ratiibun: crabs from the maldive islands. 129 



towards the antero-lateral margin. The frontal and orbital region is set off by 

 a sinuous groove. 



Fronto-oibital width greater than length of carapace; front divided by a 

 deep median notch into two broad oblique rounded lobes having at their outer 

 ends a small triangular tooth. 



The superior margin of the orbit has two triangular notches, the outer one 

 much the larger; a broad gap below the outer angle. No subhepatic tooth. 

 Antennal flagellum sparingly fringed with hair. 



The lateral margin is cut into three teeth besides the outer orbital; the last 

 one has a spinule at the extremity. 



Chelipeds unequal. Chelipeds and legs pubescent and hairy, except the 

 lower distal portion of the larger palm which is bare, and also the extremity of 

 the digits. The surface of the wrist is smooth except toward the inner angle 

 where it is spinulous; the angle itself is tipped by a small spine. The outside 

 of the palms is covered with subacute granules or tubercles arranged largely in 

 rows, and becoming smaller toward the lower margin; similar granules orna- 

 ment the fingers except towards the end. The thumb is short, in the large 

 cheliped shorter than its height. 



The legs are rather broad, pubescent, and beset with long hairs on the 

 margins. 



Dimensions. — Length of mature female, 5.4 mm.; width, 7.6 mm.; fronto- 

 orbital width, 6 mm. ; lower width of front, 2.9 mm. 



Type locality. — Nallandu, at anchorage, 24 fathoms, January 18 ; one female. 



This species is near P. sluiteri de Man,^ but is distinguished by its wider 

 carapace, relatively wider across the front and orbits, forming straighter sides, 

 its deeper areolation and shorter immovable finger. 



Pilumnus hirsutus Stimpson'? 



Pilumnus hirsutus Stimpson, Proc. Acad. Nat. Sol. Phila., X. 37 [34], 1858. Not 

 P. hirsutus Haswell, 1882, nor Borradaile, Proc. Zool. Soc. London, 1900, 

 p. 581. pi. XLIL fig. 9, and Fauna Maldive Arch., I. pt. III. 245, 1902. 



One young specimen, 3.2 mm. wide, from the centre of Male Lagoon, 30 

 fathoms (December 26), seems to be nearer P. hirsutus than any other species. 



The following is Stimpson's description extracted from his unpublished 

 report on the Crustacea of the North Pacific Exploring Expedition : 



"Body and feet hirsute above, not very thickly, with setae of variable but moder- 

 ate length. Carapax scarcely areolate, broad; proportion of length to breadth, 

 1: 1.43; surface nearly smooth. Anterolateral margin short, with four sharp 

 teeth, including the angle of the orbit ; no subhepatic tooth. Inferior margin of 

 orbit denticulated. Eyes with rather long peduncles. Front emarginate, with a 

 row of long setae just above the margin. Chelopoda rather small ; larger hand 



1 See Alcock, Joum. Asiatic Soc. Bengal, LXVII. 194, 1898. 



