Benson, 1966, p. 321-324 (in part); pl. 22, figs. 15-16 (not figs. 17-18): Ceratospyris polygona Haeckel Ceratospyris polygona Haeckel, 1887, Challenger Rept., Zool., Vol. 18, pp. 1066-1067, Pl. 86, fig. 1; Popofsky, 1913, Deutsche Südpolar-Exped., vol. 14, pp . 305-308, P1. 30, fig. 1 ; text figs. 23-25. Ceratospyris mulderi Haeckel, 1887, Challenger Rept., Zool., vol. l8, p.1067, Pl. 86, fig. 4. Ceratospyris
allmersii Haeckel, 1887, Challenger Rept., Zool., vol. 18, p.1067, Pl. 86, fig. 3. Ceratospvris strasburgeri Haeckel, 1887, Challenger Rept., Zool., vol. 18, pp. 1067-1068, Pl. 86, fig. 2. Ceratospyris mulderi H.?, Popofsky, 1913, Deutsche Südpolar-Exped., vol. 14, pp. 308-309, text fig. 26. Three variations of the bilocular cephalis are present in this species. The majority of specimens have large polygonal pores separated by three-bladed intervening bars from the nodes of which arise three-bladed spines (Pl. 22, figs. 15-16). The number and size of pores are variable; two pairs of large pores are present on the dorsal, upper, and ventral sides of the sagittal constriction, the pores of each pair separated by the sagittal ring. The second form has the large polygonal pores on either side of the sagittal ring that are separated by three-bladed bars, but the lateral portion of each lobe is composed of a smooth, rounded, small-pored lattice (Pl. 22, fig. 18). The third variation of the cephalis is represented by a few specimens having large, subequal, circular pores, but the intervening bars separating them have traces of a three-bladed cross-sectional shape (Pl. 22, fig. 17); most of these specimens have spines arising from the nodes of the intervening bars; this form may represent a response to an increase in dissolved silica in the surface waters of the Gulf. All three types of cephalis have the same structure of the collar ring and sagittal ring. Four large collar pores, cardinal and cervical pores, are similar in size to those of Petalospyris
cf. ophirensis but with polygonal outline and separated by three-bladed, not cylindrical, bars. In fully developed forms, seven downward-divergent, three-bladed to conical feet of variable length arise at an angle from the collar ring, and correspond to the dorsal, secondary lateral, cardinal, and primary lateral feet or spines of P. cf. ophirensis. A pair of nearly horizontal, three-bladed to conical, ventrally extending spines are present in most specimens, each spine originating from the ventro-lateral corner of the collar ring as in P. cf. ophirensis. The primary and secondary lateral bars extend as and are collinear with short, thin, three-bladed to conical spines. Sagittal ring three-bladed, with one blade in the sagittal plane projecting inward, two blades extending laterally outwards from which originate the bars of the latticed cephalis; ring approximately D-shaped but asymmetrical; median bar short, generally cylindrical, with a short axial thorn; a three-bladed to conical apical spine of variable length extends from and is collinear with the vertical, straight apical bar; in all tests a pair of laterally ascending accessory spines are present, each spine originating from the base of the apical spine on its right and left, in their proximal portions represented by intervening bars separating the upper dorsal pair of sagittal cephalic pores from the dorsal pair of sagittal pores of the upper face of the cephalis; a. three-bladed to conical vertical spine of variable length extends from and is collinear with the vertical bar of the sagittal ring. Measurements; based on 30 specimens from stations 92 and 93: sagittal height of cephalis 50-82 µm, maximum breadth 96-163 µm; length of feet 5-100 µm (generally 20-40 µm), of apical spine 3-15 µm, of vertical spine 5-25 µm. Remarks. The species listed in the synonymy are all characterized by three-bladed bars and spines and a variable but maximum number of seven three-bladed feet or short spines corresponding to feet. The number and size of polygonal pores of the cephalis are not constant within the Gulf species. The above species were separated by Haeckel on the basis of these variable characters; therefore, they were placed in synonymy. The three variations of the latticed cephalis may represent subspecies but most likely represent individual variations. All three types were considered as belonging to the same species because they have the same structure of the sagittal and collar rings and the same number of feet and primary spines. Distribution. This species is cosmopolitan in the Gulf but rare at all stations where it occurs except 115 where it is common (2.6%). It is absent at stations 64, 130, 184, 194, and all those to the north. It has a greater frequency in the axial portion of the Gulf and does not appear to respond to upwelling because it is absent or very rare at stations located within regions of upwelling. It has about the same average frequency throughout the entire Gulf but prefers an offshore Habitat. Haeckel (1887, p. 1067) states that C. polygona is cosmopolitan, occurring at the surface of the Atlantic, Pacific, and Indian Oceans. Popofsky (1913, p. 307) reported the same species from the tropical part of the western Indian Ocean and from the equatorial Atlantic. C. mulderi Haeckel (1887, p. 1067) was reported from the Indian Ocean in the Sunda Straits. Popofsky (1913, p. 309) reported the same species from the tropical part of the western Indian Ocean. C. allmersii Haeckel (1887, p . 1067) was reported from the tropical Atlantic at "Challenger" station 347. C. strasburgerii Haeckel (1887, p. 1068) was reported from the western tropical Pacific at "Challenger" station 225. The species from the Gulf, therefore, is cosmopolitan in recent tropical seas.