268 



of the 4''' pair are, however, distinctly stouter than those of the 5"'. Of one of the two 

 fiill-o-rown females from Stat. 45 the measurements of the three last joints of these legs (Fig. 

 63W, 63;/) are the following: of the 4''^ pair carpus 3 mm., propodus 4,2 mm., dactylus 3 mm., 

 of the s'** pair carpus 4 mm., propodus 5 mm., dactylus 3,1 mm. These numbers show that 

 the dactyli of the 4"' pair are as long as the carpus, of the 5"^ slightly shorter than it, while 

 the carpus of the 4''' pair is one-fourth shorter than that of the 5'''. 



Like in Pont, occidentalis, one observes both in the male and in the female a small 

 sharp spine between the peraeopods of the second pair. 



The pleopods of the male from Stat. 300 resemble those of the male of Pont, gracilis 

 (S. 1. S.MiTii, Bull. Mus. Comp. Zool. Vol. X, N" 1, 1882, p. 38, PI. VII, figs. 3 and 3«). 

 Of the I'' pleopod of the male (Fig. 63 f, 63/, f^it]) the outer ramus which is 2,45 mm. long, 

 is 3,4-times as long as broad and fringed on both margins with plumose setae; the inner ramus 

 measures three-sevenths the length of the outer and is 4-times as long as broad; the 

 truncate tip of the inner ramus is notched, so that the inner |jart of the tip projects slightly 

 as a lobe armed with 4 cincinnuli, the outer margin is glabrous, Ijut the inner bears along its 

 distal half 8 or 9 very short setae, that become slightly longer backward, while the proximal 

 half is sinuated. Of the 2"'' pleopod of the male (Fig. 63?', d^s, 63/) the inner ramus is but 

 little shorter than the outer, the distance between their tips being only one-eighth the length 

 of the outer ramus; the styliform appendix interna is 0,85 mm. long, a little more than one- 

 third the length of the inner ramus, it is lo-times as long as thick, glabrous and bears a large 

 number of cincinnuli at the tip; appendix ma.sculina half as long as the stylamblys, but thicker, 

 o-labrous, except 2 or 3 short setae on the tip. The pleopods of the 3''^, 4"^ and 5"' pair agree 

 with those of the 2"^', except of course the absence of the appendix masculina. 



Of the adult ova-bearing female the inner ramus of the i*' pleopod (Fig. 63?/) measures 

 f(Hu--fifths the length of the outer; it is narrow, nearly lo-times as long as broad and fringed 

 on both margins with long feathered setae, that are also implanted on the tip. Of the 2"*^ 

 pleopod (Fig. 63 f) both rami show the same length, but the inner is less broad, the proportion 

 of the width in the middle being like 5:7; stylamblys half as long as the rami, a little thicker 

 than in the male, 8-times as long as thick, fringed with long, feathered setae on the outer 

 maro-in, excepting the distal fifth, and on the distal fifth of the inner; cincinnuli on the tip. 

 Pleopods of the following pairs like the second. 



Eo-crs very numerous, small, 0,6 — 0,7 mm. long. 



Male long 35,5 mm., female 48 mm. 



Pontopliilus occidentalis I'axon from the Gulf of Panama differs from the present specimens 

 bv its much larger size, this species attaining the length of 73 mm., furthermore by the 

 shorter abdomen; the abdomen, indeed, 52 mm. long, appears in the american species only 

 2V„-times, in the variety indica, however, 3-times as long as the carapace, rostrum included; 

 a third difference, finally, is caused by the anterior gastric spine being of the same size as 

 the posterior. 



The variety indica is, however, also closely allied to Pont, gracilis S. I. Smith and 

 should perhaps be considered with more right as a variety of this species, in which the abdomen 



