NO. 5 CUSHMAN AND MCCULLOCH : SOME BULIMINIDAE 293 



"Length of the type specimen, 0.43 mm ; diameter, 0.25 mm." 



The original description is quoted above. This species was described 

 from the Pleistocene of California and has been recorded from the 

 Pliocene and also from Recent material off California and Washington. 



The specimens average a little smaller than the types and the strength 

 of ornamentation varies considerably. Also, more elongate forms are in- 

 cluded than the type figure would indicate, but this is known to be true 

 from a study of typical specimens from the Pliocene of California. 



This is one of the baggi-hughesi-semitrigona group and, again, the 

 separation seems to be arbitrary ; forms which are tricarinate toward the 

 apertural end and more or less completely costate being placed here. The 

 separation between A. semitrigona and A. hughesi, var. picta, n. van, is 

 mainly on the basis of the ornamentation, that in var. picta being more 

 strongly developed toward the initial end and including spines. 



Numerous specimens from a large number of stations are referred 

 to this species: Or. 8, 1, 60, 73, 76, 80, 82, 83, 106, 109, 111, 113, 114, 

 203, 222, 225, 232, 248, 249, 256, 271, 286, 299, 409, 412, 414, 417, 

 423, 466, 469, 471, 472, 652, 653, 666, 1017, 1062, 1063, 1068, 1070, 

 1072, 1073, 1075, 1096, 1097, 1098, 1102, 1104, 1111, 1112, 1114, 

 1116, 1118, 1119, 1120, 1127, 1132, 1136, 1138, 1139, 1140, 1143, 

 1144, 1145, 1146, 1147, 1151, 1153, 1157, 1158, 1159, 1160, 1161, 

 1163, 1165, 1166, 1167, 1168, 1170, 1171, 1172, 1175, 1177, 1179, 

 1182, 1183, 1184, 1186, 1187, 1190, 1193, 1196, 1198, 1201, 1203, 

 1205, 1216, 1218, 1219, 1220, 1221, 1222, 1223, 1229, 1230, 1231, 

 1232, 1238, 1241, 1242, 1245, 1246, 2063, 2065, 2087, 2097, 2130, 

 2131, 2152, 2157, 2164, 2165, 2168, 2169. 



Distribution. — These records include Bombay, India; Kobe, Japan; 

 ofif the Channel Islands ; off Mexico ; in the Gulf of California and off the 

 Galapagos Islands with depths ranging from surface to 160 fms. 



Genus TRIFARINA Cushman, 1923 

 Trif arina bradyi Cushman 



Plate 34, Fig. 12 



Rhabdogonium tricarinatum H. B. Brady (not Vaginulina tricari- 

 nata d'Orbigny), Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 525, 

 pi. 67, figs. 1-3. — H. B. Brady, Parker, and Jones, Trans. Zool. Soc. 

 London, vol. 12, 1888, p. 223, pi. 45, fig. 3.— Silvestri, Mem. Pont. 



