ECONOMIC RELATIONS, ANATOMY, AND LIFE HISTORY OF GENUS LERN^A. 1 95 



Specific characters of female. — Cephalothorax in line with the neck axis and sending out at right 

 angles on either side a long tapering and imbranched horn and dorsally a single very short horn, slightly 

 bifid at the tip. Neck of uniform width as far as the third pair of legs, then increasing gradually in 

 diameter and passing insensibly into the trunk, which is widest at the posterior end, with a short bilobed 

 prominence over the base of each egg string. Between these on the ventral surface is the pregenital 

 prominence, which is about half the length of the abdomen and the same width. On the dorsal surface 

 is the abdomen, tapered considerably but bluntly rounded and tipped with the two tiny anal laminae, 

 each carrying a short terminal seta. Egg strings half the diameter of the genital segment and two- 

 fifths the entire body length, cylindrical, and about the same diameter throughout; eggs not arranged in 

 rows, about 200 in each string. 



Head small, nearly circular in outline, and projecting only a little; first antennae four-jointed, basal 

 joint the shortest and stoutest, second joint the longest; first three joints with a heavy fringe of setae 

 along their anterior margins, third joint giving off at the distal end a very large and long seta, fourth 

 joint short and narrow with a terminal tuft of setae. Second antennae two-jointed, basal joint about 

 half the length of the terminal, the latter tipped with a stout claw and a tuft of large setae. Maxillae 

 projecting well beyond the tip of the mouth tube, their terminal claws large and sharply-pointed. 

 Maxillipeds tipped with five rather short and slender claws, basal joint with a prominent knob at the 

 inner distal comer and a smaller knob, tipped with a spine, on the inner margin. Tlie swimming legs 

 are of the usual pattern, the most essential difference being in their respective locations as seen in the 

 table on page 176. 



Total length, 10 mm. Transverse length of two arms and head, 6 mm. Diameter of neck, 0.33 mm. 

 Greatest diameter of trunk, i mm. Length of egg strings, 4 mm. 



Color (preserved material), a uniform grayish-white. 



{dolabrodes, dolabra, a pickax and eWos, similarity.) 



• This species is easily recognized by its pickax form and by the short dorsal horn. These observa- 

 tions can then be supplemented by the position of the swimming legs and other details. 

 Lemaea pectoralis (Kellicott), 1882. 



LerntEocera pectoralis, Kellicott, Proceedings American Society, Microscopists, vol. 4, p. 77. 

 Host and record of specimens. — Found in the axilla of the redfin shiner, Notropis cornutus, from 

 the Shiawasee River, Mich. 

 Lemaea lagenula (Heller), 1865. 



LerncFocera Lagenula, Heller, Reise der Fregatta Novara, p. 246; pi. 24, fig. 9. 

 Host and record of specimens. — Found upon an undetermined fish from Brazil. 

 Lemsea catostomi (Kr(i)yer), 1863. 



Lernceocera catostomi, Kr^yer. Bidrag til Kundskab om Snyltekrebsene, p. 321; pi. iS, fig. 4, a-e. 

 Host and record of specimens. — Taken by Kr0yer from the large-scaled sucker, Moxostoma macrole- 

 pidotum, caught in the Mississippi River near St. Louis, Mo. 

 Lemaea tortua (Kellicott), 1881. 



Lernaocera lorlua, Kellicott, Proceedings American Society, Microscopists, vol. 2. p. 41, i unnumbered pi. 

 Host and record of specimens. — Found in tumors upon the external surface of the bullhead, Ameiurus 

 nebulosus, in Grindstone Creek near Lake Ontario. Subsequently found upon the hog sucker, Catos- 

 tomus nigricans. 



Lemaea phoxinacea (Kr<#iyer), 1863. 



Lernaocera phoiinacea, Kr0yer, Bidrag til Kundskab om Snyltekrebsene, p. 325; pi, 18. fig. 3, a-d. 

 Host and record of specimens. — A single specimen was taken from the European minnow, Phoxinus 

 marsilii, obtained from the Vienna Museum. 

 Lemaea esocina (Burmeister), 1835. 



Lenueocera esocina. Burmeister, Acta Acad. Caes. Leop. Carol. Nat. Cur., vol. 17, p. 312. Nordmann, Mikrographische 

 Beitrage, 1832. part 2, p. 123; pi. 6. figs, i to 6. 



Host and record of specimens.— Found upon various species of European perch, carp, roach, pike, 

 Stickleback, burbot, etc. 



Lemaea haplocephala (Cunnington), 1914. 



LerniBocera haplocephala, Cunnington. Proceedings Zoological Society ot London, 1914, p. S26; pi. i, fig. 4-7. 

 Host and record of specimens. —Taken from different species'of the ganoid genus Polypterus in Lake 

 Tanganyika and the White Nile. 



