218 EEY. E. BOOG WATSON ON THE 



neither strongly marked nor constant. The consequence is that 

 the lists of species arranged under Turritella (with subgen. Hau- 

 stator), Torcula, and Zaria are arbitrary in the extreme ; and 

 these divisions only cause confusion. 



There are two remarkable features of Turritella which do not 

 seem to have been noticed. The first is the system of microscopic 

 spirals which covers the entire shell, and which I have found on 

 every even fairly preserved specimen which I have examined. 

 The second is the presence of an epidermis. This is very dis- 

 tinctly recognizable in T. carlottce and in T. austrina, and some- 

 what doubtfully in T admirabilis. It is filmy, calcareous, and 

 in drying seems to contract, so as to rise off the surface of the 

 shell in the furrows, remaining attached only on the tops of the 

 spirals and in the suture. It also splits in the lines of growth. 

 All this renders it of course very caducous ; and, as Mr. E. 

 Smith remarks, " the fact of all Turritellas appearing to be de- 

 void of an epidermis is quite comprehensible, seeing how exces- 

 sively thin it is in this instance" (i. e. of T. carlottce). Hardly 

 sufficient importance seems generally given to the sinuation of 

 the outer lip, which is a feature quite as distinctly marked as in 

 Pleurotoma. 



1. TlJEEITELLA EUNCINATA, 11. Sp. 



St. 162. Ap. 2, 1874. 39° 10' 30" S., 146° 37' E. S.E. Aus- 

 tralia, off East Moncceur Island, Bass Strait, 38-40 fathoms. 

 Sand. 



Shell broadly conical, a little rounded at the basal angle and on 

 the base, with a distinct suture and a deep labial sinus, thinnish, 

 translucent, and speckled. Sculpture. Longitudinals — the sur- 

 face is closely covered with very fine and strongly curved lines of 

 growth, which on the base are stonger and radiate very straight, 

 but interruptedly, out from the centre. Spirals — there are on 

 each whorl two strongish, but rounded and somewhat ill-defined, 

 carinations : of these, the lower and stronger lies about one fifth 

 of the whorl's height above the suture ; the upper and less definite 

 lies a little more than halfway between the lower carina and the 

 superior suture : between these two carinas, but nearer the upper 

 one, lies a thread with almost enough of prominence to form a 

 third carina, and this one sometimes supersedes the upper carina 

 altogether. Besides these, the whole surface is sharply fretted 

 with fine, rounded, unequal, irregular, interrupted, spiral threads, 

 of which a considerable number are stronger than the rest, espe- 



