594 rnocEEDiNGS of the national museum. 



88. PORTUNUS (ACHELOUS) ANGUSTUS, new species. 

 (Plato X LI V, fig. 2.) 



Front advanced, S-toothed; lateral teeth alternately large and small; 

 lateral spine only slightly longer than seventh tooth; a spine at posterior 

 distal angle of merus of swimming feet. 



Carapace narrow, pubescent except upon the transverse granulated 

 lines; in shape resembling V. ordwayi (Stimpson). Front advanced; 

 four middle teeth subacute, the outer pair broader at base than the 

 inner, and separated from the inner pair by wider sinuses than the 

 median sinus, and from the supra antennal angle by a deep V-shaped 

 sinus. Supra-antennal lobe bidentate; teeth acute. Antero-lateral 

 teeth alternately large and small, the last tooth or lateral spine very 

 little longer than the seventh. The inner suborbital tooth is acute and 

 equally advanced with the second pair (reckoning from the middle) of 

 frontal teeth; there are no teeth on either side of the outer orbital 

 fissure. 



The merus of the cheliped of the type specimen, a female, has four 

 spines on its inner margin, graduated from a large one near the distal 

 end to a small one near the ischium; a very small spine on the outer 

 margin at the distal end. Carpus with a small external distal spine 

 and a long inner spine reaching, when the arm is flexed, to the spine 

 next to the smallest on the merus. The hand has two large spines, 

 one next the carpus and one on the sui)erior margin at one third its 

 length Irom the dactylus. The ridges on the carpus, propodus, and 

 dactylus are very coarsely granulated with acorn-shaped granules. 

 The depressions are pubescent. The extero superior surface of the 

 merus is crossed by a longitudinal ridge. The inferior margin of the 

 merus of the left natatory foot is armed with a sharp spine near 

 the distal end ; on the right foot there are two smaller spines in the 

 same position. 



Color. — Although this crab has been for a long time in alcohol, it 

 seems to be of a reddish hue. The basal half of the fingers is red, the 

 next quarter is white, the remainder is brown, except the tips, which 

 are white. 



Dimensions. — Female: Total length of carapace, 25.5 mm. ; total width, 

 37.2 mm.; width between the last sinuses, 33.5 mm.; exorbital width, 

 21 mm. 



Type.—^o. 21587, U.S.KM. One female; off Hood Island, Gala- 

 pagos, 20 fathoms, station 2812. 



This species has considerable resemblance to Charyhdella { = Cronius)j 

 but the basal antennal joint is not so strongly produced as in that 

 genus. It can also be told by its narrower carapace and frontal teeth, 

 and few spines on the hand. 



