Figure 245. — Subfamily Mithracinae, tips of right first pleopods of males; A, Mithrax spinosissimus (Lamarck), 

 sternal view; B, Mithrax verrucosus H. Milne Edwards, sternal view; C, Mithrax hispid us (Herbst), sternal 

 view; D, Mithrax pleuracanthus Stimpson, sternal view; E, Mithrax forceps (Milne Edwards), sternal view; 

 F, Microphriis oicornutus (Latreille). sternal view: G, Microphrys antillcnsis Rathbun, sternal view; H, Steno- 

 cionops furcata coelata (Milne Edwards), sternal view; I, Stenocionops spinimana (Rathbun), sternal view; 

 J, Macrocoeloma trispinosum (Latreille), lateral view; K, Macrocoeloma camptocerum (Stimpson), lateral view; 

 0.33 mm. indicated. 



pubescence, and, in addition, long, stiff, curled 

 hairs on front, gastric region, and lateral portions 

 of branchial regions; wide at level of orbits, nar- 

 rowing distinctly in hepatic portion, widening 

 again posteriorly; with four strong spines on 

 dorsal region, one on gastric, one on cardiac, and 

 one on each epibranchial region. Posterolateral 

 spines subcorneal, regularly tapering, acute, and 

 directed slightly backward; posterior median 

 spine shorter, acute, obliquely erect. Rostral horns 

 acute, rather regularly divergent from base. 

 Spines on basal article of antennae rather slender, 

 divergent. Orbital tubes, pre- and post-orbital 

 spines protuberant laterally, preorbital spine 

 curving a little forward. 



Chelipeds of male strong, longer than carapace; 

 merus with a few short spinules above; carpus 



somewhat nodose with a tubercle at inner angle; 

 palm widest near articulation; fingers tipped 

 with black or dark brown. Walking legs nearly 

 smooth. 



Abdomen with seven separate segments. in both 

 sexes. 



Measurements. — Carapace: male, length, 40 

 mm., width, 36 mm.; female, length, 24 mm., 

 width, 20 mm. 



Variations. — The rostral horns may be straight 

 or slightly curved outward at tips, and range in 

 length from one-sixth to one-third the total length 

 of the carapace. The interspace between horns 

 may vary from a narrow V-shape to almost a 

 right angle. The posterolateral spine may be 

 straight in frontal section or curved upward and 

 nearly transverse or directed strongly backward. 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



265 



