. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. PLIOCENE MARINE INVERTEBRATES FROM LANGEBAANWEG I 83 Material Five specimens, of similar size, largest with longest diameter 13,2 mm, altitude 5,0 mm. L14187/P. Remarks The possibility exists that the present material belongs to the Patellidae, but several factors give an impression of Siphonaria rather than Patella. These factors include the small size, the raised dome-like central portion with its faint groove possibly indicating the position of the siphon. Of the Patellidae the present mate
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. PLIOCENE MARINE INVERTEBRATES FROM LANGEBAANWEG I 83 Material Five specimens, of similar size, largest with longest diameter 13,2 mm, altitude 5,0 mm. L14187/P. Remarks The possibility exists that the present material belongs to the Patellidae, but several factors give an impression of Siphonaria rather than Patella. These factors include the small size, the raised dome-like central portion with its faint groove possibly indicating the position of the siphon. Of the Patellidae the present material resembles juveniles of P. longicosta (and less obviously P. oculiis) particularly in the external ribbing. The internal doming, however, is unlike these species which are very flat when juveniles. It is also unusual, if these are Patellas, that only juveniles of a particular growth size should occur, with no sign of adult specimens, although adults of another species of Patella do occur. Of the known species of Siphonaria, the present material most closely resembles S. deflexa and particularly the variety cyanomacidata. This latter species also has strong radial ribs, but usually these are more numerous (15-20 as opposed to 9-12). S. deflexa has a present-day distribution from Natal to the Cape Peninsula and has been recorded from the Pleistocene of the Algoa Bay Fig. 7. Siphonaria sp. Class PELECYPODA Family Donacidae Donax cf. serra (Chemnitz) Fig. 8 Description Shell typically donaciform; posterior face set at angle to rest of shell, but not separated by strong ridge, with numerous fine concentric serrulations. Few very faint radial grooves just anterior to posterior face, further radial lines visible below surface layer, margin slightly undulate. Apex smoothly rounded. Maximim apex-to-posterior margin distance only slightly shorter than distance of apex-to-anterior Please note that these images are extracted from scanned page images that may have been d
Size: 1373px × 1820px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
