Mr. E. A. Smith on Volutharpa Perry i. 347 



XL VIII. — Notes on Volutharpa Perry i. 

 By Edgae a. Smith. 



The British Museum has recently obtained two specimens of 

 Volutharpa Pen^yi, collected by Mr. H. Pryer at the Loo-Choo 

 Islands. Only two brief notices of the animal of this species 

 have been published, by Troschel* and Dunkerf. The latter's 

 account reads almost like a latin translation of the description 

 of V. aivpullacea given by A. Adams \. Troschel more par- 

 ticularly describes the odontophore and notes (erroneously ?) 

 the absence of an operculum. From an examination of the 

 two specimens at hand I have drawn up the following 

 description. 



The animal (in spirit) is of a pale orange colour, copiously 

 mottled with black on the head, tentacles, siphon, and upper 

 part of the body. The creeping-disk is similarly coloured, 

 but the lateral edges are unspotted. The body is rather 

 large, narrowed posteriorly, and somewhat squarish in front, 

 where there is a free edge, distinct from the foot-margin, as in 

 Buccmum. The head, tentacles, and the position of the eyes 

 are about the same as in B. undatum. The odontophore, 

 which I have examined, does not quite correspond with the 

 figure given by Troschel. The central teeth have six similar 

 dentations, but the lateral plates are more regular than those 

 depicted in his work j those on one side constantly have 

 live dentations, those on the other six. The outside tooth is 

 the largest, the innermost the next in size, the rest gradually 

 diminishing, so that the fourth on the one plate and the fifth 

 on the other, or, in other words, those next to the large outer 

 teeth, are the smallest. 



The most remarkable point in connexion with this species 

 is the minuteness of the operculum, which has only a diam- 

 eter of If millim. It is oval, very thick for its size, and 

 externally appears to consist of four or five concentric layers. 

 The under surface is excavated and irregular, but exhibits to 

 some extent a concentric character of growth. 



Troschel states that his specimen was without an opercu- 

 lum ; but it seems to me quite possible that he may either 

 have overlooked it on account of its minuteness, or it may 

 have been knocked off, as is the case in one of the two speci- 

 mens under examination. Its former presence, however, is 



* ' Das Gebiss der SclineckeB,' vol. ii. p. 72, pi. vi. fig. 14. 



t Index Mollusc. Japon. p. oti. 



+ Ann. & Mag. Nat.^Hist, 1860, vol. vi. p. 109. 



