ENTOMOSTKACA OF MINNESOTA. 229 



KEY TO TIIE SUBGENUS CAMPTOCERCUS (VERUS). 



I. Beak pointed. 



A. Head depressed. 



a. Pigment spot larger than the eye biserratus, 229 



5. Pigment spot smaller than the eye luacriirus, 229 



B. Head directed forward rectirostris, 230 



II. Beak truncate below latirostris, 230 



III. Beak cleft below or with a forwaid projection. 



A. Antennules shorter than the beak lilljeborgii, 230 



B. Antennules longer than the beak I'Otlliiclus, 230 



Caiuptocerciis biserratus Schoedler. 



Plate LXII, Fig. 4. 



Is very nearly related to the next, from which it is distinguished 

 chiefly by the fact that the pigment fleck is larger than the eye. 

 Schoedler overlooked the fact that in C. marmrus there is a lateral 

 line of scales on the abdomen, and lelied upon that character to dis- 

 tinguish this form. (Schoedler says that the pigment fleck in C mac- 

 rnnis is smaller than the eye, P. E. Mueller says they are nearly equal, 

 while in oar specimens they are much smaller or nearly equal.) ]f 

 much variability is found, Schoedler's species seems to rest on a slen- 

 der basis. The basal spine of the claw, however, seems to be peculiar 

 in sitting on a distinct prominence. 



*Caniptocercus luacruriis Mueller. 



Plate LXI, Figs. 10, 10a. 



Lynceus mncrurus — Lilljeborg. Schoedler, P. E. Mueller, Kurz, Birge, Herrick. 



This universally distributed species occurs in our larger bodies of 

 water and is not rare, though hardly abundant. 



The body is long and nearly rectangular; the head strongly arched 

 and keeled. The keel of the head is extended down the whole dorsal 

 line. The dorsal line is moderately curved, while the shell is but 

 slightly excavated below. The head extends into a blunt beak look- 

 ing downward; the direction of the head is somewhat variable (from 

 vertical to an angle of about 30 degrees). The eye is much larger 

 than the pigment fleck; the antennules are shorter than the beak, and 

 have one elongated terminal seta. The post abdomen is very long 

 and has numerous anal teeth as well as a lateral row of scales. The 

 basal spine of the claws is large and serrate, the claw itself being 

 nearly straight and armed with an increasing series of spines to be- 

 yond the middle. The lateral scales of the post abdomen are incon- 

 spicuous. The shell gland is long. The antennules reach to almost 



