. Bulletin of the British Museum (Natural History). 256 C. P. NUTTALL Remarks. Neither Pilsbry & Olsson's (1935) text nor their extensively retouched and cut-out illustrations suggest that the type material of Hemisinus (Verena) avus consists of numerous broken moulds associated with Longiverena and Pachydon in blocks of decalcified mudstone. Parodiz (1969: 140) tentatively assigned this species to Pyrgulifera but re-examination of this material establishes that the original placement of it in Verena was correct. V. laevicarina from the same formation appears to be synony- mous.
. Bulletin of the British Museum (Natural History). 256 C. P. NUTTALL Remarks. Neither Pilsbry & Olsson's (1935) text nor their extensively retouched and cut-out illustrations suggest that the type material of Hemisinus (Verena) avus consists of numerous broken moulds associated with Longiverena and Pachydon in blocks of decalcified mudstone. Parodiz (1969: 140) tentatively assigned this species to Pyrgulifera but re-examination of this material establishes that the original placement of it in Verena was correct. V. laevicarina from the same formation appears to be synony- mous. Its type material consists of worn, semi-decorticated, shells in a coarse sandstone. The very strongly carinate shoulder appears to be a preservational feature and traces of spiral ribbing typical of Verena may be seen on these speci- mens. None of the available specimens of V. crenocarina ava attains the size of the very similar living V. crenocarina, Several apparent differences such as spire angle and whorl profile are features which appear to change with growth. At present the two are treated as being distinct, with V. creno- carina, s. sir. being distinguished by its less crenulate carina at the shoulder. Verenaguaduasensis (Anderson, 1928) Fig. 277 *v 1928 Ampullaria guaduasensis Anderson: 23; pi. 1, figs 19,20. 1977 Pomacea quaduasensis (Anderson) [sic] Boss & Parodiz: 109. HoLOTYPE. CAS 2721, 'Eocene . . Guaduas Beds, near San Juan de Rio Seco, upper valley of Rio Magdalena' (Anderson 1928). This is probably Santa Teresa Formation of late Oligocene to early Miocene age, possibly at km 106, Cambao to Bogota highway (Butler 1939, 1942; Porta 1966). No other Fig. 277 Verena guaduasensis (Anderson). CAS 2721, internal mould; holotype of Ampullaria guaduasensis Anderson, figured by Anderson (1928: pi. 1, figs 19, 20), originally described as being from the supposedly Eocene Guaduas Beds from near San Juan de Rio Seco, but probably from the late Oligocen
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