Lff" 



V 



ACHELOUS AFFINIS 



23 



ACHELOUS Db IIaan. 



Siebold's Fauiui Japonicaj Crustacea, p. 8, 1833 



Achelous spinimanus (Latr.). 



r 



Fortumts spmimanus Lath. Nouv. Diet. d'Hist. I^at., 2^ ed., XXVIIL ^1, 1819. 

 Portunus {Achelous) spinimamis De Haan, Eauiia Japoiiica, Crustacea, p. 8, 1833. 



Station 3368. 66 fathoms. 2 males. 



These specimens differ from the typical form in havirg a shorter arm and 

 hand a lono-er spine on the inner side of the carpus; in having a short spine 

 at the distal end of the superior border of the propodus a,nd two small spines 

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

 the lart^er 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 mm.; breadth, 15 mm.; length of dactylus, 25 

 mm.' len(>-th 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 region 



the form may be called Achelous hrevimanus, 



Aehehits spmimanus inhabits the Atlantic coast of America from Cape 

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



of Chile. 



Achelous afllnis Fax. 



Plate IV., Fig. 1, 1% T\ 



F 



Bull. Mus. Comp, ZooL, 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- 

 an^ndar 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 which separates the front from the inner orbital angle. 

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



.4 



* -s 



