1885.] 'lightning' and 'porcupine' expeditions. 43 



over the spiral ridges, a nodose or tuberous appearance is caused by 

 their intersection ; the base is covered with delicate and close-set 

 spiral striae ; apex smooth : colour pearly white : suture slight : 

 spire short, turreted : whorls .5-6, convex ; the last occufiies three 

 fourths of the shell ; the first or topmost whorl is bulbous and 

 intorted : mouth large, polygonal, irregularly sinuated at its base ; 

 outer lip thin and prominent : fissure placed a little below the 

 suture of the last whorl ; it is broad, deep, and ends in a curved 

 indentation : inner lip none : pillar semicircular : umbilicus narrow, 

 but distinct and deep-margined outside, and defined by a slight 

 ridge or keel which terminates in a sharp and projecting point. 

 L. 012.5, B. 01. 



'Porcupine' Exp. 1870: Atl. St. 16, 17, 17a. 



Distribution. Bay of Biscay (' Travailleur' Exp.). 



Not (S. eritima of Verrill, judging from the description and 

 figure. 



3. Seguenzia tricarinata', Jeffreys. (Plate V. fig. 2.) 

 Shell globose, very thin and fragile, transparent, and of a glassy 



lustre : sculpture, three spiral thread-like striae or keels on the body- 

 whorl, viz. one encircling the periphery, another at a short distance 

 below it, and a third at a somewhat greater distance above the peri- 

 pheral stria ; the penultimate whorl is marked with a similar stria, 

 a little above the suture ; the next whorl is keeled at the top : colour 

 whitish : suture deep : spire short and compressed : whorls 3-4, 

 convex ; the last is disproportionally large ; apex flattened : mouth 

 roundish, angulated at the base : outer lip thin ; fissure wide but 

 shallow, forming an angular indentation : inner lip filmy : pillar 

 gently curved and thickened : umbilicus narrow and shallow, mar- 

 gined outside by a slight but distinct semicircular stria or keel. 

 L. 0-075. B. 0-075. 



'Porcupine' Exp. 1870: Atl. St. 17a. A single but character- 

 istic specimen. 



Distribution. Off C. Verd. I. ('Talisman ' Exp.) ; 1192 fms. 



4. Seguenzia carinata, Jeffreys. (Plate V. figs. 3, 3 a.) 



5. carinata, Jeffr. Proc. R. S. 1876, p. 201 ; Ann. & Mag. Nat. 

 Hist. 1877, p. 320. 



' Porcupine ' Exp. 1870 : Atl. St. 16, 17a, off C. Espichel, 22. 



Distribution. North Atlantic (' Valorous' Exp.), off Fayal, Azores 

 (' Challenger' Exp.), off Marocco, Sahara, C. Verd. 1., and Azores 

 ('Tahsman' Exp.); 681-2199 fms. 



This species has a labial slit as in the typical species S. formosa, 



5. Seguenzia reticulata, PhiHppi. 



Solarium reticulatum, Phil. Moll. Sic. ii. p. 149, t. xxv. f. 6. 



'Porcupine' Exp. 1870: Atl. St. 9, 16, 17, 17a. 

 Distribution. Coast of Portugal (' Travailleur ' Exp.), off Ascen- 

 sion I., and Culebra I. (' Challenger' Exp.) ; 390-1791 fms. 



1 Having three keels. 



