45 



II. Species from the Atlantic side of America. 

 7. Acetcs brasilicnsis n. sp. Figs, i — 7 in the text. 



The Copenhagen Museum possesses this species from a single place. 

 Brazil. COLLIN. i male, i female. 



Male. — The anterior keel on the carapace has only a single tooth (fig. i), as the 

 denticle, which in most forms e.xists between the tooth mentioned and the rostrum, has disap- 

 peared. The rostrum is short with the end obtuse. Eyes about as in A. spiniger. Antennulse 

 with the peduncle long ; third joint very 

 elongated, a little less than two and a 

 half times as long as the inner margin 

 of second joint. (The thickened part of 

 the upper flagellum mutilated). Lower 

 flagellum (fig. 2) has lost its distal joints 

 in my specimen; its shaft is 3-jointed ; 

 the two proximal joints of the main 

 "branch" are apparently fused and have 

 a close row of 6 thick, obtuse spines, 

 and outside this row 2 spines ; the fol- 

 lowing joint has a strongly curved and 

 very robust spine twice as long- as any 

 of the other spines, but the third joint 

 of the shaft has no produced free part, 

 and no trace could be found of the 

 very long spine projecting in all other 

 species from that free part. The antennal squama reaches the end of second joint of the 

 antennulse. Coxje and trochanteres of third pair of legs without any tooth at their distal 

 inner angle. Genital coxae considerably broader than long, anteriorly very broadly rounded. 

 Exopod of uropods (fig. 3) nearly four and a half times as long as broad; the ciliated part 

 occupies scarcely two-fifths of the outer margin, and a minute tooth is seen at the end of the 

 glabrous part. 



The petasma (figs. 4 — 6) is peculiar. Pars astringens is completely wanting. Pars externa 

 well developed, about two and a half times as long as broad; its distal two-fifths triangular 

 and slightly longer than broad. Pars media is moderately slender; its free proximal part is 

 long with the lateral margins subparallel, and the basal margin somewhat deeply and obliquely 

 concave, while the inner proximal corner is produced into a somewhat short, obtuse process, 

 the outer corner much broader, rounded. Beyond the insertion of pars externa pars media 

 narrows greatly to the thickened capitulum, and a processus ventralis could not be made out; 

 the capitulum is subglobular, but consists of four lobes, the inner long, sausage-shaped (fig. 5), 



Figs. I — 7. Acetes brasilicnsis n. sp. 



Fig. I. Front end of the carapace of the male. 



Fig. 2. Proximal parts of upper and lower flagellum of left male antennula. 



Fig. 3. Exopod of left male uropod. 



Fig. 4. Left petasma, from behind. 



Fig. 5. Capitulum of the same petasma, from behind. 



Fig. 6. Same capitulum, from in front. 



Fig. 7. Genital area and proximal parts of third legs of a female. 



