64 COLLECTIONS FROM MELANESIA. 



C. pupa, and C. petrosum, may be recognized in all its forms by the 

 oblique varix on the back of the body-whorl, a feature not found in 

 C. moms and O. pattens ( = rugosum). The typical form and the 

 variety G. variegatum are pupiform, having the spire acutely conical 

 towards the apex and the last whorl scarcely broader than the 

 preceding one. The granulations appear to be never in more than 

 three rows on the upper whorls, but on the penultimate a fourth is 

 frequently, but not always, observable a^oining the lower suture. 

 The body-whorl has normally seven principal series of granules ; 

 but in many instances the minor or intermediate series attain as 

 large a size as the principal ones, when the number of rows may be 

 nine to a dozen or even more. The variations in colour are consider- 

 able : normal specimens are whitish varied with black, brown, and 

 white tubercles. 



The var. variegatum is irregularly blotched with light or dark 

 brown, and some specimens are almost entirely of a uniform dark 

 brown (Conch. Icon. iig. 41 a). Another has a light brown band im- 

 mediately beneath the suture and a second broader one at the base 

 of the body-whorl, as in C. pupa (Conch. Icon. fig. 84), which is 

 remarkable on account of the remoteness of the tubercles on sub- 

 distant longitudinal costae. All of these forms of the variety varie- 

 gatum. have a more or less lilac-tinted aperture ; but in others (yide 

 Conch. Icon. flgs. 41 6, c) it is white, and the style of colouring reverts 

 more to the typical form of the species. The form which has been 

 named 0. petrosum (Wood, Index Test. Suppl. pi. iv. fig. 9 of Stroma 

 6ms) and its varieties (Sowerby, Thes. Conch, figs. 171, 172 ; Conch. 

 Icon. figs. 43 a, b) differ very considerably from the normal C. tuber- 

 culatum ; but in the specimen depicted by the two last figures we 

 find the connecting link. 



In the type figured by Wood, now in the British Museum, the 

 tubercles are much compressed and united laterally so as to form 

 lirffi continuous on and between longitudinal folds ; however, upon 

 the uppermost volutions the granules become more prominent. 



The colouring of this shell is similar to that of the variety C. 

 pupa, excepting some of the tubercles and lirse being black, indi- 

 cating a return to the black nodulation of the typical O. tuberculatum. 



2. C. morus, the synonymy of. which is given above, has three 

 rows of granules on the upper whorls, and if a fourth be present 

 on the penultimate whorl, as is sometimes the case, it invariably 

 consists of much smaller tubercles than those on the three other 

 series. The last varix is situated on the side of the body-whori 

 exactly opposite the labrum, and never on the back of it, as in C. 

 tuberculatum and its varieties. The principal rows of granules on 

 this whorl are six in number, and may best be counted upon the 

 labrum, where the sixth or lowermost terminates at a little distance 

 from the canal, those actually ending at the canal being secondary 

 or smaller series and wind round the short basal cauda of the whorl. 

 The labrum also becomes more thickened in adult specimens of this 

 species than in C. tuberculatum. The specimens collected by Dr. 



