500 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVIII. 



This toi-ininul portion roprcseiits the oxopod iiud in many species of 

 l)oth Cif//'(/i/s and L< i<(<)j>]if]i(''n'iix there is also a distinct endopod 



(e", ii^\ 7), with two setse on its 

 apex attaclied to the base of the 

 exopod {Lejx'ophtJnli'iis jx-cforaUx, 

 (JaUf/its rap(i,i\ etc.). 



The mouth openino- is terminal 

 or tcrmino-ventral and ma\' be 

 either circuhir in outline (('aligux 

 hon'ito^ Lepeoj'/ttlu h'lis < <lin(ii'(Ji<!)^ 

 transversely elliptical ( C(tl!(jih-i ni- 

 jxi'i')^ or even strongly hmate 

 ( C(iJ/(/w^ curtii.!^., Lepeophtltelrns 

 pt'cforaHs). 



Whatever its shape it is always 

 surrounded by a frinoe of long'- 

 hairs. Often in the incision at the 

 center of the under lip is a small 

 tuft of hails considerabl}' longer 

 yet. In living specimens these 

 hairs are seen to l)e luotile and 

 they nuist assist in drawing the 



Fig. 5.-THE second aktexx.e am. the first blood up the RlOUth tu))e bv UUlk- 



MAXILL.S OF THE ADULT CaLIGUS B(,)NIT0. . . i • • j i. j.1 .1 ' 



UPPER FIGURE, THE MALE: LOWER, THE FEMALE. l"g thC JOHlt at thc UlOUth OpeUlUg 



tighter. 

 The fi-amework of the mouth is quite complicated and consists of 

 two sets or series of rods running lengthwise, connected by others 



mx. 



a 



Fig. 6. — Mouth parts, a, dorsal surface of mouth tube of Lepeophtheirus hippoglossi; b, 



VENTRAL SUHFACE; c, MANDIBLE; d. MANDIBLE OF CaMCUS BONITO; 1", FLEXIBLE FLAP AT ANTERIOR 

 END (IF rPPI'.ll LIT; r. P.OIl (IN LATKKAL .^LVRGIN (IF FRAMEWORK OF LOWER LIP. 



which are transvers(\ There is first a long rod on either side, running 

 the entire length of the framework along the lateral margins and 

 funiisjiing the i-e(|uisite su])p()i-t for (he whole mass ( r. fig. 6. an.d r\ 



