MONTGOMERY : GORDIACEA. 29 
seems to be also untenable, though it may correspond to @. violaceus 
Baird, as is supposed by Villot (87) and by Romer (96); Villot's 
G. deshayesi, eneus, and prismaticus seem to me to be also doubtful, 
though the last two may be preliminarily retained, since Camerano 
has found further specimens which appear to agree with them. Römer 
has given good reasons to show that G. verrucosus Baird is too poorly 
described to be tenable; and there is the greater reason for relinquishing 
this species, since Camerano (’93) has described under the same name 
a form which appears to be a Chordodes ; hence this name must be 
dropped from the American fauna, if not altogether from the nomen- 
clature of the Gordiacea. Leidy’s (56, ’79) descriptions of his G. 
robustus are sufficient for purposes of identification, though in the 
descriptive part of our paper I shall rank this form as a subspecies of the 
European G. aquaticus Linn. 
There remain then the following species from the American continents 
which appear tenable: Gordius varius Leidy, G. robustus Leidy, E. line- 
atus Leidy, G. platyurus Baird, E. eneus Villot, E. paranensis Camer., 
G. alfredi Camer., @. danielis Camer., G. latastei Camer., @. obesus 
Camer. ; Chordodes pilosus Möbius, ©. brasiliensis Janda, © peracce 
Camer., ©. variopapillatus Römer, ©. balzani Camer., O. bouvieri Villot, 
C. feste Camer., and ©. talensis Camer. Thus all of the species described 
by Camerano appear tenable, but since most of his descriptions are unac- 
companied by figures the reidentification of them is rendered very difh- 
cult, The following species are to be regarded as doubtful, if not 
even needing elimination: G. fasciatus Baird, G\ prismaticus Villot, 
G. deshayesi Villot, and G. verrucosus Baird. 
It seems to be questionable whether the specimens of @. violaceus 
Baird and @. aquaticus Linn., described by Römer from Arizona and 
South America respectively, really belong to these species; but this 
point will be more fully criticised in our description of G. aquaticus 
robustus (Leidy), and of the two new species, @. platycephalus and G. 
densareolatus. 
In the following descriptions, unless otherwise specified, it will be 
understood that the cuticle has been examined on surface preparations 
and sections in Canada balsam. 
