NOTES ON SOME BRITISH NUDIBRANCIIS. 347 



The rudula is small and hard to find. The inner tooth (Fig. 4. a.) is 

 squarish, with three small denticles (not one, as according to Alder and 

 Hancock). The outer tooth (Fig. 4. b.) is a squarish plate with a rudi- 

 mentary denticle. 



LAMELLID0KI8 PU8ILLA. 



(Ai.DER and Hancock, Mon. Brit. Nad., Fain, i., pi. 13.) 

 This little species seems to be characterized in life by its white 



branchite and rhinophores. 



The radula is somewhat as in L. ohlonga. The inner tooth (Fig. 5.) 



lias a douljle convexity at the side, and a few ridges, which hardly 



amount to denticles, near the tip. 



PLEUROPHYLLIDIA. 

 PLEUROPHYLLIDIA LOVENl, BERGH. 



(Hergh, Biilrag til en Monogr. of Plenrophyllidienie, 1866, p. 29; Id. Mai. 

 Bluffer, 1879, pp. 77-86. Jeffrey's Brit. ConrJiol, vol. v. pp. 17-18.) 



Two specimens from Plymouth. I was informed that the animals 

 were reddish when alive. 



The larger is .'35 mm. long and 2G mm. broad, tapering rather 

 suddenly at tlie tail. The colour is dull yellowish brown, with about 

 fifty rather lighter stripes on the back, of which nine are larger than 

 the others. The branchi;e are thin, and about twenty. The side 

 lamell.e al)Out thirty, very thick, and generally interrupted in the 

 middle. 



The smaller specimen is much bent, but would be about 30 mm. long 

 if straightened out and 13 broad. The colour is pale yellowish brown, 

 with a sort of purple glazing in many places, and there are about thirty 

 stripes on the back. 



The jaws l^ear five rows of denticles in one specimen and six or 

 seven in the other. 



The formula for the radula is in the first 25 x 35.1.35, and in the 

 second 34 x 32.1.32. Tn both the median tooth bears seven denticles on 

 each side of the central cusp. The first lateral is larger than the rest, 

 and bears six or seven ratlier coarse denticles. In the larger specimen 

 the first twelve laterals are denticulate (generally with five to six 

 denticles) and the thirteenth very faintly so. The rest are smooth. In 

 the smaller specimen only eleven teeth are denticulate. 



It would appear that tiie Pleurophyllidia found on the Britisii coast 

 is this species, and not P. lincata, as it is often <lescri1)ed. Bergh also 

 appears to have shown that the correct name of the Mediterranean 

 species is P. undulnf.a, not P. lineata, and the latter specific name should 

 be cancelled. 



NEW SEKIES. — vol.. VII. NO. 3. Z 



