436 PROF. G. O. SARS OX 



size is so slight that we have everj^ reason to believe it to represent 

 an immediately succeeding stage. But, whereas in the pi-eceding 

 stage the larval characters were very apparent, they are wholly 

 lost in the present specimen, which accordingly has entered the 

 postlarval period, representing here in all probability the very 

 first stage. 



The length of the specimen examined measures 2-70 mm., and 

 thus very little exceeds that of the preceding larva. The adult 

 ovigerous female of the present species attains, according to 

 Dr. Caiman, a length of 6'70 mm. 



The general form of the body (figs. 1 & 2) is very slender, even 

 more so than in the preceding stage. 



The carapace is of a quite similar shape, and the rostrum is 

 very short a,nd spiniform ; but on its upper edge three or four 

 small denticles have appeared (fig. 2). 



The eyes considerably project laterally and exhibit a somewhat ^ 

 fusiform shape, their pedicles being conspicuously dilated in the 

 middle. The corneal part, on the other hand, appears somewhat 

 less expanded than in the preceding stage. 



The metasome is more powerfully developed, and exhibits the 

 Caridea-n bend on the middle very distinctly (see fig. 2). The 

 epimeral plates of the live anterior segments are deeper, extending 

 slightly beyond the ventral faces of the segments. 



On the appendages several changes have taken place, the most 

 conspicuous of which are the complete loss of the natatory 

 exojjodites on the legs and the reduction of those attached to the 

 maxillipeds, the natatory function being now wholly transferred 

 to the metasome and more particularly to the pleopoda. 



Striicture of the Appendages. 



The antennul(E (fig. 3) have the joints of the peduncle more 

 sharply defined and several additional plumous setaj have appeared 

 inside the joints. The flagella are still rather short, but on both 

 a distinct subdivision has taken place, the inner one being com- 

 posed of three, the outer of four well-defined joints. On the 

 outer flagellum, moreover, a short uniarticulate appendicular 

 ramus has developed from the end of the second joint, carrying 

 on the tip a bundle of sensory filaments. 



On the antennce (fig. 4) the scale is nearly unaltered, whereas 

 the flagellum has considei-ably increased in length, being now 

 fviUy twice as long as the scale. It is, moreover, divided into 

 several joints, the outer of which are very sharply marked ofi:" 

 from each other and provided with small hair-like bristles, whereas 

 the proximal ones are still imperfectly defined. The flagellum 

 also appears to be freely mobile in relation to the peduncular 

 part, as it is found in some cases extended forwards, in other 

 cases more or less obliquely backwards (figs. 1^2). 



The mandibles (fig. 5) agree on the whole in their structure 

 with those in the preceding stage, though the molar prominence 



