l62 



ECHINOIDEA. II. 



cellarige, only the widened part at the point is smaller, the blade is more curved, and, generally, the 

 edges of the basal part are distincth- serrate for a short space. This form reaches a size of ca. i""" 

 length of head; it is, indeed, not sharpl>- distinguished from the tridentate pedicellarise, transitional 

 forms being found, which may almost with equal right be referred to either of these kinds. On the 

 other hand a smaller form of rostrate pedicellarise (PI. XIX. Fig. 4) may also be found, which is more 

 like the form known from lyrifera. In quite small specimens the widened part in the point of the 

 blade is comparatively larger (PI. XIX. Fig. 25) — if upon the whole this form ought to be regarded 

 as a rostrate pedicellaria; it might perhaps as well be termed tridentate. The ophicephalous pedicel- 

 larise (PI. XVIII. Fig. 10), which are only occasionally found in the larger specimens, are rather char- 

 acteristic. The basal part is quite small; the blade is rather broad in the outer end, its edges are 

 serrate almost down to the articular surface; the apophysis is sometimes very broad. (PL XVIII. 

 Fig. 13).' — The triphyllous pedicellaria; are like those of lyrifera. 



This species is evidently rather common and widely distributed along the American side of 

 the Atlantic. I have seen specimens from the following stations of the (Albatross » : 2077 (1255 fathoms) 

 2230 (1168 fms.), 2343 (279 fms.), 2378 (68 fms.), 2401 (142 fms.), 2562^ (1434 fms.), 2571 (1356 fms.), 2684 

 (11 06 fms.), 2748 (1163 fms.). I have further dredged a specimen myself off Christiansted, St. Cruz, in 

 ca. 200 fathoms. It may not be too hazardous to prophesy that probably many more of the American 

 specimens referred to Br. lyrifera will prove to belong to this species, while the rest will be Br. alta 

 or the species described below, Br. clongata, or even Periaster litnicola, whereas I doubt if there are 

 any true Br. lyrifera among them. 



Some specimens from the stations 2077, 2208, 2230, 2571, 2684 and 2748 are somewhat broader 

 than those from the other stations named ; some of them are narrowed towards the posterior end. 

 Also the posterior petals may be more sunken than is generalh' the case in the narrower form; the 

 colour seems to be darker and the test more fragile than in the narrow form. (The species has upon 

 the whole a rather fragile and thin test). Generally, but not always, this broad form has onl\- three 

 pairs of pores within the fascicle; the labrum is also somewhat more prominent. As, however, the 

 other features, especially the petals and pedicellarise are alike, I do not think it possible to keep the 

 broad form as a distinct variety, or even a distinct species, the more so, as there are transitional forms. 

 That the broad and narrow form may occur together (e. g. from St. 2077) need not, of course, imply that 

 they cannot be distinct species. After the material at my disposal I must regard them all as one 

 species, which is rather variable in regard to the width of the test. In PI. III. F'ig. 17 is represented a 

 specimen of the broad form. 



In the Museum of the Yale College I found in a .specimen from St. 2268 (68 fms.) a very curious 

 kind of 'tridentate* pedicellarise (PI. XIX. Fig.s. 14, 22, 30). It has no less than S valves, a case quite 

 unparalleled. The valves are rather narrow and flat, the point bending inwards as a hook. The speci- 

 men otherwise agrees with atlantica, and both kinds of globiferous pedicellarise are found on it. There 



' This form of ophicephalous pedicellana was found in a very young specimen, whose identification is not 

 beyond doubt. 



^ The specimens (one .md some fragments I from this station have the petals somewh.it less distinctly crescent-shaped 

 than is otherwise the case in this species; none of the more characteristic pedicellariie were found. I dare not assert 

 beyond doubt therefore that it is really this species, though 1 for my part think it really is. 



