A. E. Verrill — Mevision Genera and Species of Starfishes. 155 



to the furrow-series are distinctly larger than the others, two to a 

 plate on the proximal half of the series ; those of the furrow-series 

 are slender, equal, obtuse, regularly placed in a row, four to each 

 plate. One or two of the distal lower marginal plates of each series 

 bears a small conical tubercle, but the doi'sal plates are smooth, 

 naked, without tubercles, though considerably elevated centrally. 



I have also examined four young specimens of this species from the 

 " Blake " Exp., preserved in the Museum of Comparative Zoulogy. 



Three of these (a, c, d) were types of Pentagonaster parvus Perrier. 

 They agree perfectly with those of similar size collected by the 

 steamer "Albatross" in the West Indies. (See H and I above.) 

 With the latter they form a complete series, connecting the smallest 

 with the full grown examples from the same region. 



The smallest of the specimens {b) from the " Blake " Exp. is from 

 station 253. It is enumerated under P. parvus by Perrier, but is 

 not marked as a type, but it- agrees with the others. Its lesser radius 

 is 7™™ ; greater radius, 10™™. In this there are, for the most part, four 

 upper marginal plates, above and below, on each side ; but in one 

 case there is a small triangular plate interpolated between the first 

 interradial and the next normal one, while there is a normal plate 

 next the apical one, so that there are four marginal plates on one 

 side of this ray and the adjacent semi-margin. On another interradial 

 margin there is a small, triangular, odd interradial marginal plate of 

 the upper series, similar to that in Odontaster. 



The lower marginal plates are usually six to a side, but on one 

 margin there are seven. The distal plate of some of the series is 

 small and only recently developed. The marginal plates of both 

 series are covered with granules. The papular pores are few in 

 number, in small radial groups. 



The specimens next in size are 25 to 35™™ in diameter (types of 

 P. j^arvus) and usually have six marginal plates on each side, above 

 and below. In the smaller of these the upper and lower marginal 

 plates and the actinal interradial plates are nearly or quite covered 

 with small granules, but in the somewhat larger specimens more or 

 less of the central area of these plates is naked. Most of them show 

 a distinct central swelling where the conical tubercles would have 

 appeared later. In some the abactinal plates ai-e entirely covered 

 with granules, but in others the central area is naked, the amount of 

 naked surface increasing with age, but not regularly so. The papular 

 pores increase in number with age and cover more and more of the 

 median radial areas and the central area of the disk, but these areas 

 have no sharp boundaries. 



