1884.] ' LIGHTNING' AND ' PORCUPINE ' EXPEDITIONS. 135 



and glossy : colour pale yellowish-white : spire short, abruptly 

 tapering; ; apex pointed : whorls 7-8, convex ; the last equals two 

 thirds of the shell when placed in a supine position, and more than 

 one third of the spire when the shell is placed with the mouth 

 downwards : suture deep : mouth nearly round, slightly angular at 

 the upper corner : outer and inner lips somewhat expanded ; peri- 

 stome continuous ; there is a small umbilical chink between the 

 inner lip and the pillar. L. 015. B. 0'075. 



'Porcupine' Exp. 1870: Atl. St. 9, lb, 17, Ma, Setubal B., 2G ; 

 Med. Adventure Bank. 



Distribution. Bay of Biscay (' Travailleur ' Exp. 1881); 1093 

 fms. 



Fossil. Pliocene : Messina (Seguenza) ! 



I have compared this little species with the young of all the 

 known species from the North Atlantic and the Mediterranean, and 

 I am satisfied that it is distinct. 



s. 8. Scalaria semidisjuncta 3 , Jeffreys. (Plate X. fig. 7.) 



Shell corkscrew-shaped or forming a twisted cylinder, thin, 

 semitransparent, and rather glossy : sculpture, numerous and close- 

 set flexuous and sharp lamellar ribs, of which there are about 20 

 on the body-whorl ; the first 3 or 4 whorls are smooth and regular ; 

 the ribs as well as their interstices are crossed by equally numerous, 

 but very fine spiral striae : colour pale yellowish-white: spire elon- 

 gated or drawn out, and gradually tapering ; apex conical and 

 mammillar ; ichorls 7-8, convex, angular, and spinous (muricei) at 

 the top of each ; the last nearly equals one half of the shell when 

 placed on its back, and between one third and one fourth of the 

 spire in a reversed position : suture deeply excavated : mouth cir- 

 cular, with a slight angularity at the upper corner : outer and inner 

 lips thin-edged, the latter being expanded, and folded back on the 

 pillar ; peristome continuous or complete ; no umbilical chink. 

 L. 0-5. B. 0-5. 



'Porcupine' Exp. 1870: Atl. St. 16, 17, 17«. Three specimens 

 of different sizes, and fragments of four other specimens. 



Distribution. Azores (' Talisman ' Exp. 1883); 2199 fms. 



This very remarkable species has many of the characters belong- 

 ing to the last species ; but I do not think it can be a monstrous 

 form of S. nana, because (in addition to other characters which may 

 be observed by comparing the descriptions of both species) so mauy 

 similar specimens and fragments of the present species occurred 

 with the other species in the extraordinary haul off the coast of 

 Portugal, which I noticed in my report of the second ' Porcupine' 

 Expedition of 1870. See the ' Proceedings of the Royal Society' 

 for that year, pages 155 and 156. 



S. disjuncla of Brown from Castellarquato is described as having 

 the last whorl furnished with a convex keel on the base. 



2 Half-disjoined. 



