96 FOSSIL ECHINI OF THE WEST INDIES. 



bank of the Jacaguas River, 1 specimen, paratype (also a fragment, 

 both olive gray), station 188, American Mus. Nat. Hist. No. 18575. 

 Same locality and data; 1 specimen, which is referred doubtfully to 

 this species, station 189. All of the above specimens of this species 

 were collected by C. A. Reeds under the auspices of the New York 

 Academy of Sciences, the Porto Rican Government and the American 

 Museum of Natural History cooperating. 



Eupatagus vaughani, new species. 

 (Plate 17, Figure 2; Plate 18, Figures 1, 2.) 



The following is a description of this species : 



Test massive, oval, elongate, a little contracted anteriorly; low, rounded, 

 dome-shaped dorsally, presenting almost an equal curve anteroposteriorly, 

 but is a little steeper anteriorly; strongly rounded on the border, especially 

 posteriorly. Posteriorly, rising in a rounded outline rather than a steep 

 face. Ventrally, nearly flat on the marginal outline, hollowed into the 

 anterior peristome. The plastron is elevated strongly, and posteriorly 

 it presents almost a median ridge. The anterior furrow is wanting, except 

 ventrally, close to the peristome. Ambulacra flush, wide, petaloid, curved, 

 excepting ambulacrum III, which is narrow, straight, inconspicuous, widen- 

 ing as it approaches the peristome. The pores of ambulacrum III can not 

 be made out dorsally, as the specimen is much worn, but ventrally they 

 appear as single pores in a furrow, which widens as it approaches the per- 

 istome. The paired ambulacra are wide, petaloid, curving, the petals 

 extending to the ambitus. The anterior pair II and IV are widely diverging, 

 at an angle of about 145° to each other, curving forward as they approach 

 the ambitus; the posterior pair I and V are a little wider than II and IV, 

 much less diverging, and present an acute angle of about 60° posteriorly; 

 they are only slightly curved. The pores of the paired areas are very much 

 alike, rounded, and prominent; the inner and outer pores are in a straight 

 line, separated by a moderately short space, and situated on the outer 

 border of the plates; the interporiferous area is narrow. The interam- 

 bulacra are wide and the plates are strongly curved on the horizontal suture 

 lines. The details of plate-sutures and tubercles are almost gone from 

 mechanical wear of the surface in the holotype, but in the second specimen 

 or paratype the sutures are quite obvious and a few tubercles are preserved. 

 These tubercles are small, perforate, scrobiculate, not crowded. The apical 

 disk is small, excentric anteriorly, but no details of the plates are preserved. 

 The peristome is transversely elongate, labiate, excentric, quite near the 

 anterior border of the test. The periproct is very large (23 mm. high, 19 

 mm. wide), oval in a vertical plane, situated on the posterior face and just 

 barely visible from above. The plastron is very large, triangular, wide 

 and strongly elevated posteriorly, so much so that this area stands out 

 as a distinct bulge below the ambital outline when seen in profile. Fascioles 

 are not preserved in either specimen. 



The holotype, which is the more complete of the two known specimens, 

 measures 50 mm. in height through the plane of apical disk, 134 mm. 

 in length, and 118 mm. in greatest width through interambulacra 

 1 and 4. 



