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TERTIARY FAUNA OF FLORIDA 



ribs, the intervening ones being free from spines, longitudinally finely striate, 

 and show when very perfect minute scales. The adult shell is rather short 

 and rounded and less inflated than usual in the genus. The species is remark- 

 able for its small hinge-area. 



In the variety chipolanns Dall there is no radial striation on the inter- 

 spatial ribs, but rather a concentric sculpture; there are many more spinose 

 ribs, the shell is more oval and more inflated, and, as far as the material goes, 

 seems to attain a larger size. It may prove distinct with more perfect speci- 

 mens, in which case the varietal name may be taken as specific. 



Spondylus rotundatus Heilprin. 



PLATE 35, FIGURES 25, 253. 

 Sponilylus rotimdiitus Heilprin, Trans. Wagner Inst., i., pp. 99, 103, pi. 14, fig. 33, 1887. 



Pliocene marls of the Caloosahatchie and Shell Creek, Florida; Willcox 

 and Dall. 



This fine species was represented in the original publication by a very 

 poor figure drawn from a very imperfect lower valve, so I have had another 

 figure prepared showing the characters. It is characterized by the presence 

 of eight or ten primary ribs with longer spines, which arc broad, spathulate, 

 and longitudinally ridged ; at the end, when perfect, the spine is decurved like 

 a half-shut hand. Between the primaries are two or three smaller ribs densely 

 clothed with similar but smaller and shorter spines whose backs are so close 

 together as to almost conceal the whole surface. The cardinal area is of 

 moderate size, triangular and twisted. The lower valve is similarly sculptured, 

 but with less regularity. Traces of coloration indicate that the shell originally 

 was of deep red or purple color. S. rotundatus is less similar to the recent 

 most foliaceous specimens of S. ccliinatiis than is the Oligocene bostrycldtcs. 



Spondylus echinatus Martyn. 



Os/i'ti'ii t'lJiiihitii Martyn, Univ. Conch., ii., fig. 154, 1784. 

 Spondylus armatus Humphrey, Mus. Calon., p. 54, No. 1021, 1797. 

 S/i,>inty/iix <r<<< v/ Humphrey, Mus. Calon., p. 55, No. 1022, 1797; Arango, Moll. Cubana, 



p. 271, 1880. 

 Sfniiily/iis <ioininit<nsh Boltcn, Mus. Bolt., 1st cd., p. 193, 1/98; 2<1 eel., p. 135, 1819; 



(Chemn., vii., p. 79, pi. 45, fig. 465.) 

 S/>iiify/ns aiinin/iiii'its Boltt-n, op. cit., p. 195, 1798. 

 Sfi,tv/i/s 11111,-i-ii-nnns Lam., An. s. Vert., vi., p. 188, 1819; (Knc. Mcth., pi. 195, figs. 



I, 2;) Reeve, Conch. Icon., pi. 4, fig. 17, 1856. 



