IQQ BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



Diagnosis. — Three tubercles on anterolateral margin, one at widest 

 part of carapace, one hepatic, one between the two. Front bidentate. 

 Five posterior spines. 



Description. — Body and appendages everywhere granulated except 

 the ambulatory dactyls. Carapace, exclusive of spine, a little longer 

 than wide; intestinal and cardiac regions defined by rather deep fur- 

 rows on either side; hepatic region slightly swollen; cervical sulcus 

 partially defined at hepatic region; granules of surface distant from 

 one another by spaces equal to two or three times their diameter; 

 anterolateral margin shghtly sinuous. Of the five posterior spines, 

 the median one is intestinal; the intermediate pair is marginal and 

 in the adult equally long and more evenly conical; the outer pair very 

 small, with tip strongly upturned, is situated on the branchial region 

 over the insertion of the posterior legs. There is a tubercle at middle 

 of lateral margin and another on the hepatic margin; also between 

 the two and directly behind the hepatic suture a small granulated 

 tubercle. Frontal teeth elevated, tips subacute. 



Merus of chehpeds cyUndrical, longer than carapace exclusive of 

 spine, granules densely crowded; granules of hand smaller, also 

 crowded; hand broader than thick, upper face nearly three times as 

 long as wide; fingers longer than palm, armed within with minute 

 and acute teeth varjdng in size. Ambulatory feet naked (except 

 dactyli), cylindrical, and microscopically granulated; those of first 

 pair one and two-thirds times as long as carapace; dactyh with two 

 fringes of hair on upper and outer surface. 



Variation. — In size of granules, especially noticeable on the an- 

 terior part of the undersized type of M. constrida, which in no other 

 way differs from the average quinquespinosa. In immature speci- 

 mens the median spine is usually longer than the posterior marginal 

 pair. 



In one specimen from off Puerto Kico the spines of the postero- 

 lateral pair are longer than those of the posterior pair and inter- 

 mediate in length between the posterior pair and the median spine, 

 the latter being longer than in typical specimens. 



Color. — Yellowish white with a very delicate pinkish tint in legs 

 and pincers; light brownish yellow on first joints of legs. Pure white 

 beneath. (Henderson.) Buff to buff yellow on proximal and distal 

 extremities of leg articles and margins of carapace; front between 

 eyes darker, almost orange-ochraceous. (W. L. Schmitt.) 



Measurements. — Male (66484), length of carapace 45.6, width 40; 

 length of chehped, outer edge, 106 mm. Largest male (Caracas), 

 length from tip of frontal tooth to middle of posterior margin, 68.2; 

 from median sinus to tip of median spine, 71.8, width 65 mm. 

 (Copenhagen Mus.). 



Range. — Massachusetts to Venezuela. 50-572 fathoms. 



Material examined. — See table 53, page 168. 



