498 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 91 



Holotype. — ^A single male carrying M.A.C.N. tag No. 9817, con- 

 tained in a bottle with an unattached left cheliped surely the same 

 species with an M.A.C.N. tag, No. 4186, affixed, together with 

 a specimen of each of two other species without tags. Of these last, 

 one i.- u female of ^. huniahuaca, 22.0 mm. in length of carapace 

 aiHJ rostrum together, the other a male of A. dbtao, of 28.0 mm. 

 In the catalogs of the Museo Argentino Ciencias Naturales entry No. 

 4186 reads simply, "Neuquen, Mayo 16, 1898 ; Sr. Carlos Burmeister" ; 

 entry No. 9817 concerns specimens of Mytilus chorus Molina received 

 in exchange from Dr. Carlos S. Keed, 21-V, 1919. As a result, it is 

 impossible to determine satisfactorily the type locality for the 

 species, and there is no locality at all for the other, untagged, speci- 

 mens in the same bottle. It is a mixed lot of material, or else a case 

 of misattached label or labels. 



Remarks. — As pointed out under A. papudo above, this is the only 

 other species in which the several suture lines that meet to form 

 the anterolateral angles of the cardiac area of the carapace combine 

 to form a short, quite longitudinally oriented bar (fig. 58). In all 

 other species except these two this short "bar" is oriented so as to 

 be very nearly transverse, or at least obliquely so. 



AEGLA HUMAHUACA, new species 



FiGxmE 59; Plate 27, D 



Description. — A species of moderate size. The largest of five 

 specimens seen measures about 28 mm. in length of carapace and 

 rostrum taken together. 



Carapace moderately convex, front relatively narrow. Rostrum 

 rather thick looking, proximaUy more or less broadly flattened- 

 triangular, noticeably depressed anteriorly, bent downward, so much 

 so that in lateral view the rostral extremity is about on or even 

 slightly below the level of the anterolateral spines; distally the 

 rostrum becomes somewhat lingulate, slightly parallel sided, low, 

 and broadly blunt-ridged, scarcely to be called carinated ; only very 

 shallowly excavate either side of median carina; carina marked in 

 basal half with three or four very irregularly intermingled rows of 

 corneous scales, becoming distally more or less a single scattered 

 row, which near tip of rostrum tends to disappear, scarcely or not 

 distinguishable from the few scattered corneous scales on the dorsum 

 of the apical portion of the rostrum. Epigastric prominences and 

 anterior margins of protogastric lobes poorly developed. 



Orbital sinus fairly narrow, more or less V-shaped; orbital spine 

 small, placed well up on inner slope or margin of anterolateral 

 spine and separated from it by only a small notch. Anterolateral 

 spine relatively small, short, and flattened-conical. Anterolateral 



