1896.] NATURAL SCIENCES OF PHILADELPHIA. 243 



51 — Development of the spanisli mackerel (Cybium maculatum). 

 Bull. U. S. Fish. Comm., 1, 1881, pp. 135-172, 4 pis. 



52 — On the retardation of the development of the ova of the shad 

 (^Alosa sapiclissiinct), with observations on the egg fungus and bac- 

 teria. Bull. U. S. Fish Comm., 1, 1881, pp. 177-190. Including an 

 appendix on the histological rationale of retardation, also in Kep. 

 U. S. Comm. Fish and Fisheries, 1881, pp. 795-811. (2ded. revised). 



53 — A contribution to the development and morphology of the 

 lophibranchiates {Hippocampus antiquonwi, the sea-horse). Bull, 

 U. S. Fish Comm.,1, 1881, pp. 191-199,1 pi. 



54 — The micropyle of the egg of the white perch. Bull. U. S. 

 Fish Comm., 1, 1881, p. 282. 



55 — Development of the silver gar (Belone longirodris), with ob- 

 servations on the genesis of the blood in embryo fishes, and a com- 

 parison of fish ova with those of other vertebrates. Bull. U. S. Fish 

 Comm.,1, 1881, pp. 283-301, 3 pis. 



56 — On the nuclear cleavage-figures developed during the seg- 

 mentation of the germinal disk of the egg of the salmon. Bull. U. 

 S. Fish Comm., 1,1881, pp. 335-339,1 pi. 



57 — Notes on the breeding, food and green color of the oyster. 

 Bull. U. S. Fish Comm., 1, 1881, pp. 403-419. 



58 — Additional observations on the retardation of the develop- 

 ment of the ova of the shad. Bull. U. S. Fish Comm., 1, 1881, pp. 

 422-424. 



59 — The protozoa and protophytes considered as the primary or 

 indirect source of the food of fishes. Bull. U. S. Fish Comm., 1, 

 1881, pp. 236-251 ; and Rep. U. S. Comm. Fish and Fisheries, 1881, 

 pp. 755-770. (2d ed. revised). 



60 — Notes on some of the early stages of development of the clam, 

 or mannanose {Mya arenaria Linn.). Report of T. B. Ferguson, a 

 Commissioner of Fisheries of Maryland, for 1881, pp. 81-91, 11 figs. 



61 — An account of experiments in oyster-culture and observations 

 relating thereto, made at St. Jerome's Creek, Md., during the sum- 

 mer of 1880, Report of T. B. Ferguson, a Commissioner of Fisher- 

 ies of Maryland for 1881, 15 figs, in text. Appendix A., pp. 1-64 

 and 76-80 (First Series). 



62 — Structure and ovarian incubation of the top minnow {Zy- 

 gonectes). Forest and Stream, Aug. 18, 1881. (The species was 

 afterwards determined to be Gambuda patrue[is,a.nd the subject was 

 treated of more fully in No. 65 of this bibliography). 



63 — Incubation of shad eggs in brackish or sea-water. Sea- 

 world, Fishing Gazette and Packer's Journal, AVednesday, Oct. 12, 

 1881. 



64 — Observations on the species of planarians parasitic on Limu- 

 lus. Amer. Nat., 1882, pp. 48-51, 10 figs, in text, of egg-capsules, 

 embryos and adult. 



65 — Structure and ovarian incubation of Gambusia patruelis, a. 

 top-minnow. Amer. Nat., 1882, pp. 109-118. (Describes the 



