Geometridaa of the Argentine Bepuhlic. 
219 
111 }' new genus Metasiop>ds, next to be described. It does 
not seem to liave been observed, unless possibly by Moschle]- 
in erecting his genus Leptostciles, how frequent is the double 
areole in the smaller new-world Acidaliids, which super¬ 
ficially might have passed as congeneric with the Ptychopoda 
or the Acidalia of the Palaearctic Region. 
Metasiopsis (Prout), nov. gen. 
Face normal (broad, flat, smooth-scaled) ; palpus minute in the 
type-species, always small, shortly rough-scaled below; tongue pre¬ 
sent, slender ; antenna of ^ dentate, with single longish bristles and 
fascicles of longish cilia,* of ^ subserrate, minutely ciliated. Hiiid- 
tibia in short, spurless, somewhat hairy, hindtarsus wholly, or 
almost wholly aborted ; hindtibia in $ with terminal spurs only, 
and these usually not long. Forewing with co-sta subconcave or 
nearly straight, apex (especially in 9,which is narrow-winged) acute, 
though not produced; hindwing rather narrow, particularly in the 
9- Forewing with cell somewhat over one-half ; SC 2 arising from 
cell well before its apex, anastomosing very shortly with SC' and 
then more strongly with forming a double areole ; stalk of 
SC®-® from just before apex of cell; radials normal; M' approxi¬ 
mated to R®. Hindwing with C anastomosing at a point with SC, 
thence gradually diverging ; SC® long-stalked with R' ; M' closely- 
approximated at its base to R®. 
Type of the genus : Metasiopsis dcxicosta (Warten) = 
Ptychopoda fiexicosta, Warren. 
I can find no existing genus, with the possible exception 
—if Moschler’s characterisation is defective—of Leptostales, 
to which Warren’s fiexicosta ai d its nearest allies can be 
referred. Its double areole, and its narrower hindwing, 
with C closely approximated to cell for some distance 
beyond the subbasal fusion, separate it from Ptychopoda. 
Moreover Mr. A. F. Bayne tells me that its resting posture 
is different, the wings being more closed. The sexual 
* \o.plemyraria, Guen. ( = balisturia, Gnen. = perirrumta, Pack.), 
which is rather closely allied to typical Metasiopsis, the bristle is 
long and strong, the cilia apparently ill-developed ; I presume the 
bristles are the “ lames, longues, mais extremement minces ” of Guenee 
(Spec. Gen. des Lep., ix. 453), who classes the antenna as “pectinee.” 
It may well be that Mdschler’s troublesome Leptostales (Abh. Senck. 
Ges., xvi. 238), which is also defined as possessing pectinated ^ 
antenna, comes under the same heading, and that Metasiopsis will 
prove to be a development ot this ; but he gives the f hindtibia as 
having two spurs. 
