136 MOLLUSCA. 
behind, connecting it with the sac, and with two other — 
frena, connecting it with the sac before. 
“Sp. 1. Cranchia seabra—Sac rough, with hard, rough 
tubercles. . 
“ Sp. 2. Cranchia maculata—Sac smooth, beautifully 
mottled with distant ovate spots.” (Narrative of an Ex- 
pedition to explore the river Zaire, usually called the 
Congo in South Africa, in 1816, under the direction of 
Captain J. K. Tuckey, R. N. London, 1818, p. 410.) 
Head surrounded with Hight Arms without Feet. 
The suckers have soft margins. The sac is destitute of 
fin-like expansions, and is either simple or strengthened in 
the interior by two short corneous processes. The head is 
united with the sac behind, without the intervention of a 
neck. 
a. Arms all equal in Size. 
Genus Octorus.—Suckers arranged in a double row. 
The suckers are sessile. The oviduct is double. The 
margin of the anus is simple. The Sepia octopodia of Lin. 
is the type of the genus. 
Genus ELrepona.—Suckers on the arms disposed in a 
single row. 
M. Lamark has figured and described two species of this 
genus, in the Mém. de la Soc. d’ Hist. Nat. One of these is 
a native of the Mediterranean, and is remarkable for giving 
out an odour like musk. 
b. Arms unequal. 
Genus OcytTHor.—Two of the arms at their inner ex- 
tremities furnished with membranaceous expansions. 
In this genus, which was instituted by M. Rafinesque, 
the suckers are in a double row, and supported on foot- 
