59 MR. A. HANCOCK AND THE REV. A. M. NORMAN 
very point where analogy with S. brevipes would lead us to expect such a division. We 
should therefore perhaps be wrong to describe the cephalothorax as consisting of one 
segment only. 
The first antenne (Pl. XV. fig. 3 a), which are minute and concealed beneath the head, 
are three- or four-jointed. The basal and largest joint is furnished with three, and the 
second joint with one or two, stout spines on the inner margin. The second antenn:e 
(P1. XV. fig. 3 b) are comparatively large. They consist of a large, fleshy basal joint anda 
tapering, hook-formed second joint. The stout hook is bent inwards, and has on its outer 
margin two spines, that nearest to the extremity being the longer; at the base of the 
hook there is also a stout process, terminating in a short spine. The mouth lies between 
the second antennz, and is provided with a largely developed subtriangular labrum. 
'The rounded apex of the triangle (Pl. XV. fig. 3 c) is situated between the roots of the 
second antenne, while the base overhangs the oral orifice, and to a considerable extent 
conceals the underlying mandibles with its produced and rounded angles. The man- 
dibles (Pl. XV. fig. 3 d, and Pl. XVI. fig. 8) are small, and placed close to the sides of the 
mouth; the basal portion is soft and flexible, and, tapering a little, gives support to a 
flattened chitinous process, which is a little enlarged, obtuse, and recurved at the ex- 
tremity, and bears three or four denticles. The maxille (Pl. XV. fig. 3 e), which are so 
minute as to be quite rudimentary, lie immediately behind and within the mandibles, in 
the form of ovate fleshy processes, bearing, though it could not always be seen, an 
exceedingly delicate styliform organ, slightly curved, and inclining inwards and forwards. 
The first pair of foot-jaws (Pl. XV. fig.3 f, and Pl. XVI. fig. 9) are of about the same 
size as the mandibles. They project inwards and forwards, are soft and flexible at the 
base, which, after slightly tapering, is surmounted by a styliform process, a little curved 
at the point, and, as seen in some positions, appearing a little denticulated; but whether 
this was really the case could not be satisfactorily determined. The second pair of foot- 
jaws (Pl. XV. fig. 3 g) are very peculiar in character, and difficult to observe. They are 
small, like most of the other oral organs. At first they are considerably attenuated, but, 
passing inwards and forwards, they suddenly enlarge; their inner margins come into 
contact with each other, and are thus projected side by side between the first foot-jaws 
and maxille, until they almost reach the labrum. The extremity of each appears to be 
furnished with a curved process; but its exact form could not be ascertained. 
There are two pairs of thoracic feet (Pl. XV. figs. 1 a, 5, & 6). "These feet are of 
similar structure to each other. "Those of each pair are widely separated. "They are 
composed of three or four indistinct articulations, which gradually taper, the last joint 
being very slender and terminating in a delicate hook. The basal joint is stout and 
thick, and gives off from its inner margin a short, obtuse process (a, figs. 5 & 6), which 
represents the usual second branch or member of these feet ; and the second or third is 
furnished with three or four minute spines. 
The abdomen (Pl. XV. fig. 16) is composed of two articulations, the first of which 
(fig. 2 b), or genital segment, is somewhat flask-shaped, considerably narrower than the 
posterior extremity of the cephalothorax in front, but widening behind and produced 
into two blunt lobes on each side of the origin of the second abdominal segment. This 
