Melicerita atlantica Busk 1884

Melicerita atlantica Busk, 1884

(FIg. 3; TAbLE 5)

Melicerita atlantica BUSK, 1884: 96, PL. 14, FIG. 1.

Material examined. CRBA-58243, STN PAT0209DR04, FRAgMENT 12 MM LONg, 3 MM WIDE, LACKINg DISTAL PORTION. CRBA-58244, STN PAT0209DR04, COLONY 27 MM LONg, 3 MM WIDE. CRBA-58245, STN PAT1108DR11, FRAgMENT C. 16 MM LONg, 2 MM WIDE, LACKINg DISTAL PORTION. Other: SEM MICROgRAPHS OF NHMUK 1887.12.9.438, LECTOTYPE OF Melicerita atlantica BUSK, 1884.

Description. COLONY ERECT, bILAMINAR, COMPRISINg A SINgLE FLATTENED bLADE; OVERALL SIZE NOT KNOWN. AUTOZOOIDS HEXAgONAL, FLAT, SEPARATED bY THIN RIDgES. CRYPTOCYST gRANULAR. OPESIA SITUATED IN DISTAL HALF OF AUTOZOOID, TRANSVERSELY D-SHAPED, WIDER THAN LONg, PROXIMAL bORDER STRAIgHT, WITH TWO DENTICLES CLOSE TO THE CORNERS. OVICELL APERTURE A WEAKLY CRESCENTIC, NARROW TRANSVERSE SLIT AT EXTREME DISTAL END OF AUTOZOOID. AVICULARIA NOT ObSERVED. COLONY ATTACHED bY RHIZOIDS.

n, number of measurements made; SD, standard deviation Remarks. THANKS TO THE COURTESY OF MARY SPENCER JONES (NHMUK), WE WERE AbLE TO EXAMINE SCANNINg ELECTRON MICROgRAPHS OF BUSK’S (1884) MATERIAL OF M. atlantica FROM THE ARgENTINIAN CONTINENTAL SHELF, CONFIRMINg THE IDENTITY OF OUR NEW MATERIAL. THIS SPECIES RESEMbLES M. temaukeli MOYANO, 1997 FROM CHILE IN THE CHARACTERS OF THE OPESIA (TRANSVERSELY D-SHAPED, WIDER THAN LONg, PROXIMAL bORDER STRAIgHT, WITH TWO DENTICLES), bUT M. temaukeli HAS AVICULARIA. M. antarctica D’HONDT, 1985 FROM THE SOUTH INDIAN OCEAN HAS FEWER ZOOIDS IN EACH TRANSVERSE ROW (2–3, COMPARED TO 4–5) AND THE ORIFICE IS HIgHER-ARCHED.