84 



PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



SYNALPHEUS RATHBUN^ffi, new species. 



The frontal margin suggests jS. goodei; the rostrum is narrow, with 

 parallel margins, hardly one-sixth of the width of the lateral teeth 

 and slightly longer; the lateral teeth have almost exactly the form, 

 inverted, of the intervals between them and the rostrum, but a little 

 narrower. 



The articles of the antennule are to one another as 1.2, 1, 1 ; they 

 are a little wider at the distal extremity and the flagella are stout; 

 the stylocerite reaches the distal third of the basal article. 



The superior angle of the basicerite is prolonged in a strong spine 

 reaching as far forward as the stylocerite. This is the only case that 



Fig. 51. — Synalpheus KATHBUNiE. a, frontal and antennal region ; K, large chela ; 



k', SMALL CHELIPED OF FIRST PAIR; I, FOOT OF SECOND PAIR; m, FOOT OF THIRD PAIR; 

 m', DACTYL OF THIRD PAIR ; t, TELSON ; U, UROPOD. 



I have as yet noticed in the L.evimanus group, so that this detail 

 enables one to identify the species immediately. The outer spine, 

 rather slender, reaches the middle of the distal antennular article. 



The scaphocerite is reduced to its lateral spine, which has a con- 

 cave inner margin, is much wider than the spine of the basicerite, and 

 reaches the middle of the distal antennular article. The carpocerite 

 surpasses the antennule by hardly one-half of the same article; it is 

 4.6 to 4.8 times longer than wide. 



The proportions of the large chela are : Fingers 1 ; total length 3.5 ; 

 height 1.25, But I have also found in one of the few specimens car- 



