43 



NOTE ON STROMBUS BELUTSCHIENSIS, Melvill. 

 By Edgar A. Smith, F.Z.S., etc. 



Bead l'2fh January, 1900. 



A numerous suite of specimens of various ages of this recently 

 described species l having been presented to the British Museum by 

 Br. Jayakar, who collected them at Muscat on the Arabian coast, 

 enables me to supplement the original description in a few particulars. 

 In the first place I would call attention to the considerable variation 

 in the coloration. The typical form beneath the periostracum is 

 whitish, " squarely but irregularly spotted and dashed with bright 

 brown markings." Other specimens exhibit a close reticulation of 

 a deep brown colour upon the light ground and two or more irregular 

 transverse bands of the same dark tint upon the last whorl. A 

 tendency to be transversely banded is exhibited in almost every 

 specimen. Other examples are banded, blotched, streaked, and 

 reticulated with even a darker brown colour, which occasionally in 

 some cases becomes nearly black. It is practically impossible to 

 convey an idea of the irregularity and variability of the coloration 

 except by means of numerous coloured figures. The interior of the 

 aperture is often of a rich salmon -red tint. In form some difference 

 is also observable, but chiefly in the greater or less elevation of the 

 spire. The figure of the type represents the medium in this respect. 

 The coloration of the spire is not referred to by Mr. Melvill. It is 

 scarcely ever uncoloured like the type, but invariably exhibits lines 

 and blotches of various shades of brown. The protoconch is light 

 corneous and small, consisting of three smooth convex whorls. The 

 next whorl is also rounded, but spirally striated. Those which follow 

 are gradate, angled at the middle, longitudinally costate, and spirally 

 lirate. Often a few white varices occur upon the upper part of the 

 spire, and the anterior end of the body- whorl is faintly transversely 

 sulcate. The outer lip is thin, acute, white within, and not produced 

 upward as in many other species, but merely reaches the angle of 

 the body-whorl. At this part it is rather deeply incised, and in 

 well-grown adult shells has a much deeper anterior sinus than in the 

 shell figured by Mr. Melvill. The largest example is 53 mm. long and 

 32 wide. 



In describing this form the author observes that the discovery 

 of a new species of Strombus was of exceptional interest, because 

 "no addition to the genus has been recorded since 1857." Whilst 

 admitting the interest attaching to the discovery, I would point out 

 that since the date mentioned at least three species have been 

 described, namely, S. cancellatus, Pease, in 1860 ; S. robustus, 

 Sowerby, in 1874; and S. Yerburyi, Smith, in 1891. 



1 Mem. and Proc. Manchester Lit. and Phil. Soc., 1898, vol. xlii, No. 4, 

 p. 37, fig. 



