PYCNOGONIDA. 37 



The body is very slender, quite smooth, with very widely separated long lateral 

 processes. Anteriorly it is slightly curved downwards. 



The Cephalon is long and slender, longer than the second and third segments, and 

 expanded di.stally into two dorsal lobes for the articulation of the chelifori. 



The Ocular tubercle lies immediately in front of the first pair of lateral processes. 

 It is short, merely a low rounded hump, in fact, bearing four well-developed eyes. 



The Abdomen is very small, directed upwards, and not separated from the trunk 

 by an articulation. It is rather conical and extends but little beyond the trunk, not 

 nearly so far as the posterior lateral processes. 



The segmentation of the trunk is distinct, the joints occurring immediately behind 

 the lateral processes. 



The Proboscis is directed downwards, cylindrical, with a slight swelling about 

 the middle of its length ; it is as long as the cephalon, and its extremity is rounded. 



The Chelifori arise above the proboscis, each on a lobe of the cephalon, which is 

 here rather more than twice its diameter posteriorly. The scape is single-jointed, 

 longer than either the proboscis or the chela. A few delicate setae are scattered along 

 its length, and there is an inconspicuous distal fringe. The chela is a little shorter, 

 the palm and dactyli occupying equal halves ; the former is covered with fine setae 

 which also form a fringe round the base of the movable finger. The fingers are slender 

 and much curved near the tips. Both are provided with a row of fairly stout teeth of 

 nearly uniform size, rather closely set. 



The Palps arise below the chelifori and at the sides of the proboscis ; they are 

 built on exactly the same plan as in the genus Nymphon (fig. la). The first joint 

 is small and stout, the proportions of the remainder being 8:5:3:4. The second 

 joint is sparingly setose except for a distal fringe ; the other joints become more 

 and more setose to the last, which is richly supplied. On the outer side they are more 

 abundant than elsewhere. 



The Ovigers are ten-jointed and present in both sexes. (Fig. 1 b. ) They arise 

 from very short but conspicuous processes on the lower side of the cephalou, 

 immediately in front of the first pair- of lateral processes. The details of this 

 appendage are as in Nymphon. The first joint is very small, the second is twice the 

 size, and the third, which has a very oblique termination, is a little longer still ; none 

 of these bear setae. The fourth joint is very long, slender, and slightly curved ; it 

 carries a glandular aperture on its outer side about a quarter of its length ; all the 

 setae are small ; very few occur except as a distal fringe. The fifth joint is longer still, 

 the longest of the appendage, and its distal half is enlarged in diameter ; it is covered 

 throughout with fine setse. The sixth joint is rfither more than half the length of 

 the fifth, slightly curved, and on the outer side of the curve plentifully supplied 

 with fine sette. Of the four terminal joints the first is little more than half the 

 length of the preceding, the other three are shorter and sub-equal ; very few setae 

 occur, except distally. They carry a single row of denticulate spines (fig. !(). These 



