172 ENTOMOLOGICAL SOCIETY 



species are found there, only 5 or 6 genera of a tropical character 

 have as yet been collected, and the evidence is insufficient to 

 prove the region to belong to the neotropical. His remarks 

 were based mainly upon the recent collections of Mr. Hubbard, 

 who has captured more Coleoptera at Yuma than any other one 

 collector. These specimens, however, were captured in the 

 winter time, and summer collecting might produce stronger evi 

 dence in favor of the tropical idea. The speaker suggested that 

 close collecting, if it were possible in the great mesquite forests 

 southwest of Tucson, or in the Colorado desert itself, might show 

 that the tropical elements enter our territory at these points 

 rather than in the immediate valley of the Colorado River. 



Mr. Howard exhibited specimens of a new genus of Mono- 

 phlebinae taken by Mr. Hubbard on the creosote bush at Palm 

 Springs, and said that the only American representatives of this 

 subfamily of scale-insects are neotropical and that therefore this 

 finding had some significance as substantiating Dr. Merriam's 

 statements that this region is tropical. 



Dr. Gill agreed with Mr. Schwarz and said that he did not 

 think Dr. Merriam justified in mapping this region as tropical. 

 He does not think, even with the forms which most guided Dr. 

 Merriam, viz.', the mammals and birds, that the evidence is com 

 plete. The fish fauna of the lower Colorado is poor, but all the 

 forms are temperate in their character. The reptiles of the re 

 gion offer the best evidence in support of the tropical idea, but 

 even this is inconclusive. 



Mr. Schwarz exhibited further a curious spiny Psyllid 

 which belongs to the genus Rhinocola, which Mr. Hubbard had 

 collected in the same region, and spoke of the spiny character of 

 the plants of the region and the apparent correspondence of the 

 spiny armature of the insects'. 



Mr. Marlatt asked as to the connection between the spinosity 

 of the plants and the insects. Mr. Ashmead considered it to be 

 a plain case of protective resemblance and referred to the pecu 

 liar Heteropteron Pronotacantha as a species which profited in 

 this way. Mr. Schwarz said that an insect living on a spiny 

 plant is protected by the spines of the plant itself and theoreti 

 cally needs no spines of its own. Mr. Marlatt said that with so 



