of the North American Orthuptera. 417 



add 9 Blalla doinuigcmis, Pal. dc Beauv., Ins. ; 1^2, I'J. i 

 b., iig. 4. (1805.) 



Seaboard of Mass., (H. Coll.) Indiana, (Mus. Com p. 

 Zoiil.) Mexico, (Uhler.) Texas, (Mus. Comp. Zolil., Uhler.) 



rLATAMODKS, Nov. f^cn. (TrAara/xoj^/;?.) 



A genus more closely allied to Periplaneta than to any 

 other, but readily distinguishable from it by its much nar- 

 rower and more elongated body, — the sides being sub-par- 

 allel to one another throughout their whole extent, while 

 in Periplaneta the abdomen is much swollen. The wings 

 and wing-covers extend beyond the abdomen, the latter 

 being well rounded at the tip. The supraiinal plate is reg- 

 ularly rounded, but lacks altogether the fissuration seen in 

 Periplaneta ; but at the same time it is not squarely docked 

 as in Styhpyga. The anal cerci are somewhat shorter, 

 and not so flattened as in Periplaneta, while the anal 

 styles are very short and turned abruptly downwards. In 

 Periplaneta the sub-genital plate does not extend so far 

 backward as the supraiinal. In Platamodes it extends 

 backward farther. A further distinction between the two 

 genera may be seen at the inner borders of the eyes, 

 which in Platamodes are nearly parallel ; while in Peri- 

 planeta they approach one another anteriorly. I have only 

 seen males. 



1. P. PENNSYLVANICA. 



Blatta pennsi/lvanica, De Geer, Mem. ; III. 537. PI. 44, 



fig. 4. (1773.) 



" « Oliv., Enc. Meth. ; II. 317. (1791.) 



Indiana, (Mus. Comp. Zool.) Maryland, (Uhler.) 5 ^. 



* 2. P. uNicoLOR, nov. sp. 



Blatta pennsylvanica, H. Cat. ; 56, (non De Geer.) 



Blatta rufescens and bicolor? H. Cat.; (non Pal. de 

 Beauv.) 



Wings and wing-covers uniform pale shining reddish 

 brown ; head and prothoracic shield nearly the same, but 



JOURNAL B. S. N. H. 53 NOVEMBER, 1862. 



