88 FOSSIL ECHINI OF THE WEST INDIES. 



above, is obviously an abnormal feature, as 4 pores are the typical 

 generic character; the absence of a genital pore in Recent Echini is not a 

 very rare occurrence, as I have elsewhere noted (Phylogeny of the Echini, 

 p. 170). 



Another specimen in the Guppy collection at Washington (my plate 15, 

 fig. 4) is larger than the one that Cotteau described. It measures 17 mm. 

 in height, 34 mm. in length, and 23 mm. in width. This specimen is much 

 broader anteriorly than the type, but otherwise has the essential species 

 characters. As it is nearly twice as large as the type, possibly this change 

 in shape may be a matter of development, or it may be a variation. The 

 shape would be apparently the only feature of difference. Cotteau says 

 that having only one small specimen to represent this species, it may be 

 that it is the young of some larger one not yet known. It differs from the 

 Recent West Indian species Brissus unicola Leske by being longer and 

 narrower, dorsally more carinate at the posterior end, and by the close- 

 ness of the poriferous areas of the paired ambulacra, which do not have 

 any appreciable intermediate area. 



Oligocene, Anguilla formation, island of Anguilla, Guppy collection ex 

 Cleve, 1 specimen, holotype, U. S. Nat. Mus. No. 115396. Anguilla, 

 Guppy collection, 2 specimens, U. S. Nat. Mus. No. 115378. Evidently 

 these last are the specimens referred to by Guppy in his Trinidad paper 



as "the examples of this species recorded by me in 1866 as 



dimidiatus were much larger and in better preservation than 



the single specimen of the Cleve collection." Guppy in 1911 notes that 

 Brissus exiguus has lately been obtained from "Miocene" [Oligocene] 

 beds in Trinidad associated with the characteristic fossils of that 

 formation. 



Genus EUPATAGUS Agassiz, 1847. 



Type species.— Eupatagus valenciennesii Agassiz, 1847, Catalogue 

 Raisonne, Ann. Sci. Nat., ser. 3, vol. 8, p. 9. 



This is Cotteau's Euspatangus, an emended spelling. The West 

 Indian fossil species of Eupatagus are very different from the single 

 Recent species from Australia. They are readily distinguished from each 

 other, as follows: 



Key to the West Indian Fossil Species of Eupatagus. 



A. Apical system only a little excentric anteriorly; petals II and IV widely diver- 

 gent, but not nearly at right angles to long axis of test. 

 B. Petals II and IV half as wide as long; their interporiferous areas labout 60 per 



cent, of their width E. grandifiorus 



BB. Petals II and IV not nearly half as wide as long; their interporiferous areas 



half their width E. clevei 



AA. Apical system very markedly anterior; petals II and IV nearly at right angles 

 to long axis of the test. 



C. Petals relatively short, so that intrafasciolar area does not cover most of abactinal 



surface; petals II and IV not curved. 



D. Interporiferous area of petals (especially of I and V) widest at middle or 



distally E. antillarum 



