670 General Notes. [June, 
Below the chitin-forming epithelium, is a bed of conjunctive 
tissue, having all the essential traits of the dermis of higher ani- 
mals 
When the animal molts, it casts off only the external layer of 
the epidermis, and below this may be already seen other yet soft 
chitinous beds proceeding from the epidermis. 
he digestive canal of the Crustacea is lined bya chitinous bed, 
the structure and mode of formation of which is the same as that 
of the external teguments. In examining this lining, M. Vitzon 
discovered the presence of salivary glands. 
he internal as well as the external lining is cast off in the 
molt, but the Brachyuraand Macroura do not molt in the same 
manner. The former keep their usual posture during the change, 
the abdomen is freed before the cephalo-thorax and chele, an 
the carapace separates from the epimera. The latter lie upon their 
side, the membrane between the cephalo-thorax and first abdom- 
inal somite is broken, and the cephalo-thorax is freed at once. 
measurements of the rejected carapace and of the pr 
before and after its change of covering, M. Vitzon arrives at the 
belief that the increase in size of the creature takes place rari 
the change, which is caused by it, and not, as usually s 
during the time that the carapace is soft. of 
Previous to the formation of the chitinous envelope, a pede 
glycogenous matter is deposited around the body below Aa 
carapace, and this reserve of nutritive matter has disappeared n 
the new tegument is formed. These glycogenous subi i 
constantly being stored up in the liver, ovaries, lymph, etc. pe 
for the change that will exhaust them. In the Macroura, fs 
reous depositions are formed in the stomach previous to ser 
and in the Brachyura lime salts are abundant in the bloog W 
the time of the change approaches. The 
HINCKLEY ON THE MOUTH STRUCTURE OF Tare aii 
Proceedings of the Boston Society of Natural linet 
the results of observations upon the mouth structure 0! ~ 
poles of Rana silvatica, R. catesbeiana, R. halecind, R. fi and HY- 
R. palustris, Bufo americana, B. fowleri, Hyla versicolor 5 
lodes pickeringii. The mouths of these adele a tad 
merous shap” 
‘thin the lips, om¢ 
pointed teeth, and also several fleshy folds within These 
three within the upper and two to four within the pele appeat 
folds are set along their free edges with fine teeth, W. gre action 
out at right angles with the lip, but are laid back when ©" pi nged 
wishes to reject any substance caught. The under lip is 
under 
with papillæ. In Rana the upper lip is shorter than in the ip 
three 
All 
