TELLINIDiE. 169 



those species. Among recent shells they are represented by Tell, 

 concentrica, Gould (not id. Reuss or d'Orb.), and one or two 

 others. For many years paliBontologists have separated these 

 shells from Tellina and applied to them the name of Arcopagia. 

 T. metastriata, Conr. (cxi, 61). 



ARCOPAGrA, Leach, 1827. Shell rounded-oval or orbicular; 

 two lateral teeth in one valve. T.fausta, Donov. (cxi, 62). 



PHYLLODA, Schum., 1817. Shell oblong, much compressed, 

 posteriorly angular and carinated ; cardinal teeth divergent, 

 sublamellar. T. foliacea, Linn, (cxi, 63). 



ANGULUS, Schum., 1817. (Tellinula, Chemn. Fabulina, Gray, 

 1851.) Shell oblong, subtriangular, compressed; anteriorly 

 rounded, posteriorly more or less pointed or angulated ; a single 

 lateral tooth in one valve. T. polita, Say (cxi, 64, 65). 



TELLiNiMERA, Courad, 1860. (Tellimera, Conr., 1870.) Shell 

 thin, elongated, subtriangular; right valve with three cardinal 

 teeth, the shortest extending to the apex; left valve with two 

 cardinal teeth, the posterior one bifid; no lateral teeth. Closely 

 related to Angulus in form. T. eborea, Conr. (cxii, 100). Cret. ; 

 U. S. 



TELLiNiDES, Lamarck, 1818. Shell oval, compressed, slightly 

 flexuous posteriorly ; hinge with a single lateral tooth, contiguous 

 to the cardinals. T. Tiinorensis.i Lam. (cxi, 66). 



HOMALINA, Stoliczka, 1870. (Homala, H. and A. Adams, not 

 Schum.) Shell oblong, compressed, inequivalve, inequilateral, 

 anteriorly short, rounded ; posteriorly flexuous, obsoletely cari- 

 nate, somewhat produced, narrowed ; one lateral tooth near the 

 hinge. T. triangularis, Gh^van. (cxii, 99). 



PERON^A, Poll, 1791. (Omala, Schum., 1817.) Shell oblong, 

 oval; anteriorly short, rounded, posteriorly somewhat flexuous, 

 subangulate ; lateral teeth obsolete. T. planata, Linn, (cxi, 67). 



METIS, H. and A. Adams. Shell suborbicular, compressed, 

 valves sillonated, posterior flexuosity submedian ; no lateral 

 teeth. T. Meyeri, Phil, (cxii, 69). 



^NONA, Conrad, 1870. Shell subtriangular, inequilateral, 

 hinge-margins equally declined, beaks not prominent, lunule 

 very narrow, lanceolate, marked by a deeply impressed line ; two 

 very small, widel}'' diverging cardinal teeth in the right valve, 

 one bifid and one rudimentary tooth in the left valve. T. Eufa- 

 lensis, Conrad (cxii, 70). Cretaceous; U. S. 



[mactromya, Agassiz, 1842. This group, which I have placed 

 in Anatinidae (p. 149), Stoliczka classifies as a distinct genus 

 of Tellinidse. Zittel refers species of Mactromya to several 

 groups in Tellinidse and Paphiidas.] 



Arcopagella, Meek. 

 Distr. — 2 sp. Cretaceous ; U. S. A. Mactroides, Maek (cxii, 6). 

 12 



