162 Bulletin, Vanderbilt Marine Museum. Vol. II 



at either end of the urogastric groove and posterior to this on the 

 cardiac region there is a short, broken, transvei-se carina on the me- 

 dian cardiac region, and opposite each end of it on the summit of the 

 branchial region is a linear tubercle. The female abdominal belt is 

 ovaL seven segmented and has transverse carinae on each the second 

 and third segments. 



The chelipeds are equal, the merus with three acute spines on the 

 anterolateral margin and one acute spine at the distal end of the 

 posterior margin: the carpus is very sharp and has four longitudinal 

 carinae, one extending onto the tip of the acute spine at the outer dis- 

 tal angle : there is also an acute spine at the inner carpal angle : the 

 propodus is robust, with the upper surface wider than in most Amer- 

 ican Poriunids; there are five denticulate longitudinal carinae on the 

 palm : the uppermost of these is curved and terminates distallv in an 

 acute up- and forward-pointing spine. The carina immediately below 

 the uppermost one is composed of very coarse, denticulate graniiles ; 

 the median carina has a large, acute tooth at its base ; the fourth and 

 fifth carinae are less denticulate and are continuous on the lower 

 finger to its tips. The upper finger has three carinae on its outer face, 

 the uppermost of which is denticulate proximally. The right hinged 

 finger of the female has a very large basal tooth; the other teeth of 

 both fingers are smaller, triangulate. 



The ambulatories are exceedingly slender, the carpus, propodus and 

 espedallv the dactyl grooved longitudinally. The dactyli are slender, 

 acuminate, about as long as the propodus. 



The natatory legs of the present specimen are missing. Those of 

 the type are said to be of the typical Poriunid form. 



The eye is reniform. shining black, composed of many facets and 

 filling the orbital cavity. 



The antennules have the basal article greatly enlai^ed : the second 

 and third articles are verv slender and fold transverselv within the 

 fossett. 



The antennae have the basal article situated in the orbital sinus, 

 stocky, without a node at the inferior distal angle: the second and 

 third articles are successively smaller : the flagellum is about twice as 

 long as the long diameter of the orbit. 



The external maxillipeds are typically those of Porfunus: the 

 ischium is rectangular, with a longitudinal groove ; the merus has the 

 external distal angle somewhat flaring, the distal margin truncate and 

 the inner angle well excavate for the reception of the palp. 



