92 



OCEANIC TINTINNOINA OF LAST CRUISE OF CARNEGIE 



Xystonella clavata may be distinguished at once from 

 other species by the aboral expansion. Xystonella longkauda 

 is similar in general shape but has a needle-like lance. 



Recorded from two stations, one each in the Adantic and 

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

 (64) in the South Pacific middle latitudes. 



There are 2 pump samples, of which i each was taken at 

 50 and 100 meters. Frequency, minimum. 



Temperature: Atlantic, 25?3i; Pacific, i5?9o. Salinity: 

 Atlantic, 37.15; Pacific, 34.54. Density: Atlantic, 24.89; 

 Pacific, 25.43. pH: Adantic, 8.27; Pacific, 8.10. 



Xystonella curticauda, new species 

 (Figure 6::) 



The elongated, narrow-conical lorica, with short lance, has 

 a length of 6.14 oral diameters. The oral rim is a low, in- 

 turned, barely evident cuff. It is surrounded by the shallow, 

 angular suboral trough, the outer edge of which is higher 

 than the oral cuff, which in turn forms its inner rim. The 

 trough has a diameter of 1.4 oral diameters. The bowl tapers 

 evenly and regularly (11°) for almost 0.77 total length, 

 and at its lower end has a diameter of 0.65 oral diameter. 

 The lower part of the bowl is a narrow cone (33°) with a 

 length of i.o oral diameter. At its lower end is a short 

 (0.5 oral diameter), rodlike lance with a minutely blunted 

 free end. 



The wall is thick, 0.17 oral diameter near the suboral 

 region, and then thins so that near the lance it is only 0.08 

 oral diameter across. There are thin inner and outer laminae 

 which enclose a single layer of subequal, rectangular, radial 

 secondary prisms; these prisms, in turn, enclose tiny primary 

 alveoles. The surface has hexagonal areas of uniform size. 

 A few coccoliths adhere to the wall. 



Length, 3601.1. 



Xystonella curticauda was originally recorded in our pro- 

 tocols as longkauda, but this identification appears to have 

 been in error. It is now designated as a new species, which 

 differs from all others in the extreme shortening of the 

 lance. It is, possibly, most like X. flemingi, but it lacks the 

 suboral flare, the median concavity, and the aboral swelling 

 of that species. Its lance is also shorter, and it is much longer 

 (36011 as against 229^1). 



Recorded from four stations in the Adantic, as follows: 

 one (4) in the Adantic drift, two (14, 16) in the Gulf 

 Stream, and one (19) in the Sargasso Sea. 



There are i pump and 5 net samples, of which i was 

 taken at the surface, 3 at 50 meters, and 2 at 100 meters. 

 Maximum frequency, 18 per cent at station 4 at 50 meters; 

 other records above minimum (2 to 6 per cent) from stations 

 14, 16; average in net samples, 6.2 per cent. 



Temperature: pump sample 25?3i, net samples i3?37- 

 23?64 (i5?99). Salinity: pump sample 37.15, net samples 

 35.59-36.41 (35.96). Density: pump sample 24.89, net sam- 

 ples 24.84-27.01 (26.44). pH: pump sample 8.27, net sam- 

 ples 8.06-8.23 (8.16). 



Type locality, station 4, at 50 meters; latitude 44° 39' 

 north, longitude 33° 06' west. 



Xystonella flemingi, new species 

 (Plate I, figure 4) 



The simple, trumpet-shaped lorica has a length of 5.45 

 oral diameters. The oral rim stands up erect as a low, barely 

 evident cuff around the opening. It is surrounded by the 

 suboral trough, which is shallow and concave. The outer 

 edge of the trough is higher than the oral cufi, which forms 

 its inner rim. The trough has a diameter of 1.2 oral diam- 

 eters. The bowl may be subdivided into three divisions. Of 

 these, the first is an inverted truncated cone (29°) with a 

 length of 0.2 total length, and with a diameter at the pos- I 

 terior end of 0.77 oral diameter. The sides of this section 

 are distinctly concave, and gracefully contracted from the 

 outer rim of the trough; especially do they contract in the 

 upper three-tenths. The second subdivision is an inverted 

 truncated cone (about 5°). It has a length of somewhat less 

 than 0.5 total length, and its diameter at the posterior end is 

 somewhat less than 0.64 oral diameter. The sides are even 

 and regular. The third section is, again, an inverted trun- 

 cated cone (46°), with a length of 0.15 total length; its diam- 

 eter at the posterior end is 0.35 oral diameter. Its sides are 

 even, regular, and rounded at their junction with the section 

 above. The lance is a narrow cone (7°) with a length of a 

 little less than o.ii total length. The sides are even and the 

 free tip is minutely rounded. The general contour of the 

 bowl as a whole is laterally concave, and it appears swollen 

 at about 0.33 total length above the aboral region, although 

 it is not actually increased in diameter. The suboral conical 

 region is decidedly asymmetrical, and one side has a generally 

 greater concavity than the other. It is the bulky overhang 

 of this region and its deep concavity that give the effect of 

 aboral swelling to the bowl. 



The wall has a subuniform thickness of 0.03 oral diameter. 

 The cuff is membrane-like, as are also the inner and outer 

 laminae. Between these laminae are large secondary prisms 

 in a single layer. Primary alveoles were not visible. The 

 surface has subhexagonal prismatic structure. These hexa- 

 gons are approximately 16 to 22 across one face of the bowl. 

 In the lance and just underneath the suboral trough the 

 prisms are smaller, more crowded, and less regular in shape. 

 Near the tip of the lance they are altogether wanting. The 

 trough is made up of hyaline material like that of the cufi, 

 with which it is continuous. The cavity of the lorica follows 

 the contour save in the suboral region, where it is more erect 

 and more like the second cone in form. 



Length, total 2291.1, lance 25J.1; diameter, oral 42|.t, shelf 

 54LI; wall thickness, 5[-l. 



Xystonella flemingi shows relationship Co X. acus, but, in 

 addition to dimensional differences, it has a greater suboral 

 overhang, a relatively shorter and stouter lance, and more 

 pronounced secondary wall structure. It differs from X. 

 lanceolata in size and in its relatively shorter lance and 

 greater suboral overhang. From X. lohmanni it differs in 

 all the above characters. It lacks the swollen, angular lance 

 of X. clavata. Its lance is short and blunt, unlike that of 

 X. longicauda, and there is no knob as in X. treforti, X. 

 minuscula, and X. scandens. 



