374 Albany Museuin Records 



to as Ijeing near to Sp. pedroanuH^ Hartt, I do not think that the 

 South African are so closely similar to this American form as to 

 warrant the apijlication of the name. Rathbun*i describes the 

 species as having 10-16 i)lications on each side of the fold or siniis : 

 the words in italics ai-e left out by Reed*^ so that he takes the 

 si)ecies to have from 10-16 ribs in all, instead of 20-32 ribs on each 

 valve. Kayser'' has, since Reed's paper appeared, figured a further 

 scries of S'/tirifer jjedroanns,* and they aiv dll too closely ruled 

 with nari'ow ribs to be like the South African forms, whiU the 

 slight sigmoid trace of the margin differenliates it strongly from 

 the Sp. antarcticus. 



The Spinfer sjj. a. of Reed is a natural i-ei)lacement of the 

 shell by calcite and is a form of fossilization which is very rarely 

 seen. The examples in the Bain collection in the Albany Museum, 

 which are probably duplicates of the slabs examined by Reed in 

 the British Museum, show the impression of the outer surface of 

 the shell together with the internal casts, and both belong to one 

 and the same species, S'p. antarcticus. A few examples with the 

 beak bent back and the mesial fold constricted in the centre and 

 generally of a moi-e rounded form I put down to Sp. (iil)i(j)nji. 



Mr Reed's figures, ojj. cit., PI. XXII., figs. 4 and ."), and PI. 

 XXIIl., figs. 2 and 3, may be taken as tyi)ical. 



Affinities : — S'p. coeJhanus, Kat/er, from Bi-azil, and Sj/. 

 chiiquisaca, Ulrich, from Bolivia. 



Cat. No. 51. Mati'ix, light grey shale easily cut with a knife. 

 Shell normal, but with very low beak ; sinus with slight median 

 fold. Donor : Mv. A. G. Bain. Locality, Warm Bokkeveld. 



Cat. No. o5, 56, 57 and 58. Internal casts of very ileep shells 

 which must have had an enormours thickness of shell substance 

 about the beak. Donor : Unknown. Locality, ^^'arm. Bokkeveld. 



Cat. No. SO. A large slab of Fossiliferous Sandstone crowded 

 with casts and inijiressions of Spliifer <nif(t rdicns ; some of the 



*'Bul]. Buffalo Soc. Nat. Sci., I., 1874, p 238, 



«^0p. cit., p 183. 



^Neues Jahrbxich ; Beil. Bel., 1893, YIII , p. G5, p IV., figs. 19-20. 



^Gruiidzuge d. Geol. d. unteren Amazcnasgebietes, Leipzig, 1903. 



