ggg ON THE CLASSES OF THE 



one sorte le corps des Myriapodes ou Mille-pieds, soit avec 

 une tete plus imparfaite, soit prive de cette partie." — 

 This author observes that the distended part of the body 

 or cincture of an earthworm, which contains the organs of 

 reproduction, commences about the 27th or 28th segment, 

 which corresponds with the last of the rings which ever 

 compose the body of a Myriapod. The sexual organs 

 of the male Juli occupy the anterior portion of the 7th 

 segment near the second or third pair of perceptible stig- 

 mata ; a position which corresponds with that of the gene- 

 rative organs in the common Leech. The same limits 

 hold good, according to M. Latreille, with respect to the 

 Setipede Annelides, whether it be by the cessation of the 

 subulate seta? or by the changes which take place in the 

 order of the branchiae . All this the reader will find explained 

 with great ingenuity in the " Comparaison des Annelides 

 avec les Myriapodes. " If to these considerations be added 

 the granular ocelli of the Nereida, their vermicular men- 

 tion, the form and disposition of their feet, the two last 

 of which are sometimes, as in Nereis margaritacea, trans- 

 formed into filiform appendages exactly similar to those 

 which terminate the body of several Myriapoda, we can 

 I conceive have little doubt of our having at length reached 

 the 



Annulosa, 

 or those white-blooded animals which are externally arti- 

 culated. The Annelides are all hermaphrodites after the 

 manner of Gasteropod Mollusca; whereas there is every 

 reason to believe that the sexes are constantly distinct in 

 the animals upon whose natural history we are now about 

 to enter, The problem becomes therefore at present to 



