37 



discal perforations ovate, small, the anterior smaller, the hinder largest, 

 with two pairs of rather large tesserae between the ends of the ambu- 

 lacra and the foramen, the upper pair subtrigonal ; oral grooves simply 

 forked near the edge. 



Hab. West Indies. 



The single specimen I have seen of this species was presented by 

 Sir John Richardson. It is rather deformed and suiuous on the right 

 side, the hmder lateral perforation being nearly obliterated on that side. 



In Echinoglyphus the tesserae of the ambulacral bands are broad 

 and band-like between the ambulacra and the ambulacral slits. 



Genus Echinoglyphus, Van Phelsum. The Encope of Agassiz. 



The large Brazilian species of this genus appear to be very va- 

 riable. The young specimens have large notches on the edge of the 

 shell, and as the animal increases in size, the marginal edges of these 

 notches more or less approximate together, and sometimes even be- 

 come united, so as to transform the notch into a perforation. M. 

 Agassiz on these variations has formed several species ; but the 

 Museum series, from the Brazils and other parts of the east coast of 

 Tropical America, show that they are all mere variations of the spe- 

 cies which Van Phelsum called Echinoglyphus frondosus, and La- 

 marck Scutella emarginata. I am induced to believe that Scutella 

 quinqueloba of Eschscholtz, Encope Valenciennesii, Encope subclausa, 

 Encope oblonga, and Encope Michelini, are only varieties of this spe- 

 cies : they are all remarkable for the large size and longly-rayed star- 

 Uke form of the madreporiform plate. 



Genus Fibularia. 



The following species is peculiar as having an oblong, longitudinal 

 vent. 



1. Fibularia OBLONGA. 



Shell ovate, elongate, ventricose ; vent oblong, longitudinal, ac- 

 cordmg to the axis of the shell. 

 Hah. N. Australia. 



Fam. 2. EchinolampidjE. 

 Genus Echinolampas. 



The species of this genus may be divided into two sections, accord- 

 ing to the form of the ambulacra. 



Echinolampas oviformis and its allies have the porous bands of the 

 anterior and other pair of ambulacra equal ; the lower side of the 

 shell flat ; the mouth oblong, transverse, with (,5) tubercles between 

 the oral ambulacra. 



The other species have the anterior porous band of the anterior 

 pair of ambulacra shortest ; under side rounded, convex ; mouth ob- 

 long, transverse, large, marked mth no tubercles, and only very rudi- 

 mentary oral ambulacra. 



