PROC. ENT. SOC. WASH., VOL. 22, NO. 5, MAY, 1920 IOI 



due to squeezing the specimen when it was captured although 

 I could not detect any indications of such a squeezing or distor- 

 tion in these specimens. 



As was mentioned above, the valves "pv" (Figs. 2 and 3) of 

 the genital appratus of the male are asymmetrically developed, 

 and being terminated by hooks "u" (Fig. 3), etc., they are very 

 like the parts of the genitalia of a male Mantid (see Figs. 70, 

 7S, etc., Plate 6, of an article on genitalia of male insects, pub- 

 lished in the Bulletin of the Brooklyn Ent. Soc., Vol. 13, p. 49); 

 and when Dr. Walker, who is at present working out the details 

 of the genitalia of the male of Grylloblatta, publishes his results, 

 I am sure that the parts will be found to resemble those of a male 

 of Zorotypus quite markedly.* The basal portions of the valves 

 "pv" (Fig. 3) are buried in the tissues of the genital apparatus, and 

 were, therefore, not shown in Fig. 3. The genitalia of male Ple- 

 coptera are usually more symmetrically developed in those forms 

 having paired penis valves, and doubtless more nearly represent 

 the primitive condition than the asymmetrical valves of the 

 Zoraptera, Mantidae and Blattidae do. Since the terminal struc- 

 tures of the Zoraptera are quite like those of the Isoptera, it is 

 quite surprising that the Isoptera have not developed penis valves 

 like those of their allies; but I have been unable to find them in 

 any of the termite material which I have examined. 



Situated near the posterior margin of the eighth abdominal tergite 

 "8'" (Fig. '2} of the apterous male insects, is a small median dor- 

 sal process "d," while a small median procurved hook "n," at 

 whose base is a second tiny prominence, is apparently borne on 

 the narrow indistinct ninth tergite. I find certain structures in 

 the Plecoptera, which are very suggestive of these organs; but I 

 have not been able to determine their significance as yet, although 

 I am hoping to do so later, when material suitable for dissection 

 is available. In examining the internal anatomy of the apterous 

 males of Zorotypus, in connection with the above mentioned or- 

 gans, I observed two flat coils of "wavy" fibers, somewhat like 

 cotton fibers in appearance (but more "crinkly" in character), 

 located in the posterior half of the abdomen. I was unable to 

 determine their relation to the above-mentioned organs,** however, 

 if any exists, and until a thorough preparatory study of the in- 

 ternal of the male Plecoptera has been made, it is useless to spec- 



* In the meantime, Dr. Walker's paper has been published in the Can. 

 Entomologist. The genitalia of Grylloblatta are not like those of Zorotypus, 

 but superficially, at least, the terminal structures of Grylloblatta are strik- 

 ingly like those of the Embiidae. 



** A further study of the coiled structures would indicate that tlu-y an 

 associated with the testes. 



