42 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 80 



Holotype.—V. S. N. M. No. 73822 (Cushman Coll. No. 15327) from 

 Upper Cretaceous of pit at Lizard Springs near Guayaguayare, 

 southeastern Trinidad, British West Indies. 



Remarks. — This is a very peculiar species of the genus, and unlike 

 any other described form. It has very limbate sutures and a pe- 

 culiar arrangement of the umbilical region, with its thickening of 

 clear shell material pierced by irregularly curved tubular openings. 



Family CAMERINIDAE 



Genus OPERCULINA d'Orbigny, 1826 



OPERCULINA CATENULA, new species 



Plate 12, Figxjbes 13 o, & 



Description. — Test broadly complanate, periphery rounded, great- 

 est thickness in the umbonal region; chambers distinct, about 15 in 

 the last-formed coil, of rather uniform shape and increasing some- 

 what in length as added ; sutures distinct, limbate, raised, ornamented 

 by numerous beadlike protuberances which are slightly elongate in 

 the line of the suture, sutures ending in the umbonal region in a 

 distinct boss which itself is somewhat beaded; wall between the 

 sutures smooth. Diameter, 2.25; thickness, 0.6 mm. 



Holotype.—IJ.^.'^.M. No. 73823 (Cushman Coll. No. 15325), from 

 Upper Cretaceous of pit at Lizard Springs near Guayaguayare, 

 southeastern Trinidad, British West Indies. 



This is one of the few species of this genus known from the Upper 

 Cretaceous, and it seems to be a very distinctive one as developed in 

 this Upper Cretaceous of Trinidad. 



Family HETEROHELICIDAE 

 Genus GUMBELINA Egger, 1899 



GtJMBELINA sp. (?) 



Plate 13, Figures la,!) 



There are a few very poorly preserved specimens of Gunibelina, 

 which it seems unwise definitely to place under a specific name. The 

 surface is not usually well preserved, and it may possibly be that 

 they are reworked specimens from some older Cretaceous source. 



Genus BOLIVINOIDES Cushman, 1927 



BOLIVINOIDES DECORATA (Jones) var. DELICATULA Cushman 



Plate 13, Figure 2 



BoUvina decorata Cushman (not Jones), Bull. Anier. Assoc. Petr. Geol., vol. 10, 

 p. 19, pi. 2, figs. 3 0, b, 1926. 



