FORAMINIFEKA OF THE NORTH PACIFIC OCEAN. 37 



bers in the last formed whorl very numerous, periphery very thin, 

 sometimes slightly keeled, sutures usually angled and sharply directed 

 backward near the periphery, surface smooth; aperture a single open- 

 ing at the base of the apertural face in addition to which there are 

 numerous secondary openings in the chambers of the last whorl, 

 appearing as large pores on the exterior. 



Diameter up to 8 or 10 mm. 



Distribution. — The only record from the North Pacific for this 

 typical form of the species has been that of Brady in the Challenger 

 Report, coral reefs of Honolulu, 40 fathoms. I have found it in 

 material collected in Gaspar Straits by Captain Rodgers of the North 

 Pacific Exploring Expedition. The smooth form seems to be much 

 less common than the following variety. 



OPERCULINA COMPLANATA (Defrance), var. GRANULOSA Leymerie. 

 Plate 19, fig. 3. 



Operculina granulosa Leymerie, Mem. Soc. Geol. France, ser. 2, vol. 1, 1846, 

 p. 359, pi. 13, figs. 12a, 6.— [?] Egger, Abh. kon. bay. Akad. Wiss. Miincben, 

 CI. n, vol. 18, 1893, p. 435, pi. 20, figs. 36, 37, 43. 



Operculina complanata (Defrance), var. granulosa H. B. Brady, Rep. Voy. 

 Challenger, Zoology, vol. 9, 1884, p. 743, pi. 112, figs. 6, 7, 9, 10.— Woodward 

 and Thomas, 13th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota for 1884 

 (1885), p. 176, pi. 4, fig. 36. — Newton and Holland, Journ. Coll. Sci. Imp. 

 Univ. Tokyo, vol. 17, 1902, p. 14, pi. 2, fig. 4; pi. 3, fig. 5.— Millett, Journ. 

 Roy. Micr. Soc, 1904, p. 606. 



Description. — Differing from the typical form in the character of 

 the surface which is granular or papillose, especially on the earlier 

 whorls, the papillae being most frequent along the suture lines. 



The varietal form seems to be much more common than the typical 

 smooth form. Brady in the Challenger Report records it from the 

 coral reefs of Honolulu in 40 fathoms. In the material I have 

 examined it was common in Gaspar Straits; in 13 fathoms off Singa- 

 pore, from Alert station 1177 in 23-118 fathoms and from Albatross 

 station D 4922 in 60 fathoms. This last is the station from which 

 Heterostegina was also found showing the southern character of the 

 fauna at that station. 



OPERCULINA AMMONOIDES (Gronovius). 



Plate 14, fig. 7. 



Nautilus ammonoides Gronovius, Zooph. Gron., 1781, p. 282, No. 1220. 



Operculina ammonoides Parker and Jones, Intr. Foram., 1862, Appendix, p. 

 810.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 745, 

 pi. 112, figs. 1, 2.— Egger, Abh. kon. bay. Akad. Wiss. Munchen, CI. n, 

 vol. 18, 1893, p. 434, pi. 20, figs. 38, 39. 



Description. — Test small, somewhat embracing, the last formed 

 whorl making up the greater part of the visible test with about twelve 



