TRANSACTIONS OF WAGNER 

 1284 



TERTIARY FAUNA OF FLORIDA 



The hinge-plate is excavated longitudinally, below the lunule, but there is not 

 a trace of lateral teeth. 



This genus is sufficiently separated from Dosinia by its separated siphonal 

 tubes and the absence in Mysia of the small anterior lateral tooth found in the 

 left valve of Dosinia. It has been said to have the posterior flexure of Tellina, 

 but I cannot find that this is correct. The specimens I have studied are without 

 it. The dental formula is - L - 10101 . There are no American species. 



R. oioio 



The subgenus Lajonkaireia Deshayes, which has been referred to Lucinop- 

 sis by several authors, is founded on a recent species of Petricola, described 

 as Venerupis Lajonkairei by Payraudeau in 1826 ; figured in the Encyclopedic 

 Methodique (pi. cclxxii., figs. 2a, 26) and named in 1827 Venus cyclolites Valen- 

 ciennes by Bory St. Vincent in his explanation of the plates of the Encyclopedic. 

 This has been referred to under Petricola. From an examination of a rather 

 imperfect valve, together with the figures of Nyst and S. Wood, I am led to 

 doubt the identity of the crag fossil of England and Belgium with the Medi- 

 terranean living form. The most conspicuous distinctive character lies in the 

 hinge, which among other differences has a vastly longer ligament and nymphs 

 in the fossil. This, however, is a question which can best be settled by natu- 

 ralists on the spot. 



Genus CYCTLINELLA Dall. 

 Cyclinella Dall, Nautilus, vol. xvi., p. 44, Aug., 1902. Type Artemis tenuis Recluz. 



Two American recent species have been referred to Mysia, the Dosinia 

 snbquadrata of Hanley and the D. tenuis of Recluz. An examination of these 

 shows, however, that they must be separated from Mysia, since they have three 

 cardinal teeth in each valve, the right posterior one bifid, the centrals being 

 stouter than the others but not bifid, the other characters agreeing with those 

 of Mysia. The dental formula is L - IOIOI -. For this group I have proposed 



R. oioioi. 



the name of Cyclinella. Carpenter referred the C. subquadrata to Cyclina, 

 which has the central tooth bifid, the margins crenulated, the lunule undefined, 

 and the sculpture reticulate; while in Cyclinella the lunule is circumscribed, 

 though not impressed, the margins are entire, and the sculpture concentric. 

 Cyclina is said by Adams to have the anatomy like Dosinia; so far as one may 

 infer from the shell characters, Cyclinella should resemble Mysia. Both of the 

 latter differ from the other Venerida by their nearly vertically directed pallial 

 sinus and by the unusual distance of the posterior adductor scar from the 

 dorsal border above it. In a dried and quite young specimen the foot appears 

 pointed, small, and triangular. 



