272 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



cellariae are as in the type; but an example of the large globiferous 

 form was also found in this specimen. It is of considerable interest 

 in having the valves somewhat prolonged into a narrow tube, on the 

 end of which the opening is situated (pi. 79, fig. 9). This recalls the 

 form of large globiferous pedicellaria found in "Petalocidaris" and 

 shows that this character is scarcely of generic value, the present 

 form being otherwise in no way nearly related to the Petalocidaris 

 group. The color is the same as in the typical form. 



Remarks. — It does not seem justifiable simply to identify this speci- 

 men with the typical form, or with the variety tuberculata as described 

 above. On the other hand the differences are not very important, so 

 that it would not seem warranted to make this specimen the type of 

 a separate species. So long as only this single specimen is available 

 the proper course seems to be to designate it as a variety, var. major, 

 of Goniocidaris (Cyrtocidaris) tenuispina. 



RHOPALOCIDARIS, new genus 6 



Diagnosis. — A genus of Goniocidaridae with small but distinct 

 grooves at the median end of the horizontal sutures, and with a broad, 

 bare, sunken median space in both ambulacra and interambulacra 

 Primary spines without basal disk; apical primaries simple or, at 

 most, with a very small terminal widening. Surface of primary 

 spines covered with a well-developed coat of fine, not branching or 

 anastomosing hairs. The primaries otherwise with rather coarse 

 longitudinal ridges and furrows, more or less strongly spinous. Sec- 

 ondary spines club shaped, not appressed. Globiferous pedicellariae, 

 both the large and small form, of the typical goniocidarid structure. 

 Very small forms. 



Genotype. — Cidaris (Discocidaris) hirsutispinus de Meijere. 



Remarks. — It has been maintained by H. L. Clark 7 that this species 

 is only the young of Goniocidaris clypeata. The study of adult spec- 

 imens, collected partly by the Albatross, partly by the author during 

 the Danish expedition to the Kei Islands in 1922, and the compari- 

 son with the type specimen from the Siboga expedition, kindly lent 

 me by Prof. L. F. de Beaufort, the director of the Amsterdam Mu- 

 seum, does not leave the slightest doubt that hirsutisjnnus is a well- 

 characterized species, and so far from being identical with G. clypeata 

 it can not even be referred to the same genus, but must form the type 

 of a new genus. The main character distinguishing this genus from 

 the rest of the goniocidarids is the peculiar club-like shape of the sec- 

 ondary spines. Only in Goniocidaris umbraculutn is there an indica- 

 tion of a similar club-like shape of the secondary spines, especially the 



« From po7ra\oi/=club. 7 The Cidaridae, p. 197. 



