232 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



*A.louopsis latisisima Kurz. 

 Plates LXI, Fig. 8; LXIII, Figs. 1 and 9. 



Body very high, compressed, with a high dorsal keel or ridge; the 

 upper outline strongly aud evenly arched, terminating behind in no 

 angle; lower margin almost angled at the anterior third, rounded be- 

 hind, fringed with long bristles anteriorly, with short ones posteriorly. 

 Head very narrow; beak extremely long; fornices small; antennules 

 nearly as long as the beak, straight and narrow; pigment fleck 

 smaller than the eye. The abdomen is long, somewhat narrowed 

 toward the end, where it is deeply cleft; the terminal claw is furnished 

 with a Jarge aud small basal spine, while there is an increasing series 

 of spines extending to the middle. 



The elongated spine of the third foot is pectinate and reaches 

 nearly to the posterior margin of the shell. The shell is marked by 

 a few strong striie which are diagonal except anteriorly where are a 

 few parallel to the front margin. The male is small and lacks the 

 crest on the back, while the lower margin is straight; the antennae 

 are longer than the beak and differ somewhat from those of the female. 

 The first foot has a claw. The post-abdomen lacks the anal teeth. 

 Kurz gives the size as 0.5 mm. 



The American form varies between 0.45 mm. and 0.55 mm., and 

 seems to have a higher dorsal keel and longer beak. Kurz speaks of 

 but a single accessory spine on the terminal claws; there is, however, 

 a second very minute spine or cluster of hairs in this as well as the 

 following. 



Found in the same gathering with the following near Minneapolis 

 (marshy offset from Bassett's creek near Oak Lake Addition):* 



*Alouopsis latissinia var. media Birge. 

 Plate LXI, Fig. 9. 



I give Birge's description verbatim. 



"Rostrum prolonged, and shell sharp, somewhat quadrangular in 

 shape, marked by strife. The dorsal margin is convex, the hinder 

 margin nearly straight. Its lower angle is rounded and without 

 teeth. The lower margin is concave and has long plumose setse. The 

 front margin is strongly convex. The post-abdomen is long and slender, 

 resembling that of Capmtocerciis, and is notched at the distal extrem- 

 ity; it has two rows of fine teeth and some fine scales above them. 

 The terminal claws are long, slender, with a basal spine, a spine in 



Note to Alonopsis Lati.ssima. (See Fi^. 1, Plate LXIII.) Since writing the above the males of 

 our American form have been found; they are shaped as the females, with a high dorsal keel; the post- 

 abdomen is rounded, with transverse series of small bristles; the claw has a minute median spine, and 

 the porus genitalis is anterior and elevated. 



