100 LIVERPOOL BIOLOGICAL SOCIETY. 
Family. PoLYcERIDE. 
Goniodoris nodosa, Montagu. 
In April, 1888, Dr. Hanitsch collected half-a-dozen 
specimens on the South Spit, at Puffin Island. 
We find that there may be a second smaller denticulated 
ridge on the large lateral spines of the radula in this 
species. 
Polycera ocellata, Ald. and Hance. 
We have found this species on both the North and 
South Spits, at Puffin Island, near low water mark, on 
11th June, 1887, on 24th March, 1888, and on 25th May, 
1889. Some of the specimens closely approach Polycera | 
lessont in their characters. 
Ancula cristata, Alder. 
A specimen of this species was found at Hilbre Island, 
on 2nd March, 1889, which was entirely of a hyaline 
transparent white colour, without any yellow markings on 
the dorsal papille, and with no opaque white pigment 
on any part of the body. On the 16th May, 1889, this 
species was very abundant at Hilbre Island, and was 
spawning. Thirty specimens were collected, and about 
twenty-five specimens were counted on an area of rock 
about one foot square. 
Sub-Order. POLYBRANCHIATA. 
Family. TRITONIIDZ. 
Tritonia plebera, Johnst. 
Two specimens found at Hilbre Island, on 2nd April, 
1889, differed considerably in their colouring, the one being 
yellowish brown, as figured by Alder and Hancock, while 
the other was marked with blues and greys. 
We have found this species on the Beacon rocks, Puftin 
