SYSTEMATIC DESCRIPTIONS SPATANGINA. 91 



furrow. Tubercles are abundant, very unequal, moderately developed, 

 nearly as numerous in the posterior interambulacrum as in the other areas 

 and circumscribed by the peripetalous fascicle. Ordinary tubercles are 

 abundant and crowded toward the ambitus in the inframarginal region and 

 on the ventral swelling of the posterior interambulacrum. They are a 

 little more widely spaced on the approach to the peristome, leaving wholly 

 smooth the ventral area of the posterior ambulacra I and V. Peristome 

 narrow, sublabiate, transversely elongate, excentric anteriorly. Periproct 

 oval, opening at the summit of the posterior face. The apical disk is narrow, 

 compact, granular, and remarkable for the development of the madreporite 

 which traverses the length of the disk, and in Cotteau's figure it is seen to 

 separate the posterior genitals 1 and 4 and oculars I and V. Four genital 

 pores, the two anterior (2 and 3) are nearer and less open than are the 

 two posterior (1 and 4). Peripetalous and subanal fascicles non-sinuous. 



Height 34 mm., length 61 mm., width 48 mm. The Washington 

 specimen is much worn anteriorly and shows little detail anterior to the 

 apical disk. This species is distinguished from E. antillarum by its 

 larger size, by the fact that it is very broadly rounded anteriorly, is pro- 

 portionately wider; is more elevated and subcarinate posteriorly; the 

 anterior paired ambulacra as far as made out (petal 1 1 is preserved in part, 

 but petal IV is completely obliterated, as is also the anterior petal III), 

 are wider and less divergent, in place of being nearly horizontal, as 

 they are in antillarum. Ambulacra II and IV present an angle of 

 about 125 to each other, and the posterior pair I and V make an acute 

 angle of about 65 to each other. The peristome is transversely elon- 

 gate, instead of being nearly round as in antillarum. 



Cotteau says that this species is rare and mentions only the Cleve 

 collection. It is probable that the Washington specimen was the only 

 one that he had, as it agrees well with his measurements, and while it 

 does not show all the details of his figures, it has nothing discordant 

 with them. 



Eocene, from the St. Bartholomew limestone, St. Bartholomew, 

 Guppy collection ex Cleve, 1 specimen, apparently the holotype, U. S. 

 Nat. Mus. No. 115379. 



Eupatagus antillarum (Cotteau). 

 (Plate 16, Figures 3 to 6.) 



Euspatangus antillarum Cotteau, 1875, Kongl. Sven. Vet. Akad. Handl., vol. 13, No. 6, 



p. 43, plate 7, figs. 8 to 12. 

 Eupatagus antillarum Guppy, 1882, Sci. Assoc. Trinidad, Proc., part 12, p. 199. 



The following is an extract from the original description of this species : 

 Species of small size, rounded and subdilated anteriorly; narrower and 

 truncate posteriorly; a little swollen dorsally, thick on the borders. Lower 

 face nearly flat, marked with an elevation corresponding to the posterior 

 interambulacrum, which is prominent and subangular. Apical disk very 

 excentric anteriorly. Anterior furrow very attenuated, nearly wanting. 

 Anterior ambulacrum III narrow, long, and straight, with very small 

 pores scarcely visible. The paired ambulacral petals are closed at their 

 tips, very unequal; the anterior II and IV transverse [at an angle of about 



