484 MURICIDA. 
M. Istanpicus, Chemnitz. 
Fusus Islandicus, Brit. Moll. iii. p. 416, pl.103. f.1,3; (animal) pl. 8.8. 
£2: 
M. propinquus, Alder. 
Fusus propinquus, Alder. 
———, Brit. Moll. ni. p.419, pl. 103. f. 2; (animal) pl. S.S.f.1. 
Notwithstanding the variation in the apex of M. Islandicus 
and M. propinquus, their distinctness may be doubtful. 
Sectio II1].—Testa inflata, varicosa vel levis, sepe spiraliter granoso-un- 
dato-striata. Canalis brevis. Apertura ovalis. Columella fastigiata. 
Operculum corneum. 
Buccinum, Auctorum. 
M. unpatvus, Linnzeus. 
Buceinum undatum, Brit. Moll. ui. p. 401, pl. 109. f.3,4,5,; pl. 110. 
f.4; (animal) pl. L.L. f. 5. et omnium Auct. _ 
B. Humphreysianum, Bennet, et Brit. Moll. ii. p. 410, pl. 110. f. 1. 
Animal with eight spiral turns, of a pale yellow ground 
colour in all parts, sparingly interspersed with irregular dark 
blotches on the upper part of the foot, the tentacula, and 
branchial fold. The mantle is of thin texture, and no portion 
of it extends beyond the shell, except the branchial fold, which 
when in action floats far beyond the emargination of the shell, 
for only slight traces of a canal remain. The head is small, 
compressed, not at all produced, and does not in the least 
interfere with the coalition of the tentacula at the bases ; 
these are long and flattish, broad at their origins as far as the 
eyes, which are placed on shortish external offsets, and the 
remaining portion terminates in rounded but not pointed 
extremities. The mouth is a vertical central fissure rather 
below the surface of the head, and from it a very long and 
powerful proboscis is exserted, armed with the usual spinous 
tongue. The foot is large, broad, and about as long as the 
shell, slightly auricled and curved in front, and rounded pos- 
teriorly to an obtuse pomt; on its upper part it carries a 
comparatively small, but strong, hight corneous, suboval oper- 
culum, having the strize of increment of the same form, with 
he nucleus about the middle of its outer edge. There are 
