MUSEUM OF COMPARATIVE ZOOLOGY. 75 



only five or six teetli, while the anterior edge is entirely unarmed ; the molar 

 area is considerably larger, and is rounded above instead of angular ; the palpus 

 is a very little larger and the second segment proportionally a little longer. 

 The proximal lobe of the protognath of the first maxilla (PI. XII. fig. 6) is 

 more angular anteriorly and its mesial edge a little longer, and the endognath 

 has but a single spine on the fold near the tip. The protognath and endognath 

 of the second maxilla (PI. XII. fig. 7) are almost exactly the same, but the 

 scaphognath is larger, more prolonged and ovate in outline at the tip, and 

 the posterior portion projects inward less prominently. The endopod of 

 the first maxilliped (PI. XII. fig. 8) is much stouter and the two distal seg- 

 ments much more nearly equal in length, and the exopod is more expanded 

 anteriorly and more prolonged at the outer than at the inner edge. The endo- 

 pod of the second maxilliped (PI. XI. fig. 9) is a very little stouter proximally 

 and has a rather shorter carpus, but differs very slightly ; the exopod is a very 

 little longer ; and the epipod is narrower at base, more ovate in outline, and 

 bears a branchia composed of only a few pairs of lamellae. 



The endopods of the external maxillipeds reach considerably beyond the tips 

 of the antennal scales, and are composed of three segments each, as in Micrsia 

 Agassizii, but are considerably stouter than in that species ; the proximal seg- 

 ment is distally stouter than any part of the other segments and nearly as long 

 as the other two together; the middle segment is scarcely more than a fourth as 

 long as the proximal, and the distal is triquetral, tapers to an acute point, and 

 is nearly naked but armed with a few minute spines near the tip. The exo- 

 pod is multiarticulate, flagelliform, as in Micrsia Agassizii, and about as long as 

 the proximal segment of the endopod. The epipod is nearly as in Micrsia. 



All the thoracic legs are furnished with exopods like the external maxillipeds, 

 and the first, second, and third pairs are furnished also with epipods as in the 

 external maxillipeds. The legs of the first pair are not stouter than the external 

 maxillipeds and fall consideral>ly short of their tips : the merus is compressed 

 and nearly as long as the proximal segment of the endopod of the external 

 maxilliped ; the carpus is scarcely half as long as the merus, snbcylindrical, 

 and slightly enlarged distally ; the chela is about twice as long as the carpus, 

 very slightly swollen proximally, and the digits nearly a third the whole 

 length, strongly curved at the tips, and the propodal one considerably stouter 

 at base than the dactylus. The legs of the second pair are very slender, and 

 reach a little by the tips of the external maxillipeds : the ischium and menis are 

 strongly compressed, and the latter is longer than in the first pair and reaches 

 to the distal extremity of the proximal segment of the endopod of the external 

 maxilliped ; the carpus is slender, cylindrical, and about half as long as the 

 merus ; the chela is slightly longer than the carpus, scarcely as long as in the 

 first pair, cylindrical, scarcely as stout as the carpus, not at all swollen, and 

 with very slender and slightly compressed digits about two sevenths the entire 

 length. The third and fourth pairs of legs are nearly alike : the ischia and 

 meri are compressed, and nearly as in the second pair, but a little longer ; the 

 carpi are a little shorter and broader than in the second pair ; the propodi and 



