802 



SCmNGE. 



[N. S. Vol. IV. No. 100. 



Bot Potsdam sandstone, as it has hitherto been 

 called), and modern placers along present 

 stream beds, resulting in part from the disinte- 

 gration of the older placers. The so-called 

 siliceous gold ores occur in the remnants of 

 Cambrian beds and included porphyry bodies in 

 the elevated region around Grey's Peak and Bald 

 Mountain, to the west of the Homestake belt. 

 The ore bodies are siliceous replacements of 

 certain beds in the upper and lower parts of the 

 formation near eruptive sheets or dikes, which 

 have been mineralized from certain north and 

 south cracks or fissures — locally called ' verti- 

 cals ' — which traverse both sedimentary beds 

 and eruptive sheets. The ores are finely dis- 

 seminated pyrite, generally oxidized with gold, 

 either free or combined with tellurium. The 

 ore bodies are of great longitudinal extent, 

 having been traced continuously in the Golden 

 Reward mine for many thousand feet ; in some 

 cases they are twelve feet thick and more than 

 a hundred feet wide. They give promise of 

 important future developments. 



Wm. F. Moesell. 



entomological society of washington no- 

 VEMBER 12, 1896. 



Mr. Ashmead exhibited specimens of Proc- 

 lytis grandis, a European species, which had 

 been collected by Mrs. Slosson, at Franconia, 

 N. H. Some discussion ensued on the occur- 

 rence of European species in North America. 



Mr. Schwarz exhibited two European beetles 

 recently found in North America, viz. , Attagenus 

 schaefferi from Wyoming, and Lathridus hirtus 

 from Montana. He also showed the Madeiran 

 Cartodere watsoni, which now occurs at Wash- 

 ington, D. C. 



Mr. Howard exhibited specimens of Coccopha- 

 gus orientalis, originally described from Ceylon, 

 but now occurring in Louisiana. 



Mr. O. F. Cook exhibited specimens of two 

 new American species of Japyx, one from Ala- 

 bama, and the other from Ventura County, 

 California. He also showed a specimen of 

 Casey's genus Gastrotheus, originally described 

 as a possible coleopterous larva, but which the 

 speaker considered a genus of true Thysanura, 

 distinct, however, from recognized families by 



the presence of two pairs of several -jointed ab- 

 dominal legs, acting as supporters to the abdo- 

 men. He thought it necessary, in consequence, 

 to admit at least a new sub-order, which he 

 would call Gastrotheoidea. The same speaker 

 also exhibited two specimens of an African in- 

 sect closely related to or identical with Dys- 

 critina West wood. He also showed a speci- 

 men of Walker's remarkable genus Semimerus, 

 collected in Liberia, but not on a rat, the sup- 

 posed habitat of Semimerus. He also showed a 

 specimen collected in Liberia, under rotting 

 wood, which will possibly form a new order of in- 

 sects of the Orthopterous series. He also showed 

 a specimen of Cryptostemma Westwood, an Af- 

 rican Arachnid, now recognized as the type of a 

 distinct order originally based on a fossil genus 

 and now known by Thorell's name of Meridogas- 

 tra. Finally he exhibited a small Arachnid col- 

 lected under stones at Muhlenberg Mission, Li- 

 beria. It has an 11-jointed abdomen distinct by 

 a constriction from the cephalothorax, which 

 has an evident transverse suture. The palpi 

 are not chelate nor modified for prehension, as 

 in the Pedipalpi. The genus has been named 

 Artacarus and will probably constitute a family 

 distinct from the Schizonotidse and also serve as 

 the type of a distinct order of Arachnida, which 

 may be known as Artacarida, although this name 

 should not be supposed to carry an implication 

 of especial afllnity with the mites. 



Mr. W. G. Johnson presented a paper entitled 

 ' Notes on the Morelos Orange Fruit- worm,' in 

 which he recounted rearing Trypeta ludens from 

 maggots found in oranges purchased at Chicago, 

 111., last February. He traced these oranges 

 through a Chicago dealer to Mexico. He de- 

 scribed the different stages of the insect, and 

 concluded that the establishment of the species 

 in orange growing regions in the United States 

 is probable. 



Mr. Howard, in discussion, called attention to 

 the peculiar present danger of such establish- 

 ment, owing to the fact that the failure of the 

 orange crop in Florida has induced extensive 

 importation of Mexican oranges. 



Mr. Schwarz read a paper upon a new cave 

 beetle, reviewing the subject of recent additions 

 to the Coleopterous cave fauna of North Amer- 

 ica, and referring particularly to a new species 



