126 Reviews — A. 8. Woodward's Catalogue of Fossil Fishes. 



some genera (Didymaspis, Tremataspis) and tlie ventral plates of 

 J^ten'chthys. 



In plates v. and vi. figures of the British species of Ptericlithys 

 are given, which are a great improvement on the old figures of 

 Agassiz. In plate v. fig. 10, however, the central plate of the 

 lower arm is lettered " anconeal," and a portion of the terminal one 

 " central," the same mistake occurring also in pi. vi. fig. 4. 



Dipnoi. 



The Dipnoi are made to include two orders, Sirenoidei and 

 Arthrodira. The Sirenoids, which are characterized by their 

 archipterygial paired fins, and bodies covered with imbricating 

 scales, are divided into the four families of Dipteridse, Phanero- 

 pleuridse, Ctenodontidas, and Lepidosirenidss ; but this arrangement 

 leaves room for revision, as JJronemus cannot be included in the 

 Phaneropleuridse, however much it resembles Phaneropleuron in 

 external shape. Under Ctenodontidse a somewhat serious error 

 occurs in connexion with the description of a fine cranial shield of 

 Ctenodus cristatus, which is also beautifully figured in plate iv. 

 Here Mr. Woodward states (p. 253) that "the median series of 

 bones is arranged exactly as in Acipenser and JPolyodon." The 

 arrangement does indeed resemble that in Acipenser, but not in 

 Polyodon, in which there is no large median plate at the back of 

 the shield, but two plates corresponding to the parietals of Palaeo- 

 niscidaj and Chondrosteidas, and like them being in contact in the 

 middle line. Another mistake occurs on p. 234, in which, referring 

 to what he gives as the " upper dental plates " of the same species 

 (fig. 36, No. 2), he says that they are " somewhat inaccurately drawn, 

 the oral aspect being in reality concave." But the fact is that they 

 are quite accurately drawn, but unfortunately represent the lower 

 and not the upper dental plates of the species in question. It is, 

 however, fair to state that this error originated with the late Messrs. 

 Hancock and Atthey, from one of whose plates the figure in question 

 is copied.^ 



Coccostens and its allies Mr. Woodward boldly places in the 

 Dipnoi, where they form the order of Arthrodira, which he considers 

 to bear " the same relation to the Sirenoidei that the Acanthodians 

 seem to hold with respect to the primitive Elasmobranchs (Ich- 

 thyotomi) or the Actinopterygians with respect to the primitive 

 Teleostomes (Crossopterygii)." This is an attractive solution of 

 the question which has often been hinted at since the discovery of 

 DinichtJiys and its Lepidosiren-\\ke teeth by Prof. Newberry. It 

 may be so, and though I myself am one of those who have enter- 

 tained the idea,^ I scarcely feel yet that the matter is sufiSciently 

 ripe for definitely raising the Arthrodira beyond the rank of 

 " incertce sedis." It may be that they were autostylic, as Mr. 

 Woodward thinks is so probable ; but the absence of an osseous 



^ Ann. and Mag. Nat. Hist. [4], vol. vii. pi. xiv. 



- " It seems therefore not unlikely that the Placodcrmnfa will eventually turn out 

 to have been an aberrant group of loricated Dipnoi." — K. H. Traquair, in Proc. 

 Eoy. Phys. Soc. Edinburgh, vol. v. p. 159 (1879-80). 



