582 PROCEEDTNaS OF THE NATIONAL MUSEUM. vol. xxvni. 



FAMILY CALIGID^E. 



Carapace ))road and usually comi)re,ssed. Cephalothorax incom- 

 pletely se<i;Mn(Mited, the free thoracic .segments often i)artially over- 

 lapped or hidden by dorsal plates. Anterior antenna' short, club- 

 shaped, with two or three free joints, their basal segments anchylosed 

 with the anterior border of the carapace. Posterior antennie in the 

 form of a simple hooked claw, not extending beyond the carapace. 

 Mouth in the form of a more or less elongated suctorial beak, formed 

 out of the upper and under lips and inclosing the toothed mandibles. 

 Maxilhe free, both pairs rudimentai'v, the tirst pair sometimes lacking. 

 Maxillipeds also free and in the form of hooked claws, the first pair 

 weak, the second much stronger and used for prehension. First four 

 pairs of thoracic legs usually Ijiramose, but the first and fourth pairs 

 frequentl}" uniramose; the fifth pair rudimentary and often invisible 

 dorsally or entirely lacking. Two simple eyes fused on the median 

 line, often lacking. Generative organs paired in both sexes; females 

 with two conl-like egg tubes, usually quite long; eggs in a single row. 

 Male usually smaller than the female and both sexes permanent pai'a- 

 sites upon fish. 



1. Tln-ee anterior segments of thorax fused with tlie liead; fonrtli and genital seg- 

 ments free 2. 



1. Two anterior thoracie segments fused with the head; third, fourth, and genital 



segments free Subfamily Tkebin.e. 



1. First thoracic segment only fused with the head, the (jthers free; one or more of 



them with i)aired dorsal {ilates; all four ])airs of legs biramose '^. 



2. F(jurtli segment witiiout dorsal plates <jr any appendages except tl>e fourth 



legs Subfamily Caligin.e. 



2. Fourth segment with a pair of dorsal plates which usually overlap the genital 



segment Subfamily Eikyphorix.e. 



o. Frontal i)lates distinct; egg cases visible their entire length. 



Subfamily Pandarin^e. 



3. Frontal plates fused with tiie carapace; egg cases convoluted, entirely hidden. 

 Subfamily Cecropix.e. 



The genera belonging to the Caligina^, are discussed in the present 

 paper; those belonging to the other subfamilies are left for subsequent 

 papers. 



Carapace broad and always fiattened dorso-ventrally; free thorax 

 segment without plates or appendages of an}- sort except the fourth 

 pair of legs. Genital segment enlarged, but usually smaller than the 

 carapace; never much larger except in the genus Ju-Jwius. First and 

 fourth thoracic legs uniramose, second and third biramose; fifth pair 

 rudimentary but often visil)le as a pair of small papilhe at the posterior 

 corners of the genital segment. Adidts active, most of the females as 

 well as the males capable of swimming about freely. 



