66 Bulletin American Museum of Natural History [Vol. LIII 
restricted to the section containing that species.’’ Though Latreille 
specified the type, Weber’s use of the generic name takes precedence. So 
Palemon must date from 1795 (‘Nomenclator entomologicus’; ct. 
Opinions rendered by the International Commission of Zoological 
Nomenclature, Smithsonian Institution, Pub. 1938, 1910, Opinion 17, 
p. 40). This is the genus, or rather coextensive with the genus dealt 
with by continental authors under the name Leander Desmarest, 1849. 
(2) “The genus Bithynis, Philippi, Arch. f. Natur., XXVL., pt. 1, 
p. 161, 1860, is restricted by Ortmann (Zool. Jahr., V., p. 748, 1891) to the 
type species only. If this restriction be sustained, the genus Palemon 
of Stimpson and Ortmann may be known as Macrobrachium, Bate.” 
This restriction of Bithynis, which seems to have been well founded, 
automatically brings Macrobrachium into good standing. 
(3). Ortmann’s use of Macrobrachium asa subgenus of Palemon 
which contained none of Bate’s original species is of course untenable and 
de Man rightly substitutes it for Ortmann’s subgenus Brachycarpus. At 
this writing I am not aware what name de Man offered in place of the 
subgenus Macrobrachium as used by Ortmann, if any. 
(4). This mistaken use of the name by Ortmann does not invalidate 
it, as Stebbing seems to think; his substitution of Macroterocheir for 
Macrobrachium is therefore beside the point, and de Man’s adoption of 
it asa subgeneric name cannot be sustained. Stebbing’s tacit acknowl- 
edgement that Palzemon can no longer be used for these forms is in line 
with Miss Rathbun’s earlier reasoning. | 
(5). Therefore it appears that: 
(a) Palemon Weber, 1795, isthe correct name for the genus of 
shrimps of which Palemon squilla (L.) is the type, and 
to which authors have commonly given the name of 
Leander. 
(b) Macrobrachium Bate, 1868, is the correct generic name for 
the group of shrimps of which Bate’s M. americanum 
= M. jamaicense (Herbst) is the type and which, until 
Stebbing suggested the name Macroterocheir, was 
commonly known by recent, non-American authors as 
Palemon. 
(ce) Macroterocheir, Stebbing, 1908, is but a synonym of Macro- 
brachium. 
(d) Bithynis Philippi 1860 is a valid, well founded genus of 
which Bithynis longimana=B. cementarius (Péppig) 
is the type. 
