242 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



perature 51.5° F. (10.8° C); D5412, in 162 fathoms (297 meters), 

 between Cebu and Bohol, bottom temperature 54.8° F. (12.6° C); 

 and D5523, northern Mindanao. 



This is the most beautifully ornamented variety of the species, and 

 is full of detailed sculpture as shown in the figure. It has occurred 

 in very large numbers at two of the stations. 



CRISTELLARIA COSTATA (Fichtel and Moll), var. SUBLAEVIS Cushman. 



Plate 49, fig. 1. 



Cristellaria costata (Fichtel and Moll), var. suhlaevis Cushman, Proc. U. S. Nat. 

 Mus., vol. 51, 1917, p. 659. 



Description. — Variety differing from the typical in having the 

 ornamentation of the test so developed that the limbate sutures and 

 their resulting costae are developed at the complete expense of the 

 other costae of the chambers or nearly so, the costae of the sutures 

 being very high and ending on the inner border of each in a large 

 raised knob; peripheral margin of the test keeled, somewhat inter- 

 rupted at the sutures ; wall of the chambers smooth or marked with 

 obsolescent striae in some cases. 



Diameter 3 to 4 mm. 



Distribution. — Type specimen (U.S.N.M. No. 9132) from Albatross 

 station D5374, in 190 fathoms (348 meters), off Marinduque 

 Island. Specimens were also obtained from D5192, off northern 

 Cebu Island, 32 fathoms (59 meters); D5212, in 108 fathoms (198 

 meters), east of Masbate Island, bottom temperature 59.9° F. (15.5° 

 C); D5523, off northern Mindanao; and D5586, Sibuko Bay, Borneo, 

 347 fathoms (635 meters), bottom temperature 44.0° F. (6.6° C). 



In this variety the costae of the chambers so highly developed in 

 var. multicosta are almost entirely lacking and the development of 

 the other set of ornamental costae is carried to a very high develop- 

 ment. Without the typical form and variety subdecorata these two 

 extremes would hardly be recognized as belonging to a single species. 



