THE SPECIES OF AEGLA — SCHMITT 463 



Larger hand very smooth appearing, but under glass finely granu- 

 lated (or minutely scaled like the carapace), more or less subrec- 

 tangular, gently convex, rising to an apparent median longitudinal 

 angle extending from a little distance behind the posterior margin 

 of the sinus between the fingers to the posterior margin of the palm ; 

 inner margin of palm can scarcely be said to be crested, it is broadly 

 rounded off but rises at a little distance before the anterior border 

 to form a conspicuous, though short, acutely corneous-tipped spine; 

 the smaller hand of this unique specimen is crushed but seems to have 

 the same conformation as the larger one. There is no lobe on the 

 outer margin of the movable finger near the base; the prehensile 

 margins of both fingers are slightly sinuous, but neither reveals any 

 trace of the large lobular tooth found in most species of Aegla. 



Carpus of cheliped granulated like hand ; ridge above spined inner 

 margin more or less obsolescent, at least not very prominent, lobe at 

 anterior angle produced to form a strong prominent spine. Dorsal 

 longitudinal margin of merus strongly and sharply spined above; 

 anterior margin unarmed, finely scabrous. Inner margin of the ven- 

 tral surface of ischium is armed with a pair of well-developed strong 

 spines; only on the left (figured type) ischium does a small acute 

 spine intervene between the two large spines ; on the right the inner 

 margin of the joint is uninterrupted. 



Merus of first ambulatory leg scabrous above; armed with an an- 

 teriorly directed spine on the posterior border of the ventral surface 

 a little behind the level of the posterior margin of the articular mem- 

 brane ; there is also a small corneous point or spine close to the anterior 

 end of the ventral margin. 



Anterior dorsal angle of epimeron of second (in lateral view, ap- 

 parent first) abdominal somite produced into a slender, sharp spine; 

 margin of the epimeron below this spine deeply concave; ventral 

 angle strongly and narrowly produced, though bluntly rounded off 

 at its extremity. 



Holotype. — The unique male specimen collected by Dr. Carlos Speg- 

 gazzini in the Rio San Lorenzo, Salta, Argentina (M.A.C.N.^* No. 

 7099) ; length of carapace and rostrum taken together, 29 mm. 



Remarks. — This species is certainly more nearly related to A. parana 

 than to A. Uruguay ana., which it superficially resembles. The strong 

 ventral spine on the ambulatory legs and the shape of the epimeron 

 of the second abdominal somite point in the direction of A. parana; 

 moreover, the inner ventral border of the ischium of the cheliped, 

 like that of A. pa/rana^ is armed with a strong hooked spine at the 

 anterior end as well as at the posterior end of the joint but, unlike 



" Museo Argentine de Ciencias Naturales. 

 435661—42 3 



