28 PANDORIM. 



and afterwards P. rostrata ; the young is the P. fleocuosa 

 of Philippi, and the animal the Hypog&a gibba of Poli. 

 It is also the Trutina solenoides of Brown. The variety 

 obtusa was described by Meuschen as Anomia tabacca, 

 by Montagu as Solen pinna, and by Leach as P. glaci- 

 alis ; the young is the P. oblonga of Philippi. Lamarck 

 changed the specific name imposed by Linne, either 

 from caprice (as seems to have been his custom), or on 

 the ground that it denoted an essential character of the 

 genus and therefore was superfluous. I am not satisfied 

 with this reason, believing that all designations, whether 

 generic or specific, are merely symbols of distinction, 

 and that the law of priority in zoological nomenclature 

 ought not to be disregarded because the name of one 

 species represents a character that is common to others 

 of the same genus. I have restored the original name, 

 by which this species is well known throughout the 

 greater part of Europe. 



Genus II. LYON'SIA*, Turton. PL II. f. 1. 



BODY oblong, somewhat compressed, rather thick: (/ills 

 forming apparently a single leaf on either side, in consequence 

 of each pair being doubled upon itself: palps long and narrow : 

 foot tongue-shaped, rather large, flattened, and provided with 

 a byssal groove. 



SHELL oblong, nearly equilateral, finely striated lengthwise ; 

 right valve more convex than the left : epidermis fibrous : 

 hinge furnished with a free plate or ossicle, which covers the 

 cartilage : muscular scars slight ; anterior oblong, posterior 

 roundish. 



A link connecting the Pandorida with the Anatinidte, 

 having the same shape and pearly nature as the former, 

 and the peculiar hinge-process or ossicle of the latter 



* Named after the late Mr. W. Lyons, an active British conchologist. 



