432 PROCEEDINGS OF THE NATIONAL MUSEUM. 



obliquely forward; the inferior margin is unarmed; the tip of the 

 rostrum is acute and reaches forward to a point opposite the distal 

 extremities of the antennal scales. The eyes are much reduced in 

 size, are without pigment, and the corneal surface comes to an 

 obtuse point in front. The-first antenna has the basal segment well 

 excavated above and provided with a small, acute spine at the outer 

 distal angle; there are two long and one short flagella, the short one 

 slightly exceeding the rostrum, the long ones somewhat longer than 

 the bodv. The second antenna has the basal segment provided with 

 a small spine near the distal end; the antennal scale is broad and with 

 subparallel margins; the tip is slightly rounded, and there is a small, 

 obtuse spine at the outer distal angle; the flagellum is slender, and 

 about twice as long as the body. The mandible has an incisor por- 

 tion with three or four sharp teeth, a small molar surface with several 

 obtuse teeth, but is without a palpus. The third maxilliped is not 

 strongl}- developed and presents no characters of importance. The 



Fig. 2.— Pal«monetes eigenmanni. 



first pair of pereiopods is chelate, and except for its much smaller 

 size is exactly like the second; the chela is slender and weak; the car- 

 pal segment is long and slender; the meros is of about the same length, 

 but stouter; the remaining segments short and rather thick. The 

 remaining pereiopods are very long and slender. The abdomen is 

 of the form usual in this genus, but the sixth segment is neither 

 elongate nor compressed; the telson narrows gradually from the base 

 to the obtusely angulate tip; on the upper surface there is on each 

 side at about the middle and again about one-fourth the distance 

 from the tip a small, appressed spine, at the tip there is on each side 

 one minute and one long, slender spine, and in the middle a fringe of 

 setje. Color in alcohol, white. Length, 23 mm. 



Nine specimens of this interesting shrimp were sent to me, three 

 from Ashton, two from Modesta, one from the cave of Jaiguan, and 

 three from the cave at San Isidro. Dr. Eigenmann reports that they 

 were common. 



