1885.] Zovlogy. 1227 
fringes are frequently in a state of apparent partial atrophy, and 
enclosed in a common dermal investment of the branchial ramus, 
or all the rami are covered by a common investment, so as to be 
absolutely functionless and immovable. This character, observed 
in the Pseudvbranchus striatus, gave Origin to its separation from 
the genus Siren. The character is, however, common to the 
Siren lacertina at a certain age, and the real difference between 
the genera depends on the different number of the digits in the 
two. 
I have been more than ever surprised on discovering that the 
functionless condition of the branchiz is universal in young indi- 
viduals of Siren lacertina of five and six inches in length; and 
lately I have observed that in a specimen of a little over three 
inches they are entirely rudimentary and subepidermal. I have, 
in fact, noticed that it is only in large adult specimens that the 
branchia are fully developed in structure and function. The infer- 
ence from the specimens certainly is that the branchiz are in the 
Sirens, not a larval character, as in other perennibrachiate Ba- 
trachia, but a character of maturity. Of course, only direct ob- 
servation can show whether Sirens have branchiz on exclusion 
from the egg; but it is not probable that they differ so much from 
other members of their class as to be without them. Neverthe- 
less, it is evident that the branchiz soon become functionless, so 
that the animal is almost, if not exclusively, an air-breather, and 
that functional activity is not resumed till a more advanced age. 
That Sirens may be exclusively air breathers I have shown by 
observations on a specimen in an aquarium which for a time had 
no branchiz at all. (See Jowrnal Academy Phila., 1866, p. 98.) 
In explanation of this fact it may be remarked that this 
atrophy cannot be accounted for on the supposition that it is 
seasonal and due to the drying up of the aquatic habitat of the 
Sirens, The countries they inhabit are humid, receiving the 
heaviest rainfall of our Eastern States, and there is no dry season. 
The only explanation appears to me to be that the present Sirens 
are the descendants of a terrestrial type of Batrachia which passed 
through a metamorphosis like other members of their class, but 
that more recently they have adopted a permanent aquatic life, 
and have resumed their branchie by reversion —E£. D. Cope. 
RECENT ADDITIONS TO THE Museum OF Brown UNIVERSITY.— 
Of late there has been made at this institution considerable effort 
to secure indigenous representatives of the animals which occur 
in the neighborhood of the college, and especially of such as are 
likely soon to be exterminated from the narrow bounds of Rhode 
Island, the most thickly settled State of the Union. Within a 
few weeks there has been secured a local representative of Bland- 
ing’s box tortoise (Amys meleagris), an animal well deserving a 
position in the cabinet, as both an early describer, Dr. John E. 
