188.5.] 'lightning' AND 'porcupine' EXPEDITIONS. 47 



Post-tertiary formation near Montreal, 13 a synonym of Torellia. 

 His C. elegans closely approaches the present species, and seems to 

 diflFer chiefly in having a smooth epidermis. 



2. Torellia ? delicata, Philippi. 



Cyclostoma ? delicatum, Phil. Moll. Sic. ii. p. 222, t. xxviii. f. 3. 



' Porcupine ' Exp. 18/0: Atl. St. 16, 17 a, 24. 



Fossil. Pliocene: Messina and Calabria (Otto f. Philippi, and 

 Seffuenza). 



Through the kindness of my friend Professor Seguenza, I have 

 compared a fossil specimen with the recent specimens from the 

 •Porcupine' Expedition ; and all of them exactly agree, as well as 

 with the description and figures of Philippi. The sculpture is most 

 delicate and exquisitely reticulated. My largest and most perfect of 

 the ' Porcupine ' specimens is more abnormal than the rest (perhaps 

 a variety), and resembles in shape Lacuna j)alliJula. I have 

 therefore figured it as a variety of the present species in Plate V. 

 figs. 6, 6 a. 



Although this shell certainly does not belong to Cyclostoma, as 

 doubtfully given by Philippi, it wants some of the characters of 

 Torellia, as defined by me in ' British Conchology,' vol. iv. p. 244, 

 viz. the velvety epidermis and tubercle on the" pillar. In my 

 correspondence with Prof. Seguenza some years ago, I had suggested 

 the generic name Trachyomn, which he adopted in his excellent 

 treatise on the Tertiary formation of Reggie province in Calabria, 

 1879. 



1. Trichotropis borealis, Broderip and Sowerby. 



T. borealis, Br. and Sow. in Zool. Journ, iv. p. 375 : B. C iv. 

 p. 245, pi. iv. f. 2 ; V. p, 216, pi. Ixxix. f. 6. 



' Lightning ' Exp. St. 4. 



'Porcupine' Exp. 1869: St. 68. 



Distribution. Arctic ocean in both hemispheres, Iceland, Faroe I,, 

 Norway, Shetland to the Dogger Bank and coasts of Ireland, N.E. 

 and N.W. America; 2-175 fms. 



Fossil. Pliocene : Coralline Crag, Sicily {Briignone). Post-ter- 

 tiary : Norway and Sweden, Scotland, Ireland, North of England 

 and Wales, Siberia, Labrador, and Canada ; 0-1360 ft. It appears 

 that the genus is not restricted to northern seas, Mr. Ball having 

 described a species from the Havana coast, below the Tropic of 

 Cancer. 



Synonyms so numerous that it would be unnecessary to quote 

 them. T. inermis of Hinds was founded on a specimen which had 

 lost its bristly epidermis. 



An imperfect specimen of a species, which Friele procured in the 

 • Vdringen ' Expedition on the arctic coast of Norway in 650 fathoms 

 and named " Trichotropis {Iphinoe) inflata," occurred at Station 23a 

 of the ' Porcupine Expedition ' in 1869. 



