452 PROCEEDINGS OF THE NATTOlSrAl. MUSEUM vol. 91 



prominence are not found in any species of Aegla other than the two 

 grouped here under D') ; movable finger without definite or real lobe 

 on outer margin near base, even though margin of finger may some- 

 times be spiny; epimeron of second (in lateral view, apparent 

 first) abdominal somite with anteroventral border more or less 

 deeply concave ; anterior dorsal angle produced to form a sharp spine 

 of good size, ventral angle also produced, narrow, extremity may 

 be blunted, sometimes sharply spined like anterior dorsal angle (in 

 certain large specimens of parana) . 

 E^. Merus of ambulatory legs armed on upper margin with several, 

 usually a full series of, strong, well-developed spines ; carpus with 

 ridge above spined inner margin, also well spined, and with a 

 second longitudinal row of normally three sharp spines on mid- 

 dorsal surface, sometimes posterior two spines of this series much 

 reduced or wanting; a well-developed lobular tooth at least on 

 fixed finger of either chela ; movable finger without a definite lobe 

 or projection on outer margin near base, sometimes, but not often, 

 a spine or several spinules in this position, not to be unexpected 

 in this otherwise very spiny species; outer margins of hands 

 spined ; inner margin of palm forming a comparatively low ridge 

 (palmar crest), which is serrate, serrations spined; sometimes 

 inner margin or ridge fairly straight and serrulate. 



parana (p. 458) 

 EP. Upper margin of ambulatory merus not armed with a number of 

 strong spines, at most scabrous or small spinulated ; carpus with 

 ridge above inner spined margin not spined, scabrous-nodulated, 

 and without a longitudinal row of spines on middorsal surface; 

 prehensile margins of fingers slightly sinuous but without lobular 

 tooth on either fixed or movable finger ; no lobe on outer margin 

 of fixed finger near base ; outer margins of hands scabrous but 

 not spined as in preceding species ; inner margin of palm scarcely 

 crested, broadly rounded off, rising anteriorly in a low keel 

 (palmar crest) to form a single short, sharp spine. 



sanlorenzo (p. 461) 

 D". No noticeably strong spine near distal end of ventral posterior margin 

 of ambulatory merus, at most a relatively small spine, tubercle or 

 scale in this position; epimeron of second (in lateral view, apparent 

 first) abdominal somite with anteroventral border more or less 

 straight, at most only slightly concave; ventral angle rounded off; 

 fixed finger at least with a definite lobular tooth of good size one 

 prehensile margin. 

 E^. Normally only first hepatic lobe well defined and anteriorly spined, 

 second and third lobes scarcely more than indicated (occasionally 

 one of other lobes fairly well marked on one or the other side of 

 carapace) ; movable finger definitely with a lobe on outer margin 

 near base; in most specimens, especially those of medium and 

 small size, the lobe furnished with a small spine or sharp scale, 

 in many of the larger specimens, such as the type, the lobe fre- 

 quently unarmed, but always distinctly present and more or less 

 angled; ischium of chelipeds with a not particularly prominent 

 tubercle (not spine), which is furnished with a corneous apex or 

 scale, at distal end of inner margin of ventral surface. 



platensis (p. 464) 



