104 DK. J. D. F. GILCHRIST ON LARVAL AND 



region, but do not extend on to the bases o£ the walking-legs. They consist 

 o£ minute dome-shaped cuticular elevations, at the apex of each o£ which 

 there is a fine hair-like process about double the length of the basal portion. 

 They occur, but more sparsely, on the ventral surface of the head region 

 from the base of the antennse backwards. Such fine (sensory?) setse do not 

 seem to have been observed on any other phyllosomas. 



The diverticula of the liver can be readily seen in the transparent thorax. 

 There are three on each side, a long one running forward on each side of 

 the oesophagus almost to the antennal gland, a much shorter one projecting 

 backwards, and a large triiobed lateral one. The condition, however, is not 

 diff'erent from that in the naupliosoma stage, in which the liver can be easily 

 seen in suitably stained specimens. 



The segmentation of the body can be made out very clearly in some 

 specimens. It consists of one distinct segment in the thoracic region — 

 namely, the second thoracic, to which the second maxillipedes belong. Four 

 segments can be clearly distinguished in the abdominal region in some 

 specimens. 



The eyes stand more out from the body, the peduncles being straighter, 

 more elongate, and with their bases somewhat nearer each other. 



The antennules (PI. 13. fig. 13) present a marked difference from those of 

 the naupliosoma. This is chiefly in the appearance of three long filamentous 

 projections. They do not project forward in the same axis as the antennse, 

 but are, somewhat abruptly, curved downwards. The other shorter, but 

 similar filaments were seen at their bases. They are not of the same 

 appearance as the ordinary spines, two of which also occur at the extremity 

 of the antennule. They were not seen in any of the phyllosomas of a larger 

 size, but may occur there also, as they are very readily broken off. It may 

 be suggested that they are of a sensory nature, especially as in stained 

 specimens a group of what appeared to be nerve-cells occurs near their 

 bases. Near the distal part of the antennule is a strong spine, and a similar 

 one occurs a short distance behind it. There are, in some specimens, slight 

 traces of a single division in the antennule. 



The antennce (fig. 14) have also changed considerably, chiefly in the 

 absence of the long swimming setse. 



In a very few, apparently just after ecdysis, the exopodite still retains 

 the indentations on its posterior border at the points of insertion of the setse, 

 but in most these are absent. The endopodite shows a marked advance. It 

 is now longer than the exopodite, a division appears forming a proximal 

 section, about one-fourth of its length. This is followed by a second section, 

 terminated by two or three spines, and, lastly, follow the rudiments of the 

 flagellum, about a third of the endopodite in length and already provided 

 with small setse. It may be noted that the endopodite and exopodite have 

 apparently changed positions (cf. fig. 2), and at first it appeared as if the? 



