6o 



OCEANIC TINTINNOINA OF LAST CRUISE OF CARNEGIE 



is subconical (up to 35°). The aboral horn reaches 0.38 total 

 length and is relatively stout subconical (9°). Its free tip is 

 pointed. 



The wall reaches a maximum thickness of only about 0.05 

 oral diameter. There are thin laminae which enclose small 

 alveoles. There are 48 definitely right-turning (10°), 

 branched, often anastomosed, heavy ribs, which fade away 

 near the distal tip of the horn and just below the suboral 

 rim; there are no fenestrae. 



Length, 317 to 377^1. 



Rhabdonella lohmanni resembles R. bcnstni in general, but 

 has oblique ribs and a stout horn, and is longer. Rhabdonella 

 torta is shorter (210 to 228|.() but otherwise rather similar. 



Recorded from two stations (138, 140) in the North Pacific 

 trade region, in 2 pump samples, i taken at the surface and 

 I at 50 meters. Frequency, minimum. 



Temperature, 26?i4-26?87 (26?5o); salinity, 34.85-35.02 

 (34.93); density, 22.80-22.90 (22.85); pH, 8.35-8.39 (8.37). 



Rhabdonella poculum (Ostenfeld and Schmidt) Brandt 



(Figure 92) 



Rhabdonella poctdtim. Kofoid and Campbell, 1929, p. 218, fig. 

 405. 



The short, wide lorica, with nearly cylindrical upper and 

 conical lower bowl, and wide conical horn, has a length of 

 1.93 oral diameters. The oral rim is entire, and is a cuff 

 which rises above the suboral trough which surrounds it. 

 The suboral trough is shallow and concave; the diameter of 

 its outer margin is i.i oral diameters. The bowl flares (10 ) 

 within the anterior o.i oral diameter, then becomes cylin- 

 drical for 0.85 oral diameter, and finally convex conical 

 (60°) for nearly 0.54 oral diameter. The aboral horn is in- 

 verted and concave conical (40°), with a basal diameter of 

 0.32 oral diameter, and with a sharply pointed free tip. 



The wall is subuniformly about 0.09 oral diameter in 

 thickness. There are 24 deflected (15°) ribs, which arise on 

 the horn or near it, and die away just below the suboral 

 flare. The ribs are often branched and sometimes anasto- 

 mosed, and the intercostal regions have 8 to 12 scattered, 

 oval fenestrae. The lorica is commonly dark brown. 



Length, 85^. 



The Carnegie loricae show much more transition between 

 lower bowl and horn than is shown in the single figure of 

 Kofoid and Campbell; they have fewer ribs (left, rather than 

 right, deflection), and have fenestrae. 



Rhabdonella poculum may be distinguished at once from 

 other species by the general form. In some ways it is like 

 R. amor, but it has a distinctly conical, well differentiated 

 horn. The shortness, and the basal width of the horn are 

 characters which are especially distinct. 



Recorded from three stations in the Pacific, as follows: 

 two (40, 41) in the Galapagos region, and one (93) in the 

 region of South Pacific island fields. 



There are 3 pump and 3 net samples, of which 4 were 

 taken at the surface, 1 at 50 meters, and i at 100 meters. 

 Maximum frequency, 13 per cent at station 41; average in 

 net samples, 5.3 per cent. 



Temperature: pump samples 2o?42-28?74 (24?45), net 

 samples i4?55-20?42 (i6?76). Salinity: pump samples 33.70- 

 34.71 (34.20), net samples 34.19-35.02 (34.40). Density: 

 pump samples 21.95-24.06 (23.07), net samples 24.06-26.11 

 (25.33). pH: pump samples 8.1 1-8.30 (8.14), net samples 

 7.87-8.. I (7.96). 



Rhabdonella quantula Kofoid and Campbell 



Rhabdonella qitantida Kofoid and Campbell, 1929, p. 218, fig. 

 402. 



The rather short lorica, with narrow, chalice-like bowl and 

 elongated horn, has a length of 3.66 oral diameters. The 

 oral rim is low and ringlike, and extends only slightly above 

 the suboral trough. The suboral trough is concave and the 

 diameter of its outer margin is 1.22 oral diameters. There is 

 some suboral flare (35°) within the upper 0.05 oral diameter. 

 The bowl tapers (16°) in the anterior 0.37 total length and 

 then becomes subconical (30°) within the posterior 0.35 

 total length. The aboral horn (0.29 total length in length) 

 is narrow conical (5°) and sharply pointed at the free tip. 



The wall is thickest across the suboral flare, where it 

 reaches o.i oral diameter; at other levels it is reduced by 

 one-half. There are thin laminae which enclose fine alveoles. 

 There are upwards of 54 subvertical, continuous, distinct, 

 unbranched ribs, and in each intercostal area are 6 to 8 small 

 circular fenestrae. 



Length, 138 to 172^1. 



Rhabdonella quantula differs from R. spiralis mainly in 

 shortness and in greater number of ribs. Rhabdonella inflaia 

 is of about the same size, but has a longer, less tapering 

 bowl; R. cornucopia has a stubby aboral horn. The lower 

 bowl of R. brandti is wider, and its horn is shorter than in 

 quantula. 



Recorded from ten stations in the Pacific, as follows: three 

 (35, 35-36, 99) in the Pacific equatorial region, two (78, 80) 

 in the Galapagos region, four (81, 82, 84, 85) in the region 

 of South Pacific island fields, and one (140) in the North 

 Pacific trade region. 



There are 3 pump and 10 net samples, of which 3 were 

 taken at the surface, 7 at 50 meters, and 3 at 100 meters. 

 Maximum frequency, 75 per cent at station 35-36; other 

 records above minimum (2 to 8 per cent) from stations 35, 

 82, 85, 99; average in net samples, 10.6 per cent. 



Temperature: pump samples 25?94-28?32 (26?77), net 

 samples i4?33-27?89 (23?48). Salinity: pump samples 

 35.02-35.95 (35.58), net samples 34.88-36.42 (35.71). Den- 

 sity: pump samples 22.45-23.75 (23.09), net samples 22.50- 

 26.06 (24.09). pH: pump samples 8.16-8.34 (8.23), net 

 samples 7.88-8.22 (8.13). 



Rhabdonella spiralis (Fol) Brandt emended Kofoid 

 and Campbell 



Rhabdonella spiralis, Kofoid and Campbell, 1929, p. 219, fig. 



414; Hofker (part), 1931, pp. 378-381, figs. 68-72 (for fig. 



67 see Rhabdoncllopsis triton); Marshall, 1934, pp. 646-648, 



figs- 23. 27(?)- 

 The moderately tall, elongated lorica, with tapering bowl 



