OF THE ‘PORCUPINE’ EXPEDITIONS. 413 
ance. The second foot shows the leaf-like lobe superiorly, and a similar tuft of 
delicate bristles (stoutest inferiorly) with long spines. The inferior division has 
superiorly three or four rather stout bristles, with the distal end of the shaft enlarged 
and furnished with alternate rows of spines. The terminal process is comparatively 
small and bifid (Pl. LX XIII. fig. 12). Near the spine is a group of stronger bristles, 
the upper with, and the lower (Pl. LX XIII. fig. 15) without the spines on the shaft 
(the terminal process is bifid, and also comparatively small); then follow some slender 
forms with eight or ten spinous rows near the end of the shaft, and slender bifid tips 
(Pl. LX-XIII. fig. 14), and others more slender than the first series, with spinous rows 
on the tip of the shaft; lastly, the dense inferior tuft with slender shafts spinous at the 
distal end, and long tapering terminal processes minutely bifid. There are a few minute 
bifid papilla on the superior and inferior edges of the lower lobe, and a tuft of long 
filiform papille (often loaded with blackish pigment) below the spine. The ventral 
cirrus is of considerable size, long and tapering; it extends nearly to the tip of the 
bristles. There are some small papille on its basal process. The third foot shows a 
diminution in the length of the inferior bristles and their processes, and an increase in 
their strength. One of the upper bristles of the inferior ventral (long-tipped) series is 
represented in Pl. LX XIII. fig. 15, the bifid tip being scarcely noticeable. ‘The dorsal 
bristles are likewise shorter; and their arrangement is interesting; for they spread 
all round in a fan-shaped manner, passing on the posterior aspect between the feet, so 
that the tips appear on the ventral surface. The leaf-shaped lobe is in front, and is the 
main cause of their disposal outward and backward. As we proceed posteriorly (e.g. in 
the region of the tenth foot) the strength of the ventral bristles increases, their number 
decreases, and their terminal processes become shorter. The filiform papille are also 
more numerous. ‘The ventral cirrus presents a slight enlargement (in spirit) at its base, 
and the tip is somewhat dilated. The dorsal tuft of bristles is similar to the others, 
forming a kind of funnel open inferiorly, where the ventral lobe of the foot completes 
it, the tip of the superior lobe occurring in the pit of the funnel. One of the bristles 
from the upper part of the ventral series is represented in Pl. LX XIII. fig. 16. 
This form appears to diverge from every species hitherto mentioned ; but, owing to 
the want of precision in the published descriptions and figures, there is reason for doubt. 
In Psammolyce arenosa, Delle Chiaje, the four eyes are so closely arranged that they 
appear as a single pair, and the pinnate processes on the scales cannot be confounded 
with the tufted eminences of the present form; M. Claparéde, moreover, describes the 
bristles of the first foot as of one kind. The Psammolyce herminie, Aud. & Ed., as 
originally described by the authors, and subsequently by M. de Quatrefages, has not 
been furnished with eyes; but they notice that the scales have their external and 
posterior margin “ valde fimbriata et cristata,” or, as in the original account, supplied 
with “petites crétes membraneuses:” it shows very close resemblances. With such 
indefinite materials for forming a judgment, I have decided to place the species under 
3K2 
