Naticae, Lamellarise, and Velutinse. 49 



rarer ones are sometimes found in company with it, as the 

 lanthina exigua and I. pallida, which last I think is only a 

 variety of the present species. These animals have no operculum. 



Scalaria, Lamarck. 

 This genus contains several British species. Authors and 

 Lamarck's commentators say, that it is allied to Turritella, but 

 I think that it has much greater affinity with the Canalifera. 

 Turritella and Scalaria, in addition to the single branchial plume, 

 appear to have the mucous strands of the Muricidce, the animals 

 of which are always provided with that appendage, besides the 

 gland of viscosity ; in other points, Turritella, by its short pro- 

 duced muzzle, circular operculum, and absence of a proboscis, is 

 nearer to the Littorime and Trochi, whilst Scalaria also, with the 

 mucous fillets, has the decided proboscis of the Canalifera ; con- 

 sequently it must be assigned, as a muricidal anomaly, to the 

 new family of the Peloridce. However, whatever may be the 

 affinities of the two genera, they will not be far apart ; the one 

 claiming, by its subcanal, both of shell and mantle, to take posi- 

 tion on the last confines of the Holostomata, the other on the 

 first lines of the Canalifefra. An attentive perusal of the account 

 of the undermentioned species will show that the Scalarice are 

 truly strange animals; the spiral operculum, single branchial 

 plume, and almost entire aperture, indicate their relation with 

 the Littorince and Cerithiadce, whilst the mucous fillets and pro- 

 minent retractile proboscis, a character of the highest value, fix 

 them amongst the immediate points of transition to the Muricida. 



Scalaria clathratula, Montagu. 



Animal occupying a densely plicated milk-white spiral shell 

 of 9-11 volutions. The animal nearly throughout is bluish 

 white, aspersed at the points of the tentacula, on the head and 

 neck, and margins of the foot, with blotches and spots of snow- 

 white matter. Mantle fleshy, reflexed on the peripheral rib of the 

 aperture, and forming also a short lax branchial fold to corre- 

 spond with the incipient canal of the shell. The head, though very 

 short, is distinct, compressed and crescent-shaped as in Murex, 

 beneath slightly emarginate in the centre, at which point is the 

 mouth that is partially transversely and vertically cloven, from 

 which a long strong fleshy proboscis is exserted, which I have 

 repeatedly seen evolved, several times in a minute. The ten- 

 tacula are moderately long, divergent, subcompressed, with 

 blunt terminations ; the eyes are very black, not fixed on off"sets, 

 but on scarcely raised eminences or decidedly external semi- 

 circular inflations that are integral parts of their bases. The 

 foot can be extended beyond the tentacula; it is nevertheless 



Ann. ^ Mag. N. Hist, Ser. 2. Fo/. xi. 4 



