ISOPODA. 55 



produced like the first externally and distally into a slender acute process, the process 

 ending in a hair-like appendage. He does not mention the articulated scale or 

 exopod. For S. fractum Chilton describes and figures the third joint as "produced 

 acutely at its antero-distal angle, bearing on the outer edge an articulated appendage, 

 which has the end rounded and supplied with a few long setse." The small fourth 

 joint, which is seen in the present species and in S. hasioelli, is not noticed or figured 

 in connexion with the other three species, as noted in the discussion of the family. 

 The fifth and sixth joints of the peduncle are elongate, the sixth slightly longer than 

 the fifth, the flagellum three times as long as the sixth joint, rather longer than the 

 whole peduncle, composed of very many little scarcely separated joints, setose. 



The upper lip is apically rounded. The two broad lobes of the lower lip have the 

 usual armature of minute spines. 



Left mandible with dentate accessory plate like the cutting edge but smaller, spine- 

 row of five serrate spines ; right mandible without accessory plate, unless it be 

 represented by the first of the five spines in the spine-row ; cutting edge with four or 

 five crowded teeth, but within the mandible the new teeth in preparation for the 

 moult are spread out in one plane ; molar long and prominent ; palp of three long 

 joints, the second carrying five short spines between two long ones, the third falciform, 

 with long spines at apex, short ones fringing the margin. 



First maxilla with three spines, a little tooth and some setules on apex of inner 

 plate, and nine more or less denticulate spines on apex of outer plate. 



Second maxilla with about four slender spines on apex of outer plate, and also on 

 that of the middle one, the rather broader and more oval inner plate carrying several 

 spines along the inner margin. 



Maxillipeds with large distally narrowed epipods reaching nearly to the apical 

 border of the broad lobes which surmount the second joint and considerably overtop 

 the fourth joint ; the third joint is short but broad, the fourth larger than the fifth, 

 both of them broad and widened distally, the sixth and seventh being abruptly much 

 narrower. 



The first gnathopods have the second joint moderately long, the three following 

 joints short, the fourth subacutely produced on the front margin ; the fifth joint is 

 setose on the hind margin ; the sixth joint is less than twice as long as its greatest 

 breadth ; the front margin is curved and carries a few setules, the hind margin 

 straight, furnished with many setse ; the palm, defined by a long spine, carries several 

 smaller pectinate spines sloping towards this palmar spine ; the finger, which curves 

 over the palm and ends in a small simple nail (broken in the specimen), has a few 

 setules on the convex margin and several microscopical spines on the concave border. 

 Chilton speaks of the palm of his species as " armed with strong serrated setse," and 

 the finger as having the "inner edge thickly fringed with strong denticulated setoe," but 

 these expressions may refer to the armature as it appears when very highly magnified. 



The second gnathopods appear to have a round-lobed first joint ; the second joint is 



