Figure 234. — Mithrax (Mithrax) spinosissimus (La- 

 marck). Male in dorsal view, legs of left side not 

 shown, 30 mm. indicated. 



shaped notch of equal length and breadth; two 

 stout spines at base of horns and two more behind 

 these but farther apart; preorbital spine stouter, 

 truncate, and less advanced than rostrum. Orbital 

 border with three small teeth exclusive of post- 

 orbital spine; suborbital margin with one acute 

 spine outside antennal segment and lateral to this 

 a larger truncate spine. Antennal segment with 

 an outer small acute spine and an inner spine more 

 advanced than rostrum bearing a small secondary 

 lateral spine near end. Lateral margin with six 

 spines, first two double, last and smallest one on 

 posterolateral margin. Other spines present on 

 suborbital, subhepatic, subbranchial, pterygosto- 

 mian regions, and at angle of buccal cavity. 



Chelipeds of adult male massive, longer than 

 walking legs; merus armed with eight or nine 

 stout spines on outer margin, others irregularly 

 placed; carpus armed with unequal spines, about 

 five on inner margin; hand deep, compressed, 

 armed above with a more or less double row of 

 spines and on inner surface with two to four 

 spines proximally; fingers curved leaving wide 

 gape, strong tooth near middle of dactyl, tips 

 spooned with edges crenate preceded by a few 

 low tubercles. Adult female with chelipeds no 

 longer and not much stouter than first pair of 

 walking legs; hand tapering somewhat distally; 



fingers narrowly gaping with numerous denticles 

 on cutting edges. Walking legs of both sexes spi- 

 nose and coarsely hairy; propodi elongate and 

 compressed. 



Abdomen of male with seven free segments, fe- 

 male with six. 



Measurements. — This is the largest species of 

 Mithrax. Carapace : male, length, 170 mm., width, 

 184 mm. ; female, length, 77 mm., width, 80 mm. 



Variations. — In old males, spines on the cheli- 

 peds tend to become blunt and tuberculiform. In 

 medium-sized individuals, the carapace is rela- 

 tively longer than in the old, spines are sharper, 

 rostral horns curve inward at the sharp tips, the 

 carapace is covered with short hair, chelipeds of 

 both sexes are small, and the gape extends only 

 half the length of the fingers. In young indi- 

 viduals, the spines are even more accentuated, 

 rostral horns are one-fifth as long as the carapace, 

 there are two spines on the suborbital margin out- 

 side the antennal segment, chelipeds are no longer 

 or stouter than the first walking legs, and gape of 

 the fingers is less than in older individuals. 



Color. — Bright carmine; vinous red with yel- 

 lowish tints; or thorax dark red; walking legs 

 brick red and chelipeds rose red with yellow 

 fingers (various authors including Rathbun, 

 1925). 



Habitat. — The species is often found among 

 rocks. The carapace is often covered with en- 

 crusting organisms ; shallow water to 98 fathoms. 



Type locality. — Ile-de-France. Locality errone- 

 ous. 



Known range. — Either North Carolina or South 

 Carolina (?) through Florida Keys and West 

 Indies to Guadeloupe. 



Remarks. — Ovigerous females have been re- 

 ported in May and June from Cuba (Rathbun, 

 1925). 



Mithrax (Mithrax) verrucosus H\ Milne Edwards 



Figures 235, 245B 



Mithrax verrucosus H. Milne Edwards, 1832, cl. 7, pi. 4 (col.) 

 [+ unpaginated description]. — Rathbun, 1925, p. 400, pi. 144 



(rev.). 



Recognition characters. — Mature males, large- 

 to medium-sized. Carapace covered with flattened, 

 closely crowded granules, nearly naked, granules 

 covered with small pits, cervical suture deep; 

 branchial region with a few dorsal spines on outer 

 part, front and orbit with truncate spines. Rostral 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



255 



