ANIMALS. 83 



Order Sarcicobrachia, J, E. Gray. 

 Diagnosis. — "The oral arms fleshy, without any shelly support."' 



Family Lingulid^ (Les Lingules), Cuvier, 1800. 



The shells of this family are more or less elongated longitudinally, pointed at the 

 beaks, sub-equivalve, regular, covered with an epidermis, and attached to marine 

 bodies by a peduncle passing out between the beaks of the valves. The branchial 

 system differs somewhat from that of other known Palliobranchs in consisting, though 

 perhaps only partially, of slightly-developed tufts or processes originating from the 

 great pallial vessels. 



Genus Lingula, Bruguiere. , 



Biagnosis. — " Testa subsequivalvis, planulata, ovato-oblonga, apice truncata, 

 basi subacuta, pediculo, carnosa tendineo, basi affixo elevata. Cardo edentulus."^ 

 (Lamarck.) 



This is probably the most long-lived genus with which the palaeontologist is 

 acquainted. Its remains are found in the very earliest fossiliferous rock (vide note, 

 p. 82) ; and it is still living at the present day ; but what is most remarkable, it has 

 never, during any period, been represented by more than a few species. 



LiNGULA Credneri, Geinitz. Plate VI, figs. 25, 26, 27. 



LiNGULA MYTILOIDES, /. Sowerhy. (King) Bull. Soc. Geol. de Fr., 2"' serie, vol. i, 



p. 30, 1844. 



— — „ Geol. Russ., vol. i, p. 222, 1845. 



— — „ Tennant, Strat. List., p. 88, 1847. 



— — „ King, Catalogue, p. 7, 1848. 



— — (?) „ Howse, T. N. F. C, vol. i, p. 250, 1848. 



" — Ckedneri, Geinitz. Versteinerungen, p. 11, pi. iii, figs, 23, 24, 1848. 



Diagnosis. — Shell thin ; finely striated ; oblong oval ; rounded in front ; with a 

 median elevation (commencing at the posterior end, and becoming flattened anteriorly) 

 from which the shell gradually slopes to the sides.^ 



1 Gray, op. cit., p. 436. 



2 Animaux sans Vertebres, t. vii, p. 386, 1836. 



2 "Die diinne, mit feinen Zuwachstreifen verzierte Schale ist langlicli oval, untengerundet und lasst 

 sine mittlere wulstformige Erhebung erkennen, die an dem kleinen Wirbel beginntund sich nach unten bin 

 verflacht und von welcher die Scbale nacb beiden Seiten bin abfallt. — Bei 10 Millimeter lange, 6-7 Millemeter 

 breit." (Geinitz, Versteinerungen, p. 11.) 



