330 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



Encope cocosi^-, new species 

 Plate 56, Figs. 48-49 



Test large, stout, with small lunules. Length 120 mm and width the 

 same; height, greatest about 35 mm from anterior margin, 12 mm; test 

 slopes ver\' gradually to the interambulacral lunule and then rather sharply 

 to margin. Unpaired petal about 40 mm long by 16 mm wide, open by 3 or 

 4 mm, only 5 mm back of the lunule ; poriferous areas about 4 mm wide, 

 the intermediate area 8 mm. Tuberculation of test very fine and close, the 

 petal-ridges with a single closely placed line of some 20 minute tubercles. 

 Anterior lunule small, oval, about 6x4 mm, only 5 or 6 mm from test 

 margin. Anterior paired lunules rather far back, a line joining them would 

 be 50 mm from anterior margin of test; they are veiy small (6-8 mm 

 long, 4-5 mm wide) and only 6-8 mm from test margin. Adjoining petals 

 short and stout, about 33x 18 mm, ending about 10 mm from lunule. 

 Posterior petals markedly longer (40 mm) than anterior pair, about 18- 

 20 mm wide. Interambulacral lunule small (9x4 mm), a little smaller 

 than the posterior pair (10 x 5 mm) which virtually accompany it, as the 

 3 lie in a straight line parallel to the nearly straight posterior margin of 

 test. Lower surface relatively uneven as the ambulacral furrows are evi- 

 dent and the vicinity of the lunules depressed. Spines of abactinal surface 

 very numerous, short and slender, each one terminating in a conspicuously 

 swollen light brown tip, resulting in a relatively smooth surface; only 

 around the margin and the lunules are the spines elongated and somewhat 

 pointed. Color clove brown becoming warm sepia on the margin; the 

 lower surface is unusually evenly dark with little difference between the 

 ambulacral and interambulacral areas. 



Besides the holotype there is only one other Encope in the collection 

 similar to this one in form and structural details and it is noticeably dif- 

 ferent in color as the swollen tips of the spines are very light cream color, 

 resulting in a very definite drab upper surface; the lower is a deep bone 

 brown. Both the brown and the drab specimens were taken in Wafer Bay, 

 Cocos Island, Costa Rica, in 2-4 fms. Although apparently a derivative 

 from the micropora stock, it is easily distinguished by the primary spines. 



Type. — Holotype, AHF no. 52, 1 paratype. 



Type locality. — Station 108-33, Wafer Bay, Cocos Island, Costa Rica, 

 2-4 fms. 



Distribution. — Cocos Island. 



Depth.~2A fms. 



Specimens examined. — The type and paratype, from 1 station. 



12 cocojt, of Cocos Island, the only place where it has been taken. 



