102 



OCEANIC TINTINNOINA OF LAST CRUISE OF CARNEGIE 



margin is sharp. The bowl expands (50°) in the anterior 

 0.27 total length to a diameter of 1.87 oral diameters. The 

 lower bowl contracts (42°) regularly to the flattened aboral 

 end (diameter nearly that of the oral opening). 



The wall reaches a thickness of 0.2 oral diameter in the 

 thickest region, and is gradually reduced by two-thirds 

 aborally. The inner collar contracts (25°); it has a length 

 of 0.19 total length, and the lower end has a diameter of 0.82 

 oral diameter. The laminae are thin, and the enclosed 

 material is clear. 



Length, 57 to 6o(X. 



Proplectella amphora is unique in the squarely flattened 

 aboral end and in the general shape. 



Recorded from one station (67) in the South Pacific 

 middle latitudes, in a net sample taken at 100 meters. Fre- 

 quency, minimum. 



Temperature, i6?3&; salinity, 34.70; density, 25.45; pH, 

 8.09. 



Proplectella angustior (Jorgensen) Kofoid and Campbell 



Proplectella angustior, Kofoid and Campbell, 1929, pp. 275- 

 276, fig. 542. 



The small, strongly ovate lorica has a length of 1.74 oral 

 diameters. The oral margin is sharp. The bowl expands 

 (48 ) to a diameter of 1.47 oral diameters at 0.4 total length 

 from the rim, and then contracts (14 anteriorly, increasing 

 to 90° and finally to 116 ). The whole lorica is distinctly 

 convex. The aboral end is blunted. 



The wall is as much as 0.24 oral diameter in thickness in 

 the inner collar, and only 0.05 aborally. The inner collar 

 is conical (36 ), is 0.31 oral diameter in length, and has 

 a diameter of 0.84 oral diameter at the lower end. There 

 are thin, dark laminae and enclosed faintly prismatic 

 material. 



Length, 50 to 62(.l. 



Proplectella angustior has a much narrower oral margin 

 and a more pointed aboral end than P. claparedei. Its bowl 

 is less angular and its aboral end more pointed than in P. 

 fastigata, and its proportions are different. It varies in 

 length, perhaps in relation to its wide temperature range. 



Recorded from eight stations, two in the Atlantic and six 

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

 (25) in the Atlantic equatorial region, two (69, 71) in the 

 Galapagos region, and four (131, 132, 134, 135) in the Cali- 

 fornia region. 



There are 8 pump and 2 net samples, of which 3 were 

 taken at the surface, 2 at 50 meters, and 5 at 100 meters. 

 Frequency, 3 loricae at stations 132, 135 in pump samples; 

 average in Pacific pump samples, 1.8. 



Temperature: Atlantic, pump sample 20?32, net sample 

 i4?6o; Pacific, i4?42-23?4<5 (i9?88) and I2?i2, respectively. 

 Salinity: Atlantic, pump sample 36.81, net sample 35.70; 

 Pacific, 33.40-35.24 (34.56) and 33.36, respectively. Density: 

 Atlantic, pump sample 26.07, net sample 26.62; Pacific, 23.75- 

 24.96 (24.43) and 25.31, respectively. pH: Atlantic, pump 

 sample 8.21, net sample 7.93; Pacific, 8.13-8.34 (8.24) and 

 8.32, respectively. 



Proplectella aulti, new species 

 (Plate I, figure 1) 



The small, robust lorica has a truncated aboral region and 

 a length of 1.6 oral diameters. The oral margin is sharp 

 and thin, and the flattened inner rim dips toward the fundus 

 at an angle (70 ); the inner rim is approximately 0.12 total 

 length in width, and its lower edge constricts the collar 

 region to a diameter of 0.8 oral diameter at the level at which 

 the bowl opens oralward. The inner wall of the bowl im- 

 mediately below this level bends sharply and leaves the collar 

 region merely a thickened area. In section, the wall is thus 

 a distorted triangle, with the base formed by the collar 

 region. The wall narrows quickly and reaches its minimum 

 thickness at or near the ambitus of the lorica, and it main- 

 tains this thickness below. The wall has a minimum thick- 

 ness of less than 0.02 oral diameter; it has distinct hyaline 

 laminae, and the middle region between lacks prisms. The 

 exterior of the lorica rounds evenly from the oral rim to the 

 level of greatest diameter, which is somewhat above the 

 upper 0.33 total length, roughly forming a truncated cone 

 (6o c ). The diameter at the base of this cone is equal to the 

 total length of the lorica. Below the level of maximum 

 diameter the bowl decreases in diameter as a full, rounded, 

 inverted truncated cone (23 ). The aboral region is squarely 

 truncated, and has a diameter equal to that of the oral 

 aperture. 



Length, 37(1; diameter, oral 2311, maximum 25".. 



The amount of the curvature of the upper bowl toward 

 the oral rim, the amount of contraction to the aboral end 

 from the level of greatest diameter, and the diameter of the 

 aboral end are among the main variable characters of this 

 species. 



Proplectella aulti differs from the described species of the 

 genus in having a flattened aboral region, except from P. 

 amphora, which it resembles more closely than any other. It 

 differs from that species, however, in being tumid instead 

 of sharply six-sided in outline; the anterior shoulder is also 

 less emphatic in aulti than in amphora, in which latter it is 

 pronounced. Proplectella aulti is unlike P. pentagona, the 

 other angular species, in being truncated aborally instead of 

 pointed, and in having the shoulder region anterior instead 

 of posterior. 



Recorded from one station (22) in the Atlantic equatorial 

 region, in a net sample taken at 100 meters. Frequency, 

 minimum. 



Temperature, i7?5o; other physical data are lacking. 



Type locality, station 22, at 100 meters; latitude 13 27' 

 north, longitude 38 00' west. 



Proplectella biangulata Kofoid and Campbell 

 (Figure 98) 

 Proplectella biangulata Kofoid and Campbell, 1929, p. 276, fig. 



532- 

 The large, angular lorica, with conical upper and aboral 

 sections and cylindrical middle part, has a length of 3.5 

 oral diameters. The oral margin is angular. The upper 



