44 BELOSEPIID. 
they serve for the seizure of food. I have been able to verify 
this fact a second time in examining the Calamaries—which pur- 
sued a troupe of little fishes, capturing them with these members. 
Moderate forward or backward progression is not due solely to 
the fins, but is assisted by the expulsion of water from the funnel; 
if the animal move forward, the funnel is recurved in front, and 
forms nearly a right-angle with the body; in retrograde move- 
ment the siphon becomes horizontal; it is placed to the right or 
left when the Sepia would turn, and is strongly recurved from 
front to back when it would mount to the surface of the water. 
The variations of form of the siphon are indisputable, and one 
eannot doubt their influence upon the direction taken by the 
animal, but the marginal fins are not less useful; their undulations 
commencing anteriorly when the animal moves forward, and 
posteriorly in backward movement; they change suddenly as 
the direction may be varied. The same facts were remarked 
with regard to the Calamary. 
SEPIELLA, Gray, 1849. Cuttle-bone weaker, subcartilaginous, 
always without either carina or posterior beak. At the posterior 
part of the bone is a profound subcutaneous pouch, opening by 
a large pore at the posterior extremity of the mantle between 
the fins. 
HEMISEPIUS, Steenstrup, 1875. 
Distr.—H. typicus, Steenst. (xxvii, 46, 47). Cape of Good 
Hope. 
Differs from Sepia by the sessile arms having only two rows 
of suckers ; the ventral surface of the mantle with aqueous pores 
situated in little nipples, and connected together by a longitu- 
dinal groove. The very rudimentary calcareous partitions of 
the inner side of the cuttle-bone only cover a portion of the 
excessively thin plate. 
TRACHYTEUTHIS, Meyer, 1846. 
Syn.—Cocoteuthis, Owen, 1855. Glyphiteuthis, Reuss ? 
Distr.—3 fossil species from the Jurassie of Europe. T. hastt- 
formis, Ruppell (xxviii, 71). 
Shell like Belosepia, thickened ventrally by horny, instead of 
chalky layers. ; 
The shell resembles Sepia in the dorsal side being granulated, 
but the ventral side is horny instead of chalky; the posterior 
end has long wing-like expansions. 
Famity BELOSEPIID #4. 
BexoseprA, Voltz, 1830. 
Distr.—5 fossil species. European Eocene. 8B. sepioidea, 
Blainv. (xxviii, 64, 65). 
