TAXONOMY AND DISTRIBUTION 



109 



Temperature, 16^36; salinity, 34.70; density, 25.45; pi I, 

 8.09. 



Undellopsinae, new subfamily 



This subfamily includes only the genus Undellopsis, in 

 which there is a suboral ledge. 



UNDELLOPSIS Kofoid and Campbell 

 Undellopsis Kofoid and Campbell, 1929, pp. 266-267, 271. 



This genus has a suboral ledge, which is lacking in Am- 

 plectella, but otherwise has a rather great diversity ot form. 

 All the species are distinctly tropical. 



Seven species are described here. 



Undellopsis cubitum Kofoid and Campbell 

 (Figure 97) 



Undellopsis cubitum Kofoid and Campbell, 1929, p. 268. fig. 

 5I7- 



The moderate-sized lorica, of rectangular optical section, 

 has a length of 2.5 oral diameters. The oral margin is thin. 

 There is a concave suboral ledge with almost no posterior 

 contraction (1.3 oral diameters in diameter). The bowl is 

 subcylindrical (0.87 total length in length), with a posterior 

 diameter of 1.11 oral diameters. Below the lower end it con- 

 tracts (30 ) subconically to the nearly flat (160°) aboral 

 end. The aboral end is introverted and umbilicated after the 

 manner of ttmbilicata. 



The wall has a thickness of 0.04 oral diameter in the 

 middle of the bowl; it is thicker suborally and thinner 

 aborally. There are extremely thin laminae and enclosed 

 hyaline matter. 



Length. 115 to 123U. 



The lorica of this expedition has an umbilicated aboral 

 end unlike those described earlier. 



Undellopsis cubitum resembles U. subangulata, but is 

 more slender, with much less suboral expansion, longer 

 aboral cone, and a different aboral end. The remaining 

 species are very different. 



Recorded from one station (45) in the Galapagos region, 

 in a net sample taken at 100 meters. Frequency, 5 per cent. 



Temperature, 2i?6g; salinity, 35.21; density, 24.48; pH, 

 8.12. 



Undellopsis entzi Kofoid and Campbell 



(Figure 105) 



Undellopsis entzi Kofoid and Campbell, 1929, p. 268, fig. 516. 



The moderate-sized lorica, with salt-cellar shape, has a 

 length of 2.56 oral diameters. The oral margin is sharp- 

 edged. There is a sharp-angled (8o°) suboral ledge (1.28 

 oral diameters in diameter) which occupies the anterior 0.36 

 oral diameter. The bowl below the ledge is subcylindrical 

 (1.08 oral diameters at the lower end), and its length is 0.47 

 total length. The lower bowl expands subconically (60°) 

 to the base, which has a diameter of 1.6 oral diameters, then 

 contracts again subconically (6o°) for nearly 0.38 total length 



to the flattened (0.68 oral diameter) aboral end. All levels 

 of change arc sharply angular, and the sides arc all planes. 



The wall is subuniformly 0.08 oral diameter in thickness 

 except in the ledge and in the truncated aboral end, where 

 it is thicker. There are thin laminae and enclosed hyaline 

 material. 



Length, 125^1. 



The Carnegie loricae are longer than those recorded earlier 

 (108 to 11511), chiefly in the longer cylindrical section. The 

 truncated aboral end is also less than an oral diameter. 



Undellopsis entzi bears some resemblance to U. insignata, 

 but is truncated instead of rounded aborally, and has a 

 cylindrical rather than concave upper bowl. It has no ring 

 on the cylinder like U. annularius. 



Recorded from two stations (55, 67) in the South Pacific 

 middle latitudes, in 1 net and 1 pump sample, both taken at 

 100 meters. Frequency, 4 per cent at station 55. 



Temperature: net sample i6?36, pump sample 1 6?~5. 

 Salinity: net sample 34.70, pump sample 34.86. Density: net 

 sample 25.45, pump sample 25.48. pH: net sample 8.09, 

 pump sample 8.17. 



Undellopsis insignata Kofoid and Campbell 

 Undellopsis insignata Kofoid and Campbell, 1929, pp. 268 269, 



fig- 5t9. 

 The moderate-sized lorica, with entzi-Wkc form but with 

 an angled division between upper and lower bowl, has a 

 length of 2.48 oral diameters. The oral margin is sharp 

 edged. The suboral ledge is angular (108 ), with a diam- 

 eter of 1.22 oral diameters at 0.3 oral diameter below the rim. 

 The upper bowl is 0.52 total length in length, with the upper 

 part cylindrical and the lower section widely flaring, so that 

 the whole is sweepingly concave. The diameter at the lower 

 end is 1.29 oral diameters. The lower bowl is potlike, the 

 sides contracting (35°), and the truncated aboral end having 

 a diameter of almost 1.0 oral diameter; the angles of change 

 are sharp in the upper region but rounded posteriorly. 



The wall reaches 0.1 oral diameter in thickness in many 

 places, although commonly a trifle less. There are thin 

 laminae with enclosed hyaline material. The lumen does 

 not enter the angular transition between upper and lower 

 bowls. 



Length, 105U.. 



Undellopsis insignata differs from U. entzi in the rounded, 

 rather than squarely truncated, aboral end. It lacks the ring 

 of U . annularius, and its aboral end is not hemispherical as 

 in that species. 



Recorded from two stations in the Pacific, as follows: one 

 (137) in the California region and one (140) in the North 

 Pacific trade region. 



There are 2 pump samples and 1 net sample, of which 2 

 were taken at 50 meters and 1 at 100 meters. Frequency, 6 

 per cent at station 137. 



Temperature: pump samples 24?84-25?94 (25739), net 

 sample 24^84. Salinity: pump samples 35.02-35.12 (35.07), 

 net sample 35.12. Density: pump samples 23.09-25.50 

 (24.29), net sample 23.50. pH: 8.34 in all samples. 



