QUARTERLY CHRONICLE. 207 
3. HyMENoPTERA, Bombus terrestris, Apis mellifica, and 
the Entomospheces. 
4. Diptera, Musca vomitoria, Pulex canis. 
). Nreuroprera, in which, as before remarked, the appa- 
ratus is less developed than in any other order of insects, 
its condition is described in Panorpa communis. 
6. In the Bues we find Cimezx lectularia, Pentatoma bacca- 
rum. 
7. OrrHorTEeRA, Periplaneta orientalis. 
II. “On the occurrence in the encysted condition of 
Distoma squamula, Rud., in the Brown Frog,” by Dr. Ernst 
Zeller.—In certain districts, and in the author’s observation 
especially in the neighbourhood of ‘Tubingen, the integu- 
ments of the frog are found to be studded with numerous 
little nodules, which do not seem to have been hitherto 
noticed or explained. When present they may vary in 
number from thirty or forty to several hundreds, and they are 
scattered all over the body, but are especially frequent in the 
hinder extremities, in the membrane between the toes, and 
on the abdomen. They project manifestly above the surface, 
and are about the size of a common pin’s head, and of a 
whitish colour, though sometimes brownish or blackish. 
They are lodged in the substance of the corium, and consist 
of a firm connective-tissue capsule which contains the colour- 
ing matter, and of a minute cyst lodged in this capsule. 
The cyst, which is easily enucleated, is spherical and 
about 0°58mm. in diameter, of a white colour, and semi- 
transparent. It contains a convoluted Distoma. 
The anatomy of the worm is then described, and it is shown 
to be distinct from’all the encysted Distomata hitherto met with 
in the frog, viz., Distomum crystallinum, Rud., Distoma 
diffuso-calciferum, Gastald, Distoma acervicalceferum, Gast., 
Distoma tetracystis, Gast. All of which, besides their dif- 
fering in anatomical structure, are lodged beneath the integu- 
ment. 
The author has satisfied himself that it is identical in the 
mature state with Distomum squamula of Rudolphi, which is 
found in the intestine of the J/tis. 
III. ‘ On the Embryonal Development of Asellus Aqua- 
ticus,” by Dr. Anton Dohrn.—This is a very long and elabo- 
rate memoir, illustrated with figures showing (1) the develop- 
ment of the embryo in the ovum of Asellus aquaticus, and 
(2) that of the internal organs—liver, dorsal vessel, stomach, 
and intestine. 
IV. “ A Contribution on the subject of the Structure of the 
Thyroid Gland,” by Dr. Peremeschko, of Casan.—The struc- 
VOL. VII.—NEW SER. P 
