36 



ECHINOIDEA. II. 



the pyramid (5) of the odd posterior interambulacruiii being considerabh- larger than the others. (Conip. 

 Lev en. Echinologica. p. 69). 



The spines are a little longer than in piisil/iis, the largest being ca. i""", and more slender. 

 Thev are provided with only a few serrations and end in rather a slender point. (PI. XII. Fig. 15.) The 

 miliarv spines are only about one third as long as the primar\- ones. The}- are a little slenderer than 

 those of pusillus. often slightly serrate near the upper end. The endcrown is a little larger than in 

 pusillus ; the longitudinal ribs are more widened at their upper end, almost joining with their edges, 

 and the radial plates are larger and broader, generally with 4 — 5 serrations, sometimes in a double 

 series. (PI. XII. Figs. 10, 16). ■ — The pedicellarise also differ rather considerably from those of pusilhis. 

 The ophicephalous pedicellaria; differ from those of pusillus in having fewer serrations along the edge 

 of the blade, otherwise the shape and structure is the same as in that species. (PI. XII. Figs. 8, 11 — 13). 

 The tridentate pedicellariae (PI. XII. Figs. 25, 28) are gradually narrowed towards the articular surface, 

 whereas in pusilhis the\' narrow abruptly at the lower end of the blade. The triph\llous pedicellarise 

 (PI. XII, Fig. 21) have a much broader blade than in pusillus, and the edge is much more closeh- ser- 

 rate; the\- are ver\- small, the head only ca. 0-04"'™. — The buccal tube-feet are not distinctly larger 

 than the other actiual tube-feet. Spicules are wanting as in piisillus. 



To this species so well distinguished by its large ocular pores, little developed petals, few 

 actinal pores, as well as b\- its spines and pedicellarice, belong all the specimens of Echinocyamus 

 pusillus» from the Blake and Albatross which I have seen (viz. from « Blake St. 5 and 239, 

 <'Albatross:> St. 2352, 2666 and 2668), as well as the specimens from the Challenger St. 122 (examined 

 in the British Museum); a pair of specimens dredged by myself in 500 fathoms off Frederiksted, St. 

 Cruz, also belong to this species. Pfobabh' all the specimens of Ec/iii/ocyanius recorded from the West 

 Indies and Florida (and Brazil) under the name of rpiisilhis!> will turn out to belong to this species 

 (and perhaps jDartly to the following species). In any case the existence of Rett, pusillus in these 

 regions must remain doubtful, until by renewed careful examination it is pro\ed beyond doubt to 

 exist there besides Ecliiuocyanius grandiporus. I have further seen rather numerous specimens of this 

 species from the Azores from depths of ca. 100 — 700 fathoms (1365 m.) and from the Josephine Bank 

 (no — 430 fathoms). 



The occurrence of this species on both sides of the Atlantic is in good harmony with the dis- 

 tribution of other Echinoids, e. g. Genocidaris maculata, Cidaris affinis a. o. — and likewise it would 

 not be contrary to these facts of geographical distribution, if F.ch. pusillus should turn out to occur 

 in the West Indian Seas; it must only be emphasized thai it cannot be considered as an establi.shed 

 fact, before the specimens of grandiporus (and possibly also of macrostomus) are distinguished from the 

 true pusillus by renewed examination. 



Echinocyamus macrostomus u. s]). The shape of the test (PI. XII. Fig.s. 17, 24) is very like 

 that of grandiporus, a little more elongated, but not so nnich that it can be relied n])on as a .specific 

 character. The peristome is generally very large; there is, however, some \arialioii in this respect, 

 but I iiave always found it considerably larger than in specimens of grandiporus of a corresponding 

 .size. Tlie edge of the peristome is not incurved; the buccal membrane is de\oid of spicules as in the 

 other species. The anal opening is generally larger and nearer the edge of the test than in grandi- 



