NOTES. 187 



five simply pinnate branchiae. As early as 1844 Philippi (Enum. Moll. 

 Siciliee, vol. ii, p. 78) pointed out that this is probably an error, but if it 

 be correct, the animal is neither D. planata nor D. argo. 



It is, of course, possible that D. testudinaria may be rediscovered in the 

 Mediterranean and prove to be a Geitodoris, in which case its identity 

 with the British form is highly probable. C. N. E. Eliot. 



Note on Oliva tigeidella, Duclos. {Read llth JVovemier, 1904.) — 

 This species was figured, but not described, by Duclos in his monograph 

 of the genus (Hist. nat. Coquilles, Oliva, pi. viii, figs. 13-16). Figs. 13, 15, 

 and 16 have been reproduced by Tryon (Man. Conch., vol. v, pi. xxxiii, 

 figs. 28, 29, 42). 



It has been hitherto considered by Eeeve, Weinkauff", Tryon, etc., 

 a variety of Oliva ispidida, Lamarck, but if a careful comparison be 

 made it will be seen that the two forms are very distinct. Oliva ispidula 

 is more cylindrical, in length nearly 2| times its breadth, and as a rule 

 much larger than 0. tigridella, which is more fusiform and quite different 

 in its proportions. It is also to be observed that in 0. ispidula the 

 markings often take the form of transverse bands, whilst if any lines 

 are observable in 0. tigridella they are invariably longitudinal. Many 

 specimens of 0. ispidula have a single band round the upper part of the 

 body- whorl. 



0. tigridella more nearly resembles 0. Duclosi, Reeve (jaspidea, Duclos), 

 than any other species, both in size and form, whereas 0. ispidula is most 

 like 0. litterata. Lam., in form, although different in size. 



It may thus be characterised : — Shell fusiform-cylindrical ; length 

 usually slightly less than 1 inch, width rather less than half the length, 

 being greatest near the shoulder, and gradually narrowing towards the 

 base ; spire about \ of the entire length ; columellar plicte rather fine 

 and numerous in young specimens ; colour and markings very variable ; 

 ground-colour generally yellow or yellowish-brown or red ; markings, when 

 forming lines, taking a longitudinal direction, but generally irregularly 

 spotted or blotched. Aperture dusky. F. G. Bridgman. 



Note on Oliva obtza, Lamaeck. (Read I2th January, 1905.) — 

 This very common species has not, I think, been satisfactorily determined 

 by Duclos, Reeve, or Marrat in their monographs. The commonest foi-m, 

 which is probably that originally described by Lamarck, is uniformly 

 white. It is so abundant that it is used by the natives of the West Indies 

 in the manufacture of shell-baskets, etc. This plain white variety has 

 been figured neither in Duclos' nor Reeve's monograph, but a figure of 

 it is given by Marrat (Thesaurus Conch., pi. xxii, fig. 391). This figure, 

 however, hardly illustrates what I regard as the typical form, which is 

 more correctly represented by fig. 387 on the same plate. An orange- 

 tipped specimen is figured in Reeve's monograph (pi. xxvii, fig. 816), with 

 the remark that " the colouring of the apex seems to be a characteristic 

 feature in this species." Duclos (pi. i, fig. 10) figures a somewhat similar 

 shell, but this is more pink than orange at the apex. I believe these are 

 all varieties of the same species. F. G. Bridgman. 



Note on some Holocene Non-Marine Mollusca from Walton 

 Heath, Surrey. {Read \^th January, 1905.) — At Walton Heath, which 

 lies just to the north of Reigate, there is a chalk quarry showing several 

 ' pipes ' in section. Pipes in the Chalk are genei'ally barren, but three of 

 these contained some non-marine mollusca, which are referable to the 

 following species : — 



