180 DISCOVERY REPORTS 



Aberration 

 Occurrence: St. 170. South Shetlands. 1 $ 12 mm. 



Remarks. The specimen from St. 170 found in conjunction with two specimens of 

 the variety described below constitutes an interesting aberration ; were it not for this 

 aberrant specimen the new variety would have been accorded specific rank. 



The rostrum is short, extending barely half-way along the 1st joint of the 1st antenna. 

 Dorsal processes as in the typical form, except that pleon segment 3 has no tooth, only 

 a rounded medio-dorsal keel, which is higher than in the variety. Lateral tubercles on 

 peraeon segments obsolete. 



Distribution. Palmer Archipelago, 129 m. 



var. miothele, n. 



Occurrence: 1. St. 170. South Shetlands. 2 mutilated $$ (1 ovig.). 



2. St. 195. South Shetlands. 2 <$$ 7-5 mm., 2 ovig. $$ 9-10 mm., 1 juv. 5-5 mm. Types. 



Description. Less spinose and tuberculate than the typical form. Head carinate, 

 produced in a short rostrum extending half-way along 1st joint of antenna 1. Antero- 

 lateral angle rounded-quadrate. Eyes large, circular, pale. Peraeon segments 1-4 

 smooth, dorsally rounded; segments 5-7 each with a pair of dorsal, adpressed, short 

 processes, those on segment 5 apically subacute (in dorsal view), the others acute. No 

 tubercles on lower margins of the segments. Side-plates 1-3 ovate, 1 narrowing to a 

 subacute apex, somewhat curved forwards, 2 and 3 rounded below; 4 broadly rounded 

 below. Pleon segments 1 and 2 each with a single medio-dorsal acute, decumbent 

 process, not upstanding as in crenulata; segment 3 with a low rounded medio-dorsal 

 keel. Postero-inferior margins of pleon segments 2 and 3 serrate as in crenulata. Telson 

 as in crenulata. 



Antennae, mouth-parts, and other appendages as in crenulata. The 2nd joints of 

 gnathopods 1 and 2 have the same regular row of short spinules on the hind margins 

 (on outer surface) as I find in the present examples of crenulata. Hind margins of 2nd 

 joints of peraeopods 3-5 feebly serrate. 



Parepimeria major, n.sp. (Fig. in). 



Occurrence: St. 177. South Shetlands. One specimen 17 mm. 



Description. In general habitus like crenulata var. miothele. Head carinate, with short 

 deflexed rostrum. Eyes broadly oval, quite white as preserved. A sinuous oblique ridge 

 from upper hind margin of eye to middle of hind margin of head. Peraeon segments 

 1-4 rounded dorsally; 1 with a transverse groove, 2-4 each with the posterior margin 

 gibbous ; segments 5-7 each with a pair of long acute processes ; no tubercles on lower 

 margins of segments. Side-plate 1 acutely produced forwards; 2 and 3 ovate, subacute 

 below; lower hind margin of 4 concave. Pleon segments 1 and 2 each with a strong 

 projecting acute medio-dorsal tooth; segment 3 with a rounded keel posteriorly; 

 postero-inferior angle of segment 1 quadrate, of 2 shortly pointed, of 3 quadrate with 

 a short tooth ; lateral margins of segments 1 and 2 slightly angular, of 3 with a small up- 



