NO. 1 CUSHMAN, MCCULLOCH : ARENACEOUS FORAMINIFERA 69 



This species differs from Ammofrondicularia angusta Schubert in 

 the broadly rhomboid form and much greater increase in size of 

 chambers. 



Our species is characterized by its very rough wall composed of 

 calcareous flakes rather roughly cemented and in some respects resem- 

 bling Flabellammina but the earlier chambers are not coiled. Schubert 

 has described a peculiar form for which he has erected the genus Ammo- 

 frondicularia. His specimen, however, consists of a section only and 

 details of its full characters are lacking. Our species is very unique and 

 we have referred it tentatively at least to Ammofrondicularia. It has 

 occurred at numerous stations as follows: 248, 290, 296, 264, 299, 318, 

 447, 546, 2013, 2031, 2032, 2057, 256, 2018. 



Distribution. — Type locality, Cartago Bay, Albemarle, Galapagos 

 Islands, in 32 fms. On the shore below sandy beach of Gorgona Island, 

 Colombia; numerous stations in the Gulf of California in depths rang- 

 ing from 15 to 81 fms. 



Family Ammodiscidae 



Genus AMMODISGUS Reuss, 1861 



Ammodiscus pacificus Cushman and Valentine 



Plate 5, Figs. 1, 2 



Ammodiscus pacificus Cushman and Valentine, Contr. Dept. Geol. 

 Stanford Univ., vol. 1, no. 1, 1930, p. 7, pi. 1, fig. 1. 



Test large, planispirally coiled, proloculum nearly spherical, later 

 coils covering about two fifths of the previous coil; chamber tubular, 

 not compressed, the coils increasing slightly in diameter as added; suture 

 distinct, depressed ; wall smoothly finished, consisting largely of reddish- 

 brown cement with numerous fine angular particles of sand; aperture 

 semicircular. 



Diameter up to 3.15 mm. 



This species was originally described from the Pacific and has 

 proved to be rather common in our material occurring at the following 

 localities: 136, 444, 328, 482, 488, 411, 207-2, 403, 73. 



Distribution. — This investigation extends the range of this species 

 from off San Pedro, California, southward along Mexico and into the 

 region of Galapagos Islands where a number of records show a depth 

 range of 9 fms. in James Bay, James Island, to 250 fms. at Cartago 

 Bay, Albemarle Island. 



