1882.] ‘LIGHTNING’ AND ‘PORCUPINE’ EXPEDITIONS. 663 
D. lobatum, G. B. Sowerby, jun., Thes. Conch. 1866, vol. iii. 
p. 100, fig. 44. 
‘ Lightning’ Exp., St. 1. 
‘ Porcupine’ Exp. 1869: St. 19, 42, 89. 1870: Atl. 17. 
Distribution. Arctic ocean from Spitzbergen and Novaia Zemblia 
to Finmark, ‘ Valorous’ Exp., G. St. Lawrence to southern coast 
of New England; 15-1750 fms. 
Fossil. Miocene: Vienna Basin (Hérnes)? Post-tertiary : Nor- 
way, 82° 30' N. lat. (Fetlden), Canada; 4-240 ft. 
Not Dentalium vitreum of O. G. Costa. 
* Discar1peEs Birissus, 8. V. Wood. 
Dentalium bifissum, 8. V. Wood, (Publ. Pal. Soc.) Crag Moll. i. 
p- 190, t. xx. f. 3, a-d. 
‘ Porcupine’ Exp. 1870: Atl. St. Vigo B., Setubal B. ; Med. 50, 
50a, Benzert Road, Adventure Bank. 
Distribution. G. Gascony, Mediterranean from Gibraltar to 
Sicily, Morocco, Canaries; 5-180 fms. 
Fossil. Pliocene: Coralline Crag, Italy. Post-tertiary : Selsea. 
Bony whitish, gelatinous: mané/e rather thick, forming a collar 
round the front opening of the shell: captacula issuing from within 
the mantle, numerous, capable of so great an extension as to exceed 
the shell in length ; stalks very slender ; terminal bulbs oval: foot 
cylindrical and narrow, protruded from the middle of the mouth 
as from a sheath ; it is occasionally thrust out in a darting manner 
and suddenly withdrawn, and so swiftly that the point of the foot 
could not be observed ; the foot is usually curved towards the point : 
anal tube protruded beyond the narrower end or extremity of the 
shell; it consists of an outer and inner part, the latter being folded to 
suit the slit on each side: gills rather short, of a brownish colour. 
There are several useless synonyms. ‘This species appears to be 
Dentalium coarctatum of Deshayes, but not of Lamarck. It was 
erroneously considered by me Dentalium olivi of Scacchi, for which 
see Cadulus. A species of Dischides, dredged by the late Admiral 
Sir E. Belcher in the North Pacific, somewhat resembles the present 
species, but is proportionally wider and the terminal slits are 
shorter and more open. The generic character of Dischides is the 
bilateral position of the terminal slits. Gadus bilabiatus and G. pa- 
risiensis of Deshayes, Eocene fossils, are not unlike D. difissus in 
shape; but the terminal point or base is jagged as in Siphodentalium 
vitreum, and the slit is much shorter. Besides, Gadus has been 
very long and notoriously used in Ichthyology. 
yy 1. Capuxus oxrvt, Scacchi. 
Dentalium olivi, Sc. Not. foss. Gravina (Ann. Civ. 1835), p. 56, 
to 2.4. 0, 2s 
‘ Porcupine’ Exp. 1869: St.17. 1870: Atl. 9. 
Distribution. Floré, Norway, a fragment (Norman), Bay of Biscay, 
Palermo (Monterosato), ‘ Valorous’ Exp., New England (Verril/) ; 
80-1450 fms. 
Ge Beil 
