SYNOPSIS AND DESCRIPTIONS OF SUBGENEBA AND SPECIES. 



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DESCRIPTIONS OF SUBGENERA AND SPECIES. 



Class PELECYPODA. 



Order PRIOXODESMA < 'EA . 



Superfamily PECTINACEA. 



Family Pectinid^e. 



Genus Pecten » Miiller. 



1776. PecUn (Klein, 1753) Miiller, Prodr. Zool. Dan., ji. 248. 



1778. Pcctm Da t'osta, Brit. Conch., p. 140. 



1798. Peclen Bolten, Mus. Bolt., p. 165. 



1799. Pecicn Lamarck, Prodr. d'uu Nouv. Class. Coq., p. 88. 



1898. Pectm Dall, Trans. Wagner Free Inst. Sci., vol. o, pt. 4. p. 689. 

 Type, Ostrea maxima Linne. 



GENUS PECTEX MVLLER. 



"The shell of Pecten comprises two generally more or less discrepant valves, 

 united along a long, straight hinge line by an inconspicuous ligament and a 

 central strong resilium. A single rounded adductor leaves its impression pretty 



U 



Fig. l.—Pertcn rircularis Sowerby var. a-quisutcatus ('arpenter. Right valve, i. e., the valve having the byssal notch; 

 exterior. Dimensions: "Altitude" Ls distance tjetweeti tlie base (B) and the apex of tiie shell or umbo (U); 

 "longitude" is the distance between the anterior extremity (A) and the posterior extremity (Pj; "diameter" is 

 the maximum perpendicular distance iranx the plane of the periphery (margin or border) to the top of the arched 

 disk, when the sliell is lying interior downward; A, anterior end: P, posterior end; B, base; U, umbo: U P B A, 

 disk; ae, anterior ear or auricle; pf, posterior ear or auricle; bn, byssal notch or sinus: ba. byssal area: jm. posterior 

 sinus; Km. submargins or lateral areas; r, ribs; is, interspaces. 



iiigh up. a little before the mesial line of the valves, and the pedal retractors 

 are usually attached to the left valve above it, being often obsolete on the right 

 side. The ends of the resilium are received by subtriangular or oval pits in the 



« The generic and subgeneric classification and descriptions, and also the general discu-ssion relating to Peetev, are 

 taken from Doctor Dall's monograph of the genus in "The Tertiary Fauna of Florida," Trans. Wagner Free Inst. Sci., 

 vol. 3. pt. 1, 1898, pp. 689-7.^8. In many cases parts of the discussion and descriptions have been copied verbatim. Un!es.s 

 otherwise stated, all passages occurring in quotations have been copied from the above monograph. 



