330 CRUSTACEA 



FAMILY 1. BRANCHIPODIDAE. 



Body elongate, being composed of many segments and without cara- 

 pace; head distinctly set off; first antennae filiform; second antennae of 

 male used for clasping the female, being very large and composed of 2 elon- 

 gated segments and with or without extra frontal appendages between 

 them; thoracic segments and appendages mostly 11; abdominal segments 

 8 or 9 in number; 2 stalked eyes present; a pair of egg sacs extend from 

 the last thoracic segment of female: 8 genera; the animals live in fresh 

 and salt pools and swim on their backs. 



Key to the genera of Branchipodidae here described: 



tti Frontal appendages present. 



61 Frontal appendages simple in form 1. BRANCHIPUS 



6 2 Frontal appendages branched 2. CHIBOCEPHALUS 



a 2 Frontal appendages absent. 



&! Abdomen with 8 segments 3. ABTEMIA 



6 2 Abdomen with 9 segments 4. BRANCHINECTA 



1. BRANCHIPUS Schaeffer. Beween the second antennae of male 

 are 2 unbranched frontal appendages; abdomen consisting of 9 segments 



Fig. 507 Fig. 508 



Fig. 507 Branchipus vemalis male (Packard). 1, first antenna; 2, second 

 antenna ; 3, frontal appendage. Fig. 508 CTtirocephalus holmani front view of 

 head of male (Packard). 1, eye; 2, first antenna; 3, second antenna; 4, frontal 

 appendage. 



and 2 long caudal projections which have setose margins: 2 American 

 species. 



B. vernalis Verrill. The fairy shrimp (Fig. 507). Body semi- 

 transparent and pinkish in color; length 23 mm.; frontal appendages 

 broad and flat: eastern North America, in fresh- water pools during the 

 spring, autumn, and winter, passing the summer as resting eggs; often 

 common, but sporadic. 



2. CHIROCEPHALTJS Prevost. Between the second antennae of male 

 2 very long, branched, and coiled frontal appendages; abdomen con- 

 sisting of 9 segments and with 2 long, broad caudal projections with setose 

 edges: 1 American species. 



C. holmani Ryder (Fig. 508). Body slender, 15 mm. long: eastern 

 North America (Philadelphia, Long Island). 



