158 PANAMIC DEEP SEA ECHINI. 



parison of Gregory's figures will show the incorrectness of the statement. 

 Even the plates and fragments of C. elypeaius showed plainly the abactinal 

 system and the surrounding coronal plates and the anal system (PL XXXV b , 

 Bgs. 10, 11). These characters cannot be studied in the specimen described 

 by Gregory, and it seems to me a very hazardous identification. 



I do not see why Neumayer should be cpuoted as mentioning Cystechinus 

 as one never found above the 1000 fathom line. All the information we had 

 on the subject at the time Mr. Gregory wrote his article was derived from 

 the data given in the Reports of the " Challenger." 



As regards the statements made on the subject of Calymne in the Report 

 of the "Challenger" Echinoidea, the single specimen sent to me was marked 

 "'Trawl,' 2650 fms. May 27, 1873." The -Trawl" was so indistinctly 

 written as to be mistaken for Fayal. It was not until after the Report had 

 been printed that my mistake was discovered. 



Gregory 1 is mistaken in stating that at the time he described C. crassus 

 the genus was only known from the Antarctic and China Sea. See "Chal- 

 lenger" Echinoidea, p. '2. IS. lie also speaks with some doubt of the genus 

 Cystechinus having been dredged by me in deep water off the western eoa>t 

 of Central America. While it is true that my remarks on the two species 

 collected (('. Loveni A. Ag. and C. Rathbuni A. Ag.) are short, 1 must insist 

 that the photographs given of the species'- are sufficient to denote their 

 affinities to C. Wyvillii and C. vesica. But like man} 7 of the criticisms 

 directed against short preliminary notices, they lose their value if the ac- 

 companying illustrations are taken into account, and not ignored, as is 

 usually the case. 



Cystechinus Loveni A. Ag. 



Cysjtechinua Loveni A. Ag., Bull. M. C. Z. 1898, XX XII. Xo. .*>, p. 79, Plate IX. 



Plates B, fig../; 75-79. 



This species is closely allied to Cystechinus Wyvillii A. Ag. 3 It can be 

 distinguished from it by its comparatively stout test, its circular or pyri- 

 form anal system (it is transverse in C. Wyvittii and C. elypeaius), the 

 great size of the actinal plastron, and by the marked differences in the 



1 Gregory, Relations of Echinid Faunas. Hull Geol. Soo. of Am., Vol. 3, 1891. p. 10. 

 - Bull. M. ('. Z. 1898, XXXII. No. 5, p. 79, Pis. IX, X. 

 » "Challenger" Echinoidea, PI. XXIX". 



