11 Pisces. 
PISCES. 
CHONDEOPTERYGII. 
Balfour, F. A Monograph on the Development of Elasmobranch 
Fishes. London ; 1877, 8vo, 300 pp., 20 pis. [See Zool. Rec. xiv. 
Pisces, p. 8]. 
A very extensive work, the result of studies followed out principally in 
the laboratory at Naples. The development of this class of fishes is 
j traced from the earliest stages of cell-division and formation of the 
; primitive cell-layers ; many results of the highest physiological interest 
' have been obtained. The author has arrived at the conclusion that the 
i, paired fins of fishes have been formed by the specialization at the 
shoulder and hip of a pair of continuous lateral fins similar to the con- 
tinuous dorsal fin of many kinds of fishes. He traces the development of 
the kidneys of all the Vertebrates back to a series of isolated coiled 
tubules, a pair of which corresponded to each joint of the backbone, each 
\ tubule having a funnel-like mouth opening into the body-cavity. 
^ . On the development of the Proto-vertebrae in Elasmobranchs. A 
{ Note in Rep. Br. Ass. xlvi. p. 147. 
— r— . On the Structure and Development of the Vertebrate Ovum. 
Q. J. Micr. Sc. (n.s.) xviii. pp. 383-438, pis. xvii.-xix. 
The present paper records observations on the ovary of but two types, 
Mammalia and Elasmobranchii. The main points dealt with are 
these : — 1. The relation of the germinal epithelium to the stroma. 2. 
The connection between primitive ova in Waldeyer’s sense and the per- 
manent ova. 3. The homologies of the egg membranes. Development 
of the Elasmobranch ovary, pp. 384-418. Post-embryonic development 
of the ova, pp. 401-416. Summary of observations on the development 
of the ovary in Scyllium and in Raia, p. 415. 
f A single number of Bronn’s “Klassen und Ordnungen des Thier- 
{ Reichs ” has been issued, pp. 49-80, pis. ix. & x., continuing the description 
^ of the anatomy of the Elasmobranch fishes. 
/ Parker, W. K. On the Structure and Development of the Skull in 
Sharks and Skates. Tr. Z. S. x. pp. 189-234, pis. xxxiv.-xlii. 
Of this elaborate memoir, a summary, which it would be impossible 
further to compress, was given in P. Z. S. 1876, p. 699. 
Reichert, — . Ueber das vordere Ende der Chorda dorsualis bei friih- 
zeitigen Haifisch-Embryonen (Acanthias vulgaris). 1. Geschichtliche 
Einleitung, pp. 1-64. 2. Anatomische Beschreibung des Embryo’s, 
pp. 66-90. 3. Anatomische Feststellung des vorderen gebeugten 
Abschnittes der Chorda dorsualis, pp. 91-106. Ergebnisse, pp. 105- 
. . 113. Abh. Ak. Berl. 1877 [1878], pp. 49-113, pis. i. & ii. 
On the anterior extremity of the chorda dorsalis in early Dog-fish em- 
bryos. Historical introduction ; anatomical description of the embryo ; 
j determination of the anterior segment of the dorsal chord. Results are 
summed up at pp. 105-113. The author gives an abstract of precisely 
similar investigations on early embryos of [^Spinax] Acanthias nigeVy in 
I SB. nat. Fr. 1878, pp. 161-169. 
