14 GEO. H. HORN, M. I). 



We owe to John B. Smith, of the National Museum, a carefully 

 prepared translation, so that those unacquainted with the language 

 of the original may read the views of Gerstaecker in " Entomologica 

 Americana" vol. iii, pp. 202-211. 



I propose to pass the paper of Gerstaecker in review as briefly as 

 consistent with accuracy, while the reader will have in the j)receding 

 pages and the plate, the material on which my arguments are founded. 

 Gerstaecker begins with the statement of the well known fact that 

 the larger divisions, called families among insects, divided more or 

 less ]iaturally and sharply into subordinate groups, but that genera 

 often occur with such varied relationships that it is diflicult to place 

 them, as different authors will give greater regard to characters sub- 

 ordinated by others. 



After stating what material he has studied, he says he has exam- 

 ined the superficial characters and those not immediately visible, and 

 hesitates no longer in asserting that Pleocoma belongs to a group 

 remote from Geotrupini. 



Then follows a resume of LeConte's writings, as has been given in 

 the preceding pages, quoting more liberally than I have done. He 

 seems not to have seen the second edition of the " Classification." 



Dr. Gerstaecker correctly surmises that Pleocoma cost LeConte 

 considerable thought, but the changes of opinion are merely the 

 dropping off of supposed affinities, first " Dynastiform" disappears, 

 then " Coprini," but the Geotrupide idea is permanently retained. 

 The first })erfect specimen LeConte saw fixed the idea that its affini- 

 ties were with Geotrupes. 



Then Gerstaecker proceeds to picture the train of thought which 

 caused LeConte to arrive at his final conclusion, but the thought does 

 not seem to have ai-isen in Gerstaecker's mind that probably LeConte 

 examined the spiracles. That LeConte did examine the spiracles I 

 can assert positively, and the specimens used were those mentioned 

 in the foot note in the paper in the Pacific R. R. Reports. 



" But Avhat, actually, is the structure of the abdomen ?" asks Ger- 

 staecker. " This examination proved, positively what I fully ex- 

 pected, — that the lai-ge spiracles of the second and third, and the 

 smaller ones belonging to the fourth and fifth abdominal segments 

 had, in Pleocoma, precl><ely the same situation, as in Melolontha, that is 

 on the superior portion of the ventral segments, and not on the mem- 

 brane connecting the corneous, dorsal and ventral plates, as in Geo- 

 trupes." 



