702 



SCIENCE. 



[N. S. Vol. XVI. No. 409. 



Urolithen; Scupln, important reference to 

 Ehynchodont dentition; Manigault, on the 

 source of the S. C. phosphate deposits; and a 

 number of omitted references in the case of 

 such authors as Priem, Rohon, Sauvage (of 

 this author no titles given after '88), Traquair 

 and Smith Woodward. And so on through the 

 book, doubtless, if a critic chooses to use a 

 microscope. I note, by the way, no reference 

 at all to the Devonian ' lamprey ' Palwospon- 

 dylus, upon which much has been written 

 during the past decade. Probably this omis- 

 sion is due to the absence of this vertebrate in 

 American localities, a reason which would be 

 valid, even in the case of so interesting a 

 form, had the author not repeatedly violated 

 his rule and given prominent reference to such 

 exotics as Arcli(Bopteryx, Pareiosaurus and 

 monotremes. Also there is no reference to 

 conodonts, which are surely American enough, 

 but omitted, doubtless, on account of their 

 questionable kinship to vertebrates. Certainly 

 they at least deserve mention, since some of 

 them, as Hinde has shown, are strikingly simi- 

 lar in structure to the dental cusps of hag- 

 fishes. 



Dr. Hay has of course made a number of 

 name changes on the score of priority, a result 

 which was to be expected and dreaded in such 

 a work, for it is a sad trial to have a long- 

 known friendly name whisked away and a 

 strange one, archaic, often intrinsically objec- 

 tionable, substituted. Sometimes, though, we 

 have to be grateful for an accustomed name 

 even in bad Greek or misspelled, and the 

 purists' use of Lepisosteus and Crocodylus is 

 the smaller thorn in our flesh. I think, how- 

 ever, that Dr. Hay has overdone the matter in 

 certain cases, for my feeling is that the com- 

 munity at large will resist any name-change 

 where there is the slightest chance of mistaken 

 identity, or where an older group-name is made 

 useful only by torturing its definition into 

 shapes which its author never dreamed of. As 

 a pertinent example of a change of the former 

 kind take the use of Acanthoessus for the 

 well-known paleozoic shark Acanthodes. Both 

 are names given by Louis Agassiz, who, having 

 received better material, rejected Acanthoes- 

 sus, which may have been based upon congen- 



eric specimens : but as Agassiz, who was in a 

 position to decide the matter, does not assure 

 us that the forms were the same, I can see no 

 adequate reason for resurrecting the . earlier 

 name, especially since the types of Acanthoes- 

 sus are lost! As an example of a change of 

 the latter class observe the dilatation of Cope's 

 order of sharks, Ichthyotomi, so as to include 

 the cladodont sharks of Ohio (Pleuropterygii). 

 Now as a matter of fact this term, even in its 

 restricted sense, can be used only by twisting 

 the definition heroically, for, as many know, 

 it was based upon some Permian shark heads 

 in which Cope mistook artifacts for separate 

 bones, and his definition of Ichthyotomi has 

 in consequence been found to be erroneous on 

 every count; but as it happened that the 

 sharks in question were Pleuracanths, well 

 known in the Permian of Europe, there grad- 

 ually filtered into the collapsed definition the 

 facts of Pleuracanth vertebral column and fins 

 — but no facts or modifications which could 

 warrant placing within this group the clado- 

 selachian sharks when later these became 

 structurally knovsm. In this connection I may 

 note that Claj^pole's Ohio ' Cladodus ' is the 

 same as Cladoselache, for although Claypole 

 did not give reasons for his position, he failed 

 to acknowledge the validity of the newer 

 genus. So it comes about that Dr. Hay has 

 one half of the Pleuropterygians arranged 

 under one order and the other half under 

 another. A second instance of the use of a 

 term insufficiently defined to be of legitimate 

 value is the resurrected Aspidoganoidei of 

 Gill. On the other hand, in creating a new 

 group-term, Aristoselachii, it seems to me that 

 Dr. Hay does not practice what he preaches in 

 this very matter of priority. Por this term 

 includes precisely the forms for which Selacha 

 was used by Bonaparte about 1840. Another 

 inconsistency is in his use of Pisces for fishes 

 not including sharks, rays and chimaeroids: 

 for this rather startling use of the term he 

 cites as authority the X. ed. of Linne, but I 

 fancy that priority itself does not require us 

 to hold fast to this misconcept of Linne for 

 since the time of Aristotle or even Bay and 

 Artedi, the term Pisces has just about the 

 same meaning in which it is accepted to-day. 



