1008 : PISCES. 
Bilal i Ma 
Viscera of male Shark, (After Clift. ) 
a, heart; 6, liver; c, esophagus; d, stomach; e, 
pyloric portion of stomach ; g, pancreas ; h, i, in- 
testine ; k, testis ; 1, vas deferens ; m, urinary blad- 
der; 0, rudimental penis; p, p, peritoneal open- 
ings ; q, q, claspers. 
troduced into the cloaca of the other sex in the 
act of impregnation. The following is Cuvier’s 
description of these remarkable organs, which 
are met with in the males both of the Sharks 
and Rays and likewise of the Chimere, and 
from the composition and relations of the car- 
tilages and muscle which enter into their struc- 
ture are evidently only an extension orappendage 
of the ventral fins, They consist in the Rays 
and Skates of two cartilages articulated end to 
end, situated along the inner side, which forms 
the basis of the whole apparatus. The first of 
these cartilages, which is a sort of femur, ar- 
ticulates with the pelvis, and supports, in con- 
junction with the second (the tibia), the rays 
of the ventral fin. 
A third cartilage unites this fin with the 
genital portion like a kind of astragalus ; this 
. after to be described. 
articulates with the longest cartilage of the 
limb. 
On the side of the astragalus is an oval car- 
tilage having a sharp inferior margin, to which 
may be applied the name of os cu/cis. 
he os calcis articulates posteriorly with 
another principal piece of the limb which may 
be called the metatarsus. This extends all 
along the upper and inner border of the limb 
as far as its extremity, where it forms a sort of 
digit, to which is attached the tendon of the 
great abductor muscle. This large piece is 
formed by the consolidation of three smaller 
ones, two of which run parallel to each other, 
so as to constitute a semi-canal, into which 
opens a duct derived from a large gland here- 
To the metatarsus succeed seven other car- 
tilages, the shape of which is different in the 
various species of Chondropterygii, but which 
obviously represent the phalanges of the abdo- 
minal limb, which is moved by five strong 
muscles which may be named respectively the — 
depressor, the elevator, the abductor, the ad- 
ductor, and the expansor of the fin. It is, 
however, remarkable that there is no muscular 
apparatus calculated to approximate these 
members, and when separated they are brought 
together again entirely by their own elasticity, 
a circumstance which militates strongly against 
their being, as is generally su instru- 
ments of prehension. In the Sharks the clas- 
per contains morever a gland of considerable 
size situated beneath the fin, and extending to 
the exterior of the base of its genital append- 
age. Inferiorly, this gland is only covered by 
the skin, while above it is adherent by the in- 
tervention of cellular tissue to the rays of the 
fin. Its duct is a wide canal which opens into — 
the groove formed by the metatarsal cartilages 
above alluded to, and the fluid which it secretes 
of a highly viscid character. It is said that in 
the breeding season the contents of this gland, 
as well as the parietes of the spe in which — 
it is situated, are red with blood and appear to 
be in a remarkable state of turgescence. It is 
enclosed in a double tunic, one fibrous and the 
other muscular, by the assistance of the latt 
of which its contents are evacuated. 
At the lower extremity of this gland, near its” 
orifice, there is in each clasper a capsule with 
muscular and cavernous parietes, the on of 
which is traversed by slender tendinous fila~ 
ments. In thesesacs Dr. John Davy* has ob- 
served distinct pulsations, and finding that in 
the living fish they were filled with blood, con- 
siders them as accessory hearts destined 
assist the circulation of the blood in these 
appendages to the genital system. & 
he gland itself is of the shape of an olive; 
a longitudinal sulcus divides it into two por 
tions, in each of which a transverse series Of 
very delicate tubes is distinguishable. 
In the females of the Plagiostome Chon- 
dropterygii the arrangement of the sexual o 
gans conforms in an equally striking mann 
with the Reptilian type of structure, 
* Phil, Trans, 1839. 
