TRANSACTIONS OF THE SECTIONS. 161 



ZoOLOGr. 

 [For Dr. Sclater's Address see page 85.] 



On the Primary Divisions of the Chitonidse. 

 By Philip P. Carpenter, B.A., Ph.D. 



The writer showed that there were two parallel groups, the articulated or perfect 

 Chitons, and the non-articulated or inipert'ect Chitons. Each of these were natu- 

 rally divided again into regular and irregular forms, and these again into family, 

 generic, and subgeneric series. The palteozoic Chitons were all imperfect, and 

 culminated in the Carboniferous period ; very few are now living. The neozoic 

 epochs gradually developed perfect Chitons, which culminate at the present time. 

 The vrriter sought information as to unusual forms, recent or fossil. 



On the Nervous and Generative Systems of the Crinoidea. 

 By Dr. W. B. Carpenter, F^R.S. 



On the Occurrence of Moa-hones in New Zealand. By Dr. H"ector, F.R.S. 



On the Glassijication and Affinities of the Itotifera. By C. T. Hudson, LL.D. 



The author commenced by discussing Ehrenberg's classification of the Rotifera, 

 and showed by the help of illustrations and diagrams that its fundamental principles 

 were erroneous, for it was based on a supposed structure of the trochal disks which 

 really did not exist, on a forced interpretation of the term "lorica," and on the 

 presence, absence, and number of certain red spots, wJiich Ehrenberg always took 

 for granted to be ej'es, but which were not always so ; moreover, those that really 

 were eyes were often present in the young animal, but invisible in the adult. 



Ehrenberg's symmetrical system erred in both directions. It brought together 

 widely dissimilar forms, and separated those that were intimately connected. The 

 rival systems of Leydig and Dujardin were then discussed, and dismissed as inferior 

 to Ehrenberg's ; though it was pointed out that each naturalist had contributed a 

 happy idea in making his unsuccessful attempt — the former having brought into 



f)rominence the great value of the foot as a characteristic for classification, and the 

 after having hit upon the excellent notion of dividing the Rotifera into orders 

 according to their means of locomotion. 



Dr. Hudson then proceeded to re-classify the Rotifera according to a system of 

 his own, in which he availed himself of the labours of Ehrenberg, Leydig, Gosse, 

 &c., and arranged the creatures by means of their nervous, nutritive, and vascular 

 systems. 



The true position of the Rotifera was then discussed. It had long been disputed 

 whether they should be placed among the Vermes, or whether they should be 

 ranked as very hun\ble members of the Arthropoda. Leydig and Gosse had alwaj's 

 maintained the latter opinion, while the former was upheld by Cohn, Vogt, Huxley, 

 &c., and followed by the majority of modern naturalists. The various arguments 

 against the alliance of the Rotifera with the Arthropoda were severally met, and 

 it was shown how recent discoveries had tended to lessen their value — notably 

 that of PedaKon mirum, the six-legged rotifer, discovered by the author in a pond 

 near Clifton four years ago. 



Professor Huxley's reasons for considering the Rotifera to be permanent forms 

 of Echinoderm-larvae were then discussed. The Professor had asserted that the 

 Rotifera were in their forms divisible into two great groups, that, as far as it 

 was known, the one was monoecious and the other dioecious, and that a corre- 

 sponding division of form and sexual arrangements existed among the Echinoderms 

 in their larval state. " It is this circumstance," says the Professor, " which seems 

 to me 10 throw so clear a light upon the position of the Rotifera in the animal 



