468 Mr. W. N. Lockington on American Alphei. 
ditto, slender. Propodal joints of poste- 
rior pairs spinulose ..........eseeeees A, panamensis, P. 
Larger hand elongate, spineless, slightly sul- 
cate; smaller slender, spineless. No 
spines or spinules on posterior pairs. Two 
airs of spinules on telson .........+.- A. tenwimanus! P. 
es spine of antennule reaching to middle 
of second joint of peduncle ; basal joint of 
antenne with a small upper and large 
lower spine; larger hand without spines 
or sulci; smaller ditto. Posterior pairs : 
without meral spines; propodi spinulose. A. leviuseulus! P. 
b. No ocular spines. 
Eye-shields produced forwards, scarcely spini- 
form; larger hand spineless, sulcate, 
thumb distorted, smaller (?).......... A, sulcatus, P. 
Rostrum separated from ocular shields by a 
deep depression: larger hand once and 
a half as long as carapax, spineless, 
constricted ; dactylus slightly oblique, 
with large basal tooth: smaller hand 
spineless ; fingers about equal to palm. 
Posterior pairs with spinulose propodi.. A. heterochelis! A, P. 
Rostrum separated from eye-shields by a sul- 
cus: larger hand with a supericr spine, 
sulcate ; dactylus as in heterochelis, but 
obtuse: smaller hand as in heterochelis.. A. affinis, P. 
Carina of rostrum running back to nearly 
middle of carapax; larger hand once and 
a half as long as carapax, spineless ; 
smaller hand as long as larger, spineless, 
fingers longer than palm..........-... A, floridanus, A. 
Carina of rostrum continued backwards, but 
no depression between eye-shields and 
rostrum: larger hand spineless, sulcate; 
dactylus vertical: smaller hand spine- 
less. Meral joints of posterior pairs spine- 
less; propodi spinulose. Telson with 
two pairs of spinules above and a third 
GHG LA, Sea rete cre' ss = ia a eae A, spinicaudus! P. 
Hands small, nearly equal; larger spineless, 
constricted on margins; smaller slender, 
fingers equal topalm. No meral spines 
ON POsterlOY PAIS... vsscceesrceesssss A, parvimanus, P. 
Hands very unequal; larger spineless, cylin- 
drical, tapering; smaller smooth, slender, 
cylindrical, dactylus as long as palm. 
o meral spines on posterior pairs; pro- 
POG! SPIDUIORS aise sate oi 0 an aa enieee Wie A, fasciatus! P. 
Rostrum very short, obtuse; no spine on 
basal joint of antenne. Larger hand 
cylindrical, grooved externally: dactylus 
horizontal: smaller hand cylindrical ; 
fingers equal to palm a5 ssis .. «aoe A. cylindricus, P. 
B. Rostrum wanting; dactylus on lower side of 
hand. =Beteus, Dana. 
Front emarginate between eyes; hands nearly 
