50 



OCEANIC TINTINNOINA OF LAST CRUISE OF CARNEGIE 



least twice as long as that of any other species. It resembles 

 a small replica of Parajavella digitalis, but that species not 

 only is larger and longer, but also lacks teeth and inner and 

 outer collars. It is not at all like the common A. norvegica, 

 its frequent neighbor. 



Recorded from one station (125) in the Alaskan secondary 

 region, in a pump sample taken at 50 meters. There were 

 2.1oricae. 



Temperature, 5?68; salinity, 32.79; density, 25.88; pH, 

 7.98. 



Acanthostomella gracilis (Brandt) Kofoid and Campbell 



Acanthostomella gracilis, Kofoid and Campbell, 1929, p. 192, 

 fig. 360. 



The rather short, stout lorica, with cylindrical upper bowl 

 and conical, pointed aboral end, has a length of 1.7 oral 

 diameters. The oral margin is thin and erect; the inner 

 collar is cufilike and its width is nearly 0.07 oral diameter. 

 It is separated by an angular trough from the outer collar. 

 The outer collar flares (35°) and from its free edge arise 36 

 narrow, outward-projecting, subequal, subequidistant, tri- 

 angular teeth. The upper bowl is cylindrical and about i.ii 

 oral diameters in length. The bowl is conical (80°) with 

 distinctly convex sides, and its lower end is drawn out 

 bluntly. 



The wall is rather thick, about 0.03 oral diameter in thick- 

 ness, and there are thin laminae with rectangular, radial 

 secondary prisms enclosed between them. The wall thins 

 down a bit at the oral end. 



The large animal has 2 macronuclei and rather long mem- 

 branelles. 



Length, 45 to 601.1. 



Acanthostomella gracilis has a cylindrical upper bowl and 

 a blundy pointed aboral end, whereas A. norvegica, its closest 

 relative, has a laterally concave and aborally swollen bowl 

 with a distinct horn. Acanthostomella obtusa has a blunted, 

 distinct, and longer horn, and A. clongata has a much taller 

 bowl. 



Recorded from one station (119) in the East Asiatic mar- 

 ginal sea, in 2 pump samples taken at 50 and 100 meters. 

 Frequency, 2 and 4 loricae. 



Temperature, 3^42 at 50 meters; salinity, 33.05-33.13 

 (33.09); density, 26.31-26.52 (26.41); pH, 7.85-7.93 (7-^9)- 



Acanthostomella lata Kofoid and Campbell 



Acanthostomclhi lata Kofoid and Campbell, 1929, pp. 192-193, 

 fig. 364. 



The stout, goblet-shaped lorica, with low teeth, high inner 

 collar, conical bowl, and sharp, pointed aboral spine, has a 

 length of 1.25 oral diameters. The oral margin is thin, erect, 

 ancl entire. The inner collar is cufHike and about o.i oral 

 diameter in width. The outer collar, which is separated 

 from the inner by a deep trough, flares (20°) and its rim 

 has 22 short, stout, outward-spread triangular teeth whose 

 free tips are rotated to the left. The bowl is conical (about 

 15°) suborally, and wider conical (90°) toward the lower 

 end. It is full and distinctly convex. The aboral horn is a 



spine (20° ) with a length of approximately 0.25 oral diameter. 



The subuniformly thin wall has clearly marked laminae 

 and distinct prismatic structure. The spine is hollow. 



Length, 37^1. 



The Carnegie loricae agree closely with that of Kofoid 

 and Campbell, save that the wall is unusually glassy. 



Acanthostomella lata is larger than most species, and rela- 

 tively wider, with shorter teeth and higher inner collar. It 

 has more teeth than A. conicoides, a distinctly convex instead 

 of concave lower bowl, and a distinct spine. Its bowl is less 

 saccular than that of the northern A. norvegica, its spine is 

 longer, and its teeth are shorter, fewer, and rotated. 



Recorded from five stations, one in the Atlantic and four 

 in the Pacific, as follows: one (33) in the Caribbean Sea, one 

 (40) in the Galapagos region, one (65) in the South Pacific 

 middle latitudes, one (137) in the California region, and one 

 (159) in the region of South Pacific island fields. 



There are i pump and 4 net samples, of which i (137) 

 was taken at the surface and 2 each at 50 and 100 meters. 

 Frequencies did not exceed i per cent. 



Temperature: Atlantic, net sample 23?i7; Pacific, net 

 samples i5?03-27?90 ( 19^42), pump sample 25?48. Salinity: 

 Adantic, net sample 36.49; Pacific, net samples 34.30-35.75 

 (34.98), pump sample 34.97. Density: Atlantic, net sample 

 25.03; Pacific, net samples 23.01-25.83 (24.75), pump sample 

 23.19. pH: Atlantic, net sample 8.18; Pacific, net samples 

 7.83-8.37 (8.10), pump sample 8.39. 



Acanthostomella minutissima Kofoid and Campbell 



Acanthostomella minutissima Kofoid and Campbell, 1929, p. 

 t93' fig- 358. 



The rather plump, short, cuplike lorica, with numerous 

 teeth and round aboral end, has a length of 1.30 to 1.64 oral 

 diameters. The oral margin is thin and erect. The inner 

 collar is narrow, cufflike, and thin. The outer collar flares 

 sharply (50°) and carries about 25 slender, narrow triangu- 

 lar, outward-curved teeth which are about as long as the 

 width of the inner collar. The bowl is subcylindrical in the 

 anterior 0.55 and contracts as a cone (90°) in the lower 

 section. This aboral region is subhemispherical, with con- 

 vex sides. The aboral end is not especially differentiated. 



The rather thick wall has thin laminae and is pronouncedly 

 alveolar. Kofoid and Campbell (1929) found coccoliths 

 studding the whole exterior of some loricae. The cavity con- 

 forms to the outer contour. 



Length, 29 to 361.1. 



The shape of the aboral end is hemispheroidal to parabo- 

 loidal, and the wall may have coccoliths. 



This small tropical species generally resembles the north- 

 ern Acanthostomella norvegica, but differs in being smaller, 

 and in having a distinct, flaring collar. Its upper bowl is 

 typically not so long and the aboral end never has the 

 emergent point of norvegica. It is unlike any of the other 

 tropical species. Had it no teeth it would have been con- 

 sidered something like Craterella urceolata. 



Recorded from four stations, one in the Atlantic and three 

 in the Pacific, as follows: one (18) in the Sargasso Sea, two 



