16 GEO. H. HORN, M. J). 



In a resume Gerstaecker again refers to the oral organs and states 

 that the figures given by Erichson (Entomographien, pi. 1, figs, a-e, 

 g-i) of the mouth parts of Elaphocera and Pachypus might be re- 

 ferred to Fleocoma. I can see no such resemblance as any one can 

 realize by comparing the figures quoted with those prepared by 

 myself of Pleocoma. 



" After having, in the preceding remarks, disproved all the argu- 

 ments brought forward by LeConte to justify his placing P/eocor/ia near 

 Ge'ofrupes by proving its Melolonthid character — in the imago — ," 

 Dr. Gerstaecker proceeds to discuss the larva described by Baron 

 Osten-Sacken as that of Pleocoma. 



I will admit that I had grave doubts of the accuracy of the de- 

 termination of that larva until I had read the remarks of Gerstaecker 

 denying that it could possibly be the larva of Pleocoma. His oppo- 

 sition and all he says convince me that inasmuch as Pleocoma is a 

 Laparostict, and that the larva " made known by Osten-Sacken be- 

 longs to the Scarabjeidse Laparosticti, admits, indeed, of no doubt" — 

 all this satisfies me that we have truly the larva of Pleocoma, as 

 there is not that well explored part of California from which the 

 larva was obtained any other Laparostict Scarabaside, or Lucanide 

 of any size approaching that required by a larva 50 mm. long, or 

 even of a larva 30 mm. long. 



"To compare a 50 mm. long larva with Geotrupini and Trogini is 

 strange to begin with." I can hardly see what size had to do with 

 comparisons based on structure. Objection might be as well made 

 to the comparison of the larvi?e of Bkpichojihoras palmarum and 

 Calandra oryzce, which differ more greatly in size, although nearly 

 identical otherwise. 



Certain other statements regarding the plication of the segments 

 in Geotrupini and Lucanidse are certainly op'^n to very severe criti- 

 cism, but this is foreign to the object of these remarks. I will only 

 say that Gerstaecker's reference of the larva to Lucanidie is singu- 

 larly unfortunate from every point of view. 



Having gone as thoroughly over Gerstaecker's remarks as seems 

 necessary, I will give the following as a sunnnary of the results of 

 my study : 



1. Pleocoma is an undoubted Laparostict. 



2. There are six free ventral segments, the first almost entirely 

 concealed by the coxse. A small anal segment exists, always retracted, 

 visible only by dissection. 



