262 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Ad. and Ang., long, narrow, smooth, well-defined raised lateral 

 areas, brown flecked with white, a common coloration with this 

 species. 



Dr. Lamy kindly made the following literal translation of 

 Blainville's description of his C. longicymba for me : " Body very 

 elongate, very narrow, limb with very small, farinaceous scales, 

 shell very long, formed of eight large valves, increasing from the 

 anterior to the posterior, convex and perfectly smooth, the inter- 

 mediates with broad lateral areas distinguished by one angular 

 prominence ; colour greenish-brown, variegated or streaked with 

 small white spots which are wider upon the dorsal line." This 

 description absolutely accords with the specimen upon the card 

 and in no sense will agree with any other of the specimens collected 

 by Peron and Lesueur that are in the collections in Paris. 



Dr. Lamy found a manuscript description in the handwriting of 

 Rochebrune, headed " Lepidopleurus longicymba, Blainville, Chiton 

 longicymba, Blainville (Diet. Sci. Nat., vol. xxxvi, p. 542). Dufresne 

 admoram ". In which he states that the type was then in the Paris 

 Museum and giving the measurement, long. 0.99, lat. 0.12. Probably 

 allowance had been made for the width of the girdle, which is now 

 absent. Rochebrune seems later to have decided to redescribe this 

 shell under the name of Schizochiton nympha, and in the letterpress 

 gives the measurements as 32 by 11 mm. The length is correct, but 

 the width is absolutely wrong, being twice its present actual width. 



The question may very naturally be asked, how was it that only 

 eight years after Blainville's publication of his description of Chiton 

 longicymba, Blainville still being connected with the Paris Museum, 

 could Quoy and Gaimard pubHsh in 1833, in the Voyage de 

 r Astrolabe, a description of a strikingly different shell from New 

 Zealand, now known as Ischnochiton maorianus, Iredale, under 

 the name of Chiton longicymba, Blainville ? 



By no stretch of imagination can the New Zealand shell found by 

 Quoy and Gaimard be made to resemble Blainville's shell. 



I saw in the Paris Museum Quoy and Gaimard' s type from which 

 their description and figures were made, and it is certainly con- 

 specific with the shell named by Iredale I. maorianus. On another 

 card are two specimens of the same New Zealand shell, one of them 

 the black variety with white dorsal stripe ; this is marked in the 

 handwriting of Quoy, or Gaimard, " var. lineolatus, Blainville," very 

 naturally confusing it with the variety of that species that was later 

 on named by Pilsbry var. haddoni. 



I have shown in earlier papers that Blainville's lineolatus is the 

 shell that we have generally known as Ischnochiton crispus. Reeve, 

 a species that very closely approaches to the New Zealand shell 

 discovered by Quoy and Gaimard, and they would then have been 

 fully justified in considering them con- specific, the chief difierence 

 being in the girdle scales. 



