NO. 5 FORAMINIFERAL GENERA — LOEBLICH AND TAPPAN I9 



junalis, and stated that he would limit Tuhinella to forms such as T. 

 perforata Rhumbler, But this was impossible to do, as the type of 

 Tuhinella had previously been fixed. Thus Wiesner's genus Tuhinel- 

 lina immediately became a synonym. 



The type species Tuhinella inornata (Brady) is thus very close to 

 Articulina, having in fact a milioline early stage, although in this 

 species much reduced. The genus Tuhinella is probably derived from 

 Articulina by a reduction of the septa to mere wall thickenings. 



Genus TRITAXIS Schubert, 1920, emended 

 Plate 3, figures 5, 6 



Original description. — Palaont. Zeitschr., vol. 3 (1921), heft 2, 

 p. 180, 1920. 



Type species. — Rotalina fusca Williamson, 1858. Subsequent desig- 

 nation by Cushman, 1928, p. 171. 



Diagnosis. — Test circular in outline, with a low trochoid spire, free 

 in the early stage, later becoming attached by the ventral surface with 

 an irregular spreading mass surrounding the regularly coiled early 

 portion ; chambers about 10 in number, at first nearly globular with 

 4 per whorl, then increasing in breadth much faster than in height so 

 that chambers of the later whorls are low and crescentic when viewed 

 from the dorsal side, and only 3 per whorl, last chamber occupying 

 over one-half the ventral side but only a narrow crescent dorsally; 

 sutures distinct, slightly depressed, strongly curved dorsally, nearly 

 straight ventrally ; wall agglutinated, comparatively coarse grained, 

 surface roughened in appearance ; aperture ventral, on free specimens 

 an ovate opening at the base of the last formed chamber near the 

 umbilicus, and surrounded by a distinct lip, not always visible in the 

 attached later stages, but there may be tubularlike openings at the 

 outer margins of the attached portion. 



Types. — The types of Williamson's species are missing from the 

 British Museum collections. The original localities given include 

 Recent at Weymouth, Sandwich, Swansea, and dredged sands of Skye 

 and Exmouth, British Isles. Figured hypotypes (U.S.N.M. No, 

 P2i98a,b) from F. C. Helga Haul SR 331, lat. 51° 12' N., long. 11 "55' 

 W., 610 to 680 fathoms, off southwestern Ireland. 



Discussion. — Cushman designated Rotalina jiisca Williamson as the 

 type species for this genus in 1928, and at the same time placed Tri- 

 taxis in the synonymy of Trochammina Parker and Jones, i860. 

 Williamson did not figure the aperture of R. fusca, or describe the 

 attached character, as his original specimens were free. Nevertheless, 



