204 Bulletin, Vanderhilt Marine Museum, Vol. II 



The chelipeds are predominently neropalin blue basally with the car- 

 pus and propodus vivid scarlet, the finger-tips orange. The ambula- 

 tory legs have the basal, meral and carpal joints light scarlet, muscu- 

 lated with light orange yellow; the propodus reddish-brown; the 

 dactyl brownish-yellow, with black spines. The eyestalks are yellow, 

 the cornea violaceous. The above notes were made from a color plate 

 by Miss Isabel Cooper, staff artist of the Arcturus Expedition. 



Habits: Nearly two hundred years ago, Catesby, in his ''Natural 

 History of Florida, Carolina and the Bahama Islands," gives the 

 following account of this crab : ' ' These crabs inhabit the rocks over- 

 hanging the sea; they are the nimblest of all other crabs; they run 

 with surprising agility along the upright side of a rock and even 

 under rocks that hang horizontally over the sea; this they are often 

 necessitated to do for escaping the assaults of rapacious birds which 

 pursue them. These crabs, so far as I could observe, never go to land, 

 but frequent mostly those parts of the promontories and islands of 

 rocks in and near the sea, where by the continual and violet agitation 

 of the waves against the rocks they are always wet, continually re- 

 ceiving the spray of the sea, which often washes them into it, but they 

 instantly return to the rock again, not being able to live under water 

 and yet requiring more of that element than any of the crustaceous 

 kinds that are not fish." 



Technical description : Carapace discoidal ; frontal border ver- 

 tical, its depth slightly more than half its length ; anterior dorsal inter- 

 orbital surface with a median longitudinal groove which is posteriorly 

 confluent with the mesogastric lines ; a submedian notch and its slight 

 posterior sulcus bisect each half of the frontal region. The postorbital 

 tooth is acute ; slightly behind it is a second sharp tooth, just anterior 

 to the base of the latter the unusually deep cervical groove arises, pro- 

 ceeds diagonally to the urogastric region and thence runs posteriorly 

 close together outside the cardio-intestinal region. The anterior frontal 

 interorbital region is marked by irregular, transverse rows of low 

 tubercles. There are twelve prominent, transverse, slightly arcuate 

 ridges, the anterior of which begins at the inner basal angle of the 

 anterolateral tooth and curves across the carapace to near the median 

 dorsal area. All the transverse grooves become vague in the median 

 dorsal region, where the oblique grooves defining the regions of the 

 carapace predominate. The surface of the carapace between the 

 grooves is decidedly reticulated, the subcentral region of the carapace 



