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



Bosmiua boheiuica Hellich. 



Body large, slender. Head high, front nniformly rounded, flagel- 

 lum nearer the end of beak than the eye. Beak short, rounded. 

 Antennules long and arched, composed of 16 or 17 segments. The 

 triangular spine above the sensory filaments large and acute. Shell 

 as long as high, highest in the middle. Spine long, curved dorsad 

 and toothed. Shell irregularly reticulate and longitudinally striate. 

 Post-abdomen large, truncate and excavated. Inferior angle ciliate. 

 Claw protuberance long, unarmed. Claw with six spines at the base. 

 Length 0.6 mm. 



Bosuiina microps P. E. Mueller. 



Oblong, length much greater than height. Front not protuberant. 

 Caudo-ventral angle of the shell without the spine, rectangular. An- 

 tennules long, nearly straight, flagellum nearly midway between beak 

 and eye. Length 0.5 mm. or less. The shell is reticulate and the 

 antennre are very short. 



Bosiuina ruaritima P. E. Mueller. 



Oblong, longer than high, front moderately protuberant. Shell 

 strongly arched above; spine long, directed obliquely ventrad. An- 

 tennules slender, gently curved; flagellum near the beak. Shell 

 smooth. Length 0.5 mm. 



Bosiuina l>reviro!>tris P. E. Mueller. 



Oblong, length greater than height, front greatly protuberant. 

 Shell arched above, strongly spined. Antennules moderate, straight- 

 ish but inclined caudad. Flagellum near end of beak, sensory setse 

 remote. Length 0.6 to 0.7 ram. Color reddish. 



Bosmiua diapliaua P. E. Mueller. 



Gibbous, length greater than height, front not protuberant. A 

 slight sinuosity in the dorsal outline over antennce. Shell very 

 strongly arched without the sj)ine, smooth. Antennules very long, 

 curved, converging at the ends. Flagellum near the end of the beak. 

 Length 0.6 to 0.7 mm. 



Boi^niiua lilljeborgii Sars. 



Plate XLV, Fig. 3. 



Very gibbous dorsally, length and breadth nearly equal, front not 

 protuberant. Dorsal outline sinuous over the antennte. Spine ab- 

 sent. Antennules longer than the body, straight or slightly curved, 

 divergent. Flagellum near end of beak. Length 0.6 to 0.75 mm. 



