426 bulletin: museum of comparative zoology. 



CARABIDAE. 



Bembidium obductum Scudder. 



One poor specimen, No. 2,426 M. C. Z. (No. 6,529 S. H. Scudder 

 Coll.) seems to belong here. 



Amaka revocata Scudder. 



Two examples. No. 2,427 M. C. Z. (No. 3,233 S. H. Scudder Coll.); 

 No. 2,428 M. C. Z. (No. 5,580 S. H. Scudder Coll.) are referred to this 

 species though neither is in good condition. 



Amara powellii Scudder. 

 One specimen, No. 2,429 M. C. Z. (No. 264 S. H. Scudder Coll.). 



Amara cockerelli Wickham. 



A single specimen, No. 2,430 M. C. Z. (No. 7,008 S. H. Scudder 

 Coll.) referred here without much doubt. 



DYTISCIDAE. 

 BiDESsus laminarum, sp. nov. 

 Plate 1, fig. 1. 



Form similar to that of the recent B. affinis. The specimen shows 

 either a ventral view or the dorsal aspect of an insect from which the 

 elytra have been lost and givgs no sculptural characters of any value. 

 The prosternum is like that of recent Bidessus, but the sutures be- 

 tween the proximal abdominal segments are more distinct than in the 

 living form with which I have compared it. Length, 2.25 mm. 



Described from a single specimen. 



Tijpe.— No. 2,431 M. C. Z. Florissant, Col. (No. 11,166 S. H. Scud- 

 der Coll.). The stone carries a small parasitic HN'menopteron on the 

 same side as the Bidessus, while on the opposite face is Dr. Scudder's 

 number, cited above, and the insect to which it originally referred. 



