22 T. V. IIOIUJSON. 



appciidiigc are nil very sliort iiikI hroa'l ami thi(;kly bordered on both sides with hmg 

 simple seta3, some of whieh un the inner margins of the last two joints are distinctly 

 spinous. The third and fourth j(jints are much expanded internally, and the fifth 

 is a very broad stumpy joint. The second joint has short stout setsu on its distal 

 margin. The epignath is a very small rounded plate external to the l)a.sal joint. 



The pleopoda arc approximately uniform in structure. The first has been 

 removed for examination. The protopodite is short and broad ; its external margin 

 projects as a short, stout backwardly directed pnjcess, the inner margin is rounded 

 and bears a dense fringe of short plumose seta3, among which are a number of spines. 

 The exopotlite is a pointed egg-shaped structure, attached near the point ; its 

 external and distal margins are den.sely fringed with rather long plumose setae. 

 The endopodite is directed inwards from its attachment and then bent at a right 

 angle, the anterior and inner edges being thickened and straight ; they are fringed 

 with fine seta}, which ultimately Ijecome long and plumose around the distal tliird of 

 tiie joint. The inner edge is rounded. 



The pereiopoda are all very much alike. In th<> first (fig. 5) appendage the 

 basis is the largest joint and rather scantily fringed with long aetx along its dorsal 

 margin. This fringe is douljle, tliat is to .say, dorso-lateral. A strongly developed 

 distal fringe occurs ventrally, the ischium is a sliort joint and its dorsal margin 

 projects as a shield over the next joint for some distance ; this shield is fringed with 

 long setiE ; a row of .setae occurs along the side of the joint near its end ; a group 

 occurs about the mid-ventral region and a row occupies the more distal portion ; the 

 merus is very short if measured along its ventral margin, but dorsally it projects 

 quite to the middle of tlie propodus ; this projection bears numerous long setae ; the 

 ventral margin bears .some four or five strongly developed spines and several 

 weaker ones of irregular size. The carpus is (juite a small joint, roughly triangular 

 in shape, the distal half of its ventral margin is fringed with spines, which increa.se 

 in strength and size distally, the dorsal margin is reduced to a minimum ; the 

 propodus is stout, slightly curved, with four spines ventrally. The dactylus is 

 strongly developed, more than half the length of the propodus. 



The otlier aj)pendages are built on exactly the same plan, diftering only in the 

 strength and abundance of the spinous or setose armature, 'i'he four anterior pairs 

 conform most distinctly to this type ; in the remaining three the propodus is longer 

 and more slender and the dactylus shorter. 



The dorso-lateral fringes of .setae on the bases of the more posterior appendages 

 become very strongly developed. The sixth appendage is ty[)ical of the other extreme 

 of variation (fig. G). The basis has two dense dorso-lateral fringes of plumose setae, 

 a few arise ventrally just beyond the middle of its length, while di.stally they form a 

 dense tuft, 'i'he ischium is artictdated at tlie dor.sal angle <>f the basis ; it is rather 

 more than half its length, and tlie .so-called dorsal shield projects but very little — 

 it is .scarcely prominent — the merus is two-thirds the length of the ischium, and the 



