312 ( I- ASS Mil. 



a thread through the eye of a needle, WESTWOOD). These threads 

 are very long in Melopliila and OrnifAomyia, shorter in 1 Ii ppobosca. 

 Two oblong hairy plates project like a beak and cover the base of the 

 threads when they are exserted. Are these parts to be regarded as 

 maxUlce, or as palpi maxillares ? The mechanism of the sucker is 

 much more conformable to that of certain Acarina than to the 

 proboscis of the rest of the Diptera. 



These flies lay no eggs, but are viviparous. That which seems to 

 be an egg laid by these insects, and which is sometimes as big as the 

 abdomen of the mother, ought rather to be regarded as a pupa; 

 from it the perfect insect (iniago) comes to view after an interval of 

 time, dependent upon the temperature to which the pupa is ex- 

 posed. 



The intestinal canal of these insects is very long, and surpasses 

 the length of the body eight or nine times. This length is caused 

 principally by the stomach, or that part of the intestinal canal 

 which precedes the insertion of the vasa urinaria, and which presents 

 many tortuosities. The testes are two long and very tortuous 

 canals; the ovaries, two oval sacs; near the oviducts are two 

 secretory glands, consisting of very numerous branches, together 

 with two more simple receptacula seminis, of which the form varies 

 in difierent species. The lowest part of the two ovaries opens into 

 a wide sac (uterus, matrice LEON DUFOUR), in which the embryo 

 resides until it comes forth as a pupa. The nervous system has, 

 besides the cerebral ganglion, only a single round ganglion in the 

 thorax, from the posterior margin of which the nerves of the 

 abdomen arise. 



Comp. on the anatomy of this family, LEON DUFOUB, Reck, anatomiques 

 sur VHippdbosque, Ann. des Sc. not. vi. 1825, pp. 299 322. PI. 13 : also 

 his Etudes anatomiques et physiologiques sur les Pupipares, Ann. dcs Sc. nat. 

 troisifeme Sdr. Zool. Tom. m. 1845, PP- 49 95- P1 - 2 > 3- 



Phalanx I. Nycteribiidce. Head small, placed at the upper 

 part of the thorax like an obconical tubercle. Thorax semi-^ 

 orbicular. Wings and poisers none. Feet long, with first joint 

 of tarsus very long, and last supplied with two claws incurved, den- 

 tigerous at the base, and with two oval appendages. 



Nycteribia LATR. 



Sp. Nycteribia vespertilionis, Acarw vespertilionis L., Phtkiridhon rcxperii- 

 lionis HEBM., Mm. apterol. PL v. fig. i ; Nftdcribia LntrciUii Wi> 



