78 U.S. NATIONAL MUSEUM BULLETIN 236 



H. meridionalis G. O. Sars, 1927 H. meridionalis G. O. Sars, 1927 



H. gurneyi Jakubisiak, 1933 H. gurneyi Jakubisiak, 1933 



H.furcatus Lang, 1936c H. furcatus Lang, 1936c 



//. islandicus Klie, 1939 H. islandicus Klie, 1939 



H. septentrionalis Klie, 1939 H. septentrionalis Klie, 1939 

 //. trisetosus Lang, 1948 



The position of the following species is uncertain: 

 H. concinnus Dana, 1849 

 H. sacer Dana, 1849 

 H. virescens Dana, 1849 

 H. aquilinus Fischer, 1860 

 H. macrodactylus Fischer, 1860 

 H. depressus Boeck, 1864 

 H. chelifer var. T. Scott, 1894 

 H. robustus Brady, 1910 

 H. boehleri Pesta, 1916 

 H. koenigi Pesta, 1916 



The following species, which now belong to other genera, have 

 been introduced: 



H. acutifrons Dana, 1849 {=Euterpina acutifrons (Dana, 1849)) 



H. brevicornis Giesbrecht, 1902 (not O. F. Miiller, 1776) {'^Tigriopus 



californicus Baker, 1912) 

 H. cristatus A. Scott, 1909 { = Perissocope cristatus (A. Scott, 1909)) 

 H. croni Kr0yer, 1842 { = Parathalestris croni (Krj^yer, 1842)) 

 H. curticornis Boeck, 1864 {=Tigriopus brevicornis (0. F. Miiller, 1776)) 

 H . fortificationis Fischer, 1860 { = Laophonte cornuta Philippi, 1840) 

 H. fulvus Fischer {=Tigriopus brevicornis (O. F. Miiller, 1776)) 

 H. gibber Kr0yer, 1842 {=Thalestris gibber (Kr0yer, 1842)) 

 H. linearis Dana, 1853 (nomen nudum) ( = Lourinia armata (Glaus, 1866)) 

 H. simplex Brady, 1910 {= Perissocope typicus Brady, 1910) 

 H.xenus Monard, 1926 {= Perissocope xenus (Monard, 1926)) 



The species Harpacticus clausi A. Scott has been included in the 

 list of well-described species because recently it has been redescribed 

 by Sewell (1940, p. 153, figs. 9a-h, lOa-i). H. boehleri has been men- 

 tioned among the imcertaln species (and has been excluded from the 

 keys) because certain details of the mouth parts have not been 

 described by Pesta. For H. islandicus Klie, 1939, and H. septentri- 

 onalis KJie, 1939, included among the well-described forms, the 

 description of the male is not complete. These three species, nevertheless, 

 can be recognized when found; complete descriptions and especially 

 complete drawings urgently are needed. 



The following keys, for the identification of males and females, 

 have been adapted from Lang (1948, p. 317); they are far from satis- 

 fying because very few species have been described so completely 

 that characters of diagnostic value can be compared adequately. 



