SYNOPSES OF NORTH-AMERICAN 
INVERTEBRATES. 
III. THE CARIDEA oF NORTH AMERICA. 
J. S. KINGSLEY. 
In the preparation of this number of the “ keys ” now being 
published in the American Naturalist, it has been the endeavor 
to include all the shrimps and prawns reported from the waters 
of North America north of the southern boundary of the United 
States and within the 100-fathom line. It is believed that this 
key will serve for the identification of any species (except in 
the genera Hippolyte and Pandalus) now known to inhabit our 
waters; but the student may reasonably expect that several 
tropical species may later be found within these limits. The 
genera most likely to furnish additions of this character are 
Alpheus, Palamon, Peneus, Atya, and Caridina. 
In using the synopsis which follows, the student must 
remember that the characters of the key are not repeated. 
It will be seen that the mandibles furnish important characters. 
With a little practice these structures may be readily removed 
with the dissecting needle without injuring the specimen for 
exhibition purposes. Caridea should only be preserved as 
alcoholic material; any attempt to dry them proves disastrous. 
The terminology of parts employed below, with few exceptions, 
will be understood by any one who has dissected a cray fish or 
lobster. Branchiostegal spines are small spines just below the 
antenne, near the anterior margin of the carapax. The carpal 
joint is the antepenult segment of the legs and is spoken of as 
annulate, where it is broken up into a number of smaller joints 
(see Fig. 39). 
The geographical distribution of the species is roughly indi- 
cated by full-face letters following the specific name. These 
letters are: A, Alaska south; D, Monterey to San Diego; M, 
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