\DDITIONS TO WEST INDIAN TERTIARY DECAPOD 

 CRUSTACEANS. 



By Mary J. Rathbun, 



Associate in Zoology, United States National Museum. 



Among the crustaceans obtained in the Dominican Republic by 

 Dr. T. Wayland Vaughan and party in 1919 are three forms not 

 previously i^no^\^l. Two belong to Neplirops, a genus not before re- 

 corded in the West Indies, and the other is a Porfunns which appears 

 different from other fossil forms. 



NEPHROPS MAOENSIS, new species. 



Plate 25. fig£. 2 and 2a. 



3faterial.—T\])s of two fingers, from the Rio de Mao, 3 miles above 

 Taso Bajito, at Cercado de Mao, Dominican Repubhc; Cercado for- 

 mation; lower Miocene; T. W. Vaughan and C. W. Cooke, collectors 

 (8525). Cat. No. 328230, U.S.N.M. 



Description. — One of these pieces, holotype, is more than twice 

 as long as the other and resembles the tip of a major, immovable 

 finger of Al myrvegicus (Linnaeus)^ in the shape, which is nearly 

 straight until near the tip where it turns rapidly inward. The sur- 

 face, except on the prehensile edge is smootlily rounded, not longi- 

 tudinally furrowed as in norvegicus. The prehensile edge has five 

 teeth, which are stout, blunt, and of a reddish-brown color, lighter 

 at the tip than at the base; the tooth nearest the broken end is of 

 medium size and slightly broader than long; separated by a narrow 

 interval there is a much larger tooth than the first; it is longer than 

 wide, and subparallel to the finger tip, which is slenderer and sharper; 

 between the large tooth and the tip, but much nearer the former 

 there are three very small teeth, the three interspaces subequal and 

 a little wider than that between the two largest teeth; of the small 

 teeth the two distal ones are subequal and are shorter and narrower 

 than the more proximal one. The main part of the finger is a light 

 tan color and is covered with microscopic granules; the long tip is 

 dark brown, which extends as far back as the third small tooth. The 



Caricer norvegicus Linnaeus, Syst. Nat., ed. 10, vol. 1, Holmiae, 1758, p. 632. 



Proceedings U. S. National Museum, Vol. 53-No. 2343. 



381 



