52 



NOTES. 



hiWAAA 



rmMi 



Variations in Radulae. — It would be interesting to know what 

 variations have been observed in the radulae of mollusca, for in some of 

 the common species considerable modifications of the formula recognised as 

 typical have been noted. Ttie normal radula in 

 Buccinum itndafinii appears to have loo rows of teeth, 

 each row consisting of a median tooth or plate with 

 six pointed cusps between two laterals, each forming a 

 set of four slightly-hooised cusps, as represented in 

 FiGDRF A. Bcwof teeth Fig. A. Recently I have observed two variations in 

 Irom radula of «(«■<■/ "«m specimens I have mounted for the microscope. In one 

 unilatum (Rhachiglossate- '^ . .. •-, i i ■ i -r „» j\ 



type—formula i-i^i). case there are six median spikes (one being bifurcated), 



with four on the laterals of one side and five on 

 that of the other, as seen in Fig. B. In the other example there are six 

 lateral (one being bifurcated) on one side and four on the other, as in Fig. C. 

 The mollusca from which these radulae were dissected were obtained in the 

 Central Fish Market, London, so that I cannot 

 indicate the locality from which they w-ere dredged. 

 Mr. Wilfred Mark Webb has, however, within 

 the last few days, sent me an account of 22 radulae 

 of B. uiidatuiii taken at random from Brightlingsea, 

 and which show very great variation. Only eight 

 of these are normal. One example has four median 

 cusps between two sets of four lateral ones Five 

 specimens have five median between two sets of 

 four lateral projections ; and of these two examples have the second lateral cusp 

 from the outside on the left hand small and adnate to the third lateral from 

 the outside. Two specimens ha\e six points to the 

 median between four on the left hand lateral and 

 three on the right. Four specimens have a median 

 tooth showing seven points, while the lateral teeth 

 are normal. One specimen resembles the last, 

 but has an extra cusp to the median tooth ; and 

 .latum. Row of teeth from lastly, one has the cusps on the median tooth 

 radula. The right lateral plate increased to eight, while those of the lateral 

 has three complete cusps, one plates are reduced to three, 

 being bifurcated. 



George Bailey, F.R.M.S. 



FicritK B. /iini-iiiinii mi- 

 (hilKin. Row of teeth with a 

 bifurcated cusp to the middle 

 plate. 



EDITORS' NOTES. 



We thank " The Journ.al of Conchologv " for its kindly notice of our 

 previous Number, and express the hope that its new Editor and Committee of 

 I'ublication may attain to that success which it so generously wishes us. 



Corrigendum. — In Figure i on Plate I., the coil of the- intestine should 

 be on the left side of the stomach, that is, in front of, and not behind the 

 latter, as there depicted, 



