216 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



33. Genus yEGATHOA" Dana. 



Eye.s large, oval, composite. Posterior niaro-in of head produced in 

 three lobes. 



Anterior margin of first thoracic segment manifestly trisinuate. 

 Post-lateral angles of thoracic segments not produced. Epimera dis- 

 tinct on all the segments of the thorax with the exception of the first; 

 they extend the full length of the segments and are not acutely pro- 

 duced posteriorly. 



The abdomen is not narrower than the thorax, but continues the 

 oval outline of the bod3^ The abdominal segments are not shorter 

 than the last thoracic segments. Pleopods not ciliated. Uropoda and 

 terminal segment of abdomen furnished with hairs. 



ANALYTICAL KEY TO THE SPECIE8 OF THE (iENI'S .EGATHOA. 



n. Frontal margin of head produced anteriorly in a median Ungulate projection. 



^Fgathua liuguifroiix Kichardson 

 a'. Frontal margin of head not produced anteriorly in a median Ungulate projection. 

 b. Surface of head smooth, evenly convex. Second pair of antennte comj^osed of 

 ten articles. First thoracic segment longer than any of the succeeding seg- 

 ments, which are of equal length Jujathoa oculata (Say) 



¥. Surface of head with central portion sharply raised above the lateral portion, 

 which is deeply excavate just in front of the eyes. Second pair of antennae 

 composed of eight articles. First three thoracic segments of equal length; 

 last four subequal an<l somewhat shorter than first three. 



.Kgathoa medial is Richardson 



iEGATHOA LINGUIFRONS Richardson. 



jEgailioa linguifwns'R\cnAB.r>iiO's, Proc. U. S. Nat. Mus., XXIII, 1901, p. 526. 

 Locality. — Trinidad. 

 Body narrow, elongate; abdomen not narrower than thorax. 



Head with sides rounded. Frontal margin ab- 

 ruptly produced anteriorly into a median lingulate 

 projection, with apex rounded; posterior part of pro- 

 jection forming a raised surface sharply defined on 

 anterior part of head, extending l)ack to eyes. Eyes 

 large, oval, occupying two-tiiirds the width of head. 

 First pair of antennse nine-jointed. Second pair 

 more slender equal in length to first pair and ten- 

 jointed. 



First three thoracic segments long, second one 

 shortest; last four segments short, of nearly ecjual 

 Fi(i. 2LS.-.EGATHOA length. All the abdominal segments distinct; first 



UNGUn-RONS. ^ '^ I'll • 1 



five equal in length, terminal segment rounded at 

 apex. Uropoda longer than terminal segment. Inner branch obliquely 



«This genus, perhaps, represents the young of Lironeca. The figure given by 

 Schi(x>dte and Meinert of the young female of Lironeca redntdinii does not apparently 

 differ from .Egalhoa oadaia (Say). I have not suppressed the genus, however, 

 because J could not be positive of the identity of these forms. 



