TRANSACTIONS OF WAGNER 



I2q6 



^ tertiary fauna of florida 



sumably elevated, but are destroyed in all the specimens examined. In har- 

 mony with this arrangement of the sculpture the posterior end of the shell is 

 somewhat rostrate; the lunule and escutcheon are wider than in C. ballista; 

 the hinge normal, the teeth entire, the pallial sinus small and angular, and the 

 adductor scars subequal. Length of an average specimen 27.5, height 20.5, 

 diameter 14.0 mm. 



The Bowden species was confused with others and with the recent C. paphia 

 by Guppy, as above cited. Only a comparison is needed to prove their dis- 

 tinctness. 



Chione (Lirophora) gljrptocyma n. sp. 



Plate 55, Figure 21. 



Oligocene of the Oak Grove sands, at Oak Grove, Santa Rosa County, 

 Florida ; Smith, Burns, and Aldrich. 



This species is very close to the ribbed variety of C. Burnsii, from which 

 it is best distinguished by a dififerential description. 



In C. Burnsii there is a slight inflection of the posterior base in front of the 

 posterior dorsal area which gives the hinder end of the shell a look as if it 

 were slightly bent down ; in the present species the base is evenly arcuate and 

 the rostration points backward. In C. Burnsii there are but three or four con- 

 centric lamellae on a young shell five millimetres in height ; in the present 

 species eight or nine. By looking at the beaks the two can be at once sepa- 

 rated. In C. glyptocyma there are from sixteen to twenty-three ribs, in C. 

 Burnsii when the ribs are not confluent there are nine to eleven. The surface 

 of C. glyptocyma is more polished ; the radial striation on the ventral aspect 

 of the ribs stops at their base in C. Burnsii; in the present species it continues 

 over the interspace to the base of the rib below. In C. glyptocyma the ribs are 

 apparently never normally confluent, but in C. Burnsii confluence is the rule. 

 An average specimen measures : length 33, height 24, diameter 16 mm., but 

 the form may be longer or more trigonal, as in all these species I have figured 

 a youngish valve 26.5 mm. long, because it shows remains of the foliations 

 which in adult specimens are always broken off. The pallial sinus is very 

 small and angular, the adductor scars subequal, and the teeth are entire. 



Chione (Lirophora) ulocsrma Dall. 



Plate 42, Figure 5. 

 Chione ulocyma (Dall MS.) Harris. Bull. Am. Pal., i., No. iii., p. 9, 1895. 

 Venus (Anaitis) ulocyma Dall, Trans. Wagner Inst., iii., part v., p. 1198, pi. xlii., fig. 5, 

 1900. 



