CYLINDROTOMINA. 293 



species (macrocera Say). The first of these three species has 

 remained as the type of the genus ; the second, according to the 

 interpretation of Stagger, Loew, and others, is synonymous with 

 Ula pilosa Schum. ; the third is a Limnophila. The only char- 

 acter which has induced Macquart (compare Macq. Dipt. Exot. 

 I, p. 67) to separate these species from Limnobia, and to place 

 them under a common generic appellation, is the structure of 

 their antenna), which have elongated, cylindrical joints. 1 In the 

 Dipteres Exotiques the same author added three more species to 

 the genus, all of which are Erioceras, and have antennae of an 

 entirely different structure (acrostacta Wied., from Java, rufi- 

 cornis Wied., and erythrocephala Macq., both from Brazil) ! 

 This shows the vagueness of Macquart's conception of the genus 

 he was introducing. 



Stager (Xrojer's Tidskr. Ill, p. 36) based his definition of 

 Cylindrotoma likewise on the structure of the antennas. 



In 1849 Mr. Loew described Cylindr. nigriventris from 

 Siberia. He observes correctly that C. distinctissima has to be 

 considered as the type of the genus, and that the two other 

 species, added by Macquart, do not belong to it. Nevertheless, 

 the four species found by the same author in amber and mentioned 

 by him as Cylindrotomse (Ub. d. Bernstein und die Bernstein- 

 fauna, 1850), belong all to the genus Limnophila. 



Mr. Zetterstedt {Dipt. Scand. X, p. 3900 ; 1851) placed Ula 

 pilosa in the genus Cylindrotoma, together with G. distinc- 

 tissima ; at the same time Triogma exsculpta and Phal. repli- 

 cata are left among the Limnobiae, although their relationship to 

 Cylindrotoma is noticed (1. c. page 3819). 



Mr. Haliday (in Walker's Insecta Britannica, Diptera, III, p. 

 312 ; 1856) gave a detailed account of the generic characters of 

 Cylindrotoma, in which the peculiarities of the venation are 

 correctly stated. 



This recognition of the true characteristics of Cylindrotoma 

 could not be considered as completed as long as this genus was 

 not placed in the same group with Limnobia trisulcata and 



1 It is singular that Macquart in characterizing the genus calls the an- 

 tennae 13-jointed, whereas the figure he gives of C. distinctissima shows 17 

 joints. His figure of C. macroptera shows 13 joints, in conformity to the 

 description, and if this statement is correct, the species cannot be Ula 

 pilosa. 



