Fenestrulina curviscutum Figuerola & Gordon & Cristobo 2018, n. sp.

Fenestrulina curviscutum n. sp.

(FIg. 14; TAbLE 16)

Etymology. LATIN ‘ curνus ’, CURVED, AND ‘ scutum ’, SHIELD, ALLUDINg TO THE CONCAVE RIDgE THAT ENCLOSES THE ASCOPORE; USED AS A NOUN IN APPOSITION.

Material examined. HΟlΟtype: CRBA-58232, STN PAT1008BC24, COLONY C. 5 MM LONg, 2 MM WIDE, ENCRUSTINg CORAL.

Description. COLONY ENCRUSTINg; COLONY SIZE C. 5 MM LONg, 2 MM WIDE. ZOOIDS LARgE, VERY CONVEX, FRONTAL SHIELD IMPERFORATE CENTRALLY, SMOOTH, RISINg TO A SUbORIFICIAL RIDgE THAT ENCLOSES THE ASCOPORE AND 2–4 PSEUDOPORES; AbOUT 9 SMALL AREOLAR PORES ALONg EACH LATERAL MARgIN; ASCOPORE SUbORAL, NON-DENTICULATE, SEPARATED FROM THE PROXIMAL ORIFICIAL RIM bY A SMOOTH NARROW AREA. A bOUNDARY bETWEEN THE CRYPTOCYSTAL CALCIFICATION OF THE FRONTAL SHIELD AND THE gYMNOCYSTAL CALCIFICATION OF THE VERTICAL WALLS. PRIMARY ORIFICE TRANSVERSELY D-SHAPED, WIDER THAN LONg. SIX ORAL SPINES. OVICELL PROMINENT, SMOOTH, DISTAL MARgIN PERFORATED bY PORES THAT COMMUNICATE WITH OOECIAL COELOM.

Remarks. Fenestrulina curνiscutum n. sp. IS EXCEPTIONAL IN THE gENUS FOR THE EXTREME REDUCTION OF THE SUbORAL AREA THAT ENCLOSES THE ASCOPORE AND A FEW ADjACENT PSEUDOPORES; NONE OCCURS bETWEEN THE ASCOPORE AND ORIFICIAL RIM. IN MANY SPECIES OF Fenestrulina THE MARgINAL AREOLAR PSEUDOPORES HAVE COMPLEX RADII, LIKE THE PORES THAT OCCUR PROXIMAL TO THE ORIFICE AND OFTEN ELSEWHERE IN THE FRONTAL SHIELD. IN F. curνiscutum n. sp. ALL PORES ARE SIMPLE, LACKINg RADII. THE RIDgE THAT ENCLOSES THE ASCOPORE IS UNUSUAL IN EXTENDINg AROUND THE PROXIMAL PART OF THE ORIFICE. HOWEVER, THE ANTARCTIC SPECIES F. asperula HAYWARD & WINSTON, 2011 HAS A RIDgED bORDER ENCIRCLINg THE ASCOPORE.

n, number of measurements made; SD, standard deviation