CLASSIFICATION OF MEDUSA. 79 



of the Steganopthalmata are included in the Polystomous section, and the association as a 

 natural assemblage indistinctly recognised. 



The arrangement of Lamarck was no better than that of Peron and Lesueur, and, in some 

 of the details, inferior, as for instance, in the comprising of the species of Pelagia in his genus 

 Bianma, associated with numerous forms of Geryonidee. All the Pulmograda were grouped 

 under two great sections, the one characterised by a single mouth, the other by the presence 

 of several mouths; Lamarck, like Peron, having mistaken the ovarian orifices in certain 

 Steganopthalmatous species for so many digestive openings. 



Eschscholtz, whilst he greatly improved, through his personal experience of the Medusae, 

 the generic and specific arrangements, went astrdy as widely as his predecessors when he 

 attempted their classification. For, as we have already seen, he mistook the ovaries in many 

 genera for appendages of the digestive system, and regarded such forms as constituting a 

 great cryptogamic section. Hence he divides all his Biscophorce — a happily chosen term by 

 which he designates the Pulmograda — under Biscophorce phanerocarpee and Biscophorce 

 cryptocarpm. But though this was a classification based on false notions of structure, so 

 true was Eschscholtz's perception of the natural affinities of the genera, that the covered-eyed 

 forms are all assembled under his first division, and the naked-eyed under the second. His 

 minor groups are generally very excellent, though throughout all their characters the great 

 mistake just mentioned prevails, and consequently nullifies them. 



Cuvier assembled all the Pulmograda in the section of Acalephce, which he termed 

 " Meduses Propres," dividing it into five groups, of which the first, " les Equorees," is 

 characterised by the presence of a simple short mouth, without tentacula ; the second, " les 

 Pelagies," by the mouth being prolonged into a peduncle, which becomes divided into arms ; 

 the third, " les Cyanees," in which the mouth is central, and there are four lateral ovaries ; 

 the fourth, "les Rhizostomes," in which there is no conspicuous mouth, nourishment being 

 derived through the ramifications of the peduncle, the ovaries four or more ; and the fifth, 

 "les Astomes," without central mouth, or ramified peduncle, or distinct cavities for the 

 ovaries. His first and last tribes included the naked-eyed species. The whole arrangement 

 is a mistake, founded on misapprehension of the value of characters in the order. The groups 

 are neither natural nor of equal systematic value. The classifications of Peron and of 

 Eschscholtz, though founded on mistakes as great, if not greater, are much superior to those 

 of Cuvier and Lamarck, doubtless owing to the superior practical acquaintance of the former 

 naturalists with the objects under arrangement. Cuvier's personal knowledge of the 

 Discophorse seems to have been limited to two or three of the higher species ; Lamarck had 

 probably no experience in this tribe. Peron, Lesueur, and Eschscholtz had observed and 

 studied numerous forms in the living state, and consequently, though of inferior order of mind 

 to the former great naturalists, came nearer the truth in their systems, because their know- 

 ledge was sound and practicai, and not gained at second-hand. 



The arrangement of the Pulmograda proposed by De Blainville, is likewise the result of 

 book-study, and not of sea-research, and is consequently objectionable. He divides them 



