CARCINOLOGICAL STUDIES. 125 



of the first pair are indeed as long as the autennary scale : 

 in our specimens they reach scarcely to the distal end of 

 the peduncle of the outer antennae. The second pair of 

 legs project with the hands beyond the distal end of the 

 antennal peduncle, but they are still considerably shorter 

 than the antennal scale. The third pair , however , extends 

 with the fingers beyond the antennal scale. The legs of 

 the fourth pair are much shorter than those of the third, 

 and reach scarcely a little more forward than the first pair. 

 The legs of the fifth pair are much longer, they reach 

 nearly as far forward as the antennal scale, but they are 

 still shorter than the legs of the third pair. The three 

 anterior pairs of legs are unispinose at their base. I observe a 

 very small supraorbital spine, which is not mentioned by 

 Haswell ; this spinule, however, is very small and disappears 

 probably in the adult. For the rest these two specimens 

 agree perfectly well with Haswell's description. This species is 

 closely allied to Penaeus avirostris Dana from Singapore. 

 In Dana's species the teeth of the rostrum extend less 

 far forward , so that the styliform distal end occupies more 

 than half the length of the rostrum ; in Penaeus Macleayi , 

 however, the styliform unarmed part is shorter than half 

 the length of the rostrum. In Haswell's species five teeth 

 are placed on the rostrum itself and only two on the 

 cephalothorax , in Penaeus avirostris Dana two on the 

 rostrum and four on the cephalothorax. The rostrum of 

 Penaeus Macleayi is also less elevated at its base than in 

 the species of Singapore. 



Middelburg, February 1890. 



Notes from the Leyden ^Inseum , Vol. XII. 



