360 bulletin: museum of comparative zoology. 



12b, p); maxillary palpi small, spatulate, arising from the small oral 

 membrane (Plate 2, fig. 12b, mp.). 



Wings, legs, and thorax as in the female, except that the male 

 thorax has a much smaller foramen and the sclerites are more com- 

 pact. 



Abdomen pointed, membraneous, whitish, covered with small 

 bristles, no definite segmentation. Posterior portion pointed and 

 chitinous, forming the genitalia, which is on the same plan as Nyc- 

 teribosca amboinensis (Plate 2, fig. 18). The penis is a long flattened 

 tube, with chitinous sides, articulated to a thin chitinous basal lever, 

 for the attachment of muscles (Plate 2, fig. 18, p). The penis-guide 

 is a curved, thin, long sclerite, expanded at the end into two pointed 

 flaps, which turn up dorsally and unite above, thus forming a short 

 tube through which the penis passes (Plate 2, fig. 18, p. g.)\ below 

 the penis-guide is another pair of flaps with three short, stout chitinous 

 bristles at the end. 



Homologies of the female trophi. The oral membrane. The 

 proboscis of the female differs so greatly from that of the male, and 

 from any other fly known to me, that a comparison with some allied 

 forms may be of interest. I have taken Dr. G. Dimmock's x interpre- 

 tation of the trophi, which, in its main features, is the same as Dr. 

 H. J. Hansen's. 2 I can follow neither Prof. J. B. Smith 3 nor Mr. W. 

 Wesche 4 in theirs. 



In the more generalized mandibulate insects a suture marks the 

 division between the head-capsule and the labium, maxillae, and 

 clypeus, and between the clypeus and labrum. In the majority of 

 Diptera these sutures are greatly increased and form a connecting 

 membrane, which I shall call the oral membrane. In the Nematocera 

 it is not greatly developed, in some of the Brachycera (i. e. Bomby- 

 liidae) it is large, but it is among the Cyclorrhapha that it reaches its 

 greatest development. In many of the Calyptratae it forms a large 

 membraneous cone, on the apex of which the labrum and labium are 

 situated. If the muscles controlling the pharynx of Hippobosca be 

 cut, the proboscis can be drawn out and is then seen to be situated on a 

 membraneous cone; when the proboscis is drawn right in the cone is 

 invaginated (Plate 2, 3, figs. 19-20, om). In Haematobia and Glossina 



1 The anatomy of the mouth-parts of the sucking apparatus of some Diptera. 1881. 



2 Dipterernes Mundale. 1883. 



3 Contribution toward a knowledge of the mouth-parts of the Diptera. Trans. 

 Amer. Ent. Soc, 1890, 17. 



4 The mouth-parts of the Nemocera. Journ. Roy. Micr. Soc. 1904, and later 

 works. 



