I. '08. 52 



pairs are fully developed. Of branchiae, the five pleuro- 

 branchs noticed in the earlier stages are very conspicuous and 

 all are subdivided into lamellae. There is as yet no trace of 

 any arthrobranch. 



The last four pairs of pleopods are biramous, with a con- 

 spicuous appendix or stylet at the base of the endopod. The 

 stylet at the proximal end of the exopod of the first pair is also 

 represented. The telson (fig. 10) is about three and a half 

 times as long as wide and is only slightly longer than the outer 

 uiopods ; apically it is emarginate and provided with several 

 pairs of setae. Within its margin the form w^hich it assumes 

 at the next moult is clearly visible ; in this, the apex is not so 

 strongly emarginate and is furnished with four pairs of setae, 

 the outermost of which are the longest. 



The majority of the remaining specimens in the collection 

 may conveniently be termed post-larval. In these the eyes 

 exceed the rostrum in length, the pereiopods, pleopods and 

 uropods are fully formed and the telson is nan'ow. 



In a specimen measuring 16'5 mm. the eyes are longer than 

 the rostrum and the corneal area, which is now distinct from 

 the stalks, exhibits faint traces of facets. The mandibles have 

 a dentate cutting edge, but possess no palp. The first maxilli- 

 pede (fig. 18) carries a bilobed epipod and still possesses a 

 short exopod ; the ultimate joint of the endopod is about two- 

 thirds the length of the penultimate. The second maxillipede 

 (fig. 19) bears an exopod of considerable length ; the joints of 

 the endopod are taking on the adult form, but the ischium is 

 less than one-third the length of the "merus. A prominent 

 papilla at the base of the third maxillipede represents the epi- 

 pod. The telson is very slightly emarginate at the apex and 

 is provided with eight spines. 



A specimen slightly longer, barely 17 mm. in length, show^s 

 a much smaller exopod on the second maxillipede (fig. 20), the 

 ischium has increased in length in proportion to the merus, 

 but there is as yet no trace of the small epipodal outgrowth 

 present in the adult. In the first maxilla the ultimate joint 

 is shorter, in proportion to the penultimate, than in the pre- 

 viously described specimen and the exopod is dwindling 

 rapidly. The telson is abruptly truncate with the usual four 

 pairs of setae. 



In a specimen 19 mm. in length the exopods on the first 

 and second n^axillipedes have entirely disappeared. 



The small epipod of the first maxillipede first makes its 

 appearance in a specimen 24 mm. in length. 



The development of the branchiae is exceedingly slow. An 

 example of 24 mm. possesses the usual five pleurobranchs over 

 the five pereiopods, one arthrobranch (anterior) at the base of 

 the third maxillipede and arthrobranchs at the base of the 

 first two pereiopods. The arthrobranchs at the base of the 

 third and fourth pereiopods are represented merely by papillae. 

 A specimen of 28*5 mm. is provided with the full comple- 

 ment of gills, with the exception of two, viz., the posterior 



