TAXONOMY AND DISTRIBUTION 



*7 



South Pacific island fields, one (54) in the South Pacific- 

 middle latitudes, one (99) in the Pacific equatorial region, 

 and one ( 100) in the North Pacific trade region. Codonopsis 

 (Alula has a limited distribution in the central Pacific. 



There are 5 net samples, of which 2 were taken at the 

 surface, 1 at 50 meters, and 2 at 100 meters. Maximum 

 frequency, 4 per cent at stations 48, 54; elsewhere, minimum 

 only; average, 2.5 per cent. 



Temperature, i8?74~27?84 (24:35); salinity, 34.71-36.44 

 (35.50): density, 22.31-25.37 (23. 89); pH, 8.16-8.23 (8.21). 



CYTTAROCYLIDAE Kofoid and Campbell 



Cyttarocylidae Kofoid and Campbell, 1929, p. 108. 



Only one genus is included in this family, and this one is 

 allied to the higher members of the Codonellidae. It is 

 exclusively eupelagic, mostly in warmer seas. 



CYTTAROCYLIS Fol emended 

 Cyttarocylis, Kofoid and Campbell, 1929, p. 109. 



Cyttarocylis is an isolated genus with some alliance to 

 Codonella, with which it agrees in general, although more 

 complex and finished in form and wall structure. 



Cyttarocylis is widely distributed in warm seas as well as 

 in more temperate waters. It does not enter the Arctic 

 Ocean, although Cyttarocylis magna occurs in Mutsu Bay to 

 the north, and as far south as below Australia. The majority 

 of the species are tropical but not limited to either of the 

 oceans investigated in this report. 



Nine species are described. 



Cyttarocylis acutiformis Kofoid and Campbell 



(Figures 35, 36, 37, 45, 48) 



Cyttarocylis acutiformis Kofoid and Campbell, 1929, p. ill, fig. 

 221. 



The elongated, conical lorica, with flaring, distinct collar 

 and pointed aboral end, has a length of 1.78 to 2.35 (2.07) 

 oral diameters. The oral margin is minutely denticulate 

 with about 70 triangular, sharply pointed denticles, ragged 

 in a few instances, or with few larger, outward-directed 

 teeth. The collar is a basal segment of an inverted truncated 

 cone (40 to 50 ), with a length of 0.12 to 0.15 total length. 

 The sides of the collar are usually flattened or, in very per- 

 fect individuals, flat sigmoid. The nuchal shelf reduces the 

 aperture between collar and bowl to 0.77 oral diameter. It 

 is triangular and horizontal, with barely concave sides. The 

 long, conical bowl is slightly convex (about 30 ); it is 25 

 near the throat and for 0.67 of the length, and 35 ° in the 

 aboral region. The latter region is sharply pointed to 

 minutely truncated and always ends as an open canal which 

 in a few individuals may be relatively wide open. 



The wall has about 56 to 60 polygons across one face and 

 75 to 90 from rim to tip. These polygons are mostly minute, 

 and prevailingly pentagonal to hexagonal, with some tri- 

 angular ones. Large and small reticulations are inter- 

 mingled, but, in general, they are larger below the throat 



and in the upper three-tenths ol the bowl. There are one or 

 two rows of large polygons in the collar and several rows of 

 smaller ones, especially immediately below the oral rim. 

 The wall is thickest in the upper part of the bowl, being 0.04 

 oral diameter at the most. It is only barely thinner in the 

 lower bowl. Only a single layer of rectangular prisms occurs 

 except in the nuchal shelf, where there are two layers of pen- 

 tagons. The cavity of the lorica conforms to the outer con- 

 tour closely save as the nuchal shelf constricts the opening. 

 The narrow aboral canal is usually a tube. 



There are 20 macronuclei, and zooxanthellae are present. 

 The membranelles are large blades. 



Length, 213 to 326 (228.6) p.. 



The five loricae figured are extremes picked out from a 

 large number of specimens. The oral margin, flare of collar, 

 shape of bowl, and shape of aboral end are the principal 

 characters subject to variation. These loricae are longer and 

 less stout than those originally described by Kofoid and 

 Campbell, which are 200 to 257P in length, 1.54 to 1.96 oral 

 diameters. Possibly these came from cooler waters. The 

 fine meshwork is a most uniform character. 



Cyttarocylis acutiformis is most like C. magna, but is 

 generally smaller, with a more slender bowl, a more clearly 

 flaring collar, and finer reticulations. It resembles C. cassis, 

 but is greatly elongated and less convex, and lacks a terminal 

 peg; its surface is more finely reticulated. The aboral end 

 is not truncated like that of C. conica, and the bowl is not 

 so full. It lacks the aboral contraction of both C. mucronata 

 and C. obtusa. 



Recorded from thirty-one stations, twelve in the Atlantic 

 and nineteen in the Pacific, as follows: two (2, 16) in the 

 Gulf Stream, two (17, 20) in the Sargasso Sea, seven (22, 23, 

 24, 25, 27, 28, 30) in the Atlantic equatorial region, one (34) 

 in the Caribbean Sea, six (45, 46, 47, 75, 78, 80) in the Gala- 

 pagos region, two (84, 85) in the region of South Pacific 

 island fields, one (64) in the South Pacific middle latitudes, 

 three (113, 144, 145) in the North Pacific middle latitudes, 

 five (131, 137, 146, 148, 149) in the California region, and 

 two ( 150, 151 ) in the North Pacific trade region. 



There are 7 pump and 28 net samples, of which 2 were 

 taken at the surface, 18 at 50 meters, and 15 at 100 meters. 

 Maximum frequency 43 per cent at station 23 at 100 meters; 

 other records above minimum (2 to 42 per cent) from sta- 

 tions 2, 16, 17, 22, 23, 25, 27, 28, 30, 34, 45, 75, 80, 131, 137, 

 145, 146, 148, 149, 150, 151; averages, 1.5 and 1.0 loricae in 

 Atlantic and Pacific pump samples, and 11.6 and 3.6 per cent 

 in Atlantic and Pacific net samples, respectively. 



Temperature: Atlantic, pump samples i4?6o-2i?49( i8?04), 

 net samples i4?6o-36?02 (22^07); Pacific, i7?46-26?o6 

 (2i?52) and i2?i2-27?89 (2t?48), respectively. Salinity: 

 Atlantic, pump samples 35.70-36.02 (35.86), net samples 

 35.61-36.73 (36.21); Pacific, 34.42-36.17 (35.34) and 34.32- 

 36.42 (35.14), respectively. Density: Atlantic, pump samples 

 25.15-26.62 (25.88), net samples 23.79-26.62 (25.24); Pacific, 

 23.42-25.11 (24.43) anc ^ 22-48—25.55 (24.75), respectively. 

 pH: Atlantic, pump samples 7.93-8.22 (8.07), net samples 

 7.93-8.30 (8.18); Pacific, 8.14-8.33 (8.22) and 8.10-8.38 

 (8.34), respectively. 



