822 THE AMERICAN NATURALIST. [VoL. XXXIII. 
SYNOPSIS OF SPECIES. 
Group ASTACOIDEA. 
Family ASTACIDÆ. Sternum narrow; abdomen slightly narrower than 
cephalothorax. 
Genus Homarus Milne-Edwards. Lobsters. Rostrum slender, conical, 
with a few teeth on sides. 
17. H. americanus Milne-Edwards N, M 
Geri Witton (F ai Milie Edwards: First segment of abdomen with 
appendages. Species confined to Eurasia and the Pacific slope of America. 
18. Mar. 
argins of rostrum denticulate i : : : : 2 O 
18. Margins of rostrum not denticulate . : : i ‘ 2 a0 
19. Rostral acumen long; chela not barbate . A. nigrescens Stimpson 
19. Rostral acumen short; chela barbate : . A. gambeli (Girard) 
20. Rostrum short, with short acumen ; postorbital ridge without posterior 
mie amathensis Stimpson 
20. Rostrum long, with hae acumen ; powiorbital ridge with posterior 
spine or tubercle . 2I 
21. Posterior spine of postorbital wave ior’ ceded ae half as bead 
as long . . A. leniusculus Dana 
21. Posterior spine inal or fiberi dii one-third as broad as long 
A. trowbridgii Stimpson 
22. Genus Cambarus Erichson. First segment of abdomen with append- 
ages. Species confined to waters draining into the Atlantic. Fifty- 
one species and several varieties recognized by Faxon within our 
limits. Reference should be made to his monograph for identification. 
Genus Nephropsis Wood Mason. Species from deep water. 
23. Two pairs of lateral spines on rostrum : N. aculeatus Smith M 
Genus Nephrops Leach. ; 
24. . N. occidentalis Randall?! 
F. imsy Suneeein a. Anlennal ‘tank long, stout; sternum trigonal; 
none of the feet chelate. Tropical and temperate in our waters; animals 
of large size, familiarly known as spiny lobsters. 
Genus Panulirus Gray. 
25. No spine in median line of gastric region; posterior border of the lat- 
eral angles of abdominal segments with a single spine ; basal joint of 
antennulz very long ‘ P. americanus (Lam.) S 
25. Gastric region with seven spines, the middle one largest, sulci of 
abdominal segments interrupted in middle, except on last segment 
P. interruptus (Randall) P, D 
Besides, P. guttatus and P. argus may occur in Florida. They have not 
been reported from there. 
1 Described by Randall from “the west coast of North America.” Probably 
was from the Hawaiian Islands. See Bull. Essex Inst., vol. xiv, p. 131. 
