338 JOURNAL OF CONCHOLOGY. 



chon, Gironde, a box of valves of a large Anodon, which the 

 lady in charge (knowing the value of accurate localization), 

 positively assured me came from the R. Adour which flows by 

 Dax, of even larger sizes. The largest measures io'6 x 6 x 3-8 in. 

 another valve io"o x 5-8 in. ; and 9*5 x 5-5 in. are common dimen- 

 sions amongst the smaller shells. I had no books with me, and at 

 first thought I had found gigantic cygneus. It was not how- 

 ever given to me to beat Mr. Sclater this time. A friend helped 

 me to a trustworthy opinion, from Bordeaux (where there is in 

 the museum a very interesting collection of French land and 

 freshwater and Bay of Biscay shells), which positively declared 

 that these shells were not from the Adour. They appear to 

 belong to A. herciileus, sp. 7 of Mr. L. Reeve's Monograph of 

 1867. His description (from one valve in Mr. Cuming's collec- 

 tion, nn\v exhibited in the British Museum as from Japan), is 

 curiously gentrir rather than specific. The margin '' ad teriuininn 

 subalatus et siibangulatus,^ and the plicated umbos are however 

 characteristic, the former features more or less markedly in differ- 

 ent specimens. The plication is peculiar. The young shell had a 

 strongly-marked angular ridge from the umbo towards the posterior 

 end of the shell, and, on each side of this, very distinct corruga- 

 tions parallel to the ventral and superior posterior margins. The 

 umbonal region in all my shells is much eroded, but in some of 

 the least wasted there appears, from a point about an inch 

 behind the actual umbo, a series of strong waves (more 

 ])rominent in those shells whose alae are best developed) which 

 cross the lines of growth, i.e., passing from the ridge to the pos- 

 terior dorsal margin backwards show a series of long pits 

 rather than mere wavy depressions. This configuration is even 

 more distinctly visible inside, and, in a characteristic shell with 

 a well-grown wing and twelve or fourteen iridescent undula- 

 tions crossing the lines of growth, is extremely ' effective.' I only 

 just escaped shipwreck by mistaking the lights, but I believe 

 the identification is now correct. Forsan et haec olim memin- 

 isse juvabit. — R. D. Darbishire. 



J.C, iv., July, 1885. 



