ART. 10 CRETACEOUS FAUNAS OF THEi OAEOLINAS — STEPHENSON 7 



details of the peristome, apical system, and periproct, the two species 

 are similar, though not identical, but Clark's species attains a size 

 fully twice as great as the Rocky Point species. There is, how- 

 ever, a striking difference in the pore pairs of the ambulacral areas 

 in the two species, the two pores in each pair in the Rocky Point 

 species being approximately equal, while in the Euf aula species the 

 inner pore is small and round, while the outer one is long and narrow. 

 The periproct of Cassiduhos 'porreotus occupies a deeper and nar- 

 rower sulcus than is represented in Clark's illustrations. 



Another related species is Cassidulus micrococcus Gabb * also from 

 the Ripley formation, near Eufaula, Ala. I have compared the 

 types and find that the Eufaula species is smaller, slightly more 

 elongated, markedly flatter, and a little narrower anteriorly; the 

 periproct is situated higher on the test, in a slightly wider sulcus, the 

 pore pairs are unequal and are less definitely comiected by furrows, 

 and the madreporite is a little longer and more angular. The type 

 material of G. micrococcus is in certain respects not very well pre- 

 served and it is difficult to see how Clark ^ was able to describe and 

 figure the apical system and peristome in as great detail as he did. 

 No other material was available for study so far as the record 

 shows. 



Locality. — From the new Rocky Point quarries, a mile northeast 

 of Rocky Point station, Pender County, N. C. Collected by L. B. 

 Kellum in 1923, and by L. W. Stephenson in 1926. 



Geologic position. — Upper Cretaceous, upper part of Peedee forma- 

 tion, upper part of Exogyra costata zone. European equivalent, 

 upper Senonian (Maestrichtian). 



Type mateHdl. — The type material is in the United States National 

 Museum. Holotype, catalogue No. Y3420; 3 paratypes figured or 

 used in the drawing of figures, catalogue No. 73421; 11 additional 

 specimens, some of which are in good state of preservation. 



CASSroULUS EMMONSI, new species 



Plate 3, figs. 3-8; plate 4 



DesGi'iption. — Test broadly subovate in basal outline, only moder- 

 ately high and broadly domed ; the slightly conical shape of the type 

 is due to slight crushing on the sides; other specimens are broadly 

 and evenly rounded. Base moderately concave with two pronounced 

 broad radiating depressions extending from the peristome to the 

 ambitus, one on either side of the posterior center; these depressions 

 are separated from each other by a broad ridge and they produce 



* Gabb, W. M., Description of a new species of Cassidulus, from the Cretaceous forma- 

 tion of Alabama : Proc. Acad. Nat. Sei., Phila., vol. 12, p. 519, 1860. 



^U. S. Geol. Survey Mon. 54, p. 78, pi. 32, figs. 2 a-6; pi. 33, figs. 1 a^f., 1915. 



