Cyamon Gray 1867

Figure 4.Cyamon amphipolyactinum sp. n., holotype ZMA Por. 22412, A shape (arrow) encrusting a fragment of sandstone (scale 1 cm) B long thin style B1 details of apices of long thin style C short thin style C1 details of apices of short thin style D short thick styles showing size variation D1 detail of head of short thick style E polyactines (three-, four-, five-, and seven-claded) and one amphipolyactine showing size differences E1 detail of bulbous end of lateral cladus F amphipolyactines full-grown and spined (left) next to incipient smooth spicule (right).

Holotype AHF-NHMLA D34, A: shape (scale mm) (photo Phyllis Sun), B: microphoto of cross section of skeleton showing columns of styles supported by polyactines, C: microphoto of a range of polyactine shapes.

Figure 5.Map showing locality off the Mauritanian coast, where Cyamon amphipolyactinum sp. n. and Cyamon arguinense sp. n. were collected during the Netherlands Mauritania II Expedition, June 1988.

Holotype AHF-NHMLA D34, A: detail of head of long thin style, B: short thick style, B1 detail of head of short thick style, C: short thin centrotylote (strongylo-)style, C1 detail of spined apex of short thin (strongylo-)style, C2 detail of centrotylote part of short thin (strongylo-)style, D: polyactines, D1 heavily spined basal cladus of polyactine, D2 lightly spined lateral cladus of polyactine, E: diactine polyactines.

Holotype ZMA Por. 22412 encrusting a stone and SEM images of spicules. A: shape (arrow) encrusting a fragment of sandstone (scale 1 cm), B: long thin style B1 details of apices of long thin style, C: short thin style C1 details of apices of short thin style, D: short thick styles showing size variation, D1 detail of head of short thick style, E: polyactines (three-, four-, five-, and seven-claded) and one amphipolyactine showing size differences, E1 detail of bulbous end of lateral cladus, F: amphipolyactines full-grown and spined (left) next to incipient smooth spicule (right).

Figure 5.Map showing locality off the Mauritanian coast, where Cyamon amphipolyactinum sp. n. and Cyamon arguinense sp. n. were collected during the Netherlands Mauritania II Expedition, June 1988.

Holotype SMF 1618, A: fragments from holotype, B: long thin style (broken), B1 detail of head of long thin style, C: short thin style, C1 detail of head of short thin style, D short thick style, D1 detail of head of short thick style, E polyactines (From Van Soest et al. 2012).

Holotype ZMA Por. 06723 encrusting a stone, and SEM images of the spicules. A: shape (arrow) encrusting a fragment of sandstone (scale 1 cm), B: subtylostyle, B1 details of apices of subtylostyle, C: short thin centrotylote style, C1 details of apices and middle part of short thin centrotylote style, D: polyactines.

Figure 6.Cyamon arguinense sp. n., holotype ZMA Por. 06723, A shape (arrow) encrusting a fragment of sandstone (scale 1 cm) B subtylostyle B1 details of apices of subtylostyle C short thin centrotylote style C1 details of apices and middle part of short thin centrotylote style D polyactines.

Habit and SEM images of spicules, A1: Californian holotype, USNM 33630, encrusting a rock (scale = 1 cm), A2: Mexican Pacific specimen LEB-ICML-UNAM 1497, B cross section of peripheral region, C: thick section of basal mass of polyactines, D: fragments of long thin style, D1 microphoto of detail of rounded apex of long thin style, E: short thin style, F: short thick styles, G: three- to five-claded polyactines showing prominent bulbous ending of lateral cladi.

Holotype slide BMNH 1931.1.1.19a and microphotos of skeleton and polyactine. A: slide labeled ‘Cyamon vickersii (Bow.) Ind. Mus. Coll.’ in Burton’s handwriting, B: microphoto of section of skeleton made from the slide, C: characteristic polyactine with recurved hooklike spines on basal cladus and short stubby lateral cladi.

Figure 15.Cyamon hamatum sp. n. (Cyamon vickersii sensu Burton and Rao 1932), from S India, A slide BMNH 1931.1.1.19a, labeled ‘Cyamon vickersii (Bow.) Ind. Mus. Coll.’ in Burton’s handwriting B microphoto of section of skeleton made from the slide C characteristic polyactine with recurved hook-like spines on basal cladus and short stubby lateral cladi.

Holotype USNM 21412, A: massively encrusting shape with irregular surface (scale = 1 cm), B: long thin style, B1 detail of rounded end showing subterminal tyle, C: short thin centrotylote (strongylo-)style C1 detail of swollen roughened apex of short thin (strongylo-)style, D: short thick style, E: polyactines, E1 detail of basal cladus of polyactine, F diactinal polyactine.

Photo from one of Dendy's non-type slides showing polyactine with spined basal cladus and smooth lateral cladi.