POROCIDARIS MILLKRI. 25 



as perhaps belonging- to that species, is sufficiently characteristic for such a 

 generic separation. 



Dr. Mortensen names as Dorocidaris inicans specimens of a Cidaris wliich 

 he received from the U. S. National Museum, Washington, labelled as 

 Porocidaris Sharrcri (" Albatross," 1885, St. 2415), and also from the 

 U. S. Fish Commission ("Albatross," 1885, St. 2345) under the same name. 

 I beg to call Dr. Mortensen's attention to the fact that the publication of 

 the "Blake" Echini dates back to 1883, that my specimens came from 

 Nevis and the Barbados, and that 1 was in no way concerned in making 

 the collection of the " Albatross" in 1885, or with the identification of the 

 Echinoids then collected. Dr. Mortensen's statements^ in regard to Poro- 

 cidaris Sharreri are gratuitous misrepresentations of facts. Other specimens 

 have also been received by him from Washington of collections made by 

 the " Albatross " which come under the same conditions. 



Porocidaris Milleri A. Ag. 



Porocidaris Milleri A. Ag., Bull. M. C. Z. XXXII, No. 5, p. 74, Plate IV, 1898. 



Plates 6-8; 10, figs. 1-3. 



This species, PI. 6, is closely allied to P. elegans A. Ag., collected by the 

 " Challenger " ; ^ it is readily distinguished from P. clcgans by the great 

 irregularity in shape of the genital plates (PL 7, figs. 1, 2) and the scant 

 development of the ambulacral buccal plates (Pis. 7, fig. ^; 8, fig. J). Its 

 primary radioles also differ from those of P. elegans in being less tapering 

 and having finer serrations (Pis. 6; 10, fig. 3). The external appearance of 

 the primary radioles variee greatly both in different specimens from the 

 same locality or in the same specimen (PI. 6). In three of the specimens 

 from Station 3381 annelid tubes were found attached to the radioles. In 

 the long cylindrical radioles there are often as many as six or seven longi- 

 tudinal rows of blunt lamellar spines or sharp spinules ; and in the same 

 specimen we find all possible gradations between them and radioles merely 

 finely striated or with here and there remnants of a spinule or of a lamellar 

 protuberance. In the smaller, flattened, spear-shaped, and laterally serrated 

 primary spines of the actinal side a third row of spinules often develops on 

 the convex side. 



1 Mortensen, 1. c, pp. 22, 23. ^ " Challeuger " Echinoidea, PI. Ill, p. 40. 



