83 
CI DARIA TRUNCATA AND CITRATA (IMMANATA). 
(Read March 17th, 1908, by LOUIS B. PROUT, F.E.S.). 
In a paper on “ The Genus Cidaria ” read before the Society on 
April 16th, 1901, I touched on the differentiation of C. tr uncat a and 
<'. immanata, and discussed the egg and newly-hatched larva of the 
latter, but remarked that “ to work out the named varieties of these 
protean species would require a complete paper,” and therfore dismissed 
the subject for the time {vide Tram. City Land. Ent. Soc., xi., pp. 14-45). 
The present is an attempt to supply such a paper. 
The truncata- group is treated as a separate genus by Warren ( Proc. 
Zool. Soc., 1898, p. 378, etc.) and as a separate section of Larentia by 
Hampson {Ind. Moths, iii. p. 378); but both employ the name of 
Polyphasia, Steph. {111. Haust., iii., p. 227), whereas—as I pointed out 
in my former paper {loc. cit. supra)- —Hiibner’s of Dysstroma {Verz. 
p. 333) has priority. So far as I know, this name has lain dormant, 
but the reasons for fixing truncata, Hufn., as its type are over¬ 
whelmingly strong, as the following brief survey will show. 
Circ. 1825. Dysstroma, Huh., Verz., p. 333, erects for russata, 
Schiff. [ — truncata, Hufn.], variata, Schiff., simulata, Hub. [ — coynata, 
Thnb.], and juniperata, Linn. 
1831. Steph., 111. Haust., iii., pp. 227, 271, unacquainted with 
Hiibner’s work, erects respectively, Polyphasia for immanata, truncata, 
and vars., and Thera for * simulata [firmata], variata, juniperata, etc. 
1835. Steph., 111. Haust., iv., p. 416, in an abstract of Hiibner’s 
“ Verzeichniss,” cites Dysstroma for russata [ truncata ] , variata, 
v simulata [firmata] and juniperata. 
1850. Steph., List. Brit. Aniin., v., pp. 195-6, maintains both his 
own names against Hiibner’s, but indicates Polyphasia as the “typical” 
section of Dysstroma. 
1896. Hulst, Tr. Am. Ent. Soc., xxiii., p. 283 (under synonymy of 
of his comprehensive genus Hydriomena) cites truncata as type of 
Dysstroma. 
It should be noted, further, that the choice will commend itself to 
those who like to select the first species as type of a genus; and, far 
more important, that Hiibner’s diagnosis (which will not bear an 
absolutely literal translation, but the gist of which is that the forewings 
are variegated and the central fascia not definitely expressed) best suits 
truncata.'' 
The genus or subgenus Dysstroma is characterised by the double 
areole, the absence of the various abnormal structures upon which 
Meyrick bases most of his Larentiid genera, the rounded face, the 
biangulated discocellulars (genus Larentia, Hmpsn., op. cit.), the hair¬ 
like scaling and large, exserted $ claspers (section ii., id. ibid.), and 
the ciliated 3 antenna? (subsection A, Polyphasia, id. ibid.). 
* Hiibner’s words are: Die Schwingen [ = forewings] buntlich, fast verworren 
bandirt. 
xviii. 
