OPISTHOBKANCHIATA FROM THE ABBOLHOS ISLANDS. 557 
Colour. The body-colour in the preserved state is of a pale yellowish grey, 
in two specimens with a deeper yellowish-brown narrow line around the edge 
of the notaaum and the foot. In places this line bears still darker dots. In 
a third specimen the anterior end of the sides of the body, the notseum in 
front of the rhinophores and behind the branchial aperture, and the dorsal 
region of the tail are of an umber-brown covered with dark spots. The 
largest specimen has this coloration still more strongh' developed, and the 
whole of the notjeum, bod}'-, and foot is of the same umber-brown covered with 
dark irregular spots, and the anterior region of the notseum is of a very dark 
brown, almost black. Professor Dakin informs me that the living animals 
were similarly coloured, but the brown somewhat warmer. 
Dimensions The largest (and darkest) specimen measured '24 mm. long by 
13 mm. wide and 12 mm. high, but this is somewhat distorted. Three others 
were more or less of a size, and measured 20 mm. long by 9"5 mm, wide and 
9 mm. high. 
Head. The head is small and inconspicuous ; it bears a short sub-cjdindrical 
tentacle on each side, between which the mouth apjjears as a small circular 
aperture. Each tentacle bears a longitudinal groove on its under surface. 
Foot. The foot is moderately broad and its sides fairly parallel. The 
front end is abruptly rounded and the hinder end passes off to a point. 
Rhinophores. The rhinophores have a short cylindrical stalk and sub-conical 
perfoliate clavus. They are completely retractile within cavities, whose rims 
are raised into short dark-coloured tubes. 
Branchice. The five small, dark-coloured, tripinnate, branchial plumes are 
arranged in almost a complete and very narrow circle. They are retractile 
within a cavity with a circular non-raised aperture. 
Radula. The radula when removed and flattened measured 3'5by2'5 mm. 
It is well developed and has no rachidial tooth. The number of rows is from 
27-28, and the number of teeth in a row is : —in the first row 6.0.6 (?'. e., 12) ; 
in the tenth row 42.0.42 [i.e., 84) ; and in the twentieth row 46 . . 4G 
[i. e., 92). The inner teeth are small simple hooks, somewhat angular and 
without denticles. They increase markedly in size and become simple 
curved hooks. Towards the outside they decrease noticeably, and they turn 
into short hooks only slightly curved. 
The anus lies within the circle of gills at its hinder side. 
The genital aperture lies about halfway up on the side near the anterior 
end of the body. 
Notes. This species was represented by four sjiecimens collected on 
" Wooded Island." 
Eliot (38, p. 343) described a form from New Zealand of which he says, 
" Colour dirty white with irregular mottlings of dark reddish brown. The 
epidermis peels off very readily, and it is possible that the brown mottlings 
may have been much more extensive, or even that the dorsal surface may 
