SYSTEMATIC DESCRIPTIONS' — SPATANGINA. 93 



Eupatagus depressus, new species. 

 (Plate 16, Figure 7.) 



The following is a description of this species: 



Test subcordiform, broadly rounded anteriorly; narrower posteriorly; 

 very low dorsally, curving very gently from the highest point at the apical 

 disk to the relatively high rounded border on all sides; ventrally it is very 

 nearly flat as far as preserved, but wanting in part posteriorly. Anterior 

 furrow very slight, deepening and widening as it approaches the ambitus. 

 Anterior ambulacrum III narrow, 2.5 mm. wide at halfway from the apical 

 disk to the border, with small pores, widely spaced and inconspicuous. Petals 

 of the paired ambulacra slightly raised, narrow, curved, pointed, nearly 

 closed at the tips. The anterior pair II and IV is widely divergent, but 

 not transverse, at an angle of about 140° to each other, 21 mm. long, curving 

 gently anteriorly; the posterior pair I and V (ambulacrum V is wanting, 

 but the suture of its contact with interambulacrum 4 exists, thus indicating 

 its contour on that side) is longer, 28 mm. in length, curving outward and 

 forming an acute angle of about 60° to each other posteriorly. Poriferous 

 areas are narrow, sunken, with nearly round medium-sized pores connected 

 by a deep, strongly marked furrow. Tubercles are of two kinds. The larger 

 are very large, with strongly marked scrobicules, they are widely spaced on 

 the four anterior interambulacra dorsally, but are wanting on interambu- 

 lacrum 5, and are circumscribed by the peripetalous fasciole. Ventrally, 

 these primary tubercles are crowded near the border; for the rest of the 

 ventral area they are abundant but more widely spaced. The ventral side 

 is too imperfect, or in part wanting, to show much detail. Small tubercles 

 are crowded and occupy the spaces between the large tubercles and alone 

 exist on the ambulacral areas and on the posterior interambulacrum 5 

 dorsally. Peristome obscurely outlined, but wide and excentric anteriorly, 

 24 mm. from the anterior border. Periproct wanting, apical disk excentric 

 anteriorly, 27 mm. from the anterior border; it is very small, and imperfect 

 from a local fracture, but the madreporite with its large pore is preserved. 

 The peripetalous fasciole is obscurely marked, following the outline of 

 the petals ; the subanal fasciole is wanting, as the test is largely broken away 

 at that area. 



Height 13 mm., length about 65 mm., width 60 mm. This species is 

 characterized by its very low, flat form, yet, with high rounded border 

 and curving narrow ambulacra, is radically different from any other 

 fossil West Indian species of the genus. It approaches nearest to 

 Eupatagus carolinensis W. B. Clark, 1 but is much larger and natter, 

 with a distinct anterior sinus which is quite wanting in carolinensis. 



Oligocene, high bluff, 2 km. southwest of Juana Diaz, Porto Rico, 

 from huge blocks of fallen limestone where irrigation flume is covered 

 with earth, 1 specimen the holotype, station 199, American Mus. Nat. 

 Hist. No. 18573, C. A. Reeds collector, under auspices of the New York 

 Academy of Sciences, the Porto Rican Government and the American 

 Museum of Natural History cooperating. 



» Clark and Twitchell, 1915, Monograph, U. S. Geol. Sur., p. 153, plate 71, figs. 3a to 3d, i. 



