48 Bulletin American Museum of Natural History [Vol. LIII 
measurement; moreover, the lateral margins of the palm of the latter 
species are sub-parallel, while in the former the “heel” of the palm— 
the outer proximal angle—below the immovable finger is quite promi- 
nently bowed out, so much so that there is a very pronounced concavity 
in the external margin of the palm about opposite the base of the im- 
movable finger. 
Just behind the rostral convexity on the median anterior portion 
of the carapace of D. pectinatus there is a small, approximately smooth 
raised area near the anterior margin on which a tuft or tufts of hair are 
anteriorly excentrically inserted; no such area is to be observed in D. 
arrosor. 
These comparisons are based principally upon two female specimens 
of good size, the one D. arrosor from the Mediterranean of which the 
anterior portion of the carapace is 13 mm. long, and the other the oviger- 
ous female, above, from St. Paul de Loanda, with the anterior portion 
of the carapace 15 mm. long. In addition, I have examined two male 
specimens of D. pectinatus, one with the anterior portion of the carapace 
13 mm. long from Dakar, Senegal, and the St. Paul de Loanda male, 
with about a 9 mm. long anterior portion of the carapace; and a further 
specimen of D. arrosor, a small female with the anterior portion of the 
carapace only 8 mm. long. 
In this connection, at the suggestion of Dr. Mary J. Rathbun, I 
examined several specimens of D. insignis (Saussure).! This species 
seems in many ways to be intermediate between the two foregoing 
species. The ambulatory legs of D. znsignis are proportioned much like 
those of D. pectinatus, though dactyls may in older males become quite 
slender; the propodal joint of the outer left ambulatory leg, though 
similarly armed, is no more grooved than in D. arrosor. The larger chela 
is armed as in D. pectinatus, but in outline resembles more D. arrosor, 
having the greatest width across the palm contained one and two-thirds 
in the distance from the outer, lower articulation of the hand to the tip 
of the immovable finger. 
The pit, depression, or groove on the outer margin of the movable 
finger of the larger hand, just before the articulation, by means of which 
Milne Edwards and Bouvier? distinguish the former’s D. petersii is 
present in D. insignis, which leads me to believe that peters is but a 
Synonym of Saussure’s species. This pit has a bare suggestion in D. 
\Pagurus insignis Saussure, 1858, Mém. Soc. Phys. Hist. Nat. Genéve, XIV, p 
Pagurus striatus, Latr., var. Petersii,”’ 1893, Mem. Mus. Comp. Zool. Gti: XIV, p. 162, 
Pl. x1, figs. 24-35, and synonymy. 
