414 SAMUEL II. SCUDDER ON THE 



than the mai-g-in and passing fahitly aronnd the front close to the margin; a snbcircular 

 flat depression nearly a third as broad as the shield rests upon its posterior margin; the 

 edge of the shield is very delicately marginate. 



The abdomen is remarkably slender like that o^ Etoblattinaf insignis, as mentioned in 

 my memoir on Palaeozoic cockroaches, being scarcely more than a third as broad as this 

 pronotal shield, and extending beyond the middle of the outer half of the closed wings; 

 a few incisures marking segments can be seen, but the whole contour is exceedingly vagne. 



The insect is of pretty large size, much larger indeed than the other species of the genus, 

 the fore wings measuring 30.5 mm. long and 10 mm. broad, the proportion of the breadth 

 to the length being as 1 : 3, making it also slenderer than the other species. The length of 

 the whole body from front of pi'onotal shield to tip of abdomen is 29 mm., the pronotnm 

 itself being 6 mm. long and 7.75 mm. broad and the abdomen about 3 mm. broad. The 

 specimen is unusually perfect, both fore wings being neai'ly complete, as well as the apical 

 half of both hind wings, and most of the pronotal shield; the latter is in its natural posi- 

 tion in relation to the partly expanded wings, but the direct connection with it is broken; 

 the abdomen is only traced by a depression in one stone and a rough ridge in the reverse. 

 The front wings are covered throughout with a delicate but readily traceable reticulation, 

 consisting of very irregular polygonal cells in all the areas but the mediastinal, interno- 

 median, and anal, where the nervules are united by frerjuent uncertain or wavy cross veins 

 into subquadrate cells, usually square in the mediastinal area and broader than long in the 

 others; in the latter, too, and especially in the internomedian area, they tend next the 

 margin of the wing to change to the irregular polygonal reticulation. 



This species differs decidedly from either of the species of this genus hitherto known. 

 It is larger and has a much slenderer wing than either. The scapular area is of consid- 

 erably less extent, the vein far less branched, and the made in which its branches are dis- 

 tributed very diflterent; its internomedian area is also much more restricted than in the 

 others. 



The specimen occurs in an ironstone nodule found at Morris, Grundy Co., Illinois, and 

 was discovered by Mr. J. C. Cai-r of that place, through whose kindness I have been able 

 to examine it. It is now in Mr. R. D. Lacoe's collection Avith the number 2011. 



It may be added that this sijecimen is of particular interest as having the wings more 

 completely preserved than in any other paleozoic cockroach yet known, and offers even 

 a better example than Anthracohlattina sojnta^ for comparison of the neuration of opposite 

 wings; it leads us to hope that future discoveries may enable us by correlating these dif- 

 ferences to determine the distinction between individual and specific characters among an- 

 cient cockroaches, — a question we are hardly yet in a position to discuss. 



Oryctoblattina occidua. 

 PI. 32, fig. 3. 

 Oryctoblattina occidua Scudd., Proc. Acad. ISTat. Sc. Philad., 1885, 37. 



The single specimen known lies in the half of a nodule, and shows the larger part of 



'Cr". Scudder, Palaeozoic Cockroaches, Mem. Bost. Soc. v. Weissig, Nova, acta Leop-Carol. Akad., xli, 423 (1880). 



Nat. Uist., ui, 89 (1879). Geiuitz, 151attiueu uuter. Dyas 



