MUSEUM OF COMPARATIVE ZOOLOGY. 27 



Pygorhynchus Ac 

 Pygorhynchus pacificus Ac. 



This species is a living representative of the genus Pygorliynclius, thus far 

 only known as fossil. It resembles in outline Echinolampas. The vent is 

 transverse, supra-marginal. The lower side is almost flat, the edges of the 

 test being slightly raised. The very broad, smooth band, shaped like a 

 dagger, extending entirely round the mouth and reaching the anterior and 

 posterior edge of the test, and the rosette of large pores round the mouth, 

 are characters of the genus which are not easily seen in fossil specimens. As 

 specific, whole upper surface covered with short silk-like spines. Tubercles 

 of lower side large, sunken, increasing in size as they approach the smooth 

 band. Spines long, sharp, very slightly arched, comparatively much stouter 

 than on upper part of test. — Acapulco. 



Spatangus Kl. 

 Spatangus purpureus Mull. Zool. Dan. — North Europe. 

 Spatangus meridionalis Risso, Hist. Nat. Eur. Me'rid. — Mediterranean. 



Maretia Gray, Cat. Brit. Mus. 



Maretia planulata Gray, Cat. Brit. Mus. 



Syx. Spakmc/us plamdalus Lamk. An. s. Vert. ; Trichoproctus tenm 

 AG. MS. — Kingsmills Islands. 



Lovenia Ac Cat. Rais. 

 Lovenia hystl'ix Ag. Cat. Rais. — Zanzibar. 



Eehinocardium Gray, Cat. Brit. Mus. (emend.). — Amphidetus Ao. 

 Cat. Rais. p. p. 

 Eehinocardium cordatum Gray, Cat. Brit. Mns. 



Syx. Amphidetus cordatus Ag. Cat. Rais. — North Europe. 



Amphidetus Ac (emend.) 

 Amphidetus ovatus Ac Cat. Rais. — North Europe. 



Bl'issus Kleix (Ac Cat. Rais.). 

 Brissus carinatus Lamk. (non Ac), An. s. Vert. — Sandwich Islands. 

 Brissus COlumbaris Ac Cat. Rais.— Florida. 



Kleinia Gray, Ann. & Mag. 1851. 

 Kleinia nigra A. Ac 



Test rather depressed, ambulacral rosette narrow, long; peripetalo^ r 

 fasciole extending almost to the circumference ; spines rather short, sha ; , 

 stout, black. — Acapulco. 



It is with some doubt that this species is referred to the genus Kleimi : 

 should it prove a different genus, I would suggest the name Rhyssobris- r.«r 

 for it. 



