238 [September 



" The number of subdivisions in the groups, both the lower and the 

 higher," says Prof. Dana, " is three^ as in most of the Classes and Or- 

 ders that came under consideration in Article 1st." (p. 27.) Yes, but 

 this symmetry is only obtained by making Aphaniptera (the fleas) of 

 equal systematic value with Hymenoptera and Diptera, and Trichop- 

 tera of equal value with Lepidoptera and Homoptera; by splitting up 

 what remains of Neuroptera, after removing Trichoptera, into three 

 groups of equal value with Hymenoptera, Diptera, &c. ; by placing 

 Homoptera in the first Primary Division, and the closely allied Hemip- 

 tera (heteroptera) in the second Primary Division ; by uniting Forfi- 

 culidse and Blattidae together as Cursors, and Mantidfe and Phasmidae 

 together as Ambulators ; and finally by assuming the existence of an 

 unknown aphanipteroid group in the Apipenniform Attenuates, of an 

 unknown degradational group in Aptera, and as it should seem, though 

 Prof. Dana does not expressly say so, of a third unknown group, to 

 complete the mystical number three, in the Perattenuate Attenuates. 



I protest, in the name of science, against this arithmetical monoma- 

 nia, which is perpetually seeking to fetter the limbs of Nature in mathe- 

 matical formulae. The world has had about enough of ternary, quinary 

 and septenary systems ; but from the fatal facility with which they arc 

 generated, it does not seem likely that the breed of them will very 

 soon run out. Nothing is easier than by subdividing some natural 

 groups and uniting others, and by giving prominence to certain charac- 

 ters and keeping others in the back ground, to form an artificial system 

 of classification based upon any assignable arithmetical number from 

 two up to ten. And when such systems are formed, what are they 

 worth ? Absolutely nothing. 



It is perhaps hypercritical to quarrel with a mere name, but we can 

 scarcely fail to observe that this new system of Prof. Dana's is not, as 

 it professes to be, based upon his principle of Cephalization. As ori- 

 ginally expounded by him in Crustacea, Cephalization consists in "the 

 transfer of the anterior members of the thorax to the cephalic series," 



subfamily Corydalides West., because the "Nymphids" are classed as "perter- 

 restrial." (p. 22.) The only other Neuropterous group left unnamed by Prof. 

 Dana is Rhaphidiidce Westw., which Hagen unite* with Sialitia=^Semblids Dana, 

 and Embidina Hagen, which had previously been referred to Termitina. Nym- 

 phidia is a genus of Butterflies. 



