Trematooecia rotunda, Almeida & Souza & Menegola & Sanner & Vieira, 2014

Trematooecia rotunda n. sp.

( Fig. 34 View FIGURE 34 , Table 7 View TABLE 7 )

Material examined. Holotype: UFBA 533 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 1994, 26 m. Paratype: UFBA 550 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 2000, 28 m. Additional specimens: UFBA 536 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 2002, 50 m ; UFBA 548 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 2002, 23 m.

Diagnosis. Encrusting Trematooecia with unilamellar colony and elevated elliptical avicularia on tubercles.

Etymology. Latin rotunda , circle, alluding to the rounded autozooids.

Description. Colony encrusting, unilamellar. Zooids hexagonal, becoming rounded-polygonal with increasing calcification, as long as wide, delimited by distinct grooves. Frontal shield heavily calcified, with a few frontal pseudopores and 8–15 marginal areolar pores. Primary orifice large relative to frontal shield, centered, more or less hoof-shaped, wider than long, with arcuate anter and broad concave poster delimited by 2 downcurved condyles at about one-third orifice length. Secondary orifice surrounded by 3–4 (often 4) solid tubercles that frequently bear an elliptical avicularium. Each autozooid with a large suboral tapering umbo. Suboral avicularium absent. Frontal avicularia small ( 0.043 –0.079 mm long, 0.043 –0.068 mm wide), elliptical, single (rarely 2), placed at proximal margin of zooid. Interzooidal avicularium large, rostrum obovate; calcified palate occupying more than half rostral length; foramen rounded. Ooecium subglobose, inclined toward zooid surface, often with 1–3 tubercles and a single avicularium; ectooecium with slit-like membranous area.

Remarks. Trematooecia rotunda n. sp. is distinguished from all congeners by the combination of unilamellar colony and avicularium-bearing tubercles. Related species with encrusting colonies and a slit-like membranous area in the ectooecium are T. clivulata and T. hexagonalis . Trematooecia rotunda n. sp. differs from T. clivulata in having a hoof-shaped primary orifice (transversely D-shaped in T. clivulata ) and obovate interzooidal avicularia (spatulate in T. clivulata ). Differences from T. hexagonalis include frontal shield punctuation (uniformly porous in T. hexagonalis ) and the obovate interzooidal avicularia (absent in T. hexagonalis ).

Distribution. Atlantic: Brazil.