TRANSACTIONS OF WAGNER 

 1038 



TERTIARY FAUNA OF FLORIDA 



Genus STRIGILLA Turton. 



Strigilla Turton, Dithyra Brit., p. 117, 1822; Tellina carnaria Linne, non Pennant. 

 Strigella Gray, Synops. Brit. Mus., p. 91, 1842 (err. typ. for Strigilla). 

 Strigillina Stoliczka, Cret. Pel. India, p. 120, 1870; not of Dunker, 1862. 

 Limicola (Leach) Fischer, Man. de Conchyl., p. 1149, 1887; not of Leach, 1852. 

 Strigula Pfeiffer, Malacozoologische Blatter fur 1861, vii., Index; not of Perry, 1811. 



This genus is remarkably characteristic and is found with its full de- 

 velopment as early as the Oligocene. It is divisible into three groups, one 

 typified by -S\ carnaria, in which the pallial sinus is discrepant in the two 

 valves above and wholly coalescent below, the upper line uniting the adductors, 

 the external chiselled sculpture covering the whole shell ; a second in which 

 the external sculpture is similar to the preceding but the pallial sinus is alike 

 in the two valves and falls short of uniting the adductor scars ; lastly, a third 

 in which the adductors are connected by the pallial line in one valve and the 

 sinus falls short in the opposite valve, externally the oblique sculpture covers 

 part of the shell, while over the rest it is absent or the sculpture is purely 

 concentric, the boundary between the two areas being sharply defined by a 

 radial line (S. senegalensis) ; these may be regarded as sections* viz. : 



1. Strigilla s. s. Type 5. carnaria Linne. 



2. Rombergia Dall. Type S. Rombcrgi Morch. 



3. Aeretica Dall. Type 5". senegalensis Hanley. 



The fossils so far as yet known belong to the typical section. The oblique 

 external sculpture, which is the most marked characteristic of this genus, is 

 in the commoner forms convexly waved near the anterior third of the disk, 

 and this region often has the sculpture obsolete or even absent in individual 

 specimens; the posterior dorsal slope usually has the sculpture in chevron, 

 the lines sometimes more or less broken up, and the sculpture of this part 

 of the shell, as any one may convince himself by examining large series of 

 specimens, has not the constancy in pattern of that on the disk of the shell, 

 and therefore should not be used as a specific character within narrow limits. 

 Ignorance of these facts is responsible for a long list of synonyms among the 

 recent species, especially on the Pacific coast. 



Strigilla pisiformis Linn. 



Tellina pisiformis Linne, Syst. Naturae, ed. x., p. 677, 1758; Hanley, Thes. Conch., Tel- 

 Una, p. 261, pi. Ivi., fig. 30, 1847. 

 Cardium discors Montagu, Test. Brit., p. 84, 1803. 

 Strigilla pisiformis H. and A. Adams, Gen. Rec. Moll., ii., p. 399, 1856. 



