290 



PSYCHE. 



[January iSpo. 



it has fallen to his lot, in however im- 

 perfect a way, to attempt a more or less 

 monographic treatment of the extinct 

 type of archipolypoda ^ for instance, 

 comprising most of the paleozoic myri- 

 opoda ; of the paleozoic arachnida as a 

 whole, in which he had been preceded 

 by this decade by Karsch, working on 

 much slenderer material and therefore 

 at much smaller advantage ; also on the 

 paleozoic cockroaches, and on the 

 species of Mylacris^ a genus of cock- 

 roaches known from several American 

 deposits ; and on the genera allied to 

 Dictyoneura^ regarded as ancient types 

 of pkasmida. Reference should here 

 also be made to Peach's careful work 

 on the carboniferous arachnida of 

 Scotland. In my memoir on the cock- 

 roaches, embracing the discussion of 

 fifty-eight species referred to eleven 

 genera, it was claimed that their differ- 

 ences from modern types were so fun- 

 damental as to warrant their separation 

 from all subsequent and from living 

 cockroaches as a distinct and equivalent 

 group, called palaeoblattariae, and 

 that they could be further separated into 

 two divisions, called respectively my- 

 lacridae and b/attinariae., oi wWxch the 

 former was confined to the New World. 

 Brauer has since questioned the value 

 of the palaeoblattariae as a group, and 

 Brongniart has recently stated that in 

 the enormous crowd of cockroaches 

 found at Com in entry, the viylacridae 

 are as numerous as the hlattinariae^ 

 which probably means that the fauna of 

 Commentry is older than that of the 

 other carboniferous deposits of Europe 



and synchronous or nearly so with most 

 of the cockroach-yielding deposits of 

 America. 



Both Brongniart and myself have 

 also attempted new classifications of the 

 paleozoic hcxapods as a whole, which 

 differ considerably in character, but 

 which cannot yet fairly be compared ; 

 first because mine discusses nearly all 

 the known types, but includes hardly 

 any of those found at Commentry. then 

 almost wholly unknown, while Brong- 

 niart, writing later, confines himself 

 almost entirely to those of Commentry, 

 with only an occasional allusion to pre- 

 viously described types ; but principally 

 because Brongniart's work is, so far, the 

 merest sketch with hardly any structural 

 details, a forerunner of what he will 

 soon publish in extenso concerning this 

 wonderful fauna, while mine contains 

 full structural details as a basis for dis- 

 cussion and generalization. In it I 

 have endeavored to point out that the 

 existing orders of insects were not dif- 

 ferentiated in paleozoic times except in 

 a feeble way, prophetic as it were of the 

 future, so that the Palaeodictyoptera, as, 

 after Dohrn and Goldenberg. but with 

 an extension of their usage, I h:id classed 

 for the first time all known paleozoic 

 insects, could only be separated into neu- 

 ropteroid, orthopteroid and hemipteroid 

 groups. These views, which 1 urged 

 also in a special paper showing the de- 

 velopment of the insect-type in time, 

 have been so strenuously opposed by 

 Brauer and others, that their further 

 discussion can hardly be profitable ex- 

 cept for those who have an unfortunate 



