TAXONOMY AND DISTRIBUTION 



67 



of the howl. This section has full, convex sides formed by 

 low arcs. It forms an angular junction with the lowest 

 level of the conical subdivision of the bowl above it. The 

 aboral horn is a short, conical peg (30 ), the length of which 

 is only 0.16 oral diameter. 



The wall is thickened in the suboral region and the band. 

 Its greatest thickness in these places is 0.14 oral diameter. In 

 the bowl it is much thinner, being less than 0.04, more or 

 less subuniformly at all levels. The wall is filled with small, 

 irregularly arranged secondary prisms which crowd upon 

 one another so that no two are shaped alike. In the thinner 

 region of the bowl there are fewer layers of prisms than in 

 the superstructure. The outer wall is differentiated into two 

 zones by the patterning. Of these, the anterior one is the 

 narrower band. This begins at the upper edge of the suboral 

 band and continues to the oral margin. It is made up of 

 faint, roughly hexagonal prisms, about 10 in number in a 

 vertical line and approximately 60 in number across the face 

 of the bowl. They increase in size and prominence as they 

 reach the suboral ledge, and an exact plane of division be- 

 tween them and the coarse reticulum below becomes difficult. 

 The coarse surface reticulum which incrusts the posterior 

 0.85 of the bowl is made up of a prevailingly pentagonal to 

 hexagonal meshwork. The nearly uniform framework which 

 surrounds the depressed areas is heavy and thick, and gives 

 the lorica a clumsy appearance. There are 12 to 16 meshes 

 in a vertical line and about 20 to 26 across the bowl. The 

 mesh continues over the basal part of the aboral horn, but 

 the free end is devoid of extra structure. The lumen of the 

 upper bowl is a cylinder with a length of about 0.26 oral 

 diameter. Below this level it is a basal segment of a cone 

 (about 6o°) with a length of nearly 0.26 oral diameter. It 

 then follows the outer contour reasonably closely to the 

 lower end of the bowl. The horn is solid. 



Length, bowl 10011, horn 12. 5|A; diameter, oral 56.211, 

 maximum 8ij.i, lower bowl 63U.; wall thickness, 8(x. 



The shape of the lower bowl varies. Though having a 

 general tendency to be squarish, it may narrow and be more 

 or less conical. Such loricae recall Epiplocylis semireticulata. 

 The thickened zone is wider in some loricae than in others, 

 and the inner side of the throat, though typically vertical, 

 may flare outward. The surface reticulations are thicker- 

 walled and coarser in some individuals than in the general 

 run. 



Epiplocylis carnegiei is close to E. semireticulata, but dif- 

 fers from that species in more contracted oral aperture, rela- 

 tively shorter aboral horn, and less coarse reticulum. Loricae 

 from this collection have greater suboral contraction than the 

 loricae figured by Brandt (1906, pi. 58, fig. 9) and their 

 lower ends are squarish in form; otherwise they are similar. 

 This species differs from E. acuminata in its more definitely 

 oblong shape and short horn as well as in its finer and 

 heavier reticulum. The aboral horn of acuminata is nearly 

 0.33 total length in length. 



Epiplocylis semireticulata was described by Biedermann 

 (1893) and has had a checkered career, which has been 

 summed up by Kofoid and Campbell (1929). In the present 

 report it is considered as distinct from E. acuminata, with 



which the latest authors have put it. Perhaps Brandt'-, 

 lorica belongs to carnegiei and not to semireticulata; the 

 djfferences may be only minor ones within the limits of a 

 single species. 



Recorded from five stations in the Atlantic, as follows: 

 two (3, 4) in the Atlantic drill, and three (14, 15, 16) in 

 the Gulf Stream. 



There are 4 pump and 5 net samples, oi which 2 were 

 taken at the surface, 3 at 50 meters, and 4 at 100 meters. 

 Maximum frequency, 7 per cent at station 3; other records 

 above minimum ( 2 to 3 per cent) trom station 16; average 

 in net samples, 3.6 per cent. 



Temperature: pump samples 14^02-24^81 (20?52), net 

 samples i3?37~23?64 (i6?35). Salinity: pump samples 

 35.59-36.48 (36.21), net samples 35.88-36.41 (36.02). Den- 

 sity: pump samples 24.47-26.66 (25.49), net samples 24.84- 

 27.01 (26.40). pH: pump samples 8.06-8.23 (8-i6), net 

 samples 8.10-8.23 (8.15). 



Type locality, station 3, at 50 meters; latitude 44 00' 

 north, longitude 36 10' west. 



Epiplocylis constricta Kofoid and Campbell 



Epiplocylis constricta Kofoid and Campbell, 1929, p. 177, fig. 

 333; Marshall, 1934, p. 643. 



The fairly short, rotund lorica, with short free lines and 

 narrow aboral horn, has a length of 1.72 oral diameters. 

 The oral margin is thin and rounded. The bowl is dis- 

 tinctly rotund, expanding from the rim (12 ) for 0.64 total 

 length and reaching 1.09 oral diameters at that level. The 

 aboral part contracts convexly (33 increasing to 8o° pos- 

 teriorly) and the aboral horn arises from its lowermost end. 

 The horn is conical (18 ) and nearly 0.55 oral diameter in 

 length, and has a sharp free tip. 



The wall has a maximum thickness of 0.07 oral diameter 

 in the suboral region and thins to less than a third as much 

 aborally. There are thin, homogeneous laminae with en- 

 closed tiny alveoles. The reticulated region occupies the 

 aboral half of the bowl, and above that level the free lines 

 arise. The short free lines are deflected (15 to 50 ) toward 

 the left; the reticulations are thick-walled, subcircular, and 

 often overlapping, and on the upper horn are heavy vertical 

 lines. 



Length, 93 to ii2p. 



Epiplocylis constricta has shorter tree lines than E. de- 

 flexa, and no oral flare. In E. inconspicuata the deflected 

 free lines extend much farther on the wider bowl. Other 

 related species have subvertical free lines. 



Recorded from twenty-six stations in the Pacific, as fol- 

 lows: one (54) in the South Pacific middle latitudes, eight 

 (82, 83, 84, 85, 157, 158, 159, 160) in the region of South 

 Pacific island fields, four (100, 109, 140, 150) in the North 

 Pacific trade region, three (113, 142, 145) in the North 

 Pacific middle latitudes, five (137, 146. 147, 148, 149) in the 

 California region, and five (152, 153, 154, 155, 156) in the 

 Pacific equatorial region. 



There are 15 pump and 25 net samples, of which 8 were 

 taken at the surface, 16 at 50 meters, and 16 at ioo meters. 



