ASTEROIDEA OF NOETH PACIFIC AND ADJACENT WATERS FISHER. 203. 



longer tlian high throughout most of ray, and forming a sHghtly arched, steep bevel 

 to side of body; firet plate conspicuously higher, or wider, tliaii long, and longer 

 on inner than lower edge. General surface covered with evenly spaced thimble- 

 shaped granules which increase in size toward the center of each plate, the periph- 

 eral being rather small and pinched. A few j)latcs bear pedicellariie similar to 

 those of the paxillcT. Iiiferomarginals beyond the second plate alternating with 

 superomarginals and wider than liigh, forming a narrow border to tlie actinal area, 

 tliin, sUghtly longer than broad, and the upper edge angular, like the lower edge of 

 the superomarginals ; granulation rather coarser than that of su])eromarginals, square 

 or prismatic, and very few pedicellaria» on the series. 



Adambulacral plates rather regularly quadrate and remurkahie for tiie long 

 furrow spinelets, of which tliere are five in each series, strongly compressed, regular, 

 round-tipped, the adoral slightly shorter than the other four, these spinelets reach- 

 ing nearly across the furrow and tapering slightly as regards their thickness, the 

 tip being often beveled; on the actinal surface a longitudinal series of three spine- 

 lets, the central longest and about three-fourths the length of the furrow spinelets, 

 the series standing midwaj' between furrow margin and outer margin, upon which 

 are three or four less regular granules similar to those of the actinal intermediate 

 plates; first plate and a few othei-s with a pecuUar foraminate pcdicellaria on actinal 

 surface consisting of two or three slender upright spiniform jaws, occasionally 

 faintlj" spatulate, nearly as high as the inner actinal series. (PI. 57, iig. 3b.) These 

 pedicellariae do not have a depression into which the jaws fit when opened. 



Mouth plates slighth' convex actinallj' and the furrow armature consisting of 

 eight spinelets, similar in character to those of the adambulacral plates; the two 

 inner larger than the others, and those between inner and outer members of the 

 series slightly shorter, or, in other words, graduated in size from tiie middle toward 

 either end of the series; on actinal surface a number of elongate granules, and one 

 of the peculiar pedicellarise, the latter situated near the median suture at about 

 middle of plate. 



Actinal interradial areas large, the plates extending to ninth inferomarginal or 

 about half the Icngtii of ray, arranged cjuite regularlj' in series parallel to the furrow, 

 slightly convex and armed witli six to eight spaced, elongate, prismatic granules, 

 usually forming an ornate rosette. A few plates have a pedicellaria with slender, 

 high, jaws. (PI. 57, fig. 3c.) 



Madreporic body convex, oval, situated nearer than midway to margin; 

 striations coarse, undulating, intcrrupteil, centrifugal. 



Anatomical notes. — This species possesses rudimentary superambulacral plates. 

 It is necessary to treat the ambulacial and arijacent plates with caustic potasii 

 solution. After tlus is done the small indcpenilent oval ossicles are seen at the 

 lower end of the ambulacral plates. They are very similar to those of M. lequalis. 

 Tiiey were examined on eleven plates at about the miihlle of the ray. It was not 

 thought desirable to mutilate the type furtlier to ascertain if the superambulacrals 

 extended to the very base of the series, jus this jioint is not of great imixirtance. 



Young. — A young specimen from stat ion 4421 has the following dimensions : U = 

 13 mm.; r = 6 mm. It has the general facies of the adult, but all the paxillte are 



