PYCNOGONIDA. 
41 
Leionymphon grande. 
(Plate VI., fig. 1.) 
Ammothea, grandis, Pfeffer (24), p. 43. 
Ammothea charcoti , Bouvier (2), p. 295. 
Specific characters :— 
Body robust, with three prominent transverse ridges dorsally and ventrally. 
Proboscis cylindrical, very little longer than the body. 
Palp 9-jointed, the last joint a little longer than any of the four preceding ones. 
Oviger 10-jointed, without a terminal claw, the last four joints with simple curved spines, which 
increase in size to the extremity of the last joint. 
The body is stout, and with the abdomen, scarcely as long as the proboscis, 
being just less than 15mm. Its width across the second pair of lateral processes is 
10mm. Its segmentation is complete, but concealed by a very strongly developed 
pyramidal ridge which lies along the posterior margin of the three anterior segments, 
and the apex of which is raised considerably above the body level. These ridges have 
a very slight curvature forwards, which is most marked in the first. The lateral 
processes are not widely separated, the two anterior pairs are directed forwards, the 
first more than the other, and are quite close together ; the third pair is directed 
backwards slightly with a wider interval between it and the preceding pair; the last 
pair is directed backwards at such an angle as to make the interval between the third 
and fourth pair very conspicuous. All have a swelling at the distal extremity, and 
this swelling gives the process an angular appearance. 
The Cephalon is short, expanded anteriorly, and at the base of the chelifori presents 
the same angular appearance as the lateral processes. A slight median groove divides 
its anterior margin. 
The Ocular tubercle lies in the middle ; it is stout, with a very slight curvature, 
rounded at the apex, and bearing four well-developed eyes. 
The Abdomen rises from the extremity of the trunk, but without trace of 
segmentation ; it is rather stout, slightly curved, and directed upwards. There is a 
median tubercle between the posterior transverse ridge and the abdomen. Dorsally 
the entire body is rendered scabrous by the presence of small spinous setae; between 
the body ridges however they are scarce. Ventrally the three transverse ridges of the 
dorsum are represented by three similar ridges, thinner and not produced to such a 
conspicuous point; all are directed backwards to a varying degree, the first more so 
than the others. These ridges are continued on to the base of the lateral processes, 
which here do not present any trace of the angular enlargements so conspicuous 
dorsally. The spinous setae of the dorsum are not present. 
The Proboscis is stout and cylindrical, only a trifle longer than the body and 
abdomen together. It is articulated to the body, and movable through a very 
considerable angle. The mouth is large and triangular. The distal extremity of the 
organ is deeply pigmented ; for nearly three-quarters of its length it displays six 
r 2 
