PYCNOGONIDA. 49 
distinguished by the fact that in that species the abdomen is directed almost 
vertically upwards, and is situated so far forward that the posterior trunk segment 
passes over its base, a feature of, possibly, some morphological importance. 
LEIONYMPHON SPINOSUM. 
(Plate VIL, fig. 2.) 
Specific characters :— 
Body stoutly built, with the transverse ridges not very strongly developed, but with a very 
prominent spur in the mid-dorsal line. The lateral processes are rather widely separated, and bear 
distally two stout recurved spurs ; smaller ones exist on the first coxa, 
Proboscis short, not half the length of the trunk. bs 
Palps 9-jointed ; of the five terminals the seventh and ninth are a little longer than tke others. 
Oviger 10-jointed, special spines not denticulate. 
The entire animal is heavily built, and covered with fine but short sete. The 
lateral processes are rather widely separated, the intervals increasing posteriorly, two 
pairs of processes are directed more or less forward, the other two pairs backward. 
Each process bears dorsally at its distal extremity a pair of prominent recurved 
tubercular processes ; these are also distinct, though less prominent, on the first coxe. 
The body is crossed transversely by three ridges, but these do not extend on to the 
lateral processes as much as in the allied species. These ridges stand erect, but they 
are bevelled from behind in the middle line so as to form an acute point of some 
considerable elevation, and this gives them the appearance of being arched forward. 
The Cephalon is not very much expanded, and almost fills the interval between the 
first pair of lateral processes ; in front it bears a pair of tubercular processes directed 
outwards, one at the base of each of the chelifori. 
The Ocular tubercle is just behind the centre of the cephalon and is very stout, taller 
than any of the transverse ridges, and terminates in a cone above four well-developed eyes. 
The Abdomen is not separated from the body by an articulation ; it is of normal 
proportions, elongate, ovate and directed slightly upwards. 
The entire body is covered with short, fine sete, but they appear to be deficient 
between the ridges, and to some extent on the cephalon. Ventrally the transverse 
ridges are rounded, and the median spur much less prominent than dorsally ; the sete 
also are deficient. The length of the body is 13 mm., and its extreme width is 8 mm. 
The Proboscis is short and stout, being barely 5 mm in length, cylindrical, shghtly 
swollen in the middle, and movably articulated to the body. 
The Chelifori are rudimentary, they lie close together above the proboscis and are 
more than half its length. The scape is half the length of the proboscis, very slightly 
enlarged distally and clothed with short sete; the chele are only knobs, also setose, 
and with but vestiges of the fingers. 
The Palps rise laterally below the chelifori and comprise nine joints (fig. 2a). The 
first joint is short and stout, the proportions of the various joints being: 1°5:4:1:3° : 
1:1:1°3:1:1°5. The entire appendage is covered with fine setae which become numerous 
on the fourth joint; on the four following joints they form a dense patch covering the 
H 
