ORTMANN: CRUSTACEA OF SOUTHERN PATAGONIA. 653 



Color (in alcohol) whitish or grayish. 

 Length of large <$ : 14-16 mm. 



Remarks. The following species of Hyalella have been described, 

 which approach more or less closely the present one : 



1. H. dentata Smith (1874, Geol. Surv., p. 608, pi. i, f. 3-6, and Rep. 

 Fish Comm., p. 645, pi. 2, f. 8-10), United States. 1 



2. H. inermis Smith (1874, Geol. Surv., p. 609, pi. i, f. i, 2). Colo- 

 rado, Utah, Florida. 



This form is given by Faxon (1876, p. 373, textfig. 35) as Allorchestes 

 dentatus var. inermis from the region of Lake Titicaca, from San Antonio, 

 Peru (saline water, 3,300 feet above the sea), and from Puerto Bueno, 

 Smyth Channel, Strait of Magellan (probably fresh water). 



Faxon further describes (1876, pp. 374, 375, textfigs. 36, 37): 



3. Allorchestes dentattis\'ax. gmcilicornis Fax., from near Campos (Rio 

 de Janeiro), Brazil. 



4. Allorchestes longistilus Fax., from the same locality. 

 Wrzesniowski (1879, pp. 176, 177, 199) describes: 



5. Hyale jelskii Wrz., from Peru, east side of Cordilleras, 8,000 feet 

 (Pumamarca). 



6. Hyale lubomirskii Wrz., from Peru, west side of Cordilleras, 8,000 

 feet (Pacasmayo). 



7. Hyale dybowskii Wrz., from Peru, west side of Cordilleras, 7,000 

 feet (Paucal, Montana de Nancho). 



Finally, Stebbing (1899, pp. 406, 407, pi. 32, A, E] describes: 



8. Hyalella warmingi Stebb., from Lagoa Santa (Prov. Minas Geraes, 

 Brazil). 



9. Hyalella meinerti Stebb., from " Laguna di Espino." 2 



All these forms belong to the genus Hyalella, founded by S. J. Smith 

 (1874), and more sharply defined by Stebbing (1899, pp. 397-398) in his 

 key to the genera of the family Orchestiidce. 



H. dentata from the United States differs from our species (and all the 



*As has been surmised by Smith and Faxon, this species is very likely identical with Allorchestes 

 knickerbockeri Bate (1862, p. 36, pi. 6, f. i) from New York, and possibly with Amphithoe aztecus 

 Saussure (1858) from Vera Cruz, Mexico. If the latter should prove to be true, the specific 

 name of aztecus should be used. 



* I have tried to locate "Laguna di Espino," but have been unable to do so. Places called by 

 the name of "Espino" are found in Honduras and Venezuela (prov. Guarico), but no "Laguna di 

 Espino" is known to me. 



