CARCINOLOGICAL STUDIES. 117 



thorax is slightly carinated between the eyes. This slight 

 carina projects as an excessively small point bey- 

 ond the anterior margin of the cephalothorax ; this point 

 is so small , that it is observed , at least in these young in- 

 dividuals, only V7hen examined by a rather strong magni- 

 fying-glass. The dorsal interocular carina disappears back- 

 vrard , before reaching the level of the posterior margin 

 of the eyes. This species therefore is in fact 

 provided with a rostrum, as minute as it is, 

 and is closely allied to Alplieus crinitus Dana. The eyes 

 project rather much laterally, are rounded and are not 

 armed anteriorly with a tooth or an acute point. 



The first and the third joints of the peduncle of the 

 inner antennae have about the same length, whereas the 

 second joint is almost twice as long. According to Stimp- 

 son , the second joint is but little longer than the first. 

 This slight difference is certainly to be ascribed to the not 

 quite adult stage of these specimens (confer : de Man , in Ar- 

 chiv f. Naturgeschicbte, Jahrg. 53, p. 500, where I de- 

 scribed an analogous fact in Alpheus gracilipes Stimpson). 

 The external flagellum is a little longer than the peduncle 

 and about half as long as the internal one , which is a little 

 thinner. The basal spine is very short and scarcely pro- 

 jects beyond the middle of the first joint of the peduncle. 

 The peduncle of the outer antennae is a little longer than 

 the peduncle of the internal antennae; the basal joint 

 is unarmed, presenting no basal s p i n e. The scale 

 is short, much shorter than the peduncle and reaches to 

 the distal end of the second joint of the antennular pe- 

 duncle ; the spine into which the lateral margin of the 

 scale terminates, is rather long and projects a little bey- 

 ond the distal end of the scale. The flagella of the outer 

 antennae are about as long as the animal. 



The external maxillipedes project about as far forward 

 as the peduncle of the outer antennae; the terminal joint 

 is ovate , about three times as long as broad , and has 

 its external surface slightly concave and the margins or- 



Notes from the Leyden Museum, Vol. XII, 



