45U Osten Sacken: un fhe eharactern of Lli.e three divisions of 



aiTaiigcd, spinelike proccsses oii tlie segnients of tlio body. liave beon 

 often described. Lyonet, Boucho and Bcling liave stated correctly 

 that they liave ten pairs of spiraclcs, but noiic of them (iior cvon 

 Brauer) seeins to liave noticed that this is a vcry extraordinary 

 mimber, almost unique among insects. Nine pairs is the maximum 

 miniber of spiracles for all the other peripneustic larvac of Diptcra, 

 and the occurrence of a supernunierary pair on tlio thoracic segmcnts is 

 a very exceptional character. i) Zeller, in describing the larvae of 

 PenÜietria does not mention the nuniber of spiracles. 



The second section of the faniily Bihionidae consists of the 

 three related genera: Scatopse, Aspistes and CorynosceUs. (1 do 

 not know anything about Penthera Philippi, from Chili, which may 

 belong to the Bihionidae.) In the general appearance of the body, 

 the venation, the structure of the antennae and legs, and the prescnce 

 of three ocelli they are allied to the genera of the ürst section. The 

 points in which they differ are as foUows: the palpi of Äcaio/)«« and 

 Aspistes are apparently single-jointed and rather indistinct. Cory- 

 nosceUs with its three- jointed palpi forms the transition (comp. Loew, 

 Berl. Ent. Z. 1858, p. 103). The three pulvilli of the first section of 

 the Bihionidae are replaced here by a broad empodium, which looks 

 like the coalescence of the pulvilli („Haftläppchen in ein einziges 

 verschmolzen"; Schiner). The eyes oi Scatopse are lunate, con- 

 tiguous in both sexes above the antennae (at least in those species 

 which I have examined; Scatopse hißlata Halid. cf in Walk. Ins, 

 Brit. Dipt. III, Tab. 24, f. 5 is rei^resented with a broad interval be- 

 tween the eyes). In this respect the head of Scatopse resembles 

 that of some of the Cidicidae and Chironomidae, where the antennae 

 are also inserted within the excision of the lunate eyes, and where 

 the eyes in both sexes are contiguous above the antennae, and 



i) A pfirallel case occurred to Erichson among the Coleoptera 

 and excitecl his astonisliment. His remarks are worth repeating here 

 (Erichson, Zur System. Kenntn. der Insecten-Larven, in Wiegm. Arch. 

 1841, p. 92): 



„Two larvae of Lampyridae from Java, recorded in Westwood'a 

 Iritroduction etc. I, p. 254, f. 1 and p. 259, f, 1, show a peculiarity 

 which I never met with in any other coleopferous larva, and even among 

 othor larvae of I.ampyridae. While ihe thorax usually bears a single 

 spiracle on the mesothoracie, er more seldom on ihe prothoracic segment, 

 or between both, in this case there is, besides the normal mesothoracie 

 pair, a supcrimmerary one in the corresponding place of the meta- 

 thoracic segment. If this latter pair is really the opening of a spiracle, 

 and that should be ascertaiiied by dissection, then these larvae would 

 ofFer a remarkable anoraaly in having ten pairs of spiracles." 



