84 PANAMIO DEEP SEA ECHINI. 



a sketch ("Challenger" Echinoidea, PI. XLIV, figs. 25, 26). Phormosoma 

 hoplacantha also has tridentate pedicellariae clearly resembling those of 

 Asthenosoma fenestrata and of Asihenosoma hystrix ("Challenger" Echinoidea. 

 PI. XLIV, figs. 29, 29', 30). 



Dr. Mortensen ' proposes to retain the name Calveria of Thomson as a 

 generic appellation of A. hystrix, varium, and A. Grubei, of which he says 

 the former species "has unjustly been deprived." The name of Calveria 

 was dedicated to Captain Calver, and originally given by Carpenter, 

 Jeffreys, and Thomson in 1869 to "a very singular Asterid allied to Pter- 

 aster which is covered with a regular brush of long paxillse. . . . We 

 propose to give the generic name Calveria to the latter (Pteraster) with the 

 specific designation hystrix" (Proc. R. S. London, No. 121, Vol. XVIII, 

 January, 1869, p. 445), and only afterwards did Thomson apply the same 

 name to a species of Asthenosoma." 



Having stated in one part, of the " Challenger " Report that I considered 3 

 some young specimens from Stations 184 and 219 as perhaps not belonging 

 to A. gracilis, I am corrected for not repeating this every time I mention 

 A. gracilis ! These specimens Dr. Mortensen examined, and also considers 

 as very different from A. gracilis. 



Dr. Mortensen states that Asthenosoma varium and A. Grubei are distinct 

 species. He gives no figures of pedicellariae to settle the question, as his 

 figures of pedicellariae of A. Grubei are not comparable to those of .1. varium. 



According to Dr. Mortensen I have wasted my time in describing the 

 differences between Ph. bursarium and Ph. luculentum, which are so evidently 

 distinct according to the figures I have given in the Challenger Echini, 

 while I have not observed that Ph. bursarium is very similar to Ph. placenta, 

 and have not informed my readers of the characters which distinguish the 

 two. I beg to refer Dr. Mortensen to the figures of Ph. placenta published 

 in the "Blake" Report and those of Ph. bursarium published in the "Chal- 

 lenger" Report. 



If we compare the differences between the pedicellariae of A. hystrix and 

 those of A. fenestratum and A. coriaceum as figured by Dr. Mortensen, we 

 find them so slight that they certainly cannot be considered of generic 

 value as is maintained by him. We can only wonder at his constant amaze- 

 ment concerning the affinities of the various species of Echinothuriae sug- 



1 Mortensen, 1. c. p. 52. 



2 Depths of the Sea, p. 157, 1*73. Tnms R. S. Lond., 1874, p. 737. 

 8 "Challenger'' Echinoidea, p. 91. 



