108 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 6 



1930, p. 71.— Cushman and Parker, Proc. U. S. Nat. Mus., vol. 80, 

 art. 3, 1931, p. 6, pi. 2, figs. 5a-c. — Heron-Allen and Earland, Discovery 

 Rep'ts, vol. IV, 1932, p. 344.— Earland, 1. c, vol. VII, 1933, p. 85; 

 1. c, vol. X, 1934, p. 99. — Bermudez, Mem. Soc. Cubana Hist. Nat., 

 vol. 9, 1935, p. 176. 



This species was originally described from about the British Isles 

 and from the records is a species of cold water. In our collections are 

 numerous specimens which may be referred to this species. The ventral 

 side is flattened, the dorsal side usually with a low spire. The wall is 

 very variable, either of fine sand grains smoothly cemented or with in- 

 cluded sponge spicules. The form is distinctly variable but the number 

 of chambers in the adult varies little. It has occurred at the following 

 stations: 288, 285, 284, 283, 256, C-11, A-1, 286, 275, 259, 249, 226, 

 2008, 2005, 2004, 2010, 2070, 2029, 2051, 2063, 2065, 2037, 1042, 

 411, 412, 413, 414, 416, 423, 447, 478, 481, 330, 461, 39. 



Distribution. — From Ketchikan, Alaska, in 8 fms. to Sechura Bay, 

 Peru, in 10 fms., with a number of stations between these two records. 



Trochamniina squamiformis Cushman and McCulloch, new species 



Plate 12, Fig. 4 



Test small, scalelike, dorsal side convex, ventral side concave, pe- 

 riphery rounded to subacute; chambers distinct in the earlier whorls 

 which have 8-10 chambers, higher than broad, in the adult with the 

 chambers becoming much lower than broad in the whorl and much 

 reduced in number, on the ventral side triangular, often with a slightly 

 raised liplike portion over the aperture; sutures curved, little if at all 

 depressed on the dorsal side, ventrally radial or slightly tangential, often 

 somewhat sigmoid; wall finely arenaceous, smoothly finished, with much 

 cement, giving a yellowish-brown color, especially to the earlier whorls; 

 aperture a low opening at the inner end of the margin of the ventral 

 face of the last-formed chamber. 



Diameter 0.25-0.30 mm; height 0.10 mm. 



Holotype (AHF no. 19) from locality W-3. 



This is a very small but abundant species and one which keeps its 

 characters well. It differs from T. rotaliformis J. Wright in the smaller 

 size, concave ventral side, and in the decided reduction in the number 

 of chambers in the final whorl. It occurs at the following stations: W-3, 

 238, 241, 531, 2070, 1023, 1034, 2024, 2011, 2015, 2066, 2067, 2008, 

 2000, A-23, 457, 232, 263, 252, 462, 466, 258, 423, 473, 562, 579. 



