1906.] SELACHIAN FISHES, 757 



and bear well- developed radialia throughout. For Myliobatis and 

 the allied genera it may then be stated that the pectoral fins are 

 continuous, but are very muscular and have the anterior edge 

 emarginate. Gegenbaur's dissection of the pectoral fin in this 

 species shows a radial attached to the pectoral arch between the 

 first and second segments of the mesopterygium ; this is not the 

 case in my specimen. 



The mixopterygia of Dasyhatis, Tceniura and Myliobatis have 

 been described by Huber, who has shown that they are extremely 

 similar throughout. 



Bibliography. 



The well-arranged bibliography at the end of Dean's ' Fishes 

 Living and Fossil ' (1895) will be found useful. The more 

 important works dealing with Selachian classification are the 

 following : — 



1. Cuvier et Valenciennes, Histoire naturelle des Poissons, I. 



(1828). 



2. Miiller u. Henle, Systematische Beschreibung der Plagio- 



stomen (1841). 



3. A. Dumeril, Histoire naturelle des Poissons, I. Elasmo- 



branches (1865). 



4. Giinther, Catalogue of Fishes, VIII. (1870). 



5. Giinther, An Introduction to the Study of Fishes (1880). 



6. Haswell, Proc. Linn. Soc. N. S. Wales, ix. 1884, p. 71. 



7. Smith Woodward, Catalogue of Fossil Fishes, I. (1889) & 



IL (1891). 



8. Jaekel, Die Eocanen Selachier von Monte Bolca (1894), 



9. Jordan & Evermann, The Fishes of North and Middle 



America, I. (1896). 



10. Smith Woodward, Vertebrate Palaeontology (1898). 



11. Jaekel, Sitzungsb. Ges. naturf. Fr. Berlin, 1898, p. 44. 



12. Bridge, The Cambridge Natural History, Fishes (1904). 



Cuvier and Valenciennes (1), Dumeril (3), and Smith Woodward 

 (7) give general accounts of the changes in classification and 

 nomenclature inti-oduced by their predecessors. 



Gegenbaur has described the cranium and visceral arches (14), 

 the pectoral arch and fin (13), and the pelvic fins (15) in a number 

 of types. This work has been supplemented by Haswell (6) ; whilst 

 other authors have described the skeleton of isolated genera — i. e. 

 Chlamydoselachus (16), Fristiophorus (17), Scapanorhynchus or 

 Mitsitkurina (18), Somniosus (19). 



13. Gegenbaur, Unters. vergl. Anat. Wirbelth. II. (1865). 



14. Gegenbaur-, op. cit. III. (1872). 



15. Gegenbaur, Jenaische Zeitschr. v. 1870, p. 448. 



16. Garman, Bull, Mus. Comp. Zool. xii. 1885, p. 1, 



17. Jaekel, Arch. f. Nat. Ivii. 1891, p. 15. 



18. Jordan, Proc. Cal. Ac. (3) i. 1898, p. 199. 



19. Helbing, Acta Ac. German. Ixxxii. 1904, p. 335. 



