lobe projecting beyond the upper lip. 



Gnathopod 1, 6th joint distinctly narrowing distally, palm transverse, defined by two 

 spines, its margin with minute squarish denticles, finger overlapping palm. Gnathopod 2, 

 6th joint minutely chelate. 



Second joint in peraeopod 3 broadly expanded, in peraeopod 4 less so, in peraeopod 5 

 again broadly expanded; hind margins of all feebly notched. 



Uropod 3, inner ramus extending to apex of 1st joint of outer ramus, margins of both 

 rami spinulose. 



Remarks. An easily recognized species. The carination of the 3rd pleon segment, 

 raised above the insertion of segment 4, is interesting. 



Orchomenella zschauii (Pfr.) (Fig. 27 h). 



Pfeffer, 1888, p. 87, pi. ii, fig. 1. 

 Stebbing, 1906, p. 85 (part). 

 Shoemaker, 1914, p. 73. 

 Schellenberg, 1931, p. 46, fig. 24. 



Occurrence: 1. South Georgia. 3. iv. 25. Many $$ and $$ 9-13 mm. 



2. East Cumberland Bay, South Georgia. 30. xii. 26. 11-36 m., 2 $? 9 and 12 mm. 



