200 



[August 



b 



a 



On the Pupa of the Ephemerinous genus B^TISCA Walsh. 

 BY BENJ. D. WALSn, M. A. 



The pup;i that forms the subject of the present Article, and of the 

 female of which a figure is annexed, has been known to me for four 



years ; but it was not till the present year 

 that I succeeded in breeding the subi- 

 mas;o from it. Tt diifers from all de- 

 scribed Ephemerinous pupae in the an- 

 tennae being eight-jointed or thereabouts, 

 not multiarticulate.and also in the bran- 

 ch\iG being internal and not used for lo- 

 comotive purposes; and from all known 

 larvae and pupie, and indeed from all 

 known hexapod insects in any of their 

 states, in the pro- meso- and meta-uotum 

 being; connate and confluent and extend- 

 ing over one-half of the abdomen in the form of a large, dilated, convex 

 carapace or shield, thus giving the insect a very Crustacean appear- 

 ance. In the Orthopterous genus Tetrix and the Homopterous Mem- 

 hracidse, as is well known, it is by a prolongation of the prothorax 

 alone that the body of the insect is almost entirely concealed and cov- 

 ered above. In certain of the Heteropterous ScutellcriJse and in the 

 foreign Chalcididous genera Thoracantha and G^rt^'aria(Hymenoptera). 

 and the Indian Muscidous genus Celyphus (Diptera), it is by a pro- 

 longation of the mesoscutellum that the abdomen is almost entirely 

 concealed above. But in all these cases the other thoracic segments 

 are clearly distinguishable. 



I had sent a 9 specimen of the above pupa to Dr. Hagen in 1863, 

 and subjoin his remarks on it, translating from the original French 



MS. :— 



The larva No. CO is the most extraordinary animal that I have seen, so 

 that I asked myself whether it really belonged to Inseeta. But there is u<> 

 doubt of the fact of its being the larva of a hexapod insect. The large com- 

 pound eyes determ.ine at once its position as belonging to those insects which 

 liave an incomplete metamorphosis, and therefore to Orthoj^tera,* or Hemiptera. 



'According; to Erichson's and Sieboldt's views Dr. Ha'jn refers Pseudoneu- 



