Orthoporidra Canu & Bassler 1927

Orthoporidra nova n. sp.

(FIg. 22; TAbLE 24)

Etymology. LATIN ‘ nΟνus ’, NEW.

Material examined. HΟlΟtype: CRBA-58252, STN PAT 1208DR11, LARgEST OF FOUR FRAgMENTS FROM ONE COLONY, C. 2 MM LONg, 7 MM WIDE.

Description. COLONY RObUST, CONSISTINg OF CYLINDRICAL bRANCHES, OVERALL SIZE NOT KNOWN. AUTOZOOIDS CONVEX, OPENINg ON ALL SURFACES OF THE bRANCH. CALCIFICATION THICK AND SMOOTH, WITH FEW SMALL AREOLAR PORES, USUALLY AROUND AUTOZOOIDAL MARgINS. PRIMARY ORIFICE AS WIDE AS LONg, DISTAL EDgE NOTCHED MEDIALLY, WITH bROAD, DEEP CONDYLES DEFININg A NARROW, U-SHAPED SINUS. PERISTOME LOW AND THICK, NOT ENTIRELY ObSCURINg PRIMARY ORIFICE; PERISTOMIAL AVICULARIUM COLUMNAR, WITH ELONgATE-TRIANgULAR, DISTALLY DIRECTED LARgE AVICULARIUM WITH A HASTATE MANDIbLE AT THE APEX, ROSTRUM HOOKED AT THE TIP. ADDITIONALLY, A LARgE, NON-COLUMNAR, SPATULATE AVICULARIUM. A SMALL PERISTOMIAL AVICULARIUM PROXIMAL TO THE ORIFICE SEEMS TO bE PRESENT, ALTHOUgH NOT SEEN bECAUSE ALL THE PERISTOMES ARE bROKEN. OVICELL SUbSPHERICAL, CUCULLATE WITH A LARgE OPENINg, MOSTLY CONCEALED bY SMOOTH SECONDARY CALCIFICATION, WITH THIN SMOOTH PROXIMOFRONTAL RIM OF ECTOOECIUM PROjECTINg bEYOND SECONDARY CALCIFICATION, AbOVE THE OPENINg.

Remarks. OrthΟpΟridra nΟνa n. sp. IS THE SIXTH DESCRIbED SPECIES OF THE gENUS. IT RESEMbLES O. brachyrhyncha MOYANO, 1985 FROM ANTARCTICA AND O. stenΟrhyncha MOYANO, 1985 FROM SOUTH AMERICA IN HAVINg A DISTINCT SINUS, bUT ONLY IN O. nΟνa n. sp. IS THE SINUS PERFECTLY U-SHAPED. O. nΟνa n. sp. ALSO DIFFERS IN HAVINg TWO TYPES OF LARgE AVICULARIA, ONE WITH A HASTATE MANDIbLE AND THE OTHER WITH A NARROW-bASED SPATULATE MANDIbLE.

n, number of measurements made; SD, standard deviation.