416 PROCEEDINGS OF THE ACADEMY OF [1879. 



Sub-Family Ephyrinee. 



Pereiopoda with an exopoclite. 



Genus Miersia Kingsley. 1 Rostrum toothed, antennuhe biflagel- 

 latc, two anterior pairs of pereiopoda, chelate small ; the carpus 

 of the second pair not annulate ; the three posterior pairs slender. 

 Type Miersia pelagica (Risso sp.). 



The known species are : 



pelagica (Risso sp.)- Mediterranean. 

 punctulata (Risso sp. ). Mediterranean. 

 compressa (De Haan sp.). Japan. 



Family PALiEMONIDiE. 



Mandibles stout, incurved, deepl}" bipartite, apical process nar- 

 row, oblong. 



Sub-Family Alpheinae. 



First pair of feet the larger, chelate ; second slender, filiform, 

 generally chelate, carpus frequently annulate. 



Section I. Mandibles with a Palpus. 



o Genus Alpheus Fahr. 2 Rostrum very short or wanting, an- 

 tennulae biflagellate, eyes hidden under the carapax ; mandibles 

 with a two-jointed palpus; external maxillipeds slender, moderate; 

 first pair of pereiopoda generally greatly differing in size; carpus 

 of second pair annulate. Type Alpheus rapax Fabrieius. 



Alpheus minus Say. Numerous specimens were collected. The 

 localities are Beaufort, N. C, Key West, Harbor Key, Sarasota, and 

 Florida Bays, and Marcou Pass. Three specimens from Harbor 

 Key were the largest that i have ever seen, measuring respectively 

 40.3 mm., 40.8 mm , and 42.3 mm. in length. Among those collected 

 at Key West were several of the form described lyy Gibbes as A. 

 formosus, and two which approached A. Jloridanus in size, form 

 of front, and hand. 



Alpheus websteri, sp. n. Carapax slender, compressed, rostrum 

 acute, separated from the orbital hoods by deep sulci. Orbital 

 hoods acute, but not spinose. Penult joint of antennular peduncle 



1 Epliyra Roux, Edwards, De Haan, Dana, Heller (nom. praeoc). 



2 Including Betieus Dana. Vide Kingsley, Bulletin U. S. Geol. and Geog. 

 Survey, iv. p. 189, 1878. 



