CYMOTHOIDEA. 755 



all more slender, its basal joint about as long as following portion. 

 Posterior antennae a little the longer, nine (or ten) jointed, last three 

 joints smaller than the preceding; anterior pair eight-jointed, three 

 basal joints largest. Caudal segment much narrower than tergal part 

 of last thoracic segment. 



The L. Redmannii, as figured by Milne Edwards, has not the inner 

 branch of the stylets obliquely truncate, as in the longistylis. 



LlYONECA EMARGINATA. 



Corpus duplo longius quam latum. Segmentwm abdominis posticum 

 paulo transversum, fere semicircidare, posticd emarginatum, ba-si latius. 

 Appendices caudales segmentum caudale superantes, angulo basis in- 

 terne elongato, subacuto, ramis valde incequis, interno brevi, crasso, 

 compresso, ad apicem rotundato, externo tenui, obtuso, recto, longiore. 



Body twice as long as broad. Last segment of abdomen somewhat 

 transverse, almost semicircular, emarginate behind, broadest at 

 base. Caudal appendages extending beyond line of extremity of 

 abdomen ; inner angle of base elongate, subacute ; branches much 

 unequal ; inner short, stout, compressed, rounded at apex ; external 

 slender, obtuse, considerably the longer. 



Plate 50, fig. 4 a, dorsal view ; b, caudal appendage. 



From the body of a fish, at Rio Janeiro. 



Length, one inch. Colour, whitish, a little yellow. Head nearly 

 semicircular, a little more prominent; posterior angles projecting; 

 eyes indistinct. Joints of thorax subequal, first segment longest. 

 Five abdominal segments very short transverse, equal. Antennae 

 moniliform ; posterior pair a little the longest ; anterior eight-jointed, 

 three basal joints largest; posterior nine-jointed, last three joints 

 much smaller than preceding. Seventh pair of legs more slender than 

 preceding, or a little longer, and claw smaller. Claw of third pair 

 not smaller than that of second. The body is a little oblique, from 

 its position on the fish. 



