22 



OCEANIC TINTINNOINA OF LAST CRUISE OF CARNEGIE 



meters and 2 at 100 meters. Maximum frequency, 5 per cent 



at station 22; other records minimum; average, 3 per cent. 



Temperature, i7?5o-25?3i (2i?04>; salinity, 36.81-37.15 



( 56.98); density, 24.89-26.07 (25.48); pH, 8.21-8.27 (8.24). 



CODONELLOPSIDAE Kofoid and Campbell 

 Codonellopsidae Kofoid and Campbell, 1929, p. 67. 

 This family includes three genera, Stenosemella, Codonel- 

 lopsis, and Laacknianniella , of which the first two occur in 

 the material of this expedition. Laac\manniella is exclu- 

 sively antarctic, Codonellopsis is eupelagic in warm seas, and 

 Stenosemella is almost always coastal. 



STENOSEMELLA )6rgensen 

 Stenosemella, Kofoid and Campbell, 1929, pp. 67-68. 



Stenosemella is apparently the stem of the Codonellopsidae, 

 and its wall structure allies it to Tintinnopsis, to the general 

 form of which it adds a collar. Closely related is the new 

 genus Wangiella, with the type, Wangiella dicollaria, from 

 the Bay of Amoy (D. Nie, 1934). in which the collar is 

 Dictyocysta-Mke. Also allied is Luminella, a new genus 

 founded by Kofoid and Campbell (1939, p. 284), which has 

 as its principal character the demilunar openings in the 

 collar. 



Stenosemella is rare in the open ocean except as drifting 

 empty loricae may be carried from the coast; in harbors and 

 close to shore it is frequently the most common tintinnid. 

 In San Francisco harbor it is often found exclusively, and 

 off La Jolla it is often the most abundant. Most records of 

 the genus are from northern European waters. 



One species is described here. 



Stenosemella nivalis ( Meunier) emended Kofoid 

 and Campbell 

 Stenosemella nivalis, Kofoid and Campbell, 1929, pp. 69-70, fig. 

 136; Campbell, 1931, pp. 347"34 8 ; Hada - r 93^>. P- 561, fig- 

 11; Marshall, 1934, p. 638. 

 Stenosemella nucula, Hofker, 1931, pp. 362-364, figs. 40-42. 



The small, olive-shaped lorica, with thick, irregular wall 

 and narrow, hyaline collar lacking windows, has a length of 

 2.2 oral diameters. The oral margin is recurved outward, 

 and the glassy collar is a concave ring with a length of only 

 0.06 oral diameter; it lacks the spiral turns and demilunes 

 characteristic of some species, and the tall windows of 

 Wangiella dicollaria. The plump, dense, potlike bowl is in- 

 flated from the lower edge of the collar and reaches its 

 greatest diameter, which is equal to the total length, at 0.61 

 oral diameter below the oral rim, forming a rather strong, 

 rounded shoulder. Below this level it contracts in regular 

 contour to the bluntly pointed or narrowly rounded end. 



The wall of the collar is clear, but that of the bowl is 

 coarse, thick, and heavy, up to 0.2 oral diameter laterally. 

 No structure may be detected in the collar, but the bowl has 

 two or three layers of large, irregular tertiary polygons with 

 thickened margins and clear interiors. Foreign bodies adhere 

 to the outer surface. 



The animal has been carefully studied. There are 2 

 macronuclei, and 24 large, squarish membranelles of elabo- 

 rate structure (Campbell, 1931). 

 Length 40 to 46^. 



Considerable variation is apparent, especially in the rela- 

 tive narrowness or width of the bowl, the level at which the 

 greatest diameter is reached, the shape of the aboral end, and 

 the character of the collar. Cytological details also differ. 

 Stenosemella nivalis is closest to S. ventricosa in form, but 

 nivalis is always shorter, and rotund and sharper aborally. 

 The greatest diameter is reached at a level closer to the 

 collar in ventricosa. Stenosemella nivalis has a different 

 collar from Wangiella dicollaria from the Chinese coast; it 

 is smaller than S. steini, and lacks the trough below the 

 collar which distinguishes that species. Stenosemella avellana 

 is of about the same size, but its greatest diameter is nearer 

 the middle and there are long, sloping shoulders below the 

 collar. Stenosemella oliva has a narrower bowl and higher 

 collar, and is differently proportioned. 



Hofker ( 1 93 1 ) suggests that the western species is nivalis, 

 ami that the loricae from off Holland are nucula. This 

 proposition is largely based on inadequate cytological mate- 

 rial. In form, loricae from Holland as examined by us seem 

 similar in every way to those from off California. 



Recorded from one station (130) in the California region, 

 in a net sample taken at 50 meters. Frequency, 5 per cent. 

 Temperature, 12^91; salinity, 33.40; density, 25.19; pH, 

 8.26. 



CODONELLOPSIS JSrgensen 

 Codonellopsis, Kofoid and Campbell, T929, p. 73. 

 Stenosemella may be considered the stem of Codonellopsis, 

 and Luminella that of Dictyocysta. Both these primitive 

 genera are probably derived from Tintinnopsis. This hy- 

 pothesis leaves the more highly differentiated genera less 

 isolated. 



Codonellopsis is widely distributed in the warmest oceans, 

 although a few species enter the cold North Pacific, for 

 example, C. frigida, C. limosa, and C. orientalis northward 

 of Japan, and the latter and aleutiensis southward of the 

 Bering Sea. A few, such as C. contracta, also occur in the 

 tropics in deep water. None of the species enters the Ant- 

 arctic, but the allied genus Laac\manniella is peculiar to 

 that region. Laae\manniella has two, or possibly more, 

 species peculiar to the south, where they occur under the 

 ice; this genus does not occur in the Humboldt Current, 

 although the water of that current arises from the Antarctic 

 Current. It has not been reported, either, from the Cape 

 Horn Current. Laacl{manniella is remote from Coxliella 

 and related genera, and belongs properly to the Codonellop- 

 sidae. Its open aboral end is secondary. Most species of 

 Codonellopsis are circumtropical. 



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



Codonellopsis aleutiensis, new species 

 (Plate 1, figure 9} 

 The lorica has a long collar and a round bowl; its length 

 is 2.66 oral diameters. The oral margin is entire, rounded 



