360 ME. WALTEK WESCHE ON THE GENITALIA OE 



be thought to be a guide to relationships, but so far I have not been able to draw any 

 conclusion from my observations on this point, so I shall content myself with stating 



them. 



Lowne points out that on the sixth somite of the abdomen of the female Blow-fly, or 

 the third from the end, are two pairs of spiracles close to each other. I find a similar 

 arrangement on Calliphora or Frotocalliphora grcenlandlca, Zett., and Lucilia sericatct, 

 Meig., but no traces of spiracles on Musca domestica and the Antliomyid Polietes 

 lardaria, though in Ilijdrotcea dentipes and Ophijra leucostoma, Wied., the double 

 spiracles are again evident. 



In Eilara cilipes the number of segments differs, but counting from the anal 

 segment, in the same place, are a single pair of spiracles (PI. 25. fig. 42). 



Arrangement. — For convenience of discussion and description the ovipositor may be 

 divided up into four parts : — • 



(1) Tlie egg-guides or sensory organs and the other plates at the extremity. 



(2) The ultimate or anal segment. 



(3) The penultimate segment and the glue-glands. 



(4) The spiracle-bearing segments and the Receptacula seminis. 



The Egg-Guides and the AiJpendages of the Ultimate Segment of the Ovipositor. 



Egg-guides or valves. — All the ovipositors that I have examined have some appendages 

 on this segment. In a complete state, five parts are present — two dorsal valves or blades, 

 two ventral, and a single plate between ; but it is seldom that the organ is found in this 

 state. 



Nomenclature. — Nothing definite has been settled on the point of nomenclature. 

 Dziedzicki has, in the paper before referred to, named the parts in the ovipositor, but 

 these do not, in my opinion, fit the organ so weU as his male nomenclature ; so I propose 

 to call the parts the valvular superiores, the valvulse inferiores, and the lamella anterior. 

 The valvulEC superiores will correspond with the dorsal plates of Lowne*, while the 

 A-alvulse inferiores are represented in the Blow-fly by the anal scales. 



Bihionidcc. — In Bihio hortulanus there are two large hairy valvular superiores, a 

 single plate (the lamella anterior), and two ventral subtriangular pieces (the valvulae 

 inferiores) (PL 23. fig. 2). 



Cuiicidce. — In this family these parts are not so prominent, and their bases are 

 usually hidden by the last plate. In Culex pipiens the upper valves are fairly 

 pronounced, but the lower are only represented by hairy palpiform processes, well up in 

 the dorsal region of the cavity made by the last plate. Dinocerites has also in the 

 female striking genitalia, horny upper valves and fairly large lower valves, placed in 

 the same situation as in Culex. 



Tipulidce. — In Tipula oleracea all the parts are present, the upper and lower valves 

 very hard and blade-like in form (PI. 24. fig. 21). 



Trichocera hiemalis, Degeer, and Ftijchoptera albimana (Fabr.) have only one pair of 

 laro-e blade-like valves on the end of the abdomen, the dorsal aud ventral sides meeting 



* ' Kow-fly,' pp. 74o-4G. 



