242 Illinois State Laboratory of Natural History. 



on the inner margins ; inner apical angle produced in the form 

 of a moderately curved hook armed on both margins with 

 spines or teeth. Third segment narrower than the second 

 and fully three times as long as wide ; hairy on the upper 

 part of both margins, and armed on the outer margin, at the 

 beginning of the distal third, with two spines, one stout and 

 serrate and the other short and smooth; outer apical angle 

 armed with three spines, two short and smooth, the other 

 long and serrate on the inner margin ; inner margin sulcate, 

 and armed with two stout plumose setae ; apex armed with 

 two setre, the inner seta plumose on both margins, the outer 

 plumose on the inner margin and provided on the outer with 

 a hyaline lamina. 



Inner ramus of fifth leg of female three- segmented. First 

 segment hairy on the outer margin ; outer apical angle armed 

 with a moderately stout plumose seta. Second segment sub- 

 quadrate, more than twice as long as wide ; hairy on both 

 margins ; armed at the outer apical angle with a plumose seta. 

 Third segment somewhat longer and broader than the second ; 

 margins sulcate, both hairy at the upper part ; armed with six 

 stout plumose seta', two apical and two on each margin. 



Length of female 2.2 — 2.6 mm.; that of male 2.05 — 2.4 

 mm. 



The above description was prepared from specimen- of 

 ]j. macrurus sent by Professor Sars to the Illinois State Labor- 

 atory of Natural History, and from specimens of L. grimaldii 

 kindly sent by him to me. Nothing further need be said about 

 L. macrurus, the type of the genus, except in regard to syn- 

 onymy and distribution. 



The original description of the species appeared in the 

 " Forhandlinger i Yidenskabs-Selskabet i Christiana " (Sars 

 '02). De Guerne ('86) described it under the name of ( 'entro- 

 pages grimaldii ; Nordqvist, in "Die Cahmiden Finlands" ('88 ), 

 made this a synonym of L. macrurus; and de Guerne and 

 Richard, in their "Revision" ('89b), acknowledged the cor- 

 rectness of Nordqvist's view. Recently, however, Professor 

 Sars, in his "Pelagic Entomostraca of the Caspian Sea" 

 ('97), re-established de Guerne's form as a new species of 



