COLEOPTERA. 83 



piceous, translucent, first joint and base of the second rufo-testaceous. Pro- 

 thorax robust, widest at the middle, where it is four-fifths as wide as the 

 head, and slightly broader than long ; sides thence rather strongly conver- 

 gent posteriorly and feebly sinuate ; anterior margin slightly longer and 

 more arcuate than the posterior ; surface slightly and obliquely undulated 

 at the sides above, rather coarsely, very closely, somewhat irregularly and 

 variolately punctate ; canaliculation almost entirely absent, only faintly 

 seen as a feeble erosion at the middle, and close to the base. Elytra at base 

 as wide as the head, sides moderately divergent posteriorly, very slightly 

 longer than the width at base, almost straight ; together very broadly, tri- 

 angularly and moderately emarginate posteriorly; suture nearly one-fourth 

 as long again as the pronotum ; surface nearly evenly and moderately con- 

 vex, somewhat coarsely, very closely, rather deeply, and evenly punctate. 

 Abdominal segments decreasing arcuately in width, first as wide as the con- 

 tiguous elytra ; surface feebly convex, coarsely and very closely punctulate : 

 transverse carinae not cusped, finely and unevenly undulated. Legs short 

 and stout, dark piceous-brown above, paler and rufo-piceous beneath ; first 

 joint of posterior tarsi four-fifths as long again as the second, as long as the 

 last, second very slightly longer than the third. 



Male. — Posterior edge of the fifth ventral segment entire ; sixth segment 

 broadly bilobed at apex, cusp very slightly rounded and very short, arms 

 widely diverging. 



Female. — Sixth ventral segment broadly truncate at tip, truncation slightly 

 arcuate. 



Length 1.8-1.9 mm. 



Cambridge, Massachusetts, 6 ; Canada, 2 ; Lake Superior, 2. 



The parasite of this species is very large, being nearly as large as 

 the eye; its contour is nearly circular; the surface is very convex 

 and most highly polished ; it is pale rufo-testaceous in color, and the 

 abdomen is provided with very long cinereous setae, which project as 

 a fringe far behind the body; two symmetrically placed, pigmental 

 deposits, situated near the anterior border, are presumably the eyes. 

 The type specimen bears two of these huge parasites, which, if we 

 should magnify the beetle to the size of the human body, would be 

 six inches long. 



This small species has a very wide range in its geographical distri- 

 bution ; it appears to be quite rare, however, in all its localities. It 

 varies in the color of the palpi and length of the first joint of the 

 posterior tarsi, so that I at first described the specimen from Canada 

 and Lake Superior as distinct species, but afterwards concluded to 

 unite them, because of the insufficient material at hand. 



64. S. na ii nliis n. sp. — Form moderately robust. Pubescence sparse, 

 fine, moderately long, semi-erect, pale fiavo-testaceous. Head moderate, 

 robust, scarcely twice as wide as long ; interocular surface feebly convex. 



