TIPULID^. 381 



pairs of long, horny, pointed valves." The larvae (Fig. 298, 

 natural size, a larva of this family found living under stones 

 in a running brook at Burkesville Junction, Va. In the 

 American Naturalist, vol. ii, it was 

 referred to Tabanus) differ from 

 those of the neighboring families in . 

 having but a single pair of spiracles Fig. 298. 



at the anal end of the body. The head is rather large, and 

 "embedded nearly up to the mouth in the first thoracic seg- 

 ment ; the mandibles are horny and strong, and forked at the 

 end." The body is grub-like, of a uniform grayish, brownish, 

 or whitish color, and consists of twelve segments. 



"The larvae of Ctenophora, living in wood, have a soft, 

 white, smooth skin, similar to that of the larvae of longicorn 

 beetles, or of the AsilidcB, living in similar conditions. 

 The larva of Tipula living in the soil, or the larvae of those 

 species of Ctenophora which are found in wood so far de- 

 composed as to be like soil or A^egetable mould, have a much 

 tougher skin, and are covered with a microscopic, appressed 

 pubescence. This toughness, as well as some stiff bristles, 

 scattered over the surface of the skin, is probably useful in 

 burrowing. Thus the larva of Trichocera, digging in vegeta- 

 ble mould or in fungi, is covered, according to Ferris, with mi- 

 croscopic erect bristles. The larva of Ula, living in fungi, has, 

 according to the same author, still longer bristles. Those larvae 

 living in water (as some Limnobina) are soft and slimy, of a 

 dirty greenish color, and with a peculiar clothing of appressed 

 microscopic hairs, not unlike those of the larvae of Stratiomys. 

 The most anomalous of all the Tipulideous larvae are those of 

 the Cylindrotomina. That of Cylindrotoma distinctissima 

 lives upon the leaves of plants, as Anemone, Viola, Stellaria, 

 almost like a caterpillar. It is green, with a crest along the 

 back, consisting of a row of fleshy processes. The larva of 

 Cylindrotoma (Fhalacrocera) replicata, according to Degeer, 

 lives in the water, on water plants, and is distinguished by nu- 

 merous filaments, which, although resembling spines, are flexi- 

 ble and hollow on the inside. Degeer took them for organs of 

 respiration." (Osten Sacken.) 



The larvae move by means of minute stiff bristles arising 



