386 Coe and Kunkel— California Limbless Lizard. 
the phallus, but the mechanism by which the retracted organ is 
everted is much less readily understood. 
Situated immediately lateral to the phalli are very strong semi- 
circular muscles (pl. xivi, fig. 39, ¢c.m) arranged in a single band 
between the phalli and the longitudinal caudal muscles which form 
an irregular layer beneath the integument of the tail. As suggested 
by Unterhdssel (:02, p. 578), these muscles when contracted are 
capable of exerting a very considerable pressure on the posterior 
portions of the phalli and thereby initiate the process of eversion of 
the organs. 
The retractor basalis muscles may aid to some extent in the pro- 
cess of eversion as well as in drawing back the organ after its full 
extension. 
The withdrawal of blood from the sinuses of the rigid, everted 
organ allows it to return to a comparatively small size, after which the 
retractor magnus invaginates the organ to its ultimate position pos- 
terior to the cloaca. 
Although the phalli of the female remain in a rudimentary condi- 
tion throughout life, they are in this sex apparently functionless and 
quite incapable of being everted. 
At the time of copulation the phalli are doubtless everted, as has 
been witnessed in other forms, and inserted into the cloaca of the 
female. The spiral groove with which each phallus is provided then 
leads directly from the cloaca of one animal to that of the other. 
A slight elevation of the urogenital papilla, on which the opening of 
the sperm duct is situated, would bring this opening in close prox- 
imity to the base of the spiral groove. An abundant discharge of 
fluids from the cloacal glands would furnish a ready vehicle by which 
the spermatozoa ejected at the base of the groove might pass along 
the length of this canal to the cloaca of the female, whence the 
right oviduct is the ultimate destination of such as are to fertilize 
the two eggs which will develop therein. 
IV.—Brain anp Pineat AppaRATus. 
B. W. Kunket. 
Pl, xul, figs. 1-3; Pl. xuvi, figs. 44 and 45; Pl. xivu, figs. 46-51; Pl. xLvmi, 
figs. 52-54. 
The brain of Anniella, like that of the reptiles generally, possesses 
well developed cerebral hemispheres and a comparatively small cere- 
bellum. The brain on the whole is rather elongated and compressed 
laterally. 
