59 



species, which is pi'obably the smallest known, being but about 

 half the size of the P. caraboides. He calls it L. quercus. 



You will receive Peltis ferruginea from Europe, a genus 

 recently separated from Thymalus. This species much resem- 

 bles the one you caught in Northampton, and I wish you to 

 compare them closely, and if you find them to be distinct, point 

 out in what they differ, and send me the name you give your 

 species, of which I have a short description in my MSS. I have 

 a true Thymalus allied to limhatus Fabr., from which it differs 

 in being rather larger, in having larger punctures on the 

 thorax, and smaller ones on the elytra, and the series on the 

 latter more remote than in P. limhatus. I obtained it from 

 tree fungi. When you see the Peltis ferruginea you will be 

 able to tell me whether Nitidula grossa can belong to the same 

 genus. * 



Since writing the description of Melasis picea, I have dis- 

 covered that some confusion exists in regard to the genus 

 Rhipicera. Dalman founded his genus Polytomus a year or two 

 before Latreille proposed that of Phipicera, and both took for 

 the type Ptilinus mystacinus Fabr., Hisp>a mystacina of Drury. 

 Latreille (Nouv. Diet. d'Hist. Nat.) somehow or other appears 

 to have connected his genus with Ptyocerus of Thunberg, 

 established upon Melasis mystacina Fabr., a very different insect 

 from the Ptilinus and Hlspa of Fabricius and Drury. I do 

 not recollect what Thunberg says about the mandibles of his 

 genus Ptyocerus, but the antennas are 11-jointed, the three 

 basal ones simple, and the remaining ones flabellate within 

 (vid. Nov. Act." Holm., 1806). In the year 1821, Dalman 

 revised his genus Polytomus.^ and added two new species from 

 Brazil, one of Avhicli is identical with Rhipicera marginata of 

 Kirby. (Compare Ptyocerus marginatus Dalm., Nov. Act. 

 Holm., 1821, with Kirby's insect in Linn. Trans.) Your insect 

 does not answer to either of those described in the genera 

 Ptyocerus, Rhipidkis, Polytomus, or Rhipicera. 3Ielasis picea 

 of Beauvois cannot belong to Polytomus (which name, in point 



