ORDER III 



TELEODESMACEA 



417 



Family X Petricolidae. D'0rl>ignv. 



I'uloes, when not <li*i<,rti>tl, r</n<t/, fr, xomrirlmt .</"/"'".'/ Ix-Hnd, radiately sculpt" ml 

 with plain niiii-iit'ii* mi// /,iro,i.</iirnous beaks ; posterior adductor scar larger than tKe 

 pedal narrow, eloin/ot<tl^ ,tixiin <;t ; ligament and resilium external; area 

 or not defined; hinge without Intern/ Imuinae, with two or three small, us aall 

 radial cardinal t,-i-th in mr/i valve, ( Yetacrons to Recent. 



Petricola, Lain.; Chorixlutlon, .lonas; and Xarntm/u, (Irav, an- the principal l'<inn>. 



The family (;i,nici,iiiri'd't'; of otnarine or fluvial ilr hal.it, appears to lie rrla1<-l 

 to Petrinild, and include- tin- i-eccnt (Ho nnmiiin, (Bronn), Woodward, and T n i/siphon, 

 Benson. 



Superfamily 13. TELLINACEA. Blainville. 



Siphon.-; dit&inct to ///// Imxi't, itxinillii Ion// : /mll/ol I/in- ,s/ // inifr ; hi/n mr.nt external, 



seated on nymphs : ///////< normally ivith an anterior and posterior lateral in each valve, 

 two radial cardinal*, of which the anterior is commonly oij'nl, mid somewhat pedunculated, 

 mid the pn*tt'ri<n\ n* n-i'll as the laterals, often obsolete. 



Family 33. Tellinidae. Deshayes. 



Shell substance cellulo-crystalline, with an inconspicuous epidermis; valves slightly 

 unequal, free, rounded in front, more or less rostrate, oblique, and gaping behind, com- 

 pressed, usually with smooth margins, low beaks, and variable, chiefly concentric sculpture ; 

 anterior adductor scar larger, frequently irregular ; pedal distinct; resilium embraced in 



'l'iUi 

 ne;ir Ept-niay. 



Fit:. 707. 

 Desh. Eocene Damery, 



Fio. 766. 



Tellina planatu, I^iu. Miocene; Putzleins- 

 <lorf, near Vienna. 



Tellina (Linearia) bimdiatu, Zitt. Upper 

 Cretaceous ; Gosau, Austria. 



the ligament, sub-external ; area narrow, small, covered with a dark epidermis, or fre- 

 quently obsolete; hinge plate narrow, anterior laterals approximate, posterior more 

 distant from the cardinals, when present; cardinal teeth small; pallial sinus deep, 

 discrepant in the opposite valves. Jura to Recent. 



Tellina, Linn. Elongated, the rostrum more or less twisted ; two lateral teeth in 

 each valve. Jura to Recent. 



Sub-genera : Tellina s.s. (Figs. 766, 767), Tcllidora, Mbrch ; Strigilla, Turtou ; Linearia, 

 Conr. (Arcopagia, d'Orb.), (Fig. 768), etc. 



VOL. I 



2 E 



