Marshall—Some New American Water Mites. 1301 
The legs are short, and their position is another striking pecu¬ 
liarity of the genus. The posterior ones have been pushed for¬ 
ward so that they come to lie almost in the same straight line 
with the palpi, one above the other on the sides of the body. The 
first three pairs end in claws; the fourth ends in a long saber¬ 
like spine. The palpi are small, and the fifth segment is cleft 
at the end. 
F. americana resembles F. musculus, but it is smaller, and it 
differs, moreover, in several details from the European form. 
Its length is about 0.51 mm., and the color is yellow green on the 
dorsal side, yellow on the sides. The eye region projects con¬ 
spicuously beyond the anterior border of the body, and the pos¬ 
terior end has a similar, though smaller projection. The palpi 
are stouter than in F. musculus. 
A pair of large glands, like those described for the genus 
Lebertia were found, the tubes opening on the capitulum. 
Lebertia distincta nov. spec. 
(PI. II. fig. 21-23) 
This new species of Lebertia was found, a single individual, in 
Sebago Lake, Maine, Aug. 1911, by Mr. A. A. Doolittle. The 
epimeral shield somewhat resembles that of L. porosa; but it is 
more extensive and more completely encloses the genital plates. 
The outlines of the fused epimera are not so fully obliterated as 
in most species of the genus, a character which has suggested the 
specific name. The genital area is elongated and widens precep- 
tibally at the posterior end. The body and plates are finely pap- 
illiated. The palpi are rather slim and bear a few coarse hairs. 
The first pair of legs have no swimming hairs, the second and 
third have a few short ones on the fifth segment, while the fourth 
have a few on the fourth segment. All of the legs bear bristles 
The body is about 0.92 mm. long. The color was destroyed by 
the preserving fluid. 
Arrhenurus elevatus nov. spec. 
(PI. I fig., 12-15; PI. II, fig. 16) 
This species closely resembles A. longicaudatus Mar. in the 
possession of a long slender appendix; but it differs conspicu¬ 
ously from it in the greater height of the dorsal hump on the 
