TAXONOMY AND DISTRIBUTION 



71 



Epiplocylis mucronata (Zacharias) Kofoid and Campbell 



(Figures 75, 76) 



Epiplocylis mucronata, Kofoid and Campbell, 1929, p. 183, fig. 

 346. 



The tall, conical lorica, with gradually differentiated aboral 

 born and wide free region, has a length of 2.00 to 2.92 oral 

 diameters. The oral margin is sharp-edged. The long bowl 

 tapers as much as 10° for 1.2 oral diameters and shows some 

 lateral convexity. The lower bowl contracts (45° to 65 ) 

 for r.13 oral diameters, the change in diameter between 

 upper and lower bowls being gradual. The aboral horn is 

 gradually differentiated out of the lower bowl, is conical 

 (22 to 30 ), and has a length of 0.16 to 0.30 oral diameter; 

 its free tip is sharp. 



The wall reaches a maximum thickness of 0.1 oral diam- 

 eter suborally; elsewhere it is reduced to less than one-fifth 

 as much. The laminae, with enclosed alveoles, are thin. 

 The upper bowl is entirely free of lines; subvertical, thick, 

 and unbranched free lines creep to its lower edge from the 

 reticulated region below. The reticulations are coarse, thick- 

 walled, heavy, and not deeply pitted, and on the horn are 

 extended as heavy vertical ridges. 



Length, 175 to 18511. 



The Carnegie loricae are much more gradually contracted 

 at the transition of lower bowl and horn than is typical; 

 there are also strong free lines. 



Epiplocylis mucronata differs from E. obtusa, in which 

 there is a saccular bowl and short, wide horn. It differs 

 from E. blanda in larger size, more taper, and heavier reticu- 

 lum. Epiplocylis sargassensis is generally more conical and 

 wider in the aboral region. Epiplocylis acuminata has a 

 wider suboral thickening and spikelike horn, as well as 

 different mesh. 



Recorded from six stations, three each in the Atlantic and 

 the Pacific, as follows: two (28, 29) in the Atlantic equa- 

 torial region, one (31) in the Caribbean Sea, one (47) in the 

 Galapagos region, and two (64, 65) in the South Pacific 

 middle latitudes. 



There are 8 net samples, of which 2 were taken at the 

 surface, 1 at 50 meters, 4 at 100 meters, and 1 at 1000 

 meters. Maximum frequency, 54 per cent at station 47; 

 other records above minimum (2 to 3 per cent) from stations 

 28, 31, 65; average in Pacific, 14.7 per cent. 



Temperature: Atlantic, 22?56-26?79 (23?94); Pacific, 

 3?98-23?88 (i5?87). Salinity: Atlantic, 36.31-36.63 (36.51); 

 Pacific, 34.30-35.96 (34.79). Density: Atlantic, 23.79-25.22 

 (24.80); Pacific, 24.33-27.23 (25.36). pH: Atlantic, 8.19- 

 8.26 (8.22); Pacific, 7.76-8.23 (8.06). 



Epiplocylis pacifica Kofoid and Campbell 



Epiplocylis pacifica Kofoid and Campbell, 1929, p. 184, fig. 335. 



The fairly tall lorica, with moderately convex conical bowl, 

 short free lines, and long aboral horn, has a length of 1.83 

 oral diameters. The oral margin is thin and erect. The 

 bowl expands from the margin to 1.08 oral diameters at 0.3 

 oral diameter below the rim, and gradually contracts (20 



then 80 c ' in the aboral 0.5 oral diameter) to the aboral end. 

 The aboral horn is narrow conical (12°), nearly 0.46 oral 

 diameter in length, and sharply pointed at its free tip. 



The wall reaches a thickness of 0.09 oral diameter across 

 the thickest part, which is within a band 0.67 oral diameter 

 in width; the lower parts oi the bowl are less than a third 

 as much. The upper region ol the bowl, corresponding to 

 the thickened zone in width, is free ol reticulations. The 

 reticulations of the lower region arc large, commonly sub- 

 pentagonal, with thick walls, and modestly pitted, and have 

 short, unbranched, deflected (20 ) free lines. 



Length, 105 to 1 15(1. 



Epiplocylis pacifica resembles E. constricta, but its bowl is 

 decidedly less convex, its horn is longer, and the free lines 

 are much shorter and less oblique. In general form it is 

 close to E. lata, but it is obviously dillerent in the more 

 diffuse suboral thickening, and in the character of the reticu- 

 lum and its distribution. In some ways it is like E. undella, 

 but it is less wide, with more sharply differentiated horn, 

 and with shorter, deflected free lines. 



Recorded from sixteen stations in the Pacific, as follows: 

 three (35, 36, 99) in the Pacific equatorial region, one (62) 

 in the South Pacific middle latitudes, two (77, 78) in the 

 Galapagos region, four (81, 82, 83, 159) in the region of 

 South Pacific island fields, three (101, 102, 103) in the North 

 Pacific trade region, and three (133, 134, 137) in the Cali- 

 fornia region. 



There are 15 pump and 7 net samples, of which 11 were 

 taken at the surface, 5 at 50 meters, and 6 at 100 meters. 

 Maximum frequency, 7 per cent at station 77; other records 

 above minimum (2 to 5 per cent) from stations 78, 159; 

 average in net samples, 3.1 per cent; in pump samples there 

 were 1 to 4 loricae. 



Temperature: pump samples i3?28-27?93 (24?47), net 

 samples i4?33-28?6o (24^80). Salinity: pump samples 

 31.62-36.49 (34.98), net samples 34.91-36.03 (35.70). Den- 

 sity: pump samples 20.34-24.98 (22.77), net samples 22.77- 

 26.06 (23.79). pH: pump samples 8.06-8.39 (8.25), net 

 samples 7.88-8.37 (8.18). 



Epiplocylis sargassensis (Brandt) Kofoid and Campbell 



Epiplocylis sargassensis, Kofoid and Campbell, 1929, p. 185, 

 fig- 331- 



The moderately elongated, generally conical lorica, with 

 full aboral region and broad horn and lacking free lines, has 

 a length of 1.6 oral diameters. The oral margin is thin and 

 rounded. The bowl tapers (16 ) in its upper 0.52, the 

 diameter at the lower end of this upper section being 0.5 

 oral diameter. The lower bowl is subcorneal (55°), and 

 from its lower end the aboral horn is gradually differen- 

 tiated; this latter becomes narrow conical (20 ), its length 

 is 0.26 oral diameter, and its free tip is blunted. 



The wall reaches as much as 0.03 oral diameter at its 

 thickest, which is near the oral rim. In the middle and 

 lower bowl it is about two-thirds as much. There are thin 

 laminae and enclosed minute alveoles. There are no free 

 lines, but the reticulated region occupies the lower 0.83 oral 



