612 BULLETIN 159, UNITED STATES NATIONAL MUSEUM 



69. Cephalic segment with 2 to 4 soft horns, symmetrically arranged 70 



Cephalic segment with asymmetrical protuberances, or none at all 72 



Cephalic segment with a pair of profusely branched soft ventral 



laminae and another pair on the neck away from the head; 



abdomen 2-segmented; gill cavity of fishes 9 Dysphorus Kurtz, 1924 



70. Neck passing insensibly into trunk; abdomen more or less fused 



with trunk; caudal rami present; second antennae uncinate; 



flesh of fishes 9 Lernaea Linnaeus, 1758 



Trunk abruptly widened from neck; no caudal rami 71 



71. Abdomen separated from, and longer than, the trunk, 3-segment- 



ed; first antennae 5-segmented; second antennae 1-segment- 



ed, without setae; gills of fishes 9 Lernaeogiraffa Zimmermann, 1922 



Abdomen fused with trunk, without segmentation; first an- 

 tennae 3-segmented; second antennae 2-segmented, both 

 pairs with setae; flesh of fishes 9 Taurocheros Brian, 1924 



72. Neck and trunk transversely wrinkled, with traces of segmen- 



tation; head swollen, at anterior end of neck; no legs; flesh of 



fishes 9 Areotrachelus Wilson, 1924 



Trunk segmented, with mouth at its anterior end; 4 pairs of 

 legs; neck a frontal process, ending in a knob bearing anten- 

 nae only; gills of fishes 9 Therodamas Kr0yer, 1863 



73. Head and thorax smooth, without processes or horns, and in 



line with trunk axis; abdomen 1-segmented; second antennae 



chelate; fins of fishes 9 Peniculus Nordmann, 1832 (p. 479) 



Cephalothorax with horns or processes, or both, and usually bent 



at an angle with the neck 74 



74. Bilateral symmetry complete; branched frontal processes on 



the head, but no horns or lateral outgrowths; ovisacs straight 75 



Bilateral symmetry complete; lateral horns or outgrowths, but 



no frontal processes; ovisacs straight 76 



Bilateral symmetry distorted; neck attached to side of trunk; 



ovisacs coiled into tight spirals 77 



75. Head and neck straight, attached at right angles to side of trunk 



near anterior end; second antenna 2-segmented; 3 pairs of 



legs; flesh of sardine 9 Pero derma Heller, 1865 



Head and neck with sigmoid curve, attached to anterior end of 

 trunk; second antennae 3-segmented; 4 pairs of legs, first 2 

 biramose; head in heart of fish 9 Cardiodectes Wilson, 1917 



76. Two to 10 chitin horns on head; neck not enlarged behind the 



legs; 1 pair of maxillae and 4 pairs of swimming legs; flesh of 



fishes 9 Lernaeenicus LeSueur, 1824 (p. 480) 



Two lateral outgrowths on head; neck enlarged behind the legs; 

 2 pairs of maxillae and 3 pairs of swimming legs; abdomen 

 smafl; flesh of fishes 9 Sarcotretes Jungersen, 1911 (p. 484) 



77. Neck attached to anterolateral corner of trunk; abdomen 



hemispherical; trunk twisted; 4 pairs of swimming legs; 



eyes of fishes 9 Phrixocephalus Wilson, 1908 



Neck attached to center of dorsal surface of trunk; abdomen as 

 long as trunk, turned sidewise; 4 pairs of legs; gills of fishes. 



9 CoUipravus Wilson, 1917 



78. Head and neck with soft lateral processes; neck reflexed upon 



itself; abdomen two-thirds as long as trunk and tapered; 

 gills of fishes--- 9 Haemobaphes Steenstrup and Lutken, 1861 (p. 488) 

 Head with hard chitin horns, neck not reflexed 79 



