Embryology. 755 
is, like that of the periblast or merocytes in fish ova, for the pur- 
pose of appropriating the yolk substance. Two admirably drawn 
colored plates illustrate Mr. Watase’s memoir. 
DEVELOPMENT OF THE Sra-Bass (Serranus atrarius).—During 
the early part of the month of July last, in the laboratories of the 
U. S. Fish Commission, at Wood’s Holl, Mass., the writer had the 
opportunity to study the development of this form. The eggs are 
of the floating or pelagic type, and very transparent, measuring 
very nearly 1 millimetre in diameter. The buoyancy of the egg is 
no doubt increased by the presence of a moderately large oil drop 
which is embedded in the yolk, near its periphery, and at the pole 
nearly opposite the point where the blastoderm is formed. Hatch- 
ing occurs at the end of the third day, and the oil drop is pushed 
toward the cephalic end of the yolk, as the latter is nearly 
absorbed. : 
The embryos when hatched present much the appearance of the 
young Tautog or Mackerel, as respects their transparency, but they 
soon have their pigment spots arranged in a peculiar way along the 
edges of the median fin folds. Later, the arrangement of the pig- 
ment cells is somewhat different and more irregular, while a second 
kind of pale yellow pigment cells appear, forming three pretty well- 
efined transverse bands, at equidistant intervals, across the body 
and tail of the young fish. 
N THE DEVELOPMENT OF THE CALCAREOUS PLATES OF 
ASTERIAS,! is the title of a beautifully illustrated memoir by J. 
Walter Fewkes on the later history of the young star-fish, which, 
together with the memoir by Mr. A. Agassiz, makes our knowledge 
of the development of these echinoderms very complete. Five fine 
plates illustrate the paper. 
VALUES IN CLASSIFICATION OF THE STAGES OF GROWTH AND 
Decuin E, WITH PROPOSITIONS FOR A NEw NOMENCLATURE.— 
Under this title, Prof. A. Hyatt discusses the values of larval and 
growth characters, introducing a number of new terms.’ 
* Bulletin of the Mus. Comp. Zoology, Harvard College. XVII, No. 
1, July, 1888. (Studies from the Newport Marine Laboratory. 
Proc. Boston Society of Nat. History. XXIII., 1888, pp. 396-407. 
