542 W. J. Barkas — List of PalcBozoic Fishes. 



states tliat " eruptions take place from this volcano at intervals of 

 from 10 to 12 minutes ; it forms therefore a beautiful beacon by 

 nio-ht ; its intermittent fires seem like some colossal revolving 

 lio-ht." Another permanently active volcano is said to exist in 

 the Kamtschatkan group, and others would appear to occur in the 

 New Hebrides and several of the Pacific Islands. 



Mr. Mallet's suggestion, therefore, in the case of Stromboli, of 

 a geyser beneath an active volcanic vent, may be dismissed as 

 wholly unnecessary, as well as improbable, not to say impossible. 

 The promulgation, however, of this strange notion, together with the 

 arguments adduced to support it, may perhaps serve to show that 

 I was justified, when commenting on Mr. Mallet's " theory of 

 Yulcanicity," in saying that he appeared to have no very clear or 

 just notions upon the character of volcanic action, and may there- 

 fore excuse the seeming discourtesy of the remark. When a 

 physicist of some reputation — and I am far from denying Mr. 

 Mallet's claim to that title in his own sphere— produces a novel 

 theory of great pretensions, which is, by his own showing, to 

 upset the views previously held by all geologists on the subject, 

 while expressing no small contempt for their opinions and argu- 

 ments, he must expect his own views, when he deals with geological 

 facts, to be closely scrutinized and estimated at their true worth. 



II. — List of Paljeozoio Fishes. 



By W. J. Barkas, L.R.C.P. Lond., M.R.C.S. Eng. 



(Edited and Revised by William Davies, of tlie British Museum.) 



PALiEONTOLOGY, like most other sciences, has attracted a large 

 number of students since the first pioneers cleared the way for 

 inquiry and brought the fossil remains into something like con- 

 nected order. This increase in the number of inquirers has borne fruit 

 in the immense variety of fossil remains that are scattered about in 

 museums and private collections, the variety being now so great 

 that it has become almost impossible for one person to study the 

 whole of them, in consequence of which the majority of students 

 confine themselves to the fossils of one formation or to the remains 

 of a natural order, as Invertebrata or Vertebrata. Here, again, the 

 application of a number of investigators to one distinct bi'anch is 

 bringing a further increase to our knowledge in that branch. Take 

 the case of fossil fishes. It was quite possible twenty or thirty years 

 ago for the great palaeontologist Agassiz to describe and figure what, 

 as the result of seventeen years of close study, was then known of 

 the fossil fishes of all formations; but the stimulus that resulted 

 from the publication of his work has piled up the list in a wonderful 

 manner, so that it would be well-nigh impossible for any ordinary 

 palaeontologist to describe them all now in anything like a satis- 

 factory way. This great amplification necessitates inquirers to 

 confine themselves to the fish remains of a single formation, or to a 

 particular part of the fish, as for example, the teeth. One result of 

 this disjointed manner of collecting is that a number of fish remains 



