30 



BULLETIN 129^ UNITED STATES NATIONAL MUSEUM 



Fig. 8.— Achaeopsis thomsoni 

 (18769), maxilliped, x 14.5 



reduced to a tubercle; one spine on each protogastric region; a 

 slender spine above the orbit, and one at a little distance behind orbit. 



Subbranchial and pterygostomian regions 

 each armed with a spine; lateral margin of 

 hepatic and branchial regions with a few 

 spinules. Rostrum upturned; horns longer 

 than interorbital width, slightly divergent. 

 Eyestalks with some sharp granules in front 

 and a tubercle above at emargination of 

 cornea. Basal antennal article with two 

 rows of spinules and an outer terminal 

 spine; first movable article half as long as 

 second. Three rows of spines on maxil- 

 lipeds. 



Chelipeds of male : Merus armed on mar- 

 gins with numerous spines; carpus narrow, 

 spinous, the spines of upper inner margin 

 longest; manus swollen, very narrow at base, 

 upper margin armed for its proximal two- 

 thirds with a few long spines and several 

 spinules ; fingers longitudinally sulcate, thin at the margins ; teeth of cut- 

 ting edges irregular, so that the fingers though not gaping do not fit even- 

 ly^together at base. Chelipeds of female much more slender ; armature 

 similar to that of male except that in the manus the spines are con- 

 tinued to the fingers, which fit together more closely. 



The ambulatory legs diminish gradually in length from first to 

 last pair; they are furnished with long straight hairs as well as tufts 

 of curled hair on upper surface; a terminal spine on the merus; first , 

 dactylus straight except at tip, the remainder more curved, diminish- 

 ing in length but similar to one another; a fringe of hairs on lower 

 margin, also a few distant spinules pointing toward the propodus, 

 and a larger spinule near the tip. 



Color. — Reddish white (A. Milne Edwards and Bouvier). 

 Measurements. — Male (18119), median length of carapace 10.8, 

 length to tips of rostrum 13.4, width of carapace 8.8 mm. 



Range. — Western Atlantic from Nantucket Shoals to Grenada. 

 Eastern Atlantic from Faroe Islands to Cape Verde; Mediterranean; 

 Gough Island (South Atlantic) ; Agulhas Bank, near Cape of Good 

 Hope. Indian Ocean. West and South Pacific Ocean. South 

 Austraha. Depth, 100 to 2,080 meters (55 to 1,137 fathoms). 

 Material examined from American waters. — See table, page 28. 



