COPULATORY ORGANS OP THE AMNIOTA. 
33 
Explanation of Plates. 
PLATES 2-5. 
Fig. 1. Crocodiles vulgaris (nat. size).—Ventrilateral view of the penis ; the greater 
portion of the outermost cloacal chamber has been cut away. 
Gl. = left musk gland. 
Fib. = fibrous band connecting the penis with the symphysis ischium. 
Per. = continuation of the body cavity as peritoneal canal; a probe 
has been passed through the left canal. 
This specimen is in the Enyal College of Surgeons, London. 
Fig. 2. Crocodiles sp. ? (nat. size).—Ventral view of the cloaca and of the female 
genital organs ; the cloacal ventral wall has been partly cut away and the 
anus has been opened out, the clitoris now lying on one side. The peri¬ 
toneal folds and the right oviduct are removed. 
This specimen is in the Museum of Comparative Anatomy, Cambridge 
(No. 1377a). 
Fig. 3. Alligator mississipiensis, 3 (nat. size).—Left lateral view of the rectum, the 
cloacal muscles, and of the plexus pudendus. 
B. P. = bulbus penis. 
Sph. = m. sphincter. 
trans. m. = m. transversus medianus. 
tr. per. = m. transversus superficialis s. m. perinei. 
pr. cl. = the unstriped muscle, described on p. 14. 
v. c. = vena caudalis. 
a. c. = arteria caudalis. 
Sy. lat. = chain of the N. sympathicus lateralis. 
S = N. sacralis = N. spinalis xxvi. 
a — first presacral nerve. 
a =■ first postsacrai nerve. 
cd. fm. = nerves to the m. caudi-femoralis. 
v. d. = vas deferens. 
u = ureter. 
Fig. 4. Alligator mississipiensis. —The nerve branches sent from stems a and /3 to the 
penis, the anal chamber, to the lateral (E. 1.) and to the dorsal wall (E. d.) 
of the rectum ; slightly enlarged. 
MDCCCLXXXVII.-B. F 
