TRANSACTIONS OF WAGNER 

 1454 



^ J ^ TERTIARY FAUNA OF FLORIDA 



Cyclas C, Blainville, Diet. Sci. Nat, xxxii., p. 33, 1824; Man. de Mai., p. 551, 1825. 

 Galateola Fleming, Brit. Anim., p. 409, 1828. Nude name, referred to Galatea Bruguiere 



by Herrmannsen, Ind. Gen. Malac., i., p. 338, 1846. 



<^Cyrenocyclas Agassiz, Nomencl. Zool., Index, p. 329, 1847 ; = Cyanocyclas corrig. 

 ^>Fischeria Bernardi, Mon. Galat., p. 47, 1860. F. Delesserti Bern.; not Fischeria Des- 



voidy, 1830. t 



The type of this genus is 



Egeria paradoxa (Born). 



Venus paradoxa Born, Test. Musei Vindob., p. 66, pi. iv., figs. 12-13, 1780. 

 Venus reclusa Chemnitz, Conch. Cab., vi., p. 326, pi. xxxi., figs. 327-9, 1782. 

 Venus hermaphrodita Gmelin, Syst. Nat., vi., p. 3278, No. 40, 1792. 

 Venus subviridis Gmelin, op. cit., p. 3280, No. 55. 

 Galathea radiata Lamarck, Ann. du Mus., v., p. 430, pi. xxviii., 1803. 

 Donax variegata Perry, Conch., pi. Iviii., fig. I, 1811. 



Rivers of West Africa on the Guinea coast. 



This genus has been unfortunate in its nomenclature, nearly all the names 

 applied to it being preoccupied or uncomfortably close to other valid names 

 in spelling or pronunciation. In accordance with the rules I have adopted and 

 followed in this memoir, I accept the name Egeria of Roissy for the genus, as 

 it is prior to Dumeril's use of the same name. The soft parts of Egeria differ 

 very little from those of the Cyrenas, the siphons being somewhat better de- 

 veloped. The valves are heavy and thick in most of the species, subtrigonal, 

 and the hinge is very heavy and rudely, radiately striate or sulcate, obscuring 

 the character of the dentition, the separate teeth being often more or less broken 



up by deep fissures. The dental formula is essentially ^- - IOIOIO -. There are, 



* R. i.oioioi.i 



as normally in all the Cyrenida, three cardinals in each valve, the two posterior 

 of the right valve being united above and received into a /^-shaped socket in 

 the left valve, below which an isolated tooth projects and is received into a 

 socket below the united teeth of the right valve. There are two rude sulcate 

 laterals in the right valve received into an anterior and a posterior socket re- 

 spectively in the opposite valve. The body cavity of the valves is relatively 

 small, the margins entire, the pallial line with a moderate or small rounded 

 sinus. In E. concamerata Duval a buttress rises behind the anterior adductor 

 scar to support the hinge-plate. The periostracum is strong, of a brown or 

 olivaceous color sometimes radiated with violet; the shell is whitish or violet, 

 like other Cyrenacea. 



The group may be arranged as follows : 



