546 PKOF. C. H. ODONOGHUE : EEPOET ON 
Head. The head is fairly large and sub-globose ; the mouth is large and 
conspicuous, having the form of a longitudinal slit. On eacli side of it is an 
oral tentacle in the form of a large somewhat ear-shaped flap with a wavy 
margin. This measured 27 by 24 mm. 
Foot. The foot is well developed, strong, and muscular. Its front end is 
abruptly rounded and bilabiate, and the hinder end passes back to a blunt 
point. The sides of the foot are thrown out into a wide, folded, undulating- 
flange which, in the large preserved specimen, projected 16-17 mm. 
Rhinopliores. The rhinophores are well developed, and the sub-conical 
perfoliate clavus with 55-60 leaves is set at an angle of about 45° to the 
cylindrical stalk. The stalk is surrounded hj a tubular sheath with a 
smooth margin, and in some specimens the clavus is retractile within this. 
SranchicL'. The six branchial plumes are dendritic, very conspicuous, and 
arranged in a wide circle. Each of the anterior two pairs gives off a small 
branch i'rom the base, but the posterior pair each arise by two equally 
developed main stems coming from the same point. 
Radula. The radula is well developed and strong, and when removed 
and flattened measured 10'5 mm. along the middle line and 10 mm. at 
its widest point. The total number of rows in the radula is 47-49, and 
the number of teeth is in the first row 40 {i.e., 20.0.20), in the tenth 
row 130 {i.e., 65.0.65), and in the forty-fifth row 152 {i.e., 76.0.76). 
There is no rachidial tooth. The inner pleurals consist of a roughly 
rhomboidal basal plate with a small curved spine at the antero-median 
corner. As they pass outwards they increase in size, the base gets longer, 
and the spine increases very markedly. They reach their maximum just 
beyond the middle of the row, and then decrease in size mainly in the 
basal plate. Thus it comes that, while the inner pleurals are mostly basal 
plate with a small spine, the outermost teeth are mainly spine with a small 
basal plate. 
Labial Armature. The lips are guarded by a thin tough membrane which 
is beset with a large number of tiny hooked spines. 
The anus is not conspicuous and lies within the circle of gills towards 
the hinder end. 
The genital aperture is well marked, and situated up on the right side of 
the body behind the level of the front end of the foot. The penis is lono- 
and unarmed. 
Notes. Five specimens were in the collection : — 
A large one and a moderately lai-ge one with no localitj'-label. 
Two smaller ones from Pelsart Island. 
One of fair size from Wallaby Island. 
These specimens were obtained from the same place as Kent obtained his 
H. imperialis and are thus topotypic with it. While he gave a coloured 
drawing of the living form, with which the present specimen agrees closely. 
