378 Mr. F. W. Gamble on 
Paludestrina ventrosa. 
Radula measuring 60x16 w and having 40-45 rows of 
seven teeth each. 
Median (or rachidian) tooth (2°5 w in width) bears 7 cusps, 
of which the central one equals in length half the width of 
the crest of the tooth. Basal denticles one on each side, 
inconspicuous. ‘The crest of the tooth viewed in its position 
in the radula is markedly concave. 
Admedian tooth bears 9 cusps inclined inwards towards 
the median line of the whole radula; base prolonged outwards 
ina shank which reaches almost to the margin of the radula 
and which terminates in a thickened knob-like end. 
Laterals long, slender, and curved, with numerous small 
cusps, which in the outer one are difficult to resolve. ‘The 
inner lateral is more sharply curved at the point where the 
cusps cease; in the outer one the curve is far more symme- 
trical throughout. 
2) 
Formula : M12. 
a eee 
Paludestrina Jenkinst. 
Radula measuring 86-93 x 20 w and having 60-70 rows of 
seven teeth each. 
Median tooth bearing 9, or sometimes even 11, cusps, of 
which the central one is about one third the width of the 
crest. ‘This last is less concave in outline than in P. ventrosa. 
Basal denticles four on either side, very conspicuous. 
Admedian tooth bearing 9-11 cusps, inclined inwards, but 
slightly less so than in the preceding species ; in other respects 
it 1s very similar. 
Laterals long and slender, nearly straight in the shank, and 
sharply curved at the free end. Cusps numerous and easily 
visible. 
M 2 
Formula: Sots + 
LVII.— Observations on two rare British Nudibranchs 
(Lomanotus genei, Verany, and Hancockia eudactylota, 
Gosse). By F. W.GaAmBLE, B.Sc., Assistant to the Beyer 
Professor of Zoology, Owens College, Manchester. 
[Plate XVII.] 
WHILE working last summer at the Plymouth Laboratory of 
the Marine Biological Association I obtained a single speci- 
men of each of these species during successive weeks from 
