DESCRIPTIONS OF RECENTLY DISCOVERED CLADOCERA 

 FROM NEW ENGLAND. 



By Alfred A. Doolittle, 

 Of the Central High School, Washington, District of Columbia. 



The collections of Entomostraca made by the writer for the United 

 States Bureau of Fisheries in its investio;ations of the New England 

 lakes contain several Cladoceran forms which seem to be new. This 

 paper describes more fully and mth drawings a recently established 

 genus and its type-species and another recently discovered species of 

 a different family, a prelhninary diagnosis of which has already 

 appeared.^ 



Family LYNCODAPHNIID^. 



Genus PAROPHRYOXUS Doolittle. 



Parophryoxus Doolittle, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 153. 



This genus is erected to include the new species P. tubulatus Doo- 

 little, described below. 



Female. — Form ellipsoidal; dorsal and ventral margins convergent 

 and produced posteriorly; posterior margin a small fraction of great- 

 est height. Upper or dorsal posterior angle often prominent, but not 

 produced as a spine. Ventral margin sinuate, middle third setiferous. 

 Head viewed laterally, evenly rounded; produced into distinct beak. 

 Cervical sinus present. Fornix well developed, with a horizontal 

 portion running over base of second antenna and eye, and a vertical 

 portion ruiming well toward end of rostrum, resembling O'phryoxus. 

 A median keel from tip of rostrum to posterior end of test. Sides of 

 test concave. 



Eye moderate; macula nigra or ocellus quadrangular, situated in 

 base of rostrum; smaller than eye. First antennae or antennules 

 attached to apex of rostrum; long, cylindrical; a sensory seta near 

 base of each, and several unequal olfactory setse distally; otherwise 

 without conspicuous armature. Second antenna with basal seg- 

 ment annulated, and with two setse and one spine; rami with setse 

 VoV-. spines -VoV' ^^^* ^"^^^ T-Am\ about equal, reaching to posterior 

 third. Labrum with anterior and posterior lobes encoding an open- 



> New Cladocera from New England. Proc. Biol. Soc. Washington, vol. 22, pp. 153-156, July 28, 1909. 



Proceedings U. S. National Museum, Vol. 41— No. 1848. 

 94428°— Proc . N . M . vol .41— 11 11 161 



