140 TWELFTH ANNUAL EEPORT. 



maturity as in the other related species. For measurements see 

 above. Color deep opaque red or purple. Appearing in early spring 

 as soon a^ the ice is melted from the pools which it inhabits. In 

 the south it occurs in autumn. The name above given seems to 

 have the priority, although this species was figured and described 

 at about the same time m the annual of this survey. 



Sp. 6. Diaptomus longicornis, Berrick 



This name was applied somewhat loosely, the description given 

 being incomplete, but re-examination of types shows it to belong 

 unquestionably to the form since described as D, leptopiis. in our 

 state we have found another variety, in general, almost identical 

 with the type specimens, but nearly twice as large. It is now 

 proposed to extend the sis^nificance of this name so as to include 

 both varieties, which will undoubtedly be found connected by 

 intermediate forms, thus retaining the name given by Forbes for 

 the variety to which it in particular applies. 



(a) var. leptopiis, Forbes. 



This species is the commonest member of the genus in small 

 lakes and clear pools. It is tolerably constant in coloration, but 

 varies somewhat in size. The original description is insufficient to 

 identify the species definitely, but taken in connection with the 

 figure and the measurement, could hardly be refered to either of 

 the other American forms. This species is characterized by the 

 very compact thorax, the margin of the last segment of which has 

 two very minute spines; and by the form of the fifth feet. The 

 antennae reach nearly to the end of the caudal setae, while in the 

 next they fall short of the length of the stylets. The outer spines 

 of the swimming feet are denticulate on the outer margin and setose 

 within. The fifth feet of the female are compact, the inner ramus 

 is more or less obviously two-jointed; the third joint of the outer 

 ramus is almost obsolete and has two short spines; the claw of 

 second joint is strongly denticulate. The male fifth foot has a 

 rather long inner ramus which is very imperfectly two-jointed; the 

 left foot is rather long; the claw of the right foot is armed with 

 crenulate teeth. Leugth 1.5 — 1.7 mm., without setae. The body, 

 which is broadest anterior to the middle, is bluish; the tips of the 

 antennae are deep purple. The eggs are not as numerous as in the 

 next. 



