i-.Q CRUSTACEA. 



outer maxillipeds, enlarged two diameters ; c, last joint of anterior 

 less. 



-c 1 - 



Valparaiso. 



The rounded median tooth of the front appears to be a constant 

 character of this species. The inner apex of the third joint of the 

 outer maxillipeds is produced, but is quite short, and the anterior 

 margin of the last joint of the anterior legs has a small acute tooth to 

 wards the articulation. The prolongation of the apex of both the 

 penult and antepenult joints, in these legs, is less than in the, emcrlta. 



Hippa talpoida, Say, Jour. Acad. Nat, Sci., i. 100; Gjubes, Proc. Meeting of Aiuer. 



Assoc, at Charleston, 1850, p. 188. 



Subtribe V. PORCELLANIDEA. 



The Porcellanidea pertain to a single genus Porcellana. Edwards, 

 in his corresponding division, " Porcellaniens," embraces also the 

 genera iEglea and Megalopus, yet expresses bis doubts with regard to 

 such an arrangement. The genus iEglea belongs properly to a lower 

 grade of the Anomoura than Porcellana, inasmuch as the inner an- 

 tennas are posterior to the eyes, and, therefore, fall into our lowest 

 section of the Anomoura, the Anomoura inforiora. The genus Meira- 

 lopus has little actual relation to the Porcellanidea. 



Genus PORCELLANA. 



The carapax in the genus Porcellana varies much in form and 

 markings. The front is usually more or less triangular, and when 

 straight m a view from above, there is often, if not always, a triangular 

 outline when observed in a front view, so that the straight mai-in in 

 such cases, is owing to the front being deflexed, The surface m,v 

 be entirely smooth. But commonly the front and posterior mar-in of 



