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Part III. — Ttventij-first Annual Hepcrt 



sort is poured out on the blades. The other hairs on the hand midway 

 between the blade and the edge resemble those close to the latter in 

 being stouter and less tapering than the hairs on the margins of the 

 hand, dactyl, and other joints. When the jaws are closed their hook 

 tei'miiiations cross over one another and interlock. 



2-5 Pereiopods. In general appearance the remaining four pei eiopods 

 i-esemble one another much, but they are at once separated into two 

 groups. The fifth pereiopod is easily distinguished from the others by 

 the presence of the long bristles on the dactylopodite. It is moreover 

 considerably smaller than the other three. The second, third, and 

 fourth limbs on careful examination show distinctive characters by 

 which each may be recognised apart from the others. 



The number and arrangements of the hairs which were found on each 

 limb are shown in the drawings : it is only necessary to draw attention 

 to the distinguishing marks. They are found on the dactylopodite and 

 propodite. In the second (Fig. 95) and third (Fig. 93) pereiopods there 

 are on the under surface of the dactylopodite three toothed spines. The 

 integument where these are attached is thickened and strengthened 

 (Figs. 94 and 92). On the distal lower corner of the propodite there 

 is another of these toothed spines (Figs. 91, 93, and 95). In the fourth 

 pereiopod the last-mentioned toothed spine is absent (Figs. 89, 99). The 

 latter appendage is by this fact separated f j om the second and third 

 pereiopods. The second pereiopod may be readily distinguished from 

 the third by its possessing a long spine {sp) on the dorsal surface of the 

 dactylopodite (Fig. 95). 



The hairs found on the fifth pereiopod are shown in Fig. 105. A 

 little way short of the tip of the dactylopQdite three long curved bristles 

 are attached to the lower edge of joint (Fig. 102). The stoutest bristle 

 is, on its last third, furnished on the inner side of its curve with a 

 double row of teeth (Fig. 96) ; in one row the teeth are very large, in 

 the other much smaller. The longest bristle is more slender than the 

 preceding, and is minutely serrated at its tip. The short bristle is 

 smooth. 



1. (Figs. 100, 113, 111, 116, 108, and 110.) The pereiopods have 

 changed considerably. The large hook is absent from the chela, and 

 the propodite and dactylopodite have no toothed thorns. The fifth 

 pereiopod resembles the second, third, and fourth. They are still, 

 however, very difierent from those of the adult stage. 



All are profusely supplied with hairs, plain and ciliated ; they are 

 also covered with the minute ''needle-point" cilia. The anterior surface 

 of the chela has comparatively few of these little teeth. On the 

 coxopodite, basi-ischiopodite, meropodite, carpopodite, the " needle- 

 point " cilia are restricted to the borders of the joints. There are few 

 near the jaws ; some are found on the hand. The posterior surface is 

 thickly covered, with the exception of the greater part of the dactylo- 

 podite. On the other pereiopods the " needle-point " cilia are present 

 on both sides. 



The sparsely plumose (or ciliated) hairs on the limbs (Fig. 107) have 

 the cilia arranged all round the stem of the hair. 



The chela (Figs. 100 and 113) is very thickly provided with ciliated 

 hairs. The posterior surface is shown in Fig. 100 and the posterior in 

 Fig. 113. The knife-blades are not exactly on the same level, so that 

 they pass on to one another when the jaws are closed. The hinge of 

 the dactylopodite is seen in Fig. 115. On the carpopodite there is a 

 hooked tooth (Fig. 133). 



There are in this stage no marks such as served to distinguish the 

 limbs from one another in the Megalops ; minute difierences which have 



