514 GEOLOGICAL SURVEY OF THE TERRITORIES. 



greater length than width. The antennae of the second pair (claspers) 

 are more or less broadened in the males, and have principally on their 

 second interiorly directed part a flattened form. These antennae are 

 either without appendages, or only with a few little developed append- 

 ages, in the form of rounded or knob-like protuberances on the interior 

 margin of their anterior, outwardly directed, or finally with small ap- 

 pendages in the shape of denticular spines near their base. For the 

 most represents the little developed, terminally and often laterally, 

 bristled abdominal furca, a simple prolongation of the last segment of 

 the abdomen ; the furcal branches are conical or stylet-shaped, seldom 

 tabulate. Parthenogenesis is known to occur in this genus. 



Genus Branohipus. 



• 



Nine apodous dbdominal segments [Branch, stagnalis excluded f), of which 

 the first two hear the external sexual organs, the last segment located before 

 the furca being not larger, but mostly smaller than its preceding. The an- 

 tennae of the second pair (claspers) in the males have their first joint 

 stout, often with much developed appendages on their sides or at their 

 base, in the shape of digitate processes or denticular tuberosities, the 

 second part being more slender and narrower than the first ; in the op- 

 posite case the antenna is terminally divided into several branches. The 

 generally much developed, laterally and terminally, bristled furca has 

 its branches nearly always of a tabulate form, which are separated 

 from the last segment by an articulation. Parthenogenesis is unknown 

 in this genus. 



Eleven pair of legs are the common character for these two genera, 

 distinguishing them from the genus Folyartemia Fischer, which has 

 nineteen pair of legs and a lesser number of apodous segments of the 

 abdomen. 



Odessa, May 5, 1877. 



