LIMATUS 41 



Generic Diagnosis of Adtjut: 



Head moderate, eyes separated by a wedge-shaped integument which terminates 

 in front in a large quadrate projection. Palpi short in both sexes, the joints fused. 

 Antennae with the joints subegual, similar in the sexes, those of the male scarcely 

 more plumose than those of the female. Prothoracic lobes large, well separated 

 dorsally, with coarse setae along their front margins. Vestiture of flat appressed 

 scales, occiput without erect forked scales, mesonotum without setae on disk. 

 Abdomen subcylindrical, tip blunt in the female. Legs with the claws small, 

 simple in both sexes, the hind pair with but a single claw. Proboscis of female 

 rather short and stout; of male, either bent beyond the middle, with an enlargement 

 of scales, or straight and strongly swollen at the tip. 



Generic Diagnosis op Larva: 



The larvae have the characters of those of the genus Wyeomyia, so that we have 

 included the species of both genera in a common table. Head flattened, broad, 

 rounded, the antennae small; mouth-brushes thick but short; air-tube moderate, 

 with scattered hairs, no pecten. A comb of separate scales, few in number, on the 

 sides of the eighth abdominal segment. Anal segment with a dorsal plate, long- 

 haired dorsal and lateral tufts and short subventral hair; anal gills moderate. 



The genus is confined to the tropical parts of the American continent. 



Limaius is closely related to Wyeomyia; the adults differ only in the loss of 

 one of the hind tarsal claws, which affects both sexes. This condition is fore- 

 shadowed in some of the species of Wyeomyia (especially W. codiocampa D. & 

 K.), and represents only an extreme development of the condition where one 

 of the hind tarsal claws is smaller than the other. The larvae are inseparable 

 generically from Wyeomyia. However, in spite of the close affinity, we have 

 thought it advisable to recognize the genus. All the species are more gaudily 

 ornamented on the mesonotum than the species of Wyeomyia, and may be 

 superficially recognized by this character. 



The genus, together with Joilotia, was placed by Theobald in his subfamily 

 Trichoprosoponina, on account of the presence of a few scales on the postnotum. 

 We have found that scales are present on the postnotum of certain species of 

 Sabethes and Sabethinus and not on others; therefore the character is not even 

 generic. Later, Theobald established a subfamily (Limatinse) for the genus 

 Limatus, on the character of the bent proboscis (Mon. Culic, iv, 18, 1907). 

 This modification is present only in the male of some species, and, like other 

 secondary sexual characters, it has no deep significance. To this genus should 

 be referred Dendromyia paraensis Theobald (Mon. Culic, iii, 316, 1903), de- 

 scribed from a single, apparently much rubbed, female. The description, as far 

 as it goes, fits Limatus in every detail: yellow spot upon the vertex, the dif- 

 ferently colored first abdominal segment, the lateral spots of the abdomen, and, 

 above all, the peculiar scaling of the wing-veins. The specimen is probably 

 referable to L. durhamii, which Theobald had from the same locality (Para), 

 but we are unwilling to so refer it without examination of the type. 



The larval history and habits, so far as we know them, are the same as those 

 species of Wyeomyia that inhabit bamboo-joints or cocoanut-shells. The larvae 

 occur in cocoanut-husks and similar locations. The adults are diurnal, fre- 

 quenting forests. 



Tables oe the Species op Limatus. 

 adttlts, structure and coloration. 



1. Abdomen with the colors separated on the sides in an irregular line; proboscis 



of male with a bend beyond the middle, curved beyond the bend, 



heavily scaled at bend and tip 2 



Abdomen with the colors separated on the sides in a straight line; proboscis 

 of male straight, strongly enlarged at tip 



methysticus Dyar & Knab (p. 48) 



2. First abdominal segment pale golden-scaled durliamii Theobald (p. 42) 



First abdominal segment black-scaled, with bronzy luster 



cacophrades Dyar & Knab (p. 45) 



MALE GENITALIA AND LARV^. 



(See the tables under Wyeomyia, pages 55 and 57.) 



