MUSEUM OF COMPARATIVE ZOOLOGY. 457 



jecting as large lobes beyond the general outline ; the whole test was 

 made up of small limestone cells, and evidently was quite movable, 

 though tough, in its present condition ; there were deep actinal cuts in 

 the centre of the ambulacral field, the actinal membrane unfortunately 

 was not well preserved. The spines were very short, and bore about 

 the same ratio to the test which they have in Astropyga and Asthe- 

 nosoma. The tubercles were not yet separated from the general lime- 

 stone network of the test, and the spines were arranged in the 

 interambulacral spaces in two irregular main rows, and in one row 

 in the ambulacral spaces, both extending to the abactinal pole. A 

 species of a genus closely allied to Asthenosoma Grube has been 

 dredged by the Porcupine Expedition off Cape Wrath and south of 

 Cape Finistere, off" Vigo ; I presume this will prove to be the young 

 of it. Professor Wyville Thomson will soon describe this species as 

 Calveria hystrix, and, like several of the species first dredged by Mr. 

 Pourtales, and subsequently found also by the Porcupine and by the 

 Josephine Expeditions, will add another to the list of Echini common 

 to both sides of the Atlantic. They are the following, exclusive of the 

 circumpolar species : — 



Cidaris annulata Gray. ? Diadema antillarum Phil. Calveria hystrix 

 W. Thoms. Genocidaris macidata A. Ag. Trigonocidaris albida A. Ag. 

 Echinus norvegicus D. et K. ? Echinometra J\fichelini Des. Echinocyamus 

 angulosus Leske (not young of Stolonoclyp. Ravenelli). Pourlalesia mi- 

 randa A. Ag. ? Brissus columbaris Ag. Echinocardium cordatum Gray. 

 Echinocardium ovatum Gray. ? Echinocardium Icevigaster A. Ag. Bris- 

 sopsis lyrifera Ag. Lissunolus fragilis A. Ag. Schizaster fragilis Ag. 



Cambridge, April, 1871. 



