PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 357 



In some specimens, notably from Fylla, Disco Bay, Greenland, the basal segments 

 of the proximal pinnules are strongly carinatc. 



The status oj quadrata, barentsi and juvenalis. — In 1884 Dr. P. H. Carpenter diag- 

 nosed a new species which he called Antedon quadrata, giving as distinctive characters 

 the shape of the lower brachials (after the fourteenth) which are as long as, or slightly 

 longer than, wide and slightly quadrate in outline, while those in the middle of the arm 

 are distinctly quadrate, the length bearing a large proportion to the breadth, and the 

 later ones are somewhat elongated; the fact that none are shaped like an isosceles 

 triangle and much shorter than broad; and the length of the pinnules of the third pair 

 (on the sixth and seventh brachials) which are little more than half as long as those 

 of the second pair, while the basal segments of all the proximal pinnules have their 

 dorsal edges more or less produced into sharp flattened processes. 



His specimens came from Triton stations 4 and 6, and he identified with these the 

 TegetthoJ specimen, also one which he himself collected off Disco diu-ing the cruise of the 

 Valorous, two from Discovery Bay, and one from Franklin Pierce Bay dredged by 

 Fielden in the Alert, some from Challenger station 48 off Halifax, and some from the 

 Willem Barents collection dredged near the locaUty where the one taken by the Tegetthqf 

 was found. 



He says that the three Triton specimens are all of them small, like those from the 

 Tegetthqf and Valorous collections, while they have a stiffer and less feathery appearance 

 than the larger ones obtained farther north by the Alert and the Willem Barents. The 

 dorsal processes on the lower segments of the basal pinnules are less prominent than 

 usual, whUe the peculiar characters of the fii'st two pinnule segments in the outer parts 

 of the arms are by no means so marked as in larger individuals. 



In 1886 Levinsen, basing his deductions on material secured in the Kara Sea by 

 the Dijmphna, concluded that quadrata was merelj' the young of glacialis. 



In the same year Carpenter discussed this form at considerable length on the 

 basis of two specimens from Willem Barents station 21, 1880, and in the following j-ear 

 he again discussed it, describing some specimens which had been dredged by the Varna. 



In the Challenger report Carpenter described quadrata in great detail. In his key 

 to the species of the "Eschrichti group" he placed it, together with barentsi, in a special 

 division, contrasted with all the other species through having P3 composed of a few 

 elongated segments and much shorter than P2 instead of equal to, or not much shorter 

 than, P2. In this key quadrata is thus separated from glacialis {"eschrichti") by the 

 species antarcfica {=Solanometra), australis { — Solanometra antarctica), rhomboidea 

 {=Florometra magellanica) and magellanica { = Florometra) ; and in the descriptive 

 text antarctica, australis and rhomboidea are placed between glacialis and quadrata. 



The characters of quadrata as given bj' Carpenter are: Ccnti'odorsal hemispherical; 

 cirri L-LXX, 30-35; several of the segments longer than wide, the later sharpened, 

 but not distinctly carinate; radials very short; IBri longer and trapezoidal, somewhat 

 incised by the rhombic axillarj' which is as wide as, or wider than, long, with a fairl}' 

 open distal angle, and forming with it a slight prominence. The 10 arms consist of 

 about 200 smooth brachials, of which the first is rather deeply incised with a short 

 inner and much longer outer edge, the second is irregularly quadrate, and the six 

 following are more oblong or obliquely quadrate with the pmnule on the shorter side. 

 The first three brachials above the third sj'zj-gj- are sometunes nearly triangular and 

 as wide as long, but those following are distinctly quadrate and gradually become 



