212 



Subfamily LIMNOBIINAE 



I have before me the larva of one species, and the pupal exuvia 

 of two species, of Limnobia, and the larva and pupa of one species of 

 Dicranomyia. 



SUBFAMILY CHARACTERS 



Larva. — Head well developed, moderately chitinized. Posterior 

 dorsal slits extending proximad of middle; antennae elongate, base 

 elevated, first joint more than twice as long as broad ; maxillary palpi 

 much shorter than antennae, 2- jointed ; labial plate well developed, 

 dentate along its anterior margin ; mandibles stout, with one or two 

 large apical teeth, and a series of smaller teeth along their lower 

 margin on its apical half. Thorax and abdomen without pseudopods, 

 the locomotor organs consisting of a narrow transverse strip of weak 

 hairs or spinules on the dorsal and ventral surfaces of some or all of 

 the segments ; in Dicranomyia these locomotor spinules are little 

 stronger than the others on dorsum. Apical segment without finger- 

 like processes ; the spiracles in terrestrial forms not in a pronounced 

 depression but capable of being enclosed by the infolding of the apex 

 of the segment; the spiracles in aquatic forms situated in a cleft, with 

 hair-fringed margins, in apex; both terrestrial and aquatic forms 

 with short protrusive blood-gills. 



Pupa. — Head without protuberances. Thoracic respiratory organs 

 very broad, their length not exceeding their greatest width ; legs much 

 longer than wings. Abdomen with locomotor organs similar to those 

 of larva. 



Imago. — See key to subfamilies. 



HABITS OF LARVAE 



The larvae of Limnobia are fungivorous and terrestrial ; those of 

 Dicranomyia feed on algae and are aquatic or semiaquatic. A gluti- 

 nous tube is made by the larvae of both genera when nearly or quite 

 mature, and in this pupation takes place. 



HABITS OF IMAGINES 



The species of Limnobia usually occur in dense woods where fungi 

 are common ; those of Dicranomyia occur near bodies of water. The 

 species of Gcranomyia frequent flowers, as do the adults of some of 

 the other genera. 



