Plesiocleidochasma cleidostomum (Smitt, 1873)

Judith L Winston, 2016, Bryozoa of Floridan Oculina reefs, Zootaxa 4071 (1), pp. 1-81: 63

publication ID

http://doi.org/10.11646/zootaxa.4071.1.1

publication LSID

lsid:zoobank.org:pub:D47C792F-E91D-40A6-ABB7-FA7810578562

persistent identifier

http://treatment.plazi.org/id/19362D2E-202B-FF8E-BBA5-FE6BFC5AF8BD

treatment provided by

Plazi

scientific name

Plesiocleidochasma cleidostomum (Smitt, 1873)
status

comb. nov.

Plesiocleidochasma cleidostomum (Smitt, 1873)  comb. nov.

( Fig. 35View FIGURE 35; Table 34)

Lepralia cleidostoma Smitt, 1873: 62  , pl. 11, figs 217–219.

Lepralia porcellana: Osburn 1914: 209  .

Hippoporina cleidostoma: Canu & Bassler 1928 a: 104  , pl. 9, fig. 7, pl. 32, fig. 6, text-fig. 18.

Hippoporina porcellana: Osburn 1940: 428  ; Shier 1964: 633.

Cleidochasma porcellanum: Cheetham & Sandberg 1964: 1032  , text-fig. 35; Long & Rucker 1970: 19, fig. 4.2; Winston 1982: 147, fig. 80.

Schedocleidochasma porcellanum: Winston 2005: 87  , figs 244–246.

Material examined. MCZ # 90, syntype of Lepralia cleidostoma  , May 1, 1868, Cast No. 7, 26 fms [off Sombrero Key], L. Pourtales; VMNH no. 70652, 70653, 70654; USNM no. 1283259.

Description. Colonies encrusting, in unilaminar patches to multilaminar mounds. Primary layer of zooids regularly hexagonal; frontally budded zooids irregularly polygonal. Frontal shield smooth to sparsely granular, flat over most of frontal surface ( Fig. 35View FIGURE 35 B), raised around orifice, imperforate except for a few marginal pores. Orifice cleithridiate, rounded distally with proximally directed condyles, and narrow U-shaped sinus. Single or paired adventitious avicularia may occur on umbo proximolateral to orifice; rostra and mandibles acutely triangular ( Fig. 35View FIGURE 35 C). Ovicell hyperstomial, prominent and delicately striated when newly formed, becoming granular and embedded in secondary calcification with age; imperforate, with frontal area in form of a thin curved-edged plate (labellum) between two lateral slits, leaving narrowly transverse opening ( Fig. 35View FIGURE 35 A, B). Embryos reddish-pink.

Discussion. Floridan Plesiocleidochasma cleidostomum  is part of the ‘ Cleidochasma porcellanum  ’ species complex, widely distributed in tropical and subtropical habitats, including the Western Atlantic (see Winston 2005).

Soule, Soule & Chaney (1991) and Cook & Bock (1996) revised the genera and species included in the Cleidochasmatidae  . Winston (2005) placed Smitt’s species in Schedocleidochasma  , but Berning (2012) recently synonymized Schedocleidochasma  under Plesiocleidochasma  , a decision followed here.

Distribution. Cape Hatteras to Florida, Caribbean, and Gulf of Mexico.

TABLE 34. Measurements in mm of Plesiocleidochasma cleidostomum (Smitt, 1873).

Mean 0.321 0.182 0.126 0.054
0.031 0.021
0.288 0.144 0.126 0.054
0.396 0.216 0.126 0.054