18TER0IDBA OP NORTH PACIFIl IND LDJACENT WATERS nSHBB 



examples from station 3302 fine gray sand, 30 fathoi have toothed straight 



pedicellariae, but they are nol \ ery numerous. In facl the animals from the southern- 

 most part of the range eem I irly provided with stri licellariae (except 



<>n the furrow fi : but there are exceptions to this, f. >r a 



large specimen, with R W mm., and well spaced five t" seven & 



dorsal area) from 3ta1 - fathoms, gray sand and rocks, north of the end of 



(lie Alaskan Peninsula I has numerous dorsal, lateral, and actinal Btraight pedicellariae 

 which either lack or have few short teeth. This specimen also has numerous furrow- 

 spine straight pedicellariae, and the largesl rays recorded for this species. Three 

 other examples from the same station have much fewer pedicellariae and agree with 

 the generality of material from the region. 



One of : ! ><' examples from stntion 35 a rays. 



r ii'mn Island form.— Specimens from the Aleutian and Shumagin I lands 

 differ from typical beringensis in their smaller size, rather more terete and less obvi- 

 ously capitate dorsal spines. Straight pedicellariae are rather variable but in a 

 specimen from Atka they are well developed v. th : ree or four curved teeth to each 

 narrowly spatulate jaw. The largesl specimens have R :;."> mm. (Shumagin Island) 

 and 36 mm. (Atka). As compared to forma arctica, for example, from Point Frank- 

 lin, the Aleutian-Shumagin examples have more widely spaced, more uniform, 

 and longer spines, with much more conspicuous wreaths of pedicellariae. 



Young. — The young forecast some of the more salient variations of the adults and 

 therefore differ among themselves, although less \\ idely than do the mature examples. 

 There is a good series of grow th Btages from the type locality, the smallest specimen 



having K 4 mm. In this there is a distinct lateral face to the ray formed by the 



phanerozoniate marginals (about eight) and the Bat dorsal surface has only an 

 irregular carina! series and a rudiment or two of the dorsolaterals. The dorsal plates 



hear one or two spinelets and a few crossed pedicellariae have appeared. The 

 actinal plates have not yet appealed while the adambulacral plates arc relatively 

 more prominent than in larger specimens, with one or two rather slender clavaie 

 spines, relatively much longer than in the adult. A regular series of dorsalateraJs 

 next appears (K 7 mm l, while the crossed pedicellariae Increase in number. T 

 are none on the adambulacral spines which may he only one to a plate throughout 

 the ray. The Bret straight pedicellariae have appealed in the furrow, hut the larger 

 type are found first in a specimen with K mm. Here there are one or two in the 

 tnterradial groove on the actinal surface where in adult life thay appear to guard the 

 gonoduct apertures. In this specimen also the first adambulacral crossed pedicel- 

 lariae occur on the proximal spines in this specimen generally one to a plate*. By 

 the time H reaches 12 or i"> mm. the animal resembles the adult but the spines are 

 slenderer, the pedicellariae much fewer, and the actinal plates either absent or rudi- 

 mentary. Xaturally also the plate- anil spines are less numerous than on the lai 



specimens 



Brooding habits. Specimen- from the following stations are carrying young: 



Station 3240, Bristol Bay, June B, 1890, temperature not r irded ; one specimen 



Station :V_> l! , Bristol Hay. June B, 1890, bottom temperature. 38 K : one 



specimen. 



t.:i 160—30 3 



