American Species of Palicus. 97 



Palicus isthmius Rathbun, new species. 



Allied to P. alternatus, but broader. Carapace depressed. Front with 

 median sinus broader than in P. alternatus; lateral lobes faintly marked. 

 Preorbital lobe very sinuous, a small but well-marked tooth at its outer 

 angle. Both superior orbital lobes triangular, obtuse. Median lobe of 

 inferior margin subtruncate or slightly arcuate. Lateral teeth of carapace 

 two, directed obliquely outward, the anterior lobiform, the posterior a 

 little longer and subacute. 



Chelipeds in the immature 9 small and feeble, as in P. alternatus. 

 Merus of the first pair of ambulatory legs with an acute spiniform tooth 

 instead of the blunt tooth in P. alternatus. Meri of the second and third 

 pairs with the distal angle thin and almost a right angle, tipped with a 

 small sharp point. Carpi without lobes on their anterior margins. Third 

 ambulatory leg very little shorter than the second. 



Dimensions. Immature 9 : length, 5.8mm.; width, 7 ; length of second 

 ambulatory, 13.7; merus, 4; carpus, 2.5; propodus, 3.2; dactylus, 3.3. 



Type locality. One specimen only was dredged by the 'Albatross,' 

 station 2145, near Aspinwall, latitude 9 27 X N., longitude 79 54 / W., 25 

 fathoms (U. S. Nat. Mus., No. 7753). 



Palicus sica (A. Milne Edwards). 

 Palicus angustus Rathbun, new species. 

 Palicus depressus Rathbun, new species. 



Cymopolia sica A. Milne Edwards, Bull. Mus. Comp. Zool., VIII, 29, 1880. 



Among the specimens referred to Cymopolia sica by its author, there 

 appear three distinct forms, which agree in the following characters : The 

 carapace is granulate, many of the granules forming clusters on the more 

 elevated regions. Front with four small, tuberculiform teeth, the median 

 the most prominent, separated from each other by a deep triangular 

 notch, and from the lateral teeth by very broad, shallow sinuses. The 

 tooth of the superior orbital border nearest the preorbital is arcuate ; the 

 next narrower, also obtuse. The median suborbital lobe is subtriangular 

 and much less advanced than the inner lobe. The lateral margin of the 

 carapace bears three small, thickened teeth. 



First segment of the abdomen with a narrow carina on either side 

 behind the postero-lateral angle of the carapace. Second carinated 

 throughout its width, the carina much longer in the center. Third seg 

 ment carinated, but much less sharply. There is also a carina on the 

 sternum in a line with the suture between the second and third abdom 

 inal segments ; it extends well outwardly, but not so far posteriorly as 

 the second abdominal. These carinse form horizontal plates, visible in a 

 dorsal view, excepting that of the third abdominal segment in the male. 



Chelipeds slender and feeble. Ambulatory legs of moderate length, 

 the third very little shorter than the second, the first very slender and 

 reaching about midway of the carpus of the second. Meri of second and 



