6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



lar condition has been recorded by Dahl in regard to Pscudodiapto- 

 mus richardi Mrazek. He says (Dahl, 1894, p. 11) : " Interessant ist 

 die Art dadurch, dass sie als einzige mir bekannte Calanide zwei nnd 

 zwar zwei ungleichliche Eiersacke besitzt. Der linke Sack ist immer 

 grosser und enhalt 10-12 Eier, wahrend man in rechten deren 4-5 

 findet." 



Average length of female 1.22 mm. Length of male 0.883 mm. 



The tvpe specimens were collected by Messrs. Meek and Hildebrand 

 in Rio Culebra, a branch of the Rio Chepo, in Panama, in brackish 

 water. 



The tvpe of the genus, Pseudodiaptomus pelagicus was described 

 by Herrick (Herrick, 1884) from material collected in Mississippi 

 Sound in brackish water. Since that time ten other species have 

 been described. Three, P. acutus, P. gracilis and P. richardi, were 

 described by Dahl ( Dahl, 1894) from material collected at the mouth 

 of the Amazon. Two, P. hcssci Mrazek (Mrazek, 1894) and P. 

 serricaudatus Th. Scott (Scott, 1893), were in the mouth of the 

 Congo. P. sali)ia Giesbrecht (Giesbrecht, 1896) occurs in the Red 

 Sea. P. stuhlmanni Poppe and Mrazek (Poppe and Mrazek, 1895) 

 was found in the Quilimani River on the east coast of Africa. P. 

 lobipcs Gurney (Gurney, 1907), was found in tanks at Calcutta, P. 

 poppci Stingelin (Stingelin, 1900) in the fresh waters of Celebes, and 

 P. forbcsi Poppe and Richard (Poppe and Richard, 1890), in Lake 

 Sitai and river Whangpoo near Shanghai. 



Thus of the eleven described species apparently four were found 

 in fresh water, one in salt water, and the others in brackish waters. 



P. culcbrcusis is the first member of the genus to be described 

 from the west coast of America, and is very distinct in its structure 

 from the other species. Inasmuch as the genus is practically world 

 wide in its distribution, it seems probable that further collections 

 will bring to light many more species. 



PSEUDODIAPTOMUS CRISTOBALENSIS, new species 

 The first segment of the cephalothorax exceeds one-third the total 

 length of that part of the animal, and the first two somewhat exceed 

 one-half the length. The last segment is terminated with a rather 

 prominent acute spine on each side (pi. 2, fig. 5). 



The abdomen of the male (pi. 2, fig. 1) is slender. The last seg- 

 ment is about one-half as long as the preceding. The furcal rami 

 are about twice as long as the last abdominal segment and are ciliate 

 on the interior mar£>in. 



