REPORT ON THE CRUSTACEA MACRURA. 453 



large, pointed, and situated at the posterior angle of the cutting edge, but at the second 

 Protozoea stage a number of small denticles have appeared in front of the long one. The 

 mandibles are never quite symmetrical, but the out- 

 line of the left always differs a little from that of the 

 right," as shown in the following illustration from 

 Willernoes Suhm's drawings. 



The first pair of maxillae consists of a basal portion _, • „ .... . _ .. 



* r Fig. 5o. — Mandibles of Lucifer. 



made up of two joints with " cutting hairs," an inner 



ramus of two joints terminating in three slender hairs, and an outer ramus with three. 



In the first stage the hairs of the latter are simple, but on the second they are plumose. 



The second maxilla consists of a multiarticulate basal portion, a small biarticulate 

 inner ramus, and a uniarticulate outer branch. The entire inner margin of the appendage 

 carries short stout hail's ; the extremity of the inner ramus carries a few somewhat longer, 

 and the outer branch three slender plumose hairs, which are much longer in the second 

 than in the first stage. 



The next succeeding appendages, which Professor Brooks calls the first and second 

 pairs of maxillipedes, but which are homologous with the last or third pair of siagnopoda 

 and the first pair of gnathopoda according to the nomenclature in this Eeport, 

 resemble each other and consist of a two-jointed basal portion, a four-jointed inner, and 

 a single-jointed outer ramus, the former supporting four long slender hairs which are 

 simple in the first pair but regularly ciliated in the second. The second pair is smaller than 

 the first, and apparently of little functional importance. Professor Brooks here notices 

 " a small convoluted shell-gland which appears to open at the base of the first maxilla." 



In Suhm's figure of the earlier stage of this Zoea there is represented a small gland 

 (fig. 54, gl.) of a similar character, but situated on the outer side in a line with the 

 mandibles, whereas Professor Brooks describes it as being at the base of either the first or 

 second maxUla, he is not sure which, because "the constant and violent movements of the 

 limbs renders it difficult to decide with confidence exactly what its relation to them is." 



After the next moult, which Professor Brooks has observed in a great number of 

 specimens, the Zoea passes into a form that is directly comparable, so far as the 

 appendages are concerned, with the Elaphocaris-stage of Sergestes, 1 although the most 

 conspicuous features, the long compound spines, are not present in the young of Lucifer. 

 It is now about T ^j of an inch (or 1"25 mm) long ; the appendages are the same, but 

 the four pairs of pereiopoda and the appendages of the sixth somite of the pleon are present 

 as rudimentary buds. The permanent eye is now well advanced in development, although 

 there is yet no trace of a peduncle, the cornea being simply a modified portion of the 



1 It should be remembered that Elaphocaris suhmi has yet no trace of the permanent eye, and Suhm asserts, and 

 his drawing confirms the opinion, that the specimen when he captured it still contained in abundance the cells of the 

 embryonic yolk-mass, a circumstance that strongly suggests that the youngest form of Sergestes is a Kauplius in the form 

 of a blind Elaphocaris, and therefore earlier in development than the Protozoea of Lucifer. 



