206 Journal New York Entomological Society. tVoi. xxti. 



TANYPREMNA Ostcn Sackon. 



1886. Taiiyfrciinia Osten Sackcn ; Biol. Cent. Am.. Dipt., vol. i, p. 19 

 (opilio). 



1912. Stegasiiio)Wtus Enderlein; Zool. Jahrb., vol. 32, pt. i, p. 11 

 (loiigissimits). 



1912. Pehlkea Endcrkin ; 1. c, p. 15 (coluDibiaita). 



The genus Tanyprcmna was erected in 1886 by Osten Sacken to 

 receive the then iniique species, opilio, of Guatemala. The following 

 year the same author described T. manicata from Brazil. In a recent 

 paper Dr. Enderlein has erected two new genera which must be con- 

 sidered synonymous with Tanyprcmna and the two types make the _ 

 third and fourth American species. The Tipula longipes of Eabricius 

 is now known to be a member of this genus, while the new form 

 herein described as Tanyprcmna rcgina is the sixth species to be made 

 known. The species most closely allied to the genotype, opilio, are 

 cohtnihiana which Enderlein made the type of a new genus, Pchlkca, 

 and the new species, rcgina. T. colunibiana Enderlein has a strong 

 supernumerary cross-vein in cell il/, this latter character being also 

 found in rcgina. which, moreover, possesses a considerable series of 

 such veins and spurs of veins in both of the basal cells. This char- 

 acter of supernutuerary cross-veins is one which has been over- 

 emphasized in the past in the formation of genera and it is doubtful 

 whether even subgeneric rank should be given to the majority of such 

 forms. The extreme plasticity of these characters is shown in such 

 genera as Cladnra, Gnophomyia, Tricyphona, and others, in which 

 these supernumerary cross-veins may be present or absent in the two 

 wings of a single specimen. In the various subgenera of Limnophila 

 such as Ephclia, Idioptcra, Dicranopliragma, etc., which possess these 

 supernumerary cross-veins in all specimens, it is known and appre- 

 ciated that these groups are scarcely of subgeneric value. Consider- 

 ing the very close relationship existing between opilio, columhiana 

 and rcgina, and taking into account the plasticity of the characters 

 used in their diagnosis, I am unwilling to consider the forms as 

 representing more than very well-defined species of this genus, 

 Tanyprcmna. 



The species of Tanyprcmna appear to be quite uncommon and not 

 often picked up by collectors. This is well shown by the fact that 

 each species was founded upon a single specimen and scarcely a 

 dozen specimens are known to be in existence in the various museums. 



