Spigaleos simplex n. sp.

(FIg. 18; TAbLE 20)

Etymology. LATIN ‘ simplex ’, SIMPLE, ALLUDINg TO THE AbSENCE OF AN AVICULARIUM.

Material examined. HΟlΟtype: CRBA-58263, STN PAT0209DR15, COLONY FRAgMENT C. 20 MM LONg, 1 MM WIDE, LACKINg PROXIMAL AND DISTAL PORTIONS.

Description. COLONY ERECT, DICHOTOMOUSLY bRANCHINg, THE bRANCHES CYLINDRICAL; OVERALL SIZE NOT KNOWN. AUTOZOOIDS IN SPIRAL WHORLS OF FOUR, ELONgATE, CONVEX, SEPARATED bY FAINT gROOVES. FRONTAL WALL FINELY gRANULAR; MARgINAL PORES SMALL, SIDES LONgITUDINALLY TAPERINg. PRIMARY ORIFICE WIDER THAN LONg, PROXIMAL EDgE WITH A SHORT U- SHAPED SINUS. NO ORAL SPINES. PERISTOME DEEP, CONCEALINg ORIFICE. NO AVICULARIA. OVICELLS NOT PRESENT IN THE AVAILAbLE MATERIAL. BASAL SURFACE OF COLONY WITH SCATTERED PORES bUT NO SUTURES.

Remarks. SpigaleΟs simplex n. sp. REPRESENTS THE FOURTH SPECIES OF THE gENUS AND THE FIRST RECORD IN THE PATAgONIAN REgION (PREVIOUSLY REPORTED ONLY IN ANTARCTICA). ALTHOUgH HAYWARD (1992) DESCRIbED SUbORAL AVICULARIA AS AN IMPORTANT gENERIC CHARACTER, S. simplex HAS OTHER SHARED CHARACTERS WITH SpigaleΟs: ERECT COLONY DICHOTOMOUSLY bRANCHINg, CYLINDRICAL STEMS, AUTOZOOIDS IN WHORLS OF FOUR, FRONTAL WALL WITH MARgINAL PORES, PRIMARY ORIFICE WITH A MEDIO-PROXIMAL SINUS AND NO ORAL SPINES. IT IS DISTINgUISHED FROM THE TYPE SPECIES ESPECIALLY IN THE AbSENCE OF A SUbORAL AVICULARIUM. THE CHARACTER OF THE ORIFICE RESEMbLES THAT IN S. elegans DE BLAUWE & GORDON, 2014 AND S. striatula HAYWARD & WINSTON, 2011 IN WHICH THE PRIMARY ORIFICE IS WIDER THAN LONg, AND S. hΟrnerΟides (WATERS, 1904) WITH A U-SHAPED SINUS. THE NEW SPECIES HAS A FINELY gRANULAR FRONTAL WALL AS IN S. hΟrnerΟides.

n, number of measurements made; SD, standard deviation