i88 DISCOVERY REPORTS 



toward the anus are conspicuously longer than those of the opposite half of the circle and 

 thus suggest the arrangement in the "oscular" paxillae of Pter aster. When the paxillar 

 spines of Remaster are spread to their fullest extent they nearly or quite touch those of 

 neighbouring paxillae. The membrane forming the end of each fascicle is stretched taut 

 and the abactinal surface has a tessellated appearance. The supradorsal branchial space 

 is nearly as effectively protected from outside contamination as in Pteraster. 



The actinal surface of Remaster is not strikingly different from that of Korethraster. 

 The divergence is seen in the abactinal surface. Perrier's diagnosis of Remaster may be 

 superseded by the following: 



Korethrasteridae having 4-lobed abactinal plates united in a small-meshed skeleton 

 with I or 2 papulae to each interspace; abactinal and superomarginal plates with a 

 fasciculate, obconic group of specialized, broadened, often scoop-shaped, denticulate 

 spines enclosed in a sacculus enveloping the whole group ; no actinal intermediate plates ; 

 no true calcified interradial septum ; gonads interradial ; adambulacral plates short and 

 broad with a simple transverse series of prominent subambulacral spines, and usually a 

 small furrow spine. 



Type locality of Remaster gourdoni. 64° 49' 35" S, 65° 49' 18" W, off Port 

 Lockroy, Palmer Archipelago, 70 m., mud and pebbles. 



Distribution. Graham Land (south-east of Seymour Island); Palmer Archipelago; 

 South Shetland Islands; South Georgia; Shag Rocks; Falkland Islands; 10-342 m. 



Genus Peribolaster Sladen 



Peribolaster Sladen, 1889, p. 464. Type P. folliculatus Sladen.— Fisher, 191 1, p. 341 (diagnosis; 

 vide infra). 



Peribolaster folliculatus Sladen 



(Fig. C, 5) 

 Peribolaster folliculatus Sladen, 1889, p. 465, pi. 73, figs. 4-7.— Fisher, 191 1, pp. 341, 343.— Koehler, 

 1920, p. 164. 

 St. 1562. Off Marion Island, 46° 52' S, 37° 55' E, 97-104 m., i specimen. 



St. WS81. North-west of North Island, West Falkland Island, 81-82 m., sand, 1 very large 

 specimen. 



St. WS 93. West Falkland Island, 133-130 m., grey sand, i small specimen. 



The specimen from St. WS 81 is much larger than Sladen's type and of an entirely 

 different form. It measures : R 90 mm., r 52 mm., br 60 mm. The rays at base are thus 

 two-thirds R in breadth. The gonads are greatly developed, causing the very flaccid, 

 collapsed, abactinal wall to bulge at either side of the base of ray, so that from the 

 actinal aspect a considerable portion of it is visible beyond the superomarginal plates. 

 This is not true of the smallest example (St. WS 93) which measures R31 mm., 

 r 12 mm. (to actual interradial angle, not end of spines) ; br 16 mm. (measured to end of 

 spines). Even this specimen has broader rays than Sladen's type but the difference is 

 due largely to the somewhat longer abactinal spines. The extreme breadth of ray of the 

 large specimen would be greatly lessened if the body were turgid and the abactinal wall 



