Crli MR. n. U. WITTTETTOITSE OX THE [*M^'"- ''^' 



A8 a result of some discussion on the subject, Professor Dollo 

 and myself are of the o})iniou that the following moditicatiou is 

 advisable : — 



I. PriYSiOLGOiCAL, which refers to external form. 



(1) I\'//lj)idocerc(d, in)i>]\iug au ex])anded or faii-shiiped 



form. 



(2) Oxi/cercal, imi)lyinij; n tapci'lny form. 



If. Morphological, which refers to inteinnl stiucture. 



(1) Proiocercal. 



(2) J/eierocfircal. 



(3) Jfo)/wcerc((I. 



(4) GepJiijrocercal. 



For the use of those who prefer to adopt this double nomen- 

 clature, a few illustrations may be found useful. 



Rhipidocercal homocercal Poh/odon. 



]|liipidocercal gephyrocercal ... Orthagorisctts. 



Oxycei'cal hetei-ocei'cjil C'hlami/doselachiis. 



Oxycercal homocercal Jngitilla, Mastacembelus. 



Oxycercal gephyrocex-cal Fierafrfer. 



LriEHATURE. 



'1. Agassiz, a, — " On the young stages of some Osseous Fishes : 

 I. Development of the T.iil." Proc. Amer. Acad. Arts <k 

 Sci. vol. xiii. p. 117, 1878. 



2. Ayehs, II., & Jacksok, C. M. — "Morpliology of the Myxin- 



oidei : I. Skeleton and Musculature." Contrib. from the 

 ]\rorpholog. Lab. of the University of Cincinnati, March 

 1 898. 



3. ]3oiJLEKGER, G. A. — " Notes on the Classification of Teleosteau 



Fishes, IV." Ann. k Mag. Nat. Hist. vol. x., 1902. 



4. Cambridge Natural History, Vol. vii., Systematic 



account of the Teleostei. 



5. Les Poissons du Congo. 1901. 



6. Cole, F. J., & Johnstone, J. — ^^ I'leuroiiectes." Livei-pool 



Piology Committee, Memoir vii., 1901. 



7. Cope, E. D.— Trans. Amer. Phil. Soc. vol. xiv., 1870, 



pp. 452-3. 



8. " The Homologies of the Fins of Fishes." Amer. 



Nat. 1890, p. 418. 



9. Cunningham, J. T. — ' Science Pi-ogi-ess,' 1897. 



10. Dollo, L. — " Sur la Phylogeuie des Dlpneiisieft." P)ull(Miu 

 de la Societe l^elge do (Icologic, tome ix., 189;"). 

 *11. Voyage du S.Y. //f?/_f//(v/. Poissons. Anvcrs, 1 904. 



12. Emkuv, C. — ^^ Fieranfe?'.'" Fauna inid Flora des Ciolfes vou 

 Neapel. 



* It was not until tlic manuscript Avas ready for tlic jivess (liat ni\ atfontion was 

 drawn to this uxccllcnt work. 



