ISTBROIDKA 01 WORTH PACIFIC AND ADJACENT WATEHS- FI8H1 



icate, Bpatulate, gouge-ehaped, round-tipped, Bpirn of the proximal 



Imlf of the ray [fewer distally and proximally in Bmall specimens] and the clu 



e together. The channel ia usuallj . bul ool inv ariably, on the upper or abactinal 

 Bides of the spine, and in mu.mII specimens the Bpines may n<>t be channeled al nil 

 tint simply clavate, and of varying degree of robustneee. 



rly midway between the ambitus and furrow margin ia a doable ro* of go 

 Bhaped Bpines separated from the Buperomarginals by s conspicuously broad inter- 

 marginal channel and from the adambulacrals by an actinal channel, both densely 

 covered with papulae. While in this specimen there are only occasionally three 

 inferomarginal Bpines, some examples, as, station 3243, have fairly regularly three 

 on each plate of the proximal half <>f the ray, in addition to one or two -hurt 

 series <>f intermarginal -pines (springing from intermarginal ossicles The I 

 specimen from Btation 3242 has do intermarginal spine- bul another from the same 



haul, with K lot) mm., has a series extending nearly half the letiL'th of ray. nnil 



Bpaced from these, toward the margin, a second row not so Iohl'. There are thus on 

 the proximal third of ray four parallel series of Bpines, of which two are inferomarginal. 

 The inferomarginal spine- are untapered, or slightly broader at the tip than midway, 



Or the reverse, and the depth of the channel, whieh is on the adtnaririnal -ide. varies 



greatly in different examples, being absent in young. In the largest specimen the 

 Bpines are 3 to i mm. long by 1 to L.2S mm. broad. The firsl spine corresponds to 

 the eleventh adambulacral plate. The marginal and abactinal Bpines are distally 



rough and minutely thorny. 



The actinal channel is well marked hut not so broad as the intermarginal. 



There are no actinal spines, hut a single series of small actinal plate-, largely obscured 



by the inferomarginals, i- present. 



The adambulacral spines are longer than the inferomargina] (about •"> mm.) ami 

 -o placed a- to form three longitudinal row- along the margin of furrow. The 



Bpines of the innermost tow are only on alternate plates, are set rather well into the 

 furrow, on the furrow face of the plate, as in and ale compres-ed. 



tapered, and bluntly pointed. This is followed by two slightly longer, often tapered, 



hlunt -pine- (or l'.\ only one on the outer part of the ray i ha\ ing a variably developed 

 channel or groove down the outer side. The plates alternating with these I 



proximally. two grooved Bubambulacral spines; distally only one. There are thus, 

 proximally. three and two adainhulacral spine- alternating and distally two and one 

 Another large specimen from tin- station, already referred to. ha- two spine- on both 



- of plates proximally and distally two and one. alternating. The grooves <>t> the 

 Bubambulacral Bpines becomes less and less well marked in progressive^ smaller 

 specimens, It is normlly absent in small specimens even though well marked in 



large examples from the -ame locality. [The position of t lie furrow spine of alter- 

 nate plates, near the moi pli< .logical upper end of the adainhulacral plate, led I 



r Yerrill to found the genus AUatttrias. But the alternate furrow Bpines of 

 I !, ■ ..• i ./., rw, the t> pe of Asterias, have the -ame position.] 



The month plate- are Bunken ami bent down toward the aotinostome, 

 characteristic for the genus, hut the oral angle although composed of upward ol 

 pairs of contiguous adoral adambulacral plate-, i- not a thin carina as u 



and Pisasttr, hut broadens rapidly from the apex and i- -tout, and crowded with 



