PYCNOGONIDA. 



tubercle, a structure which varies considerably in shape and size. As a rule it is rather 

 stout, and bears four well-developed eyes, with a variable amount of pigment. It is 

 slightly flattened antero-posteriorly, and more or less rounded at the extremity. The 

 cephalon and the lateral processes are provided with several long setae, the latter also 

 having a distal fringe. 



The Abdomen is of moderate dimensions, pyriform, and rather thickly setose, not 

 separable from the trunk by an articulation. 



The Proboscis is cylindrical, slightly enlarged about its middle. It is directed 

 downwards, and movably articulated to the trunk. No setge are apparent on its 

 surface. 



The length of the entire body is 8mm. ; of the body only, Grnm. ; of the trunk, to 

 the insertion of the abdomen, 4 5mrn. Its width is 3mm. 



The Chelifori are well developed ; the scape is a single joint longer than the 

 proboscis, liberally provided with long setae of irregular size, and also having a well- 

 marked distal fringe. The chelae are slender, about as long as the scape. The palm 

 occupies half the length of the entire chela, and is covered with comparatively long 

 setae, which are continued far on to the immovable finger. The fingers are slender and 

 much incurved at the tips ; they are provided with a large number of closely set teeth 

 of irregular length. 



The Palps are slender and five-jointed. The first joint is quite small, the second 

 is the largest of all, and rather sparingly provided with setae, which are longest on 

 its outer side ; the third joint is a little shorter, slightly enlarged distally, the setae 

 being more numerous and more uniform than on the preceding joint. Of the two 

 terminal joints the distal one is a little the shorter, but together they exceed the 

 length of the second by a trifle. These two joints are richly setose, particularly on 

 one side. 



The Oviger is ten-jointed ; in the female the first three joints are very small, but 

 progressively increase in length. The fourth and fifth are subequal and much the 

 longer of the whole series, and slightly curved in opposite directions. The sixth joint 

 is about three-quarters the length of the fifth. Of the four terminal joints the first 

 three progressively shorten, the terminal one being a trifle longer than the preceding, 

 and it bears a long slender pectinate claw with eight teeth. The first four joints bear 

 scarcely any setae, except an inconspicuous distal fringe ; on the fifth the setae are 

 noticeable on its outer border, and those of the distal fringe are rather long and 

 slender. In this particular the sixth joint is similar. The four terminal joints are 

 all provided with a distal fringe and a number of long setae. The denticulate spines 

 are arranged as usual in a single row, and, counting the joints from the base of the 

 appendage, they bear respectively 9 : 7 : 5 : 7 of these spines (Plate X, fig. 15). These 

 numbers are not, however, rigidly adhered to. The spines consist of flattened shafts of 

 a slightly sinuous form, bearing four well-developed teeth on each side, with traces of a 

 fifth in large and uninjured specimens. The third tooth from the base is usually the 



Q 2 



