18 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
of the mouth, each being provided with a free cylindrical cirrus; an 
upper and lower lij), the latter not extending across the symphysis; 
fourth and tilth gill-oi)enings close together; eyes very small. The 
backward ])osition of the tirst dorsal distinguishes this family from all 
others in our waters. Genera two ; species about four ; large sharks of 
the warm seas. {Sei/Uiidce pt. Gunther, viii, 407-409.) 
*Teetli in botli in many series, each with a strong median cusp, and one or two 
smaller cusps on each side Ginglymostoma, 1 i. 
13.— GIWOLYMOSTOITIA Miiller & Henle, 1837. 
(Miiller & Henle, Wiegmauu’s Arch. 1837, p. — : type Squalus cirratus Gmelin.) 
Tlie characters of this genus are those of the family above given, with 
the addition of the following, which distinguish Ginghjmostoma from 
Nehrius: teeth of both jaws in many series, each Avith a strong median 
cusp, and one or two smaller cusjns on each side. {ycyyXb/j.uq, a hinge or 
hinge-like joint; <Trb/j.a, moutli.) 
18. G. firralMUi (Gmel. ) M. & H.—2\birse Shark. 
Unihtrm brownish ; young specimens Avith small, scattered, round 
black si)ots ; nasal cirrus reaching the loAver lip ; angles of the tins 
obtusely rounded; caudal fin forming nearly one-third of the total 
length. L. 0 to 10 feet. {GiintJier.) 
A large shark of the Avarmer parts of the Atlantic, abundant in the 
Gull of Mexico and the West Indies, and occasionally taken on our 
South Atlantic coast. 
ci/-m^((.s Gmeliu’s Limiipus, i, 149.1; Muller & Henle, 23 ; Gunther, Adii, 408.) 
Super-family GALEORHINOIDEA. 
{The Galeorhinoid Sharhs.) 
Family VII.— GALEORHINIDyE 
{The True Sharhs.) 
Sharks Avith tAvo dorsals and an anal tin; no spines; pectorals mod- 
erate; caudal fin not greatly elongated, not luuate, moderately bent 
upAvards, notched toAvard its end, and Avith the basal much less de\'el- 
oped than the upper; caudal iteduncle not keeled; posterior gill-opening 
above the base of the pectoral tin; eyes Avith nictitatiiig membranes; 
head not hammer-shaped, the snout being longitudinally ])roduced as 
usual among sharks. A large family of twenty or more genera and about 
