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VIII. On the Development of the Skull in Lepidosteus osseus. 
By William Kitchen Parker, F.R.S. 
Received November 3,—Read December 8, 1881. 
[Plates 30-38.] 
In the early part of 1879 I received from Professor A. Agassiz a large series of eggs 
and embryos of Lepidosteus, which by the help of Mr. Garman he had obtained from 
the Black Lake the year before. These specimens, carefully preserved in fifty-four small 
bottles, Professor Agassiz put into my hands to be worked out by Mr. Balfour and 
myself. A few years before I had received from Professor Burt G. Wilder some 
larger young of this Fish, which extended the “ stages ;; for us considerably; and 
several adults obtained by Mr. Balfour, and one which I received from Professor 
Flower, made up the total of our materials. The present communication is the 
result of my own researches into the growth of the skull and visceral arches. 
Mr. Balfour, assisted by my son, Mr. W. N. Parker, has prepared an elaborate 
memoir on the embryology of this important type, to which are added observations on 
the structure of various organs in the adult. 
When our work was scarcely begun I prevailed upon Dr. Traquair to work out the 
adult skull , and that piece of research is, I believe, nearly finished, so that this 
Holostean Ganoid will soon have had a fair amount of attention given to it. 
My observations extend over a series of embryos and young from one-third of an 
inch to four and a-half inches in length. The larger young are already quite like the 
adult; but as Dr. Traquair's paper has not yet been sent in to the Boyal Society, I 
shall preface mine by a short description of the adult skull: it will give the same 
interpretation as the promised memoir by my talented friend, for we have had several 
discussions upon the nomenclature and meaning of the various parts, and are of one 
mind as to their names and nature. 
BIBLIOGRAPHY. 
Agassiz, Professor Alexander. “On the Development of Lepidosteus .” Proceedings 
of the American Academy of Arts and Sciences (Presented Oct. 8, 1878) ; 
pp. 65-76; plates 1-5. 
Balfour, F. M. 
1. ‘Elasmobranch Fishes/ London: 1878. 
2. ‘Comparative Embryology,’ vol. ii. London: 1881. 
