378 m. F. W. Gamble on 



Paludestrina ventrosa. 



Radula measuring G0x1G/a and having A()-^6 rows of 

 seven teeth each. 



Median (or rachidian) tooth (2*5 /x in width) bears 7 cusps, 

 of which the central one equals in length half the width of 

 tlie crest of the tooth. Basal denticles one on each side, 

 incon8})icuous. The crest of the tooth viewed in its position 

 in tlic radula is markedly concave. 



Admedian tooth bears 9 cusps inclined inwards towards 

 the median line of the whole radula ; base prolonged outwards 

 in a 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 tlie 

 cusps cease ; in the outer one the curve is far more symme- 

 trical throughout. 



Formula: y + ^ + v 



Paludestrina Jenhinsi. 



Radula measuring 86-93 x 20 /a and having 60-70 rows of 

 seven teeth each. 



Median tootli 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 consi)icuous. 



Admedian tooth bearing 9-11 cusps, inclined inwards, but 

 slightly less so than in the ])receding species ; in other respects 

 it is very similar. 



Laterals long and slender, nearly straight in tlie shank, and 

 sharply curved at the free end. Cusps numerous and easily 

 visible. 



Formula: ^^+^^^^1 



LVII. — Ohservations on two rare Tiritish Xudihranchs 

 (Lomanotus genei, Veranijy and Ilancockia eudactylota, 

 Gosse). By F. W. Gamble, B.Sc, Assistant to the Jioyer 

 Professor of Zoology, Owens College, Manchester. 



[riato XVIT.J 



While working last summer at the riymouth Laboratory of 

 tlie JMarinc Bitdogical Association I obtained a single speci- 

 men of each of these species during successive weeks from 



