524 Wisconsin Academy of Sciences, Arts, and Letters, 
The dorsal antenna is on the posterior portion of the head seg¬ 
ment, just in front of the transverse neck fold; the distance from 
the neck to the lateral antennae is about two thirds of the length of 
the abdomen. 
The mastax is of a modified virgate type, in which the pumping 
action has become subordinate and the trophi adapted to the 
seizure of prey by prehension. The fulcrum is very short and 
broad. The rami are elongate, roughly triangular and strongly 
curved longitudinally; near the base there is a very large apophysis, 
projecting as a double spur towards the ventral side. The inner 
edges of the rami have near mid-length a blunt tooth, interlocking 
with its mate on the opposite side; immediately in front of this 
tooth there are some faint denticulations, and nearer the base a 
strong transverse rib forms a slightly projecting knob. The poste¬ 
rior half of the rami are armed with about twenty small, conical 
teeth, separated by relatively large interspaces. The unci have a 
single, very robust, clubshaped ventral tooth, which is connected 
to the upper end of the manubrium by an excessively thin lamella 
of irregular outline. The central section of the manubrium is 
nearly parallel-sided and slightly curved; the basal plate is tri¬ 
angular. The epipharynx consists of two symmetrical, roughly 
li-shaped pieces, imbedded in the walls of the mastax; the shorter 
branch is directed diagonally outwards and towards the ventral 
side; the longer, broadly expanded posteriorly, is nearly parallel 
to the longitudinal axis of the mastax. 
The epipharynx has been turned through an angle of approxi¬ 
mately 90 degrees in figure 5, to avoid obscuring the form of the 
rami; it is consequently somewhat foreshortened, and its true 
length is shown in figure 4. The right lobe of the mastax is con¬ 
siderably larger than the left; this condition usually indicates the 
presence of a salivary gland, but there are no structural re¬ 
mains of it. 
The oesophagus is relatively short. The gastric glands are 
very large and rounded. There is no constriction between the 
stomach and intestine. The nuclei of the ovary are unusually 
large and irregular in outline; they appear to have separate yolk- 
masses. The bladder is normal. The foot glands are nearly cylin- 
dric and as long as the foot itself; they discharge into a minute, 
spherical mucus reservoir at the base of the toes. 
The ganglion is large and saccate. The retrocerebral organ con¬ 
sists of a small, vacuolate sac and two very small subcerebral 
