14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



been noticed with more than seven. There was considerable variation 

 in the relative lengths of the terminal setae of the fnrca. 



Plate 3, fig. 12, shows the typical form from Calabasas in which 

 the second seta from the outside is considerably longer than the 

 fourth. In specimens from the savannas near Panama (pi. 3, fig. 11) 

 the second and fourth are equal in length, while in others (pi. 3, 

 fig. 10) from the Trinidad River, the fourth is" very short. Schmeil 

 considers the relative length of these setae in C. oithonoides of 

 specific importance, but this does not seem to be the case in C. tenuis. 

 There does not seem to be anything in the relative length of the setae 

 that is characteristic of one slope of the isthmus as compared with the 

 other, for specimens collected at Miraflores from the southern slope 

 had the same relative length as those collected in the Trinidad River 

 on the northern slope. 



It will be noticed that the dorsal seta in the specimen figured from 

 the savannas is abnormally long. This was not a uniform condition 

 in the specimens from this locality, but was found in some individuals. 

 There was a wide range of variation in this seta, a variation which was 

 not distinctly correlated with local distribution. 



Plate 3, fig. 7, shows the fifth foot of a specimen collected at Bohio. 

 The inner spine of the terminal segment was not in all cases distinctly 

 serrated. Plate 3, fig. 13, shows the connecting membrane of the 

 fourth feet, and plate 3, fig. 8, shows the form of the receptaculum 

 seminis. 



Cyclops tenuis was found on the southern slope at Miraflores, 

 Cocoli Reservoir, and on the savannas near Panama. On the north- 

 ern slope it was found in a pond near Bohio, in Gatun Lake, Trini- 

 dad River, in a spring at Toro Point, and in the reservoirs on the 

 northern slope, namely Comacho, Carabali, Mindi, and Agua Clara. 

 It may be considered one of the most characteristic copepods of this 

 region. 



Cyclops oithonoides has been reported from Haiti, Richard '95, 

 p. 1, and Paraguay, Daday, 1905, 142. Inasmuch as in neither of 

 these cases have the details of the anatomy been given, it seems 

 possible that the authors had C. tenuis rather than C. oithonoides. 



CYCLOPS DENTATIMANUS, new species 

 A slender species. The last cephalothoracic segment is armed on 



each side with a stout ciliated seta. 



The abdomen (pi. 4, fig. 10) is slender. The first segment is 



enlarged at the anterior end, and equals in length the two succeeding 





