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Part III. — Ttoeiity-first Annual Report 



endopodite, these cilia are only on the dorsal half of the surface. This is 

 the exposed surface of the third maxillipede. The upper surface is close 

 up against the second maxillipede, and on it (the upper surface) there 

 are none of these cilia. Generally over the body of the crab of this 

 stage the external surfaces are covered with these minute cilia, except 

 where two surfaces interact on one another, e.g. anterior surface of 

 chela on the epimeron. In the third maxillipede they are not confined 

 to the endopodite, but are also on the basal joint, and on the part of the 

 first joint of the exopodite which is exposed beyond the endopodite. 



The two sketches together show all the hairs and bristles which 

 are found on the appendage. A number of these, however, appear 

 in both drawings. They are those on the superior edge of the second 

 and third joints, and the short hairs on the edge of the first joint. 



The inner edge of the first joint of the endopodite is now minutely 

 crenate : the exact number of lobes is shown in the sketch. It is 

 furnished with a row of short hairs, all situated on the outer surface. 

 On the surface of the joint there are externally a number of plumose 

 hairs, and on the internal surface a number of hairs of which only 

 one was made out to be provided with cilia (two). 



The second joint has a notched superior edge, and on its inner side it 

 is hollowed out to receive the third joint ; the hinge between the two 

 gives a free movement antero-posteriorly. 



The number of serrated bristles on the third, fourth, and fifth 

 joints has increased. They are all on the superior surface, i.e. next the 

 second maxillipede. 



The Pereiopods, per, Plates ix., x., and xi. 



I. (Side view, Figs. 69 and 76 ; ventral view. Fig. 85). The pereiopods 

 in the first Zoea stage are hollow buds packed closely together on each 

 side of the oval-shaped rudimentary sternum {th). They are all more 

 or less club-shaped, the first pereiopod being distinguished from the 

 others by its greater size and swollen end. The remaining buds resemble 

 one another much. They are arranged round the sternum, and on 

 account of the oval form of the latter the fifth pereiopod is brought 

 round nearer the median line than the others. It is in this way often 

 hid when the buds are examined in side view. 



The buds of the branchiae (6r, Fig. 69) are seen in this stage. There 

 is a large hollow outgrowth from the outer side of the first pereiopod, 

 and two small similar buds from the outer sides of the second and third 

 pereiopods respectively. The hollow interior of the bud of the branchia 

 is continuous with that of the pereiopod bud : this is seen better in the 

 later stages. 



The buds of the pereiopods show no segmentation. 



The sternum of that part of the thorax is rudimentary like the limbs 

 that pertain to it, and it separates easily off as an oval disc : it shows 

 some traces of segmentation. 



The gut in this part of the Zoea is interesting. The gut is in the 

 adult straight, and so it is in the Zoea except at this part, where it is 

 convoluted (Fig. 162, Plate xii.). The convolutions allow for the 

 gradual expansion of this region with its growth during the Zoea period, 

 without any extra growth having to take place in the gut which is 

 functioning. 



II. (Figs. 73 and 84). The bud of the first pereiopod is now bifid. 

 The hollow structure of the pereiopods is well seen in Fig. 73. They 

 have thick walls. 



