562 PROCPJEniXdS of the I^WTIONAL MU&EUM. vol. xxxvi. 



Coleoptera. Such a comparison shows many more points of resem- 

 blance to the Coleoptera than to the Orthoptera, but at the same time 

 the similarity is of such a nature that it may be secondary rather than 

 phylogenetic. 



1. Microthorax well developed, presenting tergal, pleural, and ster- 

 nal plates (93), one of the latter almost gular in position. 



2. Presternum consisting of two plates (Ps) in all three segments 

 lying before or beside the anterior angles of the sternum (91, 94, 98). 



3. A j)reopisternum (Peps) well developed in mesothorax (94). 



4. Trochantin (Tn) present in all three segments (91, 94, 98). 



5. Propleurum (91) and mesopleurum (94) similar, differing from 

 metapleurum ( 98 ) . 



G, Metapleurum (98) in appearance similar to that of Coleoptera. 

 First preparapterum (IP) fused with front of episternum (Eps) and 

 bears internally large pronator disc (100, PD). 



7. Mesonotum (90, 92) simple, mesopseudonotum lacking. Meta- 

 notum (96, lY) complex, presenting median groove fringed with 

 recurved bristles (0). Metapseudonotum (PN) present, though 

 fused with first abdominal tergum {IT). 



8. A small rod in wing base connects with parapteral region in meso- 

 thorax (90, n) and Avitli second prepara})teruni {'2P) in metathorax 

 (98, 100, n). 



IX. COLEOPTERA. 



Species stiulied. — Calosoma Koiitafor (102, 103, 110, 113, 127, 132, 

 133, wing base 193, 197), Carabida^ Dyfm-us daui-icus (107, 108, 

 114, 128, 131, 13(), Aving base 192), Dytiscida?; Ilydrophthis tvuiiigu- 

 laris (105, 111, 112, 125, 134, wing base 198), Hydrophilidtc ; Silpha 

 surinamen^is (106), Silphida^; MeJolotitha mdgaris (117, 121, 135, 

 138, 139, wing base 195, 199), Scarabccida? ; Buprestis aurulenta (95, 

 99, 104), Buprestidfip; Tctrophnn vd}(f'nn(m (123), Cyllene rohinici' 

 (97, 101, 116, 119, 129, 130, 140, wing base 194), Cerambycida? ; 

 Dendroctonus valens (118, 120, 122, 124, 126), Scolytida?. 



Characteristics. — 1. Microthoracic plates rudimentary (95) or 

 absent. 



2. Prothoracic and mesothoracic pleura resemble each other more 

 than they do the metathoracic pleurum. Pleurites of the first two 

 vertical or oblique, those of the last horizontal. 



3. Prothoracic pleurites commonly fused with each other and with 

 tergum and sternum, but not reduced in size. 



4. Mesothoracic pleurites (97, 101, 102, 105, 106, 107, 109) always 

 distinct, usually oblique. Wing process (WP) often hidden by 

 prominent upper end of episternum, but easily seen on inner surface 

 (101, 103, 108) as is also its relation to i)leural ridge (PP). Epi- 

 merum {Epin) commonl}^ with a dorsal subdivision {epm), and 



