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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 118 



Remarks: As noted by Holthuis (1952a, p. 8), the number of fused 

 articles in the inner antennular flagellum varies with growth. In the 

 St. Helena material, it increases rather regularly from 5 or 6 at a 

 carapace length of 4.0 mm. to 13 at a carapace length of 11.2 mm. 



Distribution: Probably pantropical, littoral and sublittoral. The 

 St. Helena specimens identified by Bate and recorded by MelHss 

 (1875) as Palaemon forceps almost certainly belong to this species. 



Subfamily Pontoniinae 



Pontonia pinnophylax (Otto) 



Figure 1 

 Palaemon pinnophylax Otto, 1821, p. 12. 

 Pontonia tyrrhena. — Schmitt, 1926, p. 40, fig. 66. 



Material: James Bay; in Pinna rudis; Feb. 7, 1964; 1 male, 1 

 ovigerous female. 



Measurements: Carapace length of male to posterior margin of 

 orbit, 11.6 mm.; of ovigerous female, 13.1 mm. 



Figure 1. — Pontonia pinnophylax, male from James Bay: a, anterior part in dorsal view; 

 b, telson; c, dactyl of right third perelopod. 



Remarks: The rostrum (fig. la) of each of these specimens is 

 slightly broader and more distinctly cordiform than it is in any of 

 the five Mediterranean and West African specimens available for 

 comparison. Also, the dactyls of the last three pereiopods of the 

 St. Helena specimens have the distal tooth somewhat more strongly 

 curved (fig. Ic). Both of these characters are variable, however, and 

 the present specimens probably fall within the limits of variation 

 of P. pinnophylax. 



