236 ENTOMOLOGICAL NEWS, [Oct., 'o2 



While in Philadelphia I looked over Dr. Horn's material, 

 but found not a single specimen of the true D. geminatus, all 

 his .specimens being-from lower California, otherwise the dis- 

 tinctness of the two species would very likely not have escaped 

 him. 



Our three species may be separated by the following table : 



Sides of thorax with three spines. 



Eyes approximate, elytra scabrous with indistinct costas, apex of <^ 

 elytra bispinose, tibiae on the upper side convex.. . brevicoUis. 

 Sides of thorax with four spines. 



Eyes approximate, the first four antennal joints longer and more 

 slender, elytra smooth with few punctures near base, each 

 elytron at apex bispinose in the males, tibiae on the upper as 

 well as the outer side longitudinally sulcate forrerl. 



Eyes more widely separated, the first four antennal joints generally 

 stouter and shorter, elytra smooth with a few punctures near 

 base, each e^tron at apex in the male with only a sutural spine, 

 tibiae on the upper side convex, outer side sulcate . geminatas. 



In the larger .specimens of D. geminatus and forreri the diiTer- 

 ence in the length and .stoutness of the first four antennal joints is 

 very pronounced, while the smaller specimens have the joints 

 nearly as in forreri but the more approximate eyes, the tibise 

 sulcate on the upper side and the bispinose apex of S elytra, 

 which are all very constant characters, will easily separate D. 

 forreri from D. geminatus. 



A similar confusion of two species is found under Acantho- 

 cinus obsoletus Oliv. The true obsoletus has each elytron ob- 

 liquely prolonged, pointed in the males and .somewhat rounded 

 in the females, and is found from the northern parts of America 

 to South Carolina ; the type came from the last locality. The 

 other form has the elytra broadly rounded at apex in both 

 sexes and, as I am told by Mr, I<eng, was considered by our 

 authorities to be Kirby's (irophisurus {Acanthocinus) pusil/us, 

 which was put in .synonomy of obsoletus on the authority of Mr. 

 Bates, who stated that tlic type was a i)oorly developed speci- 

 men of A. obsoletus Oliv, If our identification of the insect is 

 correct, A. pusillus Kirby lias to be restored to our lists as a 

 good species, otherwise a new name has to be given to this 

 form. It differs from obsoletus, besides the different form of 

 the apices of elytra, in having the punctures at the base of Uk- 



