Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 467 
ammonites. The fish remains described by MM. Pictet and Humbert are 
enumerated, and the author states that others are in the possession of the Rev. 
Mr. Lewis, and at the college at Beyrout, which will probably considerably 
increase the number of known species when they are described. 
The hard chalk of Hakel is principally remarkable for the immense numbers 
of fishes found between some of the layers composing it. Hundreds of the small 
Leptosomus macrourus are preserved on slates occupying only a few square feet, 
and some other species are proportionately numerous. Several species of comatula 
and of echinoderms, cuttlefishes and crustaceans (Pseudastacus) are more or less 
common. Dr. Fraas cites the several species of fossil fishes hitherto described as 
found at Hakel, and which have been already mentioned in the previous pages 
of this memoir. Dr. Fraas describes and figures an example of the genus 
Gyrodus, consisting of the teeth and jaws (‘‘ Aus dem Orient.,” pt. 11, p. 92, 
plate 4, figs. 5, 6), which is named G. syriacus, Fr. 
As the special characteristics of the lithology and paleontology of the 
remaining strata of the Turonbildung and those of the Cenomanbildung do not 
influence the consideration of the present subject, the reader desirous of further 
information may be referred to the pages of Dr. Fraas’ most interesting work. 
III.—CLASSIFIED DESCRIPTION OF THE FOSSIL FISH REMAINS. 
The classification of the fossil fish remains described in the following pages is 
based, so far as has been practicable, on that of Dr. Albert C. L. G. Giinther, 
Keeper of the Zoological Department of the British Museum. The great and 
comprehensive summary of ichthyological knowledge contained in the ‘‘ Catalogue 
of Fishes” (1859-1870), and epitomized in his ‘Introduction to the Study of 
Fishes” (1880), will justly constitute the foundation on which future ichthyologists 
will base their researches and deductions in this branch of Zoology. Founded to a 
large extent on the classical researches of Dr. Johannes Miiller, and embracing the 
most recent work of modern embryologists and anatomists; combined with the 
experience obtained by constant association with the large and unrivalled collec- 
tions in the British Museum, Dr. Giinther’s work will always remain as a fitting 
monument of his intellectual energy in the systematic arrangement of fishes. 
The Class PISCES is divided into four sub-classes :— 
I. Patazicutuyres = Elasmobranchii, Ganoidei, and Dipnoi (Huxley). 
I]. Trveosrer = Teleostei (Huxley). 
III. Cycrosromata = Marsipobranchii (Huxley). 
IV, Leprocarpi = Pharyngobranchii (Huxley). 
