AMERICAN COLEOPTERA. 275 



A female in the cabinet of Dr. LeConte has the row of dorsal punc- 

 tures less distinct, and the last ventral segment with three marginal 

 punctures. 



Collected by H. K. Morrison in Arizona. 



AMPHIZOA. 



This genus was at first considered by Dr. Sharp sufficiently a Dytiscide 

 to be placed in his division Dytisci complicati. This view he, however, 

 recalls, and is willing to admit that Amphizoa and Pelobius must be 

 isolated from any of the great families of Adephaga. He is not, how- 

 ever, willing to admit that they should take rank as families in the same 

 sense as we receive the Carabidae or Dytiscidae, his objection being 

 based on an unwillingness to consider Amphizoidae and Pelobiidae, each 

 containing but one genus and those genera three species each, compar- 

 able with great aggregates containing many genera and numerous spe- 

 cies. 



In adopting the views of Dr. LeConte regarding Amphizoa and ex- 

 tending the idea still further in the suggestion of a family for Pelobius, 

 the number of the species was entirely a minor consideration. The type 

 of structure was taken as the standard of comparison and each particu- 

 lar type was designated by a name adopted in all cases from those in 

 use. 



To those who prefer to follow Dr. Sharp's synthetic method of treat- 

 ing the subject, I can see no reason why a single species should not 

 represent in itself all the various syntheses through which Dr. Sharp 

 passes the objects of his study. Thus a species insolens represents also 

 the genus Amphizoa, the tribe Amphizoini, the subfamily Amphizoinae, 

 and finally the family Amphizoidae, which makes part of a larger aggre- 

 gate known as Adephaga. 



It is quite within the limit of possibility that an ally of Amphizoa 

 should occur with a structure of middle coxal cavities, as in the Dytisci 

 fragmentati or the subfamily Carabinae. We would then certainly have 

 all the elements of a complete synthesis with the addition of a single 

 species. To my mind an important modification of structure has as great 

 systematic value when represented by one species as by a thousand. 



A. Joseph!, Matth., is retained as distinct by Dr. Sharp. I have care- 

 fully examined the type and find it not different from the male of in- 

 solens. 



The occurrence of a species (A. Davidis, Lucas) in the mountain 

 regions of Thibet has been recently made known. 



