396 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



SPIROLOCULINA GBATELOUPI d'Orbigny. 



Plate 78, figs. 4a, 6; plate 100, fig. 3. 



Spiroloculina grateloupi d'Orbigny, Ana. Sci. Nat., vol. 7, 1826, p. 298. — Ter- 

 QUEM, M^ra. Soc. g6ol. France, ser. 3, vol. 1, 1878, p. 52. pi. 5, figs. 5, 6.— 

 WiESNER, Archiv. Prot., vol. 25, 1812, p. 208.— Cushman, Bull. 71, U. S. Nat. 

 Mus., pt. 6, 1917, p. 31, pi. 4, figs. 4, 5. 



Spiroloculina excavata H. B. Brady (not d'Orbigny), Rep. Voy. Challenger, 

 Zoology, vol. 9, 1884, p. 151, pi. 9, figs. 5, 6.— Heron-Allen and Earland, 

 Trans. Zool. Soc, London, vol. 20, 1915, p. 554. 



The charactei-s of this species include a deeply excavate central 

 portion, great thickness at the periphery, elongate test; peripheral 

 margin broadly convex, the last-formed chamber projecting at both 

 ends of the test, the apertural end with a decided projecting neck 

 and phialine lip. 



Both megalospheric and microspheric forms occur, the latter 



reaching 3 mm. in length. 



Brady's notes in the CliaUenger 

 Report are instructive in regard 

 to tliis species. Under S. exca- 

 vata he says : 



The most ' 'excavated " specimenB take 

 the somewhat elongate contonr repre- 

 sented in the drawings, and have the 

 final segment extending a little beyond 

 the rest of the shell. Such forms must be 

 18 sought chiefly in the shallow water sur- 



FIO.S. 17, 18.— Spirocxjiina gkateloupi d'Orbigny. rounding the coral islands of the Pacific. 



X 50. End VIEW3 SHOWING APERTURE AND TEETH. tt . •,, 1 171 1 J 



17, FROM Albatross station dsi36. 18, from -tleron-AJJen and Ji(arland note 

 ALBATROSS D5136. j^ thclr material from the Ke- 



rimba Ai'chipelago off southeastern Africa, under S. excavata. 



The typical S. excavata has a nearly flat peripheral edge, but the bulk of our speci- 

 mens are very rounded * * *. This round-edged variety occurs at many stations. 



From these notes and an examination of the Philippine material 

 and that from other tropical localities of the Pacific, it seems evident 

 that this species is very well represented if not the dominant species 

 of the genus in the Indo-Pacific. It certainl}'^ is different from S. 

 excavata, and may be later separated from S. grateloupi d'Orbigny. 



It is the most common Spiroloculina in the Philippine region, 

 especially in shallow water, often occuring in great numbers and not 

 showing any great amount of variation. The microspheric form is 

 much larger and more excavate than the megalospheric. 



It has been noted at 32 stations, aU but one in the Archipelago or 

 the China Sea, none of them off the Pacific coast in deeper water. 

 It is especially abundant in the shallow water about the Sulu Sea. 

 The only record in the deeper water to the southward is in Sibuko 

 Bay, Borneo. 



