ERYONICUS C^CUS. 113 



gnath is represented by a small rounded lobe on the outer side of the base of 

 the anterior lobe of the protognath. The scaphognath is very large, broadly 

 rounded posteriorly, while the anterior portion is much narrower. 



The first maxillipeds (Plate XXIX., Fig. 2^^) display a large triangular 

 protognathal lobe, setiferous along its free margin. The endopod is slender, 

 divided into two segments, and lies along the inner edge of the exopod. 

 The exopod is of a peculiar shape, broad, and divided at the distal end 

 into two lobes. The epipod is long and broad, and terminates anteriorly in 

 a rounded lobe outside the base of the exopod. 



The second maxillipeds (Plate XXIX., Fig. 2'') are very short, scarcely 

 reaching beyond the ischia of the third maxillipeds. They consist of a 

 single series of six segments, being wholly without exopodal or epipodal 

 branches. The first, second, and third segments are short, setigerous on 

 their inner margins ; the second segment is also provided with small teeth 

 on the inner margin. The fourth segment is by far the longest of the whole 

 series ; it is very broad, too, much broader in the middle than at either end. 

 The terminal segment is tipped with a slender spine, and, like the antecedent 

 segment, is furnished with many long sette. 



The third maxillipeds (Plate XXIX., Fig. 2*') are much longer than the 

 second, reaching forward to the base of the antennae. They consist of a 

 series of seven segments, the first of which bears a very small epipod (a). 

 There appears to be a slight vestige of the exopod, in the shape of a 

 rounded tubercle on the outer side of the second segment. This tubercle 

 is too slender and acute in the figure. 



The great chelipeds are similar in form and proportions to those of other 

 recent Eryontldcn ; there are a few obsolescent spinules along the inner mar- 

 gin of the merus, and a procurved spine near the distal end of the outer 

 margin of the same joint; the carpus is long, and is armed with a spine near 

 the distal end of the external margin, and with another at the distal end of 

 the internal margin ; a spine at the distal end of the superior margin of the 

 hand, distal half of the inferior margin of the hand obsoletely spinulose, 

 fingers long and very slender, strongly incurved through their distal third, 

 their tips very acute, and probably abruptly crossed (they are imperfect in 

 the specimen in hand), prehensile edges microscopically pectinated. 



The succeeding four pairs of thoracic appendages diminish successively in 

 length and breadth. The first are rather stout, and end in a strong and per- 

 fect chela; the merus is armed with a pair of sharp spines beyond the middle, 



