52 



OCEANIC TINTINNOINA OF LAST CRUISE OF CARNEGIE 



Temperature, 22?37-26?04 (24^20); salinity, 35.23-35.94 

 (35.35); density, 23.75-24.30 (24.02); pH, 8.13-8.20 (8.16). 



Petalotrichin.\e Kofoid and Campbell 



Petalotrichineae, Kofoid and Campbell, 1929, p. 202. 



Only the single genus Petalotricha belongs to this sub- 

 family. 



PETALOTRICHA Kent emended 

 Petalotricha, Kofoid and Campbell, 1929, p. 202. 



Large, smooth-walled, well finished loricae are character- 

 istic of Petalotricha. These are among the more complex 

 Tintinnoina of the warmest parts of the ocean. One species, 

 Petalotricha joli, is limited to the eastern Pacific, but P. 

 major is circumtropical. 



Five species are described here. 



Petalotricha ampulla (Fol) Kent 



(Figure 26) 



Petalotricha ampulla, Kofoid and Campbell, 1929, p. 203, fig. 

 389; Entz, 1935, pp. 15-26, figs. 1-15. 



The stout lorica, with pointed aboral end, has a length of 

 1.06 oral diameters. The oral margin is irregularly serrate 

 with minute points. The upper collar is a horizontal shelf, 

 and the oral aperture has a diameter of but 0.87 the diameter 

 of the outer edge of this shelf. The lower collar is a basal 

 segment of a low inverted cone (28°) with full sides; its 

 width is 0.22 oral diameter. Optically dark lines separate 

 the two collars and the bowl. The bowl rounds away from 

 the throat at 58° and at the shoulder reaches a diameter of 

 0.85 oral diameter. The bowl is 0.89 oral diameter at its 

 maximum, which lies at 0.4 oral diameter below the margin. 

 Below this level it contracts (at 32° for a distance of 0.52 

 oral diameter below the level of the maximum diameter, and 

 then at 100° for the remaining distance). The aboral end is 

 broadly pointed but not prolonged. 



The thin, uniform wall is not over 0.0 1 oral diameter in 

 thickness, and is grayish; there is a row of small oval lacunae 

 at the upper end of the lower collar. A double row of 

 lacunae also occurs below the shoulder. 



The animal has about 100 small macronuclei, and 5 chro- 

 mosomes are reported in the micronuclei. If this last be 

 confirmed, the vegetative individual must be haploid, be- 

 cause the chromosome number is odd, and the reduction in 

 conjugation must be postzygotic, a condition unique in the 

 ciliates, although common in algae, mastigophorans, and 

 certain, if not all, sporozoans. 



Length, 110^. 



Entz (1935) discusses the cytology of the animal in a 

 special paper. 



Petalotricha ampulla is pointed aborally, unlike P. major, 

 which is rounded. Its bowl is short in contrast with that of 

 P. joli, in which the bowl is conical and elongated. It differs 

 from P. scrrata in its shallower, less regular, and less distinct 

 serrations and deeper throat. It lacks the curtain of P. entzi. 

 On the whole it is not likely to be confused with other com- 

 mon species, especially major and joli. 



Recorded from eight stations, four each in the Atlantic 

 and the Pacific, as follows: two (4, 5) in the Atlantic drift, 

 two (14, 16) in the Gulf Stream, two (65, 66) in the South 

 Pacific middle latitudes, one (68) in the Galapagos region, 

 and one (113) in the North Pacific middle latitudes. 



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

 taken at 50 meters and 7 at 100 meters. Maximum fre- 

 quency, 30 per cent at station 68; other records above mini- 

 mum (2 to 10 per cent) from stations 4, 5, 14, 16, 65, 113; 

 averages in net samples, 5 and 12 per cent in the Atlantic 

 and Pacific, respectively. 



Temperature: Atlantic, net samples i3?5i-23?64 (i5°77); 

 Pacific, pump sample i7?94, net samples i5?03-2i?74 

 (i7?77). Salinity: Atlantic, net samples 35.88-36.41 (35.95); 

 Pacific, pump sample 34.94, net samples 34.30-34.85 (34.60). 

 Density: Atlantic, net samples 24.84-27.01 (26.48); Pacific, 

 pump sample 25.26, net samples 24.06-25.52 (25.00). pH: 

 Atlantic, net samples 8.06-8.23 {^■'^a)\ Pacific, pump sample 

 8.12, net samples 8.10-8.23 (^-'S)- 



Petalotricha capsa Brandt 

 Petalotricha capsa, Kofoid and Campbell, 1929, p. 203, fig. 387. 



The saccular lorica, with flaring collars, goblet-shaped 

 bowl, and rounded aboral end, has a length of 0.93 oral 

 diameter. The oral margin is smooth, thin-edged, and 

 nearly erect. The upper and lower collars flare concur- 

 rently as basal segments of inverted truncated cones (62°), 

 and each is laterally sigmoid. On the inside, the boundary 

 between the lower edge of the upper collar and the upper 

 edge of the lower collar is marked ofl by an erect, short 

 ledge, and there is a similar ledge at the lower edge of the 

 lower collar where it joins the bowl. On the outside, tiny 

 oval lacunae occur along the boundary lines of the two 

 collars. The diameter of the throat is 0.77 oral diameter. 

 The bowl below rounds over a slightly developed shoulder 

 and then becomes conical (10°) for about two-thirds the 

 length of the bowl, again increasing below this to 62°, and 

 finally to 125° near the aboral end. The aboral end is hemi- 

 spheroidal. 



The wall is 0.02 oral diameter in thickness, and there are 

 thin, distinct inner and outer laminae between which are 

 enclosed two or three layers of rounded alveoles. These 

 alveoles are clearly visible externally, and the whole lorica 

 distinctly shows them. Large lacunae, of oval shape with the 

 axes directed vertically, occur in 2 or 3 rows in the upper 

 three-tenths of the bowl; they are 16 in number across one 

 face. 



Length, 1251,1. 



Petalotricha capsa resembles P. indica in having alveoles 

 in the wall in several layers. It differs from indica in its 

 lesser elongation, narrower aboral region, and more con- 

 stricted throat. From P. pacifica it may be distinguished by 

 its longer, less hemispherical bowl, and by the several layers 

 of alveoles. The remaining species have different wall struc- 

 ture. 



Recorded from two stations (158, 159) in the region of 

 South Pacific island fields. 



