96 Eathbun American Species of PaMcus. 



be due to the scarcity of material collected and does not prove its non- 

 existence.* 



Dimensions. tf, form I : Length, 6.6 mm. ; width, 7.6 ; length of second 

 ambulatory leg, 14; length of merus, 4.4; carpus, 2.2; propodus, 3.6; 

 dactylus, 3.2. 



<j\ form II: Length, 11 mm.; width, 13.2. 



Distribution. P. alternatus occurs in from 24 to 60 fathoms off Cape 

 Hatteras, N. C., and in the Gulf of Mexico between the delta of the Mis 

 sissippi and Cedar Keys, and from Cedar Keys to Florida Straits. It has 

 been taken by the steamers 'Albatross' and 'Blake' and the schooner 

 ' Grampus.' 



Type locality. Station 2374, str. 'Albatross,' lat. 29 IV 30 X/ N., long. 

 85 29' W., 26 fathoms (U. S. Nat. Mus., No. 19840). 



Palicus faxoni Kathbun, new species. 



Allied to P. alternatus, but longer and narrower; granules of the cara 

 pace similar in size ; granulated tubercles of the branchial region more 

 elevated and more squamose ; median lobes of front more advanced ; 

 superior orbital lobes triangular and separated by wider sinuses than in 

 P. alternatus; median lobe of the inferior margin subtruncate, inclining 

 slightly forward toward the median line; lateral teeth of the carapace 

 dentiform, acute, projecting outward and forward ; ridge above the poste 

 rior margin with six linear and a few smaller tubercles. 



Abdominal appendages of the single male examined slender, with long, 

 slender tips ; just posterior to the terminal portion there is a tridentate 

 lobe on the inner side. 



Chelipeds unequal, similar in the two sexes ; the right propodus about 

 twice the width of the left. They resemble strongly those of P. alternatus, 

 tf, form II. 



Meri of second and third ambulatory legs characterized by a sharp spine 

 at the end of the anterior margin ; anterior margin spinulous ; upper sur 

 face flatter and less coarsely granulate than in P. alternatus; last three 

 joints wider than in that species; the dactyli differ in having the proxi 

 mal half of the posterior margin convex. 



Dimensions. , station 2596: length, 9.5 mm. ; width, 10.7; length of 

 second ambulatory, 18; merus, 5.2; carpus, 3.1 ; propodus, 4.7; dactylus, 

 3.7. ?, Yucatan Bank: length, 15.4; width, 17.3. tf, station XXX, 

 length, 9.5; width, 10. 



Distribution. Taken off Cape Hatteras by the 'Albatross,' station 2596 

 (type, IT. S. Nat. Mus., No. 19841), and off Yucatan by the ' Blake,' station 

 XXX ; range in depth, 49 to 51 fathoms. 



* Professor Smith, in Proc. U. S. Nat. Mus., VI, 22, 1883, describes two 

 forms of the male of Ethusa microphthalma , and suggests the possibility 

 of their specific distinctness. They may, however, represent a case simi 

 lar to that of P. alternates. 



