260 NATURAL SCIENCE [April 



world have hitherto been plausibly interpreted as the forerunners of 

 the Anacanthini. 



The next deep-sea fish-fauna after that of the Cretaceous occurs 

 in the black hardened shales or slates of the Canton Glarus, Switzer- 

 land, which are commonly assigned to the latter part of the Eocene 

 period (^). Here the higher spiny-finned fishes are already repre- 

 sented by such specialised forms as the ribbon-shaped Lcpidopus ; 

 and there are also true cod-fishes of at least one genus named 

 Nemopteryx. There are still no deep-sea eels, so far as known ; 

 nor are there any traces of the degenerate angler-fishes related to 

 Lophius, such as characterise some of the greatest depths at the 

 present day. 



The general conclusion to be derived from palaeontology, there- 

 fore, is that the tenanting of the deep sea with fishes has been a 

 gradual process, beginning at latest in early Cretaceous times and 

 gradually proceeding until the present day. As new types have 

 arisen successively in the shallower waters, a few have been driven 

 from the regions of greatest competition to the refuge of the in- 

 hospitable depths. At tlie time when physostomous fishes were 

 the dominant type, the refugees were chiefly Scopeloids, allied 

 families, and primitive relatives of the herrings ; in the early 

 Tertiary period, when Anacanthini first appeared in this part of 

 the world, a few cod-fishes were added to the abyssal tribes ; while 

 at some later but undetermined period the strangest of all deep-sea 

 fishes — the highly modified eels — must have completed the remark- 

 able fauna as we now know it. A. Smith Woodward. 



References 



1. Davis, J. W.— The Fossil Fishes of the Chalk of Mount Lebanon, in Syria. Trans. 



Roif. Dublin Soc. [2], vol. iii. , pp. 457-636, pis. xiv.-xxxviii. (1887). 



2. Goode and Bean. — Oceanic Ichthyology. Bull. U.S. National Mus., 1896. 



3. Gttnther, A. — Report on the Deep-sea Fishes. Challenqer Reports, Zool., vol. xxii., 



1887. 



4. Marck, W. vender. — Fossile Fische, etc., aus dem Plattenkalk der jiingsten Kreide 



in Westphalen. Palacontographica, vol. xi. , pp. 1-68, pis. i.-xiv. (1863). 



5. Wettstein, A. — Ueber die Fischfauna des Tertiaeren Glarnerschiefers. Denkschr. 



Scliweiz. Palaeont. Gcs., vol. xiii. (1886). 



6. Woodward, A. S. — On Echid)iocepka,liis, a Halosauroid Fish from the Upper Cre- 



taceous Formation of Westphalia. Fj-oc. Zool. Soc, 1897 pp. 268-271, pi. xviii. 



