PISCES. 149 
temporal of the higher animals. Therefor^ the author adopts the view of 
other anatomists, that Cuvier’s mastoid hone is the true temporal. 
The subject of the second memoir (Ann. Sc. Nat. 1864, i. p. 241) is the 
opercular apparatus. The interoperculum is a part of the neuro-skeleton, 
whilst the operculum and suhoperculum belong to the dermo-skeleton. The 
author directs our attention to the fact that the interoperculum is constantly 
in close connexion with the mandible, and that when the opercular pieces 
are more or less disconnected from one another or from other bones of the 
skull, as in LopJiins piscatorius, the interopercle continues to be attached to 
the mandible. Hence he formerly came to the conclusion that this bone is 
the termination of the cartilage of Meckel, or homologous to the malleus ; but 
since by other researches it has been proved that that cartilage becomes 
entirely surrounded by, and terminates with, the mandibulary bone, it is 
more probable that it is homologous to the incus . — The opercle and subopercle 
are considered analogous to the branchiostegals. 
In the third memoir, on the temporal bone (Ann. Sc. Nat. 1864, i. p. 359), 
the author extends his researches over all the classes of Vertebrata, and 
starts some quite novel views : — The temporal bone of the foetus of Mammals 
is composed of four elements, viz., the petrosal, squamosal, the tympanic 
frame (cadre), and the tympanic drum, whilst the mastoid, which has gene- 
rall}'^ been considered a distinct bone, is merely the outermost part of the 
petrosal. The squamosal has been recognized in Birds by Cuvier and most 
other anatomists, but not so in Reptiles and Fishes, in which it was taken 
for a mastoid; Amphibians have no squamosal. The tympanic frame of 
Mammals becomes the os quadratum of Birds and Reptiles; the drum be- 
comes a first segment of the zygomatic arch in these two classes, whilst in 
Amphibians and Fishes it is gradually transformed into the elements for the 
articulation of the mandible. Finally, the petrosal loses more and more its 
character as a complete external covering of the labyrinth in the series of 
air-breathing oviparous animals, until, in the Fishes, it disappears entirely, 
the labyrinth being non-ossified and placed in the interior of the skull. 
D. Publications of a Popular Character. 
The Salmon. By Alex. Russel. Edinb. 1864. 8vo, pp. 248. 
The object of the book is to put clearly before the public the 
commercial importance of this fish, to review Salmon legislation 
of the past, and to discuss that of the future. Although we 
cannot enter here into the details of this work, we would not lose 
this opportunity of adding our testimony as to the excellent 
manner in which the author has treated the Natural History of 
the Salmon, giving a clear and precise account of its develop- 
ment according to the investigations made in this country by 
various naturalists. 
The FI erring ; its Natural History and National Importance. 
By John M. Mitchell. Edinb. 1864. 8vo, pp. 372, with 
Illustrations. 
This work contains a very detailed account of the habits of 
