THYSANOTEUTHIDA—ONYCHOTEUTHID A, 31 
Histioreuruis, d’Orbigny, 1839. 
Htym.—Histion, a veil, and teuthis, a calamary. 
Distr.—3 sp. Mediterranean Sea; off Nova Scotia. H. Bonel- 
liana, Fer. (xxvi, 33, 34). 
Body short, cylindrical; head long; arms long, the three 
superior pairs connected by a largely developed web, the ventral 
pair free; tentacles long, with six rows of dentated cups on their 
clubs ; buecal membrane six-lobed. Pen short and broad. 
Famity THYSANOTEUTHID A. 
TuysANoTeutTuts, Troschel, 1857. 
EKtym.— Thysanos, a fringe, and teuthis, a calamary. 
Distr.—2 sp. Mediterranean Sea. 7. rhombus, Trosch. (xxvi, 
36, 37). 
Body with large triangular fins the whole length of each side ; 
arms with lateral expansion of the skin, and two rows of pedun- 
culated suckers, from which spring thre ads which are connate 
with the surface of the lateral expansions. Shell file-shaped. 
Famity ONYCHOTEUTHID &. 
The principal character of this family is the development of 
hooks upon the arms, as a means of prehension; they replace 
the sucking disks to a greater or less extent, according to the 
several genera. A few fossil forms occur. 
Gonatus, Gray, 1849. 
Distr.—G. amena, Moll. (xxvi, 38), is found on the coast of 
Greenland. 
Body like Loligo; arms thick, with four rows of small suckers; 
tentacular clubs with many rows of small suckers, and a single 
large basal cup armed with a hook; siphon not connected to the 
head, without valve. Gladius lancet-form. 
OnycuoteuTuis, Lichtenstein, 1818. 
Etym.—Onyx, a claw, and teuthis, a calamary. 
Syn.—Ancistroteuthis, Gray, 1849. 
Distr.—10 sp. Atlantic and Pacific O., arctic and tropical ; 
Mediterranean. O. Krohni, Fer. et Orb. (xxvi, 39, 40). 
Arms with two rows of suckers, the rings of which are not 
toothed; tentacles thick, their clubs with two rows of strong 
hooks, and at the base a rounded group of suckers, with which 
they are supposed to unite the two tentacles, and use them in 
conjunction as a point d’apput, where great strength is required 
in capturing their prey. Gladius lancet- form, with a conical 
commencement. 
