Within the last few years the importance of the skeleton of the under side in 



tnatic arrangrim nt lias been brought into a prominent position, chiefly through 

 the exertions of Dr. Le Coiite and Dr. Horn. And, working upon their lines with 

 the aid of more powerful instruments, I have discovered some few points in the 

 skeleton of the Trichopterygida which I had previously overlooked. The most 

 noticeable of these exists in the size and form of their mesosti rnal epimera. In the 

 Trichcpterygida this portion of the skeleton is unusually large, and extends from 

 the outer margin of the body to the intermediate coxal cavity, inclosing the whole 

 of its outer side. This enlargement of the mesosterual epimera prevails with very 

 little variation through all the genera of the family, and is in truth one of its 

 most distinctive characters. It is clearly shown in the plates of the new genera — 

 any one of these may be regarded as a fair type of its older allies. The part 

 which I had supposed to be this epimeron, and which in size and shape closely 

 resembles that part of the skeleton in all other Clavicorn families, proves to be 

 in. inflexed apical angle of the episternum of the metasternum. The figure of the 

 under side of Nanosella fungi in PI. xiii. A, is an apt illustration of all that I have 

 endeavoured to explain in the foregoing sentences. 



I have placed Limulodes at the commencement of the Trichopterygida on 

 account of the similarity of its outline to Hydroscapha, and have also separated it 

 from the other genera as a distinct tribe, which may be characterized thus : 

 •' II. ad, pronotum, and elytra together forming a compact cone, furnished at its 

 apex with long setae." I have also good reason to believe that other species 

 belonging to this Tribe will eventually be discovered. 



I must here add a few remarks on an important essay on this Family by 

 Dr. C. Flaeh, of Vienna, published in the ' Verhandlungen der Kaiserlich-konig- 

 licheu zoologisch-botanischen Gesellschaft in Wien," xxxix. 1889, pp. 481-532.* 

 I am sorry that I cannot do this in a more satisfactory manner than by merely 

 transcribing, or rather translating to the best of my ability, Dr. Flach's original 

 descriptions. Some few, of which I have received types from Herr Reitter, will be 

 found described by myself in the course of this work, and, so far as I can judge 

 by those and by Dr. Flach's own characteristic figures of some others, I believe 

 that most of his species will prove to be genuine : — 



Ptenidium ovulum. — Thorax widest at the base ; body egg-shaped ; basal fovese 

 wanting; thorax with the elytra arched in one curve. Beetle of a fine chestnut brown, 

 thorax finely margined ; body large, upper side impunctate, transverse line on the 

 scutellum without medial impressions. Hab. near the Caspian Sea. 



Ptenidium Lederi. — Thorax with the basal and anterior fovea' small, but distinct ; 

 body oblong, pitchy black ; thorax marked with a transverse depression at the base, surface 

 very finely reticulate, very finely and sparingly punctured, thickly clothed with short 

 hair; transverse line of the scutellum with a fovea on each side near the angles. Hab. 

 Hamerat. 



Ptenidium Brenskei. — Basal fovea? distinctly round, outer fovese three times larger 

 than the interior ; thorax smooth ; body pitchy black. Hab. Morea. 



Sonic notes and criticisms by the author ou llerr Finch's essay will be found in the Ann. 

 Mu-. Nat. Eist. (6) ix. June, 189-2, pp. 442-448.— Ed. 



