BORRADAILE— ON CARIDES FROM THE WESTERN INDIAN OCEAN 407 



I. Three pairs of spines on the dorsal side of the telson, and a median feathered 



bristle at the hinder end. Rostrum does not reach end of antennal scale [and is very 



deep and straight at base]. 



A. willeyi (Borradaile), 1899. 



II. Two pairs of spines on the dorsal side of the telson, and a pair of feathered 

 bristles at the hinder end. Rostrum at least reaches end of antennal scale. 



A. Rostrum very deep, straight at base. 



A. gardineri Borradaile, 1915. 



B. Rostrum not very deep, arched at base. 



A. cooperi Borradaile, 1915. 



18. Amphipalcemon gardineri Borradaile, 1915 (Plate 59, fig. 14). 

 Ann. Mag. Nat. Hist. (8), xv. p. 209. 



The most important diflPerence between this species and A. willeyi lies in the 

 arrangement of the spines of the telson. In the New Britain species, the two anterior 

 pairs of spines on the dorsal side of this organ lie in its front half. In A. gardineri the 

 second of them lies just behind the middle of the telson. In A. willeyi (Plate 59, fig. 13), 

 the two small lateral spines of Anchistioides, which are also found in so many other Carides, 

 ha.ve migrated to the dorsal surface of the telson. In A. gardineri they are altogether 

 wanting. In the latter species, the adjoining spines, which thus become lateral, are 

 longer than in A. willeyi. The pair of feathered bristles found in Anchistioides are 

 present also in A. gardineri; in A. willeyi they are absent, but there is present 

 a single median feathered bristle, shorter than those of A. gardineri and widened 

 at the base. 



Lastly, in A. ivilleyi there are a number of unfeathered bristles, of which three 

 on each side are somewhat shorter than the rest. In A. gardineri only two such 

 bristles are present. 



Less important differences, which may quite possibly prove not to be constant, are : 

 (l) that the rostrum has the formula ^ and outreaches the antennal scale, and (2) that 

 the first leg does not reach the end of the antennal scale, and (3) that the second 

 leg outreaches the scale by only half the length of the palm, and its meropodite 

 is relatively shorter. 



The specimen, which measures 30 mm. in length, was taken in N. Male Atoll. 



19. AmphipalcBmon cooperi Borradaile, 1915. 



Ann. Mag. Nat. Hist. (8), xv. p. 209. 



This species very closely resembles the preceding, but differs from it in the following 

 points: (1) the rostrum has the formula f, barely outreaches the antennal scale, and 

 is arched at the base and decidedly less deep, (2) the first leg reaches the end of the 

 antennal scale, (3) the second leg outreaches the scale by the whole hand, (4) the 



