ENTOMOSTRAUA OF MINNESOTA. 129 
+ Antenne thick. . . . ptets oes @ } CLASSUS,tloO 
+t Antenne slender. . . trispinosus,; 130; and northumbricus, 130 
** Inner ramus of the second foot three-jointed. 
te MEM IC IR PALHORIGHE St dope i oo ie a fa es se ws ce EES or 
{f Stylets short, oval. . 85 . « . . . . .  iblinoisensis, 131 
If. Inner ramus of the fourth foot three- Hobtited 
a. Maleantennanormal.. . . » « « .. « « hibernigus, 133 
b. Male antenna reduced, hooked is thé vad: titre Btnaise tote palustris, 133 
[Not noted in the key are: tenuicaudis, 129; northumbricus var. 
americanus, 130; borcherdingii, 134; minnesotensis, 134. ] 
Canthocamptus elegantulus, C. mareoticus and C. horridus are uncer- 
tain, probably referred to the wrong genus. C.° stromii Baird 
(= Dacetylopus stromii), C. rostratus Claus (= Stenhelia ima). C. vire- 
scens, CU. linearis, and C. roseus of Dana, are marine Harpacticide of 
uncertain affinities. (©. minutus of Claus is not sufficiently described, 
but appears to be the earlier condition of C. minutus Mueller (C. sta- 
phynalis Jurine). 
* Canthocamptus gracilis Sars. 
Is elongated linear, with the abdominal segment smooth, Caudal 
stylets long and slender; external caudal seta about one-fourth the 
inner. All the feet with two-jointed inner rami; outer branch of 
fourth foot longer than the others, inflexed; basal process of fifth foot 
slightly expanded. Length 1.0 mm. 
(* Canthocamptus tenuicaudis Herrick.) 
PLATE XXIX, Fias. 15 and 16, 
At Decatur, Ala., was found a species of Canthocamptus which is 
different from any American species, and seems in many points 
nearest the above, but, unfortunately, only a hasty sketch could be 
made at the time, and the notes are insufficient to define it. The form 
is not remarkably slender; the first and second abdominal segments 
are very large. The caudal stylets are slender and elongated, the 
inner seta being very long and curved, while the outer is quite short. 
The anal plate is covered with hairs only. The antennz are normal, 
of moderate length, and the fifth foot has but a narrow process at 
the base. 
If this form be worthy a distinctive name, it may be called Cantho- 
camptus tenuicaudis, 
} Distinguished from the following by the presence of only three spines on the process of the basal 
joint of the fifth foot. 
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