402 A. E. Verrill Decapod Crustacea of Bermuda. 



The frontal horns in cornutus are rather larger and straight er 

 than in the other, and the subrostral process, between the antennula>, 

 is narrow and directed strongly backward, while in the other it is 

 wider, thick, and nearly perpendicular, with an acute, excurved tip. 



The buccal area has the anterior, lateral sinuses more strongly 

 arched in M. cornnlus, and the corresponding parts of the outer 

 raaxillipeds arc, therefore, more convex. 



There are other distinctions that might be noticed, but the wide 

 difference in the tips of the legs is the most convenient diagnostic 

 character. 



In Jf. conmtns the ratio of the proximal vertical diameter of the 

 propodus of first pair of ambulatory legs to its length is l :4.r> to 1:5 ; 

 of the dactyl us, 1:6. In 3f. spinosissimus the corresponding ratios 

 are 1 : 3 and 1 : 4. 



The propodus in the latter is strongly compressed and decidedly 

 tapered, but in J/". cornutus it is scarcely compressed, and not 

 tapered, the distal end being larger than the middle and about e<|iial 

 to the proximal end; its dactylus is also less curved am] the tip 

 very slender. 



The color of J/. cornutus in life is bright red above, lighter below; 

 when recently dried it soon changes to pale red, yellowish red, or 

 terra-cotta color, by exposure to light. 



Measurements. 



In No. 4069 the merus of chelipeds is :;.V" ra long ; greatest thick- 

 ness, without spines, 9 mm ; merus of first amb. leg, 28 mra ; thickin - 

 in middle, 6 ram ; its propodus, length, 21 mi " ; thickness, 4.5 : dac- 

 tylus, 18 mm ; proximal diameter, 3 mm . 



M. -Ed wards gives for his largest () specimen: length of cara- 

 pace, 92 mm ; breadth, 90 mm ; length of chela, 82 ram . 



The only specimen known from Bermuda (453 F. M.) was taken 

 October 12, 1905, in 30 fathoms on the Challenger Bank, by the 

 expedition from the Field Museum of Natural History. It is a 

 small and evidently young female, but it carried a considerable mass 

 of eggs. 



