137 



Macrocephalidae and most Geocoridae, there are 2 glands, 

 opening onto the 5th and 6th tergites; in a few Geocoridae, 

 however, there is an opening also on the fourth. In the 

 Tingidae, there are openings on the fourth and fifth; in the 

 Acanthiidae and Miridae, on the fourth only. 



So far as is known — but the knowledge is very scanty — the 

 ova of Cimicidae, Lygaeidae, Pyrrhocoridae, Geocoridae, Tin- 

 gidae, Anthocoridae, Clinocoridae, Eeduviidae, Nepidae, 

 Belostomatidae, Corixidae, Poekillopteridae and Issidae are 

 deposited externally, while those of Naucoridae, Notonectidae, 

 Cicadidae, Cercopidae, Tetigoniidae, Membracidae, Fulgoridae 

 and Asiracidae are inserted more or less internally. 



0. M. Renter commenced his celebrated "Hemiptera 

 Gymnocerata Europae" with the Miridae, on the ground that 

 these appear to be the 'lowest' and most authors seem to agree 

 with him, accepting the Cimicidae as the 'highest.' On the 

 contrary, I think that the nymphal, coxal and venational char- 

 acters, stamp the Cimicidae as the most primitive of existing 

 Hemiptera ; the specialized venation, the nymphal and coxal 

 characters, etc., placing the Miridae at the end of one twig of 

 the second main branch of the Pagiopod series of Heteroptera, 

 the N'otonectidae being another of the terminal twigs of the 

 great branch from which the Miridae have sprung. 



Distant, in the most recently promulgated classification of 

 the families of the Heteroptera, separates the "Pentatomidae" 

 (i. e. Cimicidae) from all the other families (6) by the 

 character of the scutellum reaching to at least the base of the 

 membrane. As a matter of fact, this is also the case in Aradi- 

 dae and some Macrocephalidae, so that Distant's classification 

 breaks down at the start. The principal divisions of 

 "Gymnocerata" and "Cryptocerata" are also now discredited. 



The following is an attempt to group the Heteroptera more 

 naturally. I have dealt with the Homoptera elsewhere C^). 



PHALANX 1 TROCHALOPODA. 



SUPERFAMILY 1 CIMICOIDEA. 



Families Cimicidae, Aradidae, Lygaeidae, Pyrrhocoridae, Geo- 

 coridae and Tingidae. 



(6) After excluding the aquatic and semiaquatic families. 

 (7) Bull. Ent. H. S. P. A., III. (1907) 



