AET. 14 FORAMINIFEEA FEOM TRINIDAD CUSHMAN AND JARVIS 43 



BoUvinoides decorata (Jones) var. delicatula Cttshman, Contr. Cusliman Lab. 

 Foram. Res., vol. 2, pt. 4, p. 90, pi. 12, fig. 8, 1927 ; Journ. Pal., vol. 1, p. 158, 

 pi. 28, fig. 7, 1927. — CusHMAN and Jarvis, Contr. Cushman Lab. Foram. Res., 

 vol. 4, p. 99, pi. 14, fig. 9, 1928. 



This elongate variety, which has already been recorded from the 

 Velasco shale of Mexico, occurs in typical form in Trinidad. The 

 ornamentation of the surface is shown in the figure, and it is quite 

 distinct from typical B. decorata (Jones) as developed in Europe. 



BOLIVINOIDES TRINITATENSIS Cushman and Jarvis 



Plate 13, Figuees 3 a, & 



BoUvinoides trinitatensis Cushman and Jarvis, Contr. Cushman Lab. Foram. 

 Res., vol. 4, p. 99, pi. 14, figs. 10 a, &, 1928. 



Test generall)^ biserial, broadest near the apertural end, tapering to 

 the subacute initial end, whole test thickening rapidly toward the 

 apertural end, which is formed of a smooth thickened area ; chambers 

 marked by the highly ornate character of the test, consisting of thin 

 convex platelike extensions backward from the thickened terminal 

 face of the chamber having a deep area below, with trusslike raised 

 costae, the areas over the chambers deeply depressed; aperture a 

 somewhat elongate opening marking the suture which is otherwise 

 obscured by the thickening of the apertural end of the test. Length, 

 0.6; breadth, 0.38; thickness, 0.2 mm. 



The figured specimen, which is the holotype, does not show such a 

 great development of the platelike extensions and the very deep 

 excavations below them as do some of the other specimens from the 

 same locality. This is one of the most highly ornamented species of 

 the genus and is closely allied to B. velascoensis (Cushman), described 

 from the Velasco shale of Mexico. 



Genus SPIROPLECTOIDES Cushman, 1927 



SPIROPLECTOIDES CLOTHO (Grzybowski) 



Plate 13, Figukes 5, 6 



Spiroplecta clotfio Grzybowski, Rozprawy Wydz. mat. przyr., vol. 41, p. 283, 



pi. 7, fig. 18, 1901. 

 Spiroplecta annectcns Cushman (not Parker and Jones), Bull. Amer. Assoc. 



Petr. Geol., vol. 10, p. 584, pi. 15, figs. 4 a, b, 1926. 

 Spiroplectokles cJotho Cushman, Journ. Pal., vol. 1, p. 159, pi. 28, fig. 6, 1927. — 



Cushman and Jarvis, Contr. Cushman Lab. Foram. Res., vol. 4, p. 101, pi. 



14, figs. 13, 14, 1928. 



Our specimens from Trinidad are very excellently preserved and 

 show especially well the sutures, which are somewhat limbate. The 

 two figures show the difference in shape and size of the microspheric 

 and megalospheric forms. When seen separately the two miglit 

 easily be mistaken for two distinct species. 



