1922.] 



S. Kemp : Notes on Crustacea Decapod a. 



M3 



TEXT-FIG. \2. — Periclimenes aesopius (Sp. 

 Bate). 



Dorsal parts of third and fourth abdominal 

 somites in lateral view. 



The first peraeopods reach the end of the scale. The carpus 

 is shorter than the merus 

 and only three-quarters the 

 length of the chela. The 

 fingers are unarmed and are 

 longer than the palm. On 

 the outer edge of the fixed 

 finger there are some tufts 

 of hairs. The second per- 

 aeopods reach beyond the 

 scale by almost the entire 

 length of the chela. The 

 merus is unarmed and 15 

 times as long as the carpus. 

 The carpus is conical and 

 about 3 times as long as its 



distal width. The chela is 25 times as long as the carpus and 

 rather more than 4 times as long as wide ; the fingers are unarmed, 

 a little shorter than the palm. 



The third peraeopods reach the end of the scale. The propo- 

 dus in all three pairs is provided with spinules on its posterior 

 border and is about 4 times the length of the dactylus. The 

 dacfylus is biunguiculate, with a deep and narrow cleft between 

 the two claws. 



The form of the remarkable compressed tooth which projects 

 backwards from the third abdominal somite is shown in text-fig. 12. 

 I know nothing resembling it in any other species of the genus. 

 The sixth abdominal somite is 2-3 times the length of the fifth. 

 The anterior pair of dorsal spinules of the telson are placed in the 

 middle of its length. As usual there are two spines, one of which 

 is movable, at the end of the external margin of the outer uropod. 



If the complete specimen were straightened out it would prob- 

 ably be about 24 mm. in length. 



The structure of the apex of the telson and of the mandibu- 

 lar palp (found loose in the tube containing the specimens) afford 

 proof that the species belongs to the Pontoniinae. It must cer- 

 tainly be referred to the genus Periclimenes in which, however, by 

 reason of the characters of the basal segment of the antennular 

 peduncle and third abdominal somite, it occupies a very isolated 

 position. 



The two specimens were found in the Gulf of St. Vincent, S. 

 Australia (Angas coll.). 



Periclimenes (Periclimenes) infraspinis (Rathbun). 



19112. Urocaris infraspinis, Rathbun, Proc. U. S. Nat. Mtis. XXIV, 



P 9°?' 



1904. Urocaris infraspinis, Rathbun, Harriman Alaska Exped. X, 



p. 31, text-figs, toff, b. 

 1921. Urocaris infraspinis, Schmitt, Univ. Calif. Publ., Zool. XXIII, 

 p. 37, fig. 22. 



California, Pacific coast of Mexico. 



