REPOET ON THE AMPHIPODA. 455 



1876. ClauS, C. 



Untersuchimgen zur Erforschung der genealogischen Grundlage des Crustaceen- 

 Systems. Ein Beitrag zur Descendenz-lelire. AVien, 187G. 



1876. Faxon, Walter. 



Exploration of Lake Titicaca by Alexander Agassiz and S. W. Gaeman. IV. 

 Crustacea. By Walter Faxon. BuUetiu of the Museum of Comparative Zoology, 

 at Harvard College, Cambridge, 1876. Vol. iii. pp. 3G1-375. 



Of tlie Crustacean fauna of tlie lake, Mr. Faxon says, " excepting a species of Cijpris, all the 

 specimens collected belong to one aniphipodous genus, AUorchede-s, which had hitherto 

 afforded but one or two authentic fresh-water species, ranging from Maine to Oregon and 

 the Straits of Magellan. Seven new species are described in this paper from Lake Titicaca. 

 Several of them are remarkable among the Orcliesfidx for their abnormally developed 

 epimeral and tergal spines. Some are also noteworthy as comparatively deep-water forms of 

 a family commoidy regarded as pre-eminently littoral." 



The genus Allo-rcliestes is thus defined : — " First maxillae with small uniarticulate palpi. Palpus 

 of the maxillipeds composed of four segments, the distal segment usually bearing a movable 

 spine at its ajiex. First antennte shorter than the second antennae, longer than the peduncle 

 of the second antennae. First and second thoracic legs subcheliform. Propodite of 

 second pair larger than propodite of first pair, and much larger in the male than in the 

 female. Telson .short and entire." HyaldJa, Smith, 1874, is given as a synonym. My 

 reasons for preferring Eyalella to Allorchestes are given in Note on Eathke, 1837. Mr. 

 Faxon Atscx'ih&s xilloreliestes armatus, n. s., figs. 1-18; Allorchestes echinus, n. s., figs. 

 19-21 ; Allorchestes longijKS, n. s., figs. 22-2-5 ; Allorchestes lucifugax, n. s., fig. 26 ; 

 Alloi'cliestes latimanus, n. s., figs. 27-28 ; Allorchestes longipalmus, n. s., figs. 29-31 ; 

 Allorchestes ciq^reus, n. s., figs. 32-34. He also figures Allorchestes dentatus, var. intrmis, 

 fig. 35, for Hyalella inermis, Smith. Of his specimens he says, " they differ from speci- 

 mens from the United States in having a firmer and less transparent shell, and a little 

 difierently shaped propodite to the second pair of thoracic legs in the male ; hardly enough 

 to warrant the establishment of a new species when one considers the variability of the 

 species within the limits of the United States." 



In a note Mr. Faxon says, "Among the Crustacea collected by the Thayer Expedition in Brazil 

 are two species of Allorchestes. One is represented by a unique female specimen taken 

 from a canal at Campos by C. F. Hartt. It differs from A. dentatus, var. inermis, 

 only in the second pair of antennae, which are half as long as the body and twice as long as 

 the first pair ; flagellum composed of thirteen segments. Length of body, 4"™. In the 

 absence of more specimens, I would consider this a variety (gracilicornis) of Allorchestes 

 dentatus," fig. 36. " The second species is repre.sented by several specimens. It may be 

 called Allorchestes longistilus, sp. nov." Fig. 37. " Differs from A. dentatus, var. 

 inermis, in its slenderer body, longer antennae, and especially in the length of the third pair 

 of caudal stylets." 



