35 



narrow in the upper part, somewhat broader below, with a feeble fold on the 

 columella. — Thef^e characters coincide with those which S. Wood gives for hi;< 

 Bulla Liijoidvaircaiia Busterot iCi-ac; Moll. I, p. 178, pi. 21, f. 5), rectius Bulla 

 mammillata Philipp!. Knnm. Mull. Sic. v. 1. p. 22-2. pi. 7. f. 20, and Wcinkautf, 

 Conch, d. Mittelm. vol. 2, p. 201, Forbes and Hanley, pi. 114 C, f. 4 and 5, so 

 that I regret very much not to have any specimens, living or fossil, at hand. 

 The size — }■ of an inch in the Crag specimens and 4 millim in those of Oji, with 

 2 in diameter — agrees also. The only ditference is the surplus of diameter which 

 is to be seen in the upper part of B. mammillata (or Lajoukaireanal, and of which 

 the specimens of Oji do not show any trace. From Wood's remarks, however, 

 it appears that this character is not quite constant and Fnvbes and Hanley s 

 figure represents another deviation from the cyliulrical form, namely a rcdiution 

 of the diameter in the middle of the shell. If all these characters were lealiy 

 variable, there would be no reason whatever to separate these 2 species. 



Bulla (l-'ylichna ) cyl inJracea Pennant. 



(Brit. Zool. vol. IV, pi. 70, f 8'). S. Wood. Crag Moll. I. p. 17.".. pi. 22. 

 f 1.— Forbes and Hanley brit. :Mo11. pi. 114 B, f il.— JelVreys, biit. 

 Conch. V. 4. p. 4l.'t. WeinkautT, Conch d. mittelmeeres. v. 2. p. l'.)4l. 



Tlie cylindrical fmn and the perfectly hidden spire together with the 

 dimensions and proportions (10 mm. of axis, 3.5 of diameter) show that the few 

 bulUe foTUid at Oji belong to B. cylin.lracea. As to Bulla pamllcla (iould, Otia 

 Conch, p. 98, moll, of Wilke's e.\pl. E.^ped. pi. 1j, f 2';7, it is e.\cluded f>y its 

 transverse stria; on both ends of the shell wiiich are totally wantmg iii the Oji 

 specimens. 



SOLENOCONCH.'R. 



Dentalium octogonum Lamarck. 



(Hist. nat. d. anim. s. vest. 2d. el. vol. V. 3, p. 701 ,— Sowerljy, Thes. 



Conch, vol. V. p. 102, pi. 223, f. 9.— Lischkc, Jaj.. J[cercs-Conch vol. 

 2, p. 103, vol 3, p. 75, pi. 5, f. 1-3.). 



The octagonal outline of the cross-section divides this species sharply from 

 the following one, even from its ribbed varieties. I omit to discuss the question 

 whether D. liexagonum Go>dd, Otia conch, p. 119, Sow. 1. c f. 10, Bischke Vol. 

 3, p. 174, pi. 5, f 4-7, is really a good species, though I thitdc this \^ not the 

 case. The few specimens found at Oji all belong to the typical octagonal form. 



Dentalium fntale Lium'. 

 (Syst. Nat. p. 12G3.-Philippi, En. Moll. Sic. Vol. H. p. 20C.-S. Wood, 

 Cras? >roll. I. p. 189, pi. 20, f. 2. and Suppl. p. f^2. pi. C. f. 20. add. pi. f. 

 12.— l-'nrlvs and Hanley. brit. :Mo11, Vol. 2. p 451. jil. 67, f 12.— Syn. 

 1>. Tarentinnm Lamarck, anim. s. vert, vol. V. p. 345, WeinkanfT, Conch, 

 d. Mittelm. v. 2, p. 41»;: Jeffreys, brit. Conch, v. 3, p. 195.). 



