292 



PSYCHE. 



[January 1890. 



that veteran in their study the Rev. P. 

 B. Brodie, a work which included more 

 than seventy-five species, treated after 

 the method employed in the revision of 

 the paleozoic forms. The publication 

 of both these memoirs on the ancient 

 cockroaches, it may faii'ly be remarked, 

 has since brought to light many more 

 new forms, so that during the past de- 

 cade there have actually been added to • 

 the number of pretertiary forms over a 

 hundred species of cockroaches, about 

 equally divided between paleozoic (53) 

 and mesozoic (57) times. A general 

 account of fossil cockroaches based on 

 these data was given in my "Cockroach 

 of the Past," in Miall and Denny's 

 "Structure and life history of the cock- 

 roach" (London, 1SS6). 



Passing "now to tertiary times, we 

 naturally cannot expect to meet with 

 discoveries of equal importance and in- 

 terest to those which throw light upon 

 the origin of insect-forms, for it is a well 

 known fact that the earliest tertiary in- 

 sects are to all general intents and pur- 

 poses identical with those of to-day. 

 They differ no doubt specifically, and 

 even to a considerable degree gen,eri- 

 cally. Most of those so far recovered 

 from temperate regions indicate a then 

 warmer climate, but, taken as a whole, 

 the grand features of insect-life appear 

 to have been essentially the same since 

 the beginning of tertiary times. By our 

 present researches upon them we no 

 doubt greatly widen our horizon, and 

 as with modern types there always are 

 found problems of interest, so will there 

 be with fossil insects, however recent. 



Activity in this field can hardly be 

 said to be relatively so great as in the 

 others, nor so great indeed as some 

 time ago when Heer and Heyden were 

 publishing extensively, but it neverthe- 

 less has not been insignificant, and it is 

 noteworthy that more sjiecial work 

 with groups has been undertaken ; thus 

 Buckton has summarized our knowledge 

 of the fossil aphides, vSchlechtendahl 

 has elaborated the psysopoda of Rott, 

 Gourret the arachnida of Aix, Hagen 

 and Kolbe the psocidae of amber, and 

 I the termitina of Florissant. I might 

 also add the butterflies of Florissant, as 

 mv paper, though not yet published, 

 has been months in type, and the gen- 

 eral results were given in a brief paper 

 on "Fossil butterflies" in general, in mv 

 "Butterflies of New England." Akin 

 to these can only be mentioned the 

 paper by Flach on the pleistocene cole- 

 optera of Hosbach, Schlechtendahl"^ 

 revision of Germar's tertiary fossils, 

 Williston's notice of the Florissant 

 SvphidaCi.-And mine of the Florissant 

 arachnida, my comparison of the Odo- 

 nata of Florissant and Green River, 

 the detailed study of Planocephalus 

 from Florissant, regarded by me as a 

 new and practically headless type of 

 ihysanura, and, finally, the discussion of 

 the structure of this strange type and ot 

 the supposed mite of the Rhenish brown 

 coal, Limnochares., both of which Bert- 

 kau reo-aids as Galortdidae. To this 

 period also belongs my general survey of 

 the paleontology|of Florissant. 



The additions to our knowledge of 

 the amber insects of Prussia durins the 



