TAXONOMY AND DISTRIBUTION 



97 



The cavity follows the outer contour almost exactly cxa pi n 

 the aboral tip, where the wall thins down to the pore. The 

 repeated subdivisions of the bowl suggest periodic behavior 

 on the part of the animal at the time of formation of the 

 lorica. They give the impression that there are five phases, 

 pauses, or changes in a regular, orderly sequence of activity. 

 The open aboral end, also, suggests that there was a connec- 

 tion between the protoplasm of the two daughter animals at 

 the time of fission, when the lorica was formed. Such an 

 explanation is in keeping with events and structures known 

 in other genera of Tintinnoina. 



Length, 2g8(.l; oral diameter, 501.1. 



Undella hawaiensis resembles U. carnegiei more closely 

 than any other species. They differ in proportions, carnegiei 

 being 8.86 oral diameters. The collar-like region is longer 

 in the latter than in hawaiensis, and the bowl is subdivided 

 into more sections in hawaiensis than in the other. The 

 aboral region of hawaiensis is laterally concave in contour; 

 in carnegiei the lateral contour is hornlike, and the aboral 

 end is a sharp, concave cone. These two species are unlike 

 others of Undella. 



Recorded from four stations in the Pacific, as follows: 

 three (132, 133, 146) in the California region and one (145) 

 in the North Pacific middle latitudes. 



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

 taken at 50 meters and 3 at 100 meters. Frequency, 2 per 

 cent at station 146; average in pump samples, 1.5 loricae. 



Temperature: net sample 20?07, pump samples i8?38- 

 1 8?5 1 (i8?44). Salinity: net samples 34.32-34.71 (34.51), 

 pump samples 33.89-34.76 (34.32). Density: net sample 

 24.24, pump samples 24.35-24.98 (24.66). pH: net samples 

 8.26-8.31 (8.28), pump samples 8.31-8.33 (8.32). 



Type locality, station 145, at 100 meters: latitude 33 27 

 north, longitude 145° 30' west. 



Undella hemispherica Laackmann 



Undella hemispherica. Kofoid and Campbell, 1929, p. 265, fig. 

 505. 



The short, wide lorica, with cuplike bowl, wide-open oral 

 opening, and thick walls, has a length of 1.0 oral diameter. 

 The oral margin is sharp. The convex bowl rounds evenly 

 trom the oral rim to the pointed aboral end. 



The wall is thick, about 0.07 oral diameter, and nearly 

 twice as much aborally. There are thin laminae, and en- 

 closed material is faintly alveolar. The lumen has an aboral 

 dent at the point above the position at which the laminae 

 bend. 



Length, 6op.. 



Undella hemispherica has a form almost unique in the 

 genus, but does have some likeness to U . turgida, from which 

 it differs mainly in proportions, in character of oral margin, 

 and in wall thickness. 



Recorded from six stations in the Pacific, as follows: five 

 (48, 86, 89, 90, 93) in the region of South Pacific island 

 fields, and one (105) in the North Pacific trade region. 



There are 5 pump and 1 net samples, of which 4 were 

 taken at the surface and 2 at 100 meters. Frequency, 4 per 



cent at station 48; in pump samples, not over 2 specimens. 

 Temperature: pump samples 25?u-28?50 (27?5i), net 

 sample 23%:;. Salinity: pump samples 34.92-36.22 (35.62), 

 net sample 36.44. Density: pump samples 22.62-24.25 

 (23.10), net sample 24.86. pH: pump samples 8.23-8.27 

 ( 8.2s ), net sample 8.23. 



Undella hyalina Daday 



(Figure 102) 

 Undella hyalina, Kofoid and Campbell, \ui<), p. i(>\, lig. 511. 



The generally large lorica, with feebly angled and pointed 

 aboral region, has a length of 2.57 oral diameters. The oral 

 margin is a simple cuff formed by the upright inner lamina. 

 The bowl is subcylindrical below this barely developed cuff; 

 this section has a length of 0.77 total length. The aboral 

 region contracts indefinitely (39 in the upper two-thirds 

 and 125 in the lower part) to the blunted aboral end. 



The wall has a subuniform thickness of nearly 0.07 oral 

 diameter. There are thin laminae and dense enclosed 

 material. 



Length, 153(1. 



The Carnegie loricae are shorter and less definitely pointed 

 than the more usual type. 



Undella hyalina resembles U . parva closely, but the latter 

 is usually more definitely angular. Undella dcclivis is also 

 quite similar to parva, and differs from hyalina in the same 

 ways. Undella attenuata is angular aborally and also more- 

 contracted. 



Recorded from eight stations, five in the Atlantic and three 

 in the Pacific, as follows: three (2, 15, 16) in the Gulf 

 Stream, one (17) in the Sargasso Sea, one (25) in the 

 Atlantic equatorial region, and three (45, 77, 79) in the 

 Galapagos region. 



There are 7 pump and 4 net samples, of which 8 were 

 taken at 50 meters and 3 at 100 meters. Frequency, not 

 above minimum except in a pump sample at station 25 at 50 

 meters, where there were 12 loricae. 



Temperature: Atlantic, pumpsamples i4?6o-23?64 (i9?72), 

 net samples 2o?57~23°64 (22^02); Pacific, 23?69-24?55 

 (24?i2) and 2i?69, respectively. Salinity: Atlantic, pump 

 samples 35.70-36.48 (36.21), net samples 36.41-36.60 (36.46); 

 Pacific, 56.04 and 35.21, respectively. Density: Atlantic, 

 pump samples 24.84-26.62 (25.74), net samples 24.84-25.71 

 (25.34); Pacific, 24.28-24.54 (24.41) and 24.48, respectively. 

 pH: Atlantic, pump samples 7.93-8.23 (8.15), net samples 

 8.16-8.27 (8.23); Pacific, 8.17-8. 19 (8.18) and 8.12, respec- 

 tively. 



Undella hyalinella Kofoid and Campbell 



Undella hyalinella Kofoid and Campbell, 1929, p. 263, fig. 506. 



The small lorica, with clevei-Wke form and with nuchal 

 constriction, has a length of 3.2 oral diameters. The oral rim 

 is thin and sharp. The bowl contracts from the margin 

 (12 ) to a diameter of 0.8 oral diameter at 1.0 oral diameter 

 below the rim, then widens to 1.0 oral diameter near 0.61 

 total length from the rim, below which level it again con- 



