ACHELOUS AFFINIS. 23 



ACHELOUS De Haan. 



Siebold's Fauua Japuuica, Crustacea, p. 8, 1833. 



Achelous spinimanus (Late.). 



Forimms spinimanus Latr. Nouv. Diet. d'Hist. Nat., 2e ed., XXVIII. 47, 1819. 

 Portunus {Achelous) spinimanus De Haan, Fauna Japonica, Crustacea, p. 8, 1833. 



Station 3368. 66 fathoms. 2 males. 



These specimens differ from the typical form in havirg a shoi'ter arm and 

 hand, a longer spine on the inner side of the carpus ; in having a short spine 

 at the distal end of the superior border of the propodus and two small spines 

 at the distal end of the merus of the last pair of legs. Of these two spines 

 the larger is on the posterior lateral angle of the segment, the smaller one 

 just above it. The carpal spine reaches half way to the extremity of the 

 spine on the upper margin of the propodus when the hand is flexed. The 

 length of the carapace is 44.5 mm. ; breadth, 69.5 mm. ; length of merus, 

 33 mm. ; length of chela, 47 mnr. ; breadth, 15 mm. ; length of dactylus, 25 

 nnn. ; length of carpal spine, measured from the anterior border of the 

 carpus, 10.5 mm. 



If these differences prove to be constant in specimens from this I'egion 

 the form may be called Achelous hrcvimanus. 



Achelous spinimanus inhabits the Atlantic coast of America from Cape 

 Hatteras to Eio de Janeiro, Brazil. It has also been recorded from the coast 

 of Chile. 



Achelous aflOLnis Fax. 



Plate IV., Fig. 1, 1% 1". 



Bull. Mus. Comp. Zobl,, XXIV. 155, 1893. 



Carapace moderately convex both longitudinally and transversely, the 

 frontal region depressed and horizontal ; surface rugose, granular, and 

 pubescent. Front not prominent, composed of four blunt teeth, not 

 counting the internal angle of the orbit ; the two teeth near the median 

 line are equilaterally triangular, separated from one another by a tri- 

 angular notch ; the next teeth on the outer side are separated from 

 those within by a shallow sinus, and fall off abruptly on the outer side 

 into the deep notch whicli separates the front from the inner orbital angle. 

 The two middle teeth of tlie front are a trifle longer than the lateral teeth. 



