850 



Charles Paul Alexander 



It is probable that other groups of species of the old genus Limnophila 

 will be found to deviate from the characters of tliis group as now restricted. 

 Species such as L. hyalipennis (Zett.), L. nemoralis (Meig.), and others in 

 Europe, and L. hrevifurca, L. emmelina, L. mundoides, L. toxoneura, 

 L. ultima, and similar anomalous forms in America, should be investigated 

 critically when opportunity offers. 



Pseudolunnophila luteipennis (0. S.) 



1859 Limnophila luteipennis O. S. Proc. Acad. Nat. Sci. Phila., p. 23G. 



Pseudolimnophila luteipennis is one of the most abundant species of 

 the tribe, and is very widely distributed thruout eastern North America. 

 The adult flies are common in swamps and along the marshy edges of 

 streams and ponds. The immature stages are characteristic swamp 

 inhabitants. They have been described in detail by Hart (1898 [1895]: 

 202-204). Malloch (1915-17 b: 222-223) adds several supplementary notes 

 and figures of Hart's material. 



Larva. — Length, 15-18 mm. 



Diameter, 1.5-1.7 mm. 



Coloration light brownish yellow, slightly darker toward posterior end of body. 



Body covered with a delicate appressed brownish pubescence and abundant stiff bristles 

 and erect hairs on each segment, arranged in about five transverse rows; these bristles more 

 numerous, coarser, and blacker, on posterior segments, forming a large tuft on sides of 

 penultimate segment of body. Spiracular disk (Plate XXXIX, 176) surrounded by four 

 lobes, the posterior pair very long and slender, finger-like, the lateral pair much shorter but 

 slender; the iimer face of these lobes with brownish black or dark brown transverse lines which 

 cover almost the entire face; an arcuate line extending from ends of ventral marks across disk 

 between spiracles; two small triangular marks located between ventral lobes; lobes fringed 

 with long, delicate hairs, those at ends very elongate, those toward base of lobes shortened 

 but continuous around disk. Anal gills four, very long and slender, exceeding ventral lobes 

 of spiracular disk. 



Head capsule short and stout, exhibiting a very generalized condition. Prefrons very 

 broad, only slightly narrowed behind and but slightly exceeding lateral plates. Labrum 

 broadly transverse, with a large tuft of hairs on either side. Mentum (Plate XXXIX, 172) 

 completely divided, each half with seven (or rarely eight) teeth along anterior margin, of 

 which the third (or foiu"th) from the inside is the largest; a flattened lobe just laterad of each 

 half of mentum; mental plates continuous behind with strong lateral plates of capsule; in 

 a normal position the two halves of mentum overlying each other to a greater or less degree. 

 Hypopharynx (Plate XXXIX, 173) with anterior margin broadly rounded, with numerous 

 (from ten to fifteen) bluntly rounded teeth. Antenna slender, with two long apical 

 papillae. Mandible (Plate XXXIX, 175) short and broad, of the generalized limnobiine 



