TAXONOMY AND DISTRIBUTION 



65 



spindle-shaped knob, long lance, and few ribs and fenestrae, 

 has a length of 5.6 oral diameters. The oral rim is a ring- 

 like cuff which rises above the suboral trough. The suboral 

 trough is flattened concave, and its outer margin has a diam- 

 eter of 1.35 oral diameters. The bowl flares {58°) within 

 the suboral 0.28, and then becomes inverted, slightly convex 

 conical (25°); its length is 0.52 total length. The pedicel is 

 tubular, with a diameter of only 0.18 oral diameter, and at 

 0.84 total length from the oral margin gives rise to a swollen, 

 spindle-like knob (0.43 oral diameter in length). From the 

 lower end arises the lance, the length of which is 0.4 oral 

 diameter. 



The wall reaches a thickness of almost 0.15 oral diameter 

 across the suboral trough and gradually thins to a tenth as 

 much in the pedicel. There are thin laminae and enclosed 

 minute alveoles in several layers. The ribs number 12; they 

 are subequidistant and unbranched, and die away before 

 they reach the knob. There are 2 to 4 minute fenestrae in 

 each intercostal area. The knob region is brownish, and on 

 its surface are a number of right-turning striae. 



There are 2 macronuclei. 



Length, 3i2|,(. 



The Carnegie loricae have unbranched ribs, few fenestrae, 

 nonstriate pedicels, and higher oral rims than is usual for the 

 species from other sources. 



Hofker's photograph (fig. 67) shows a spindle-like knob 

 unlike that of any others of his loricae. This specimen, and 

 others, are assigned by us to tr'iton. 



Rhabdonellopsis triton has a spindle-shaped knob unlike 

 the other species, save R. composita. In composita the bowl 

 is wider, and the ribs are more numerous, are deflected, and 

 have many fenestrae. 



Recorded from three stations, one in the Atlantic and two 

 in the Pacific, as follows: one (21) in the Sargasso Sea, one 

 (45) in the Galapagos region, and one (131) in the Cali- 

 fornia region. 



There are 4 net samples, of which 2 were taken at the 

 surface, i at 50 meters, and i at 100 meters. Frequency, 3 

 per cent at station 45; average in the Pacific, 3 per cent. 



Temperature : Atlantic, 26? 57; Pacific, 1 2 ? 1 2-22 ?43 ( 1 8 ? 97 ) . 

 Salinity: Atlantic, 36.28; Pacific, 33.36-35.26 (34.61). Den- 

 sity: Atlantic, 23.84; Pacific, 24.30-25.31 (24.64). pH: At- 

 lantic, 8.32; Pacific, 8.12-8.32 (8.19). 



EPIPLOCYLIDAE Kofoid and Campbell 



Epiplocylidae Kofoid and Campbell, 1939, p. 125. 



Three genera are included in the family: Epiplocylts, Epio- 

 rella, and Epicancella. All three are mainly tropical and 

 occur in the material of this expedition. 



EPIPLOCYLIS Jorgensen emended 



Epiplocylts, Kofoid and Campbell (part), 1929, pp. 172-173. 



Epiplocylis is one of the more advanced genera. The ver- 

 tical lines suggest derivation from some stem near the Rhab- 

 donellidae. The cuplike shape remotely resembles that found 

 in the Petalotrichidae. 



Epiplocylis is common in the warm regions of the ocean. 

 Some species, such as E. undella, are among the most fre- 

 quent in those areas. Others extend north and south of the 

 equator into temperate regions, but never reach really cool 

 waters. Most of the species are circumtropical, with very 

 litde limitation to any of the oceans. Some species occur in 

 such abundance as to constitute swarms, as do also some 

 species of Rhabdonella. These swarms in the sea are not 

 infrequent in some tintinnids, although, as a whole, the 

 Tintinnoina are more usually found in small percentages. 

 Areas of abundance usually extend over a wide number of 

 stations and represent relatively large areas in the ocean. 



Seventeen species are described here, one of which is new. 



Epiplocylis atlantica Kofoid and Campbell 

 (Figure 72) 



Epiplocylts atlantica Kofoid and Campbell, 1929, p. 176, fig. 

 340. 



The short, heavy-set lorica, with wide conical aboral end, 

 short horn, and low reticulated area, has a length of 1.62 oral 

 diameters. The oral margin is thinly rounded. The bowl 

 expands from the rim for 0.55 total length, and has a diam- 

 eter at the lower level of 1.07 oral diameters. The lower 

 bowl is inverted conical (93°), and joins the upper bowl 

 with a rounded angle, the lateral contour of the whole being 

 distinctly convex. The short (0.22 oral diameter) aboral 

 horn is conical (28°) and its free tip is blunted. 



The wall has a thickness of 0.067 oral diameter in the sub- 

 oral thickened region which extends 0.31 oral diameter 

 below the rim, and is elsewhere about one-third as thick. 

 There are relatively thick inner and outer laminae which 

 enclose rather small alveoles. The reticulated aboral region 

 occupies 0.32 oral diameter, and comparatively few branched 

 and anastomosing free lines extend above it for 0.15 oral 

 diameter. The reticulations are deep pits of more or less 

 subcircular form. 



Length, 88|.i. 



The Carnegie loricae are shorter than those from other 

 sources. 



Epiplocylis atlantica is shorter, wider, and more conical 

 than E. hlanda. In some characters it resembles E. undella, 

 but it has lateral convexity rather than cylindrical upper 

 bowl, a full aboral cone, and much finer reticulations. 



Recorded from five stations in the Adantic, as follows: 

 one (19) in the Sargasso Sea, and four (23, 25, 28, 29) in the 

 Atlantic equatorial region. 



There are 5 net samples, of which 2 were taken at 50 

 meters and 3 at 100 meters. Frequency, 3 per cent at stations 

 19, 23; 2 per cent at stations 28, 29; average, 2.5 per cent. 



Temperature, i4?6o-27?ii (22?73); salinity, 35.70-37.05 

 (36.26); density, 23.62-26.62 (24.92); pH, 7.93-8.29 (8.18). 



Epiplocylis blanda Jorgensen emended Kofoid and Campbell 



(Figure 73) 



Epiplocylis blanda, Kofoid and Campbell, 1929. p. 176, fig. 341; 

 Marshall, 1934, p. 644, fig. 19. 



The tall, cup-shaped lorica, with short free lines and long, 



