l62 VERRILL 



EVASTERIAS TROSCHELII Var. ALVEOLATA Verrill, nov. 



Plate LXii, figure i. 



A five-rayed, conspicuously reticulated variety, with plump, 

 rounded, tapered, subacute rays of medium length. Radii of the 

 type, 22 mm. and no mm.; ratio, 1:5. Madreporite large, round, 

 convex, yellow, surrounded by a circle of fine capitate spines. 



The dorsal ossicles are narrow, but high, with subacute summits, 

 on which are rows of small, slender, capitate spines. They surround 

 rather deeply depressed, angular, papular areas, variable in size and 

 form, but often hexagonal or pentagonal ; larger and more rectan- 

 gular ones are on the sides of the rays, between the marginals. 



The dorsal spines are somewhat unequal, the larger ones standing 

 at the intersections of the ossicles and on the median line, but forming 

 only a very inconspicuous median band ; they are not at all acervate. 



The marginal and actinal spines form five nearly simple, regu- 

 larly spaced rows proximally, all of which are similar in size and 

 form, except the upper marginals, which are shorter, thicker, and 

 more capitate. These mostly stand one to a plate, but sometimes 

 two ; or there may be one or two small accessory spines on the plate, 

 or on the connecting transverse ossicles. The spines of the other 

 rows are a little longer, short-clavate or obtuse, and mostly one to a 

 plate. 



The peractinal and subactinal rows have one or two to a plate, or 

 alternately one and two in places. The synactinal row extends to 

 about the distal fourth of the ray. 



The adambulacral spines stand mostly two to a plate; they are 

 rather stout, cylindrical, or slightly tapered, acute. 



Pedicellarise are few. Very small, ovate dermal major pedicel- 

 lariae are scattered on the dorsal side ; and larger ones, more acute 

 in form, are found on the interradial and marginal areas. 



The color, as dried, is dull purple. 



Departure Bay, British Columbia (Canadian Geological Survey, 

 1908). 



This looks like a distinct species, but is probably a short-rayed 

 variety of E. troschelii. Its rays are not only shorter and thicker, 

 but the areolations are deeper and more sharply defined, while the 

 marginal and actinal spines are larger and fewer, and the rows are 

 fewer and more widely separated. It may, however, eventually prove 

 to be a distinct species, when a more extensive series can be studied. 



