ECHINODERMATA. 291 



Family OASSIDULIDAE. 



Genus Catopygus Agassiz. 

 Catopygus oviformis Conrad. 



Plate XL, Figs. 10-15. 



1847. Catopygm oviformis Con., Jour. Acad. Nat. Sci. Phil., 



2d sen, vol. 2, p. 39, pi. i, fig. 9. 

 1868. Nucleolites oviformis Con., Cook's Geol. N. J., p. y22. 

 1891. Catopygus oviformis Clark, Johns Hopkins Univ. Circ, 



vol. 10, No<. 87, p. 76. 

 1893. Catopygus oviformis Clark, Johns Hopkins Univ. Circ, 



vol. 12, No. 103, p. 52. 

 1893. Catopygus oviformis Clark, Bull. U. S. G. S., No. 97, p. 



64, pi. 27, figs. 2 a-f. 

 1905. Catopygus oviformis Johns., Proc. Acad. Nat. Sci. Phil.^ 



1905, p. 7. 



Description. — Test ovate, broader posteriorly, ventral side 

 nearly flat, becoming slightly concave towards the margin of the 

 oral opening, lobed posteriorly, the sides rounded and inflated, 

 the dorsal surface somewhat flattened with the apex posterior to- 

 the apical disk. Ambulacral areas narrowly lanceolate, the twO' 

 posterior ones being much longer than the others, subpetaloid on 

 the upper surface where the plates are narrow, but beyond the 

 petaloid portion the plates increase in width. Interambulacral 

 areas wide, made up of large plates which are covered with 

 minute tubercles, between which are numerous microscopic 

 granules; the posterio-r interambulacrum elevated. Apical disk 

 small, eccentric, situated far in front of the apex. Oral opening 

 small, eccentric, situated towards the anterior margin. Anal 

 opening oval, placed at the upper part of a nearly vertical anal 

 sulcus, the upper margin of which forms a beak-shaped promi- 

 nence overhanging the opening. 



The dimensions of a complete individual are : length, 21.9 mm. \ 

 width, 18.75 mm.; height, 11 mm. 



Formation and locality. — Vincentown limesand. Timber Creek 

 (Clark). 



Geographic distribution. — New Jersey. 



