HEMIPTERA— nETEROPTERA— (JORIXID.E. 343 



As in the Homoptera, and for the same general reasons, it has been 

 found imperative to estabhsh in the Heteroptera a hirge number of new 

 generic groups to treat them on the same principles that guide the zoloogist. 

 Characteristics of structure in antagonism to those prevalent to-day in the 

 same groups run throughout large divisions, or even families, and must 

 be taken into account if we are to do justice to the facts. Bringing these 

 thus into prominence will serve the useful purpose of stimulating inquiry 

 into their meaning and origin, which the data at present at hand seem 

 inadequate to explain. That many of these extinct types attained a high 

 degree of differentiation is readily seen by a glance at the tabular view at 

 the end of the volume, where a large number of the genera will be found to 

 have been represented by a half dozen or more species each, some of them 

 at the time very abundant in individuals. 



Family CORIXID^^ Douglas and Scott. 



This family, which first appears in the Tertiaries,' is very poorly repre- 

 sented there. Only two European species are known, one each from 

 Oeningen and Stosschen. The latter species, very small and probably 

 immature, is hardly recognizable except as a water-bug of some kind. That 

 from Oeningen, referred like the other to the existing and wide-spread genus 

 Corixa, is intermediate in character between the two species of Corixafrom 

 Florissant we are able to add here. But the most interesting form which 

 we give below is the strange insect from Florissant, unfortunately but 

 imperfectly preserved, which seems to combine some of the cliaracters of 

 Corixid;e and Notonectidtc, and to form the type of a new genus, probably 

 most nearly allied to Sigara. 



PROSIGARA gen. nov. (Trpd, Sigara, nom. gen.). 



This is a very curious, robust, new form of Corixid*, which seems more 

 nearly related to the gerontogeic Sigara tiian the almost cosmopolitan Corixa. 

 It is, however, clearly distinguished from either in the great size of the head. 

 [This is given, however, as much too large in the plate, where the femur of 

 the left fore leg is confounded with it.] The head is even larger than in the 



'Unless the poorly preserved insect from the white Jura of Bavaria, which Oppenheim has recently 

 referred doubtfully to Corixa, is to be regarded as belonging here. 



