760 



CRUSTACEA. 



Plate 50, fig. 8 a, dorsal view ; b, first antenna ; c, second antenna ; 

 d, caudal appendage ; e, side view, showing epimerals. 



From the body of a fish, Eio Janeiro. 



Length, about one inch. Colour, mostly brownish black. Head 

 semicircular in front. Epimerals oblong, pointed, and those of the 

 last three segments acute. Inner angle of base of caudal appendages 

 prolonged and acute. Lateral processes of two anterior abdominal 

 segments longest, each nearly one-half the breadth of the rest of the 

 segment ; the others rather long and about equal. Claw of third pair 

 of legs scarcely smaller than that of second. Seventh pair of legs 

 more slender than sixth, and claw much smaller. 



This species is unlike the rnaculata and affinis in having the three 

 posterior thoracic segments either side acutely prolonged, and in this 

 character agrees with the aculeata, from which, however, it differs in 

 its stylets, neither branch of which is truncate, and in the epimerals, 

 only the three posterior of which are properly acute. Its acute 

 branches of the caudal stylets and the character of the epimerals 

 remove it from the bivittata. The epimerals of the third and fourth 

 segments project a little posterior to the segments and are obtusish ; 

 while the fourth reaches about as far as the segment ; and the fifth 

 and sixth fall short of the posterior outline of the segment. 



Nerocila aculeata. 



Plate 50, fig. 9 a, animal, dorsal view ; b, anterior antennas ; c, 

 caudal stylets. 



From the body of a fish, Rio Janeiro. 



The specimens referred to this species are similar to those of the 

 brasiliensis in the thoracic segments; but the inner branch of the 

 stylets is obliquely truncated, and the outer is hardly acute; and 

 the caudal segment is but slightly transverse. Length, about one 

 inch. Colour, light brownish black. Head subtruncate in front. 

 Epimerals of second, third, and fourth segments rather short and 

 obtuse ; of three posterior long and acute. Claw of third pair of legs 



