Testa turrita, utroque alata, acute-caudata, alba; anfractus tumidi, spiraliter striati, longitudinaliter noduloso-costati, costis crebris, lateraliter varicosi, varices compressi, aliformes, crenulati, striati, ad margines crenati; apertura ovato-rotunda, inferne longe-caudata; peristoma solutum.  Long. 20, diam. 14, apert. 4 mill. (Mus.  Brit.)

This beautiful shell was dredged in from 8 to 11 fathoms water, on a bottom of sand and shells between Cumberland Island 1.i, and Point Slade (Latitude 21 degrees South Longitude 149 degrees 20 minutes East).

The spiral striae that cross its whorls are grouped in pairs; their interstices are raised, and more or less finely crenulated; as they pass out on the expanded and wing-like varices they diverge, and the lobe-like projections that scallop the margins of the wings are separated from each other by each pair of diverging striae.  The fine ribs that cross the whorls are not present on the wings, nor on the back; they are nodulated at their decussation with the raised striae.  The wing-like varices of the whorls overlap each other alternately on each side of the shell.  The only species to which it has affinity is the R. pulchra.

Scalaria jukesiana.  Tab. 3 fig. 7.

Testa lanceolato-turrita, gracilis, alba, laevis, nitida, longitudinaliter costata, costis lamellosis, reflexis, simplicibus, nnmerosis (in ult. anfrac. 20); anfractus 11, tumidi; sutura profunde impressa; varices nulli; apertura orbicularis, margine laevi.  Long. 13, Diam. max. 14, apert 3 mill. (Mus.  Brit.)

This beautiful little Scalaria is deserving of particular notice on account of the analogy and representation which it exhibits with the S. clathratulus of the seas of the Northern Hemisphere.  It is dedicated to the author of the Voyage of the Fly.

New Genus—­MACGILLIVRAYIA, Forbes.

Shell spiral, dextral, globular, thin, corneous, transparent (in the only known species smooth or marked by obscure lines of growth) imperforate; spire not produced (with a sinistral nucleus ?).  Aperture oblong, entire, angulated below; peristome incomplete, thin, even-edged.

Operculum semicircular, horny, thin, composed of concentric layers with faint traces of a spiral structure at the centro-lateral nucleus, which is on the columellar side; from it there runs a strait rib or process continued nearly to the outer margin, and indicated externally by a depression or groove.

Animal ample, provided with four very long and rather broad linear rugose (or ciliated ?) tentacula; mantle produced into a long siphon; foot very large, expanded, truncate in front, bearing the operculum near its posterior extremity, but not accompanied by filamentous processes or lobes.  A float. (Mus.  Brit. and Geol.)