Melampm, Pedipes, and Truncatella. 281 



distinguished the same shell, along with several others generically related 

 to it, by the name of Conovulus; but he afterwards re-united this genus 

 to his Auricul(E, placing it amongst the air-breathing Gasteropoda . an 

 association in which he has been followed, though not without some 

 appearance of hesitation, by the Baron de Ferussac in his valuable and 

 masterly Tableau Systematique. Cuvier, however, had long before in 

 his Regne Animal, first edition, adopted both De Montfort's genus and 

 name; though he considered the shells included in it* as fluviatile, and 

 placed the genus between his Auricules and Acteons (TornatellceJ , all 

 three being arranged along with Pyramidella at the end of his "Pulmones 

 " aquatiques." Sowerby has also not failed to perceive both the 

 characters of the present group, and its true affinities.f 



It is not necessary to enter into the question of priority respecting the 

 names Melampus and Conovulus ; for the last, being composed of the 

 names of two established genera, is totally inadmissible by the common 

 rules of nomenclature. But it will be necessary to enter a little at large 

 into the reasons which have caused me to dissent in more important 

 particulars from the united authorities of a Cuvier, a Lamarck, and a 

 Ferussac as to the affinities of the present genus, and the nature of the 

 respiratory organs. 



The foregoing generic description is drawn up from two species, both 

 apparently new, which I have had abundant opportunities of studying. 

 They both occur on the North Coast of Madeira, between high and low 

 water mark on the beach, lurking beneath the lowest stratum of large 

 rounded stones of which it is composed, at the depth of two or three feet 

 below the surface. The singularity of this habitat led me at once to 

 suspect the true nature of the animal : and since all eflPorts at dissection, 

 to ascertain the nature of the branchial system, were baffled by the small 

 size of the species, I had recourse to a series of experiments, of which 

 the following are abstracts as they stand in my notes. 

 Experiment 1. 



A number of the animals of Melampus cequalis with others of Pedipes 



* Viz. Valuta minuta, Gmel. (Bulimus coniformis, Brug.) Bulimus monilis, 

 Brug., and Bui. ovulus, Brug. 



f See Pyramidella, Sowerb. Gen. I cannot, however, agree with my friend 

 Mr. Sowerby in adopting Lamarck's name, Conovulus. 



