xl 



placed in juxtaposition to the Lophobranchii (e. g. by J. E. Gray, Whits, 

 and Canestrini), but, no sufficient reason having been given or being ap- 

 parent, the collocation has been disregarded. 



The order (at least after the exclusion of the family of the Pegasidse) has 

 been almost universally admitted. The Pegasidse have been eliminated 

 and raised to ordinal rank by A. Dumeril, with the name Hypostomtdes; 

 associated with the ordinary fishes by Steenstrup and Gunther; and referred 

 to the order Hemibranchii by Cope. Having seen only alcoholic specimens, 

 and no skeleton of this form, the author has not been able to form an 

 opinion. 



PIECTOGNATHI. 



The order of Plectognathi has been almost as universally admitted as 

 the former, but has been criticized by M. C. Dareste, 1 and stated to be an 

 unnatural association, whose members had diverse relations. 



The fishes combined under this name by Cuvier have, however, many 

 characters in common, and are distinguished by the fusion of the several 

 elements of the lower jaw (dentary, angular, and articular) into one ; the 

 intermaxillaries and supramaxillaries are more or less closely united ; the 

 interoperculum is reduced to a rod-like element, dissevered from connec- 

 tion with the other bones, advanced far forward, and connected by ligament 

 with the lower jaw; the pre-operculum and operculum are articulated with 

 the hyomandibular bone, and the latter, as well as the sub-operculum, are 

 very much reduced in size. The post-temporal unites, more or less inti- 

 mately, with the skull; the hypo-coracoid is extended downwards. The 

 brain, vascular system, and closed air-bladder do not differ very much from 

 those of the acanthopterygian fishes. 



Dareste (Camilxe). Theses soutennes devant la Faculte des Sciences de Paris, par 

 M. Camille Dareste, Licencie es-scienees naturelles, Docteur eu medecine, Profes- 

 seur d'Histoire naturelle au College Stanislas. — Premiere These. Recherches sur 

 la classification des Poissons de Pordre des Plectognathes. — Examen de le place 

 que doit occuper dans la classification le Poisson decrit par S. Volta, sous le nom 

 de Blochius lowjirvstris. — Paris. Imprimerie de L. Martinet, • • • . 1850. [4to., 

 46 pp.] 



Recherches sur la classification des poissons de Pordre des Plectograthes. 



• • • < Annales des Sciences Naturelles. — Zoologie, 3e Serie, t. 14, 1850, p. 105 

 -133. 



Sur les affinites naturelles des poissons de la famille des Balistes. Note de 



M. C. Dareste, presentee par M. Blanchard. < Coniptes Rendus hebdomadaires 

 des seances de PAcademie des Sciences, (Paris), v. 74, pp. 1527-1530. (17 Juin, 

 1872). 



On the Natural Affinities of the Balistidse. < Annals and Magazine of Natu- 



ral History. 4th series, v. 10, pp. 68-70, July, 1872. 

 A translation of the preceding. 





