46 BROOKLYN MUSEUM SCIENCE BULLETIN 3. 3. 
synonymy. However, after exhaustive studies of the original descrip- 
tions and a large amount of material of our species, also by comparison of 
specimens with types of species as far as they are in existence here or in 
England, I am forced to restore ten of the synonyms to specific or varietal 
standing. Of the remaining names placed at present in synonymy a few 
more are wrongly listed and four of these take precedence over the names 
by which they are at present known. A few other names remain synonyms 
but of diflferent species than those with which they are listed at present. 
To these several new species and varieties are added which brings the 
number of species of Donacia known to occur in the New World to forty- 
five with sixteen varieties. 
Plateiimaris is here treated as a subgenus. Thomson made it a 
genus and it is accepted as such in Europe. This course is apparently 
justified as far as the European species are concerned but not for the 
American species. The latest paper on Donacia by the late Edmund 
Reitter, 1920, gives the following characters for Donacia and Plateiimaris: 
Legs slender, tibiae at apex narrow, rarely the anterior tibiae feebly 
dilated near apex. Body flat or feebly convex. Mandibles short, 
mostly covered by the labrum. The first abdominal segment longer 
than the remaining segments. Third tarsal joint longer than wide, 
deeply emarginate and scarcely dilated Donacia. 
Legs shorter, stouter, all or only the anterior tibiae dilated into a distinct 
tooth. Body convex. Mandibles longer, extending below the 
labrum. The first abdominal segment as long as the remaining 
segments. Third tarsal joint shorter, wider, not longer than wide. 
The upper part of elevated sutural bead before apex sinuate, leaving 
the lower part exposed Plateiimaris. 
With the exception of the sinuate sutural margin of elytra some 
American species of Donacia possess one or the other character of 
Plateiimaris as given above. This is plainly shown in the list of the 
Donaciini (Donacidae) in Genera Insectorum by Jacoby and Clavareau 
where aequalis, distincta, torosa and pubescens are listed under Plateiimaris. 
These are true Donacias and undoubtedly were unknown to the authors 
who placed them there on characters found in the descriptions of these 
species. 
The only American species with the sutural margin of elytra sinuate 
near apex, besides those which are strictly referable to Plateiimaris, is 
harrisi. This species is rather aberrant and can not very well be placed 
in either of the two subgenera. It is in some way intermediate between 
the two and reduces the strength of the only remaining character of 
Plateiimaris — the sinuate sutural margin near apex of elytra. 
