a Genus of Corbiculadce. 277 



pulchellum, a certain Galileja ienebrosa (da) ? Costa, which, on the 

 authority of Philippi, is supposed to have been described in the 

 Corrispondenza Zoologica. On consulting Philippi I find only the 

 following reference ; it is in the addenda : "Synonymis P/s/c?n 

 fontinalis, Galileja ienebrosa, Costa, Corrisp. Zool., etc." 



Gray* (1847) places Galileja under the synonymy of Pisum 

 (Pisidium), but refers to it as having been described in 1846, 

 without, however, quoting any authority. 



Pisum. 



Gray f (1847) is the first who applies this name to Pisidium, 

 on the supposition that the genus characterized as Pisum by 

 Megerle;}: von Miihlfeldt (1811) was identical with it, and must 

 consequently, by virtue of the laws of priority, supersede it. 



An examination of Megerle's description, and of the author- 

 ities referred to by him. sets this question at rest, and shows, 

 without a doubt, that the authors who have adopted the name 

 of Pisum for Pisidium have been in error. 



Megerle, in his description of Pisum, says: "The hinge has 

 {keine Seitenzahne) no lateral teeth." To any one at all familiar 

 with the characters of Pisidium this remark is conclusive. 

 Megerle further quotes two authorities, as describing the type of 

 his genus (Pisum Gallicum), Linnaeus and d'Argenville. On an 

 examination of the reference in Linnaeus,§ we find Tellina Gallica. 

 The description of this species throws no new light on the question 

 further than that it is stated as having " dente solitario." We are, 

 however, referred to another authority, which is the same as 

 quoted by Megerle, namely, d'Argenville. D'Argenville || gives 

 the following description and figure of the shell referred to by 



* Proc. Zool., Lond., xv., 18o. 



\ Proc. Zool., Lond., xv., 184. 



% Mag. G-esell. Naturf., Berlin, v.. 67. 



§ Gml. Syst. Nat. 305, spec. 88. 



| D'Argenv. Conchy!. 285, pi. xxvii., f. xi., 1772 and '92. 



