1919.] E. W. Vredenbitrg : Shells of the family Doliidœ. 179 



line; sutures sunken; ribs about as numerous as in D. variegatum, only much flatter 

 and separated by mere linear shallow grooves, without intercalary ribs. 



Doli urn per dix, Linnaeus, larger and more ovoid than Dolium chinense ; sutures not 

 appreciably sunken ; ribs quite flat and about as numerous as the primary ribs of 

 Dolium chinense, separated by linear grooves without the intercalary ribs that 

 characterise Dolium chinense. Nevertheless, the resemblance to Dolium chinense 

 becomes very close in the case of immature specimens of Dolium variegatum, which 

 are apt to be relatively much more globose than the adult. The resemblance is 

 accentuated by the fact that the intercalary ribbing is absent in the case of immature 

 specimens of Dolium chinense. Nevertheless, the immature specimens of Dolium 

 chinense are distinguished by the conformation of the terminal zone of accretions 

 which, when viewed dorsally, appears somewhat more bulging and convex, and is 

 separated from the convexity of the base by a slightly better defined concavity than 

 in the case of the immature specimens of Dolium perdix. The protoconch of Dolium 

 per dix is considerably larger than that of D. chinense. 



Tryon regards Dolium cumingii, Hanley, D. deshayesi, Reeve and D. testardi, 

 Monterosato, as varieties of D. olearium; a most unlikely interpretation, for, judging 

 from the excellent published illustrations, the absence of a circumsutural channel, the 

 shape and ornamentation of the spire, the sculpture and decoration of the body- 

 whorl, suggest a close relationship, if not specific identity, with Dolium perdix. 



2nd Division. 



Large globose shells with the ribs separated by wide intervals. 



Only one species can with certainty be ascribed to this division : this is Dolium 

 maculatum,, Lamarck. The Java fossil Dolium modjokasriense, Martin, as alread}^ 

 explained (p. 172), is perhaps identical. 



3rd Division. 



This division only includes the fossil Dolium losariense, Martin {Samml. des 

 geol. Reichs-Museums in Leiden, new series, Vol. I, p. 163, pi. xxv, figs. 377, 378), 

 distinguished from all other species by the marked posterior angulation of the body- 

 whorl. So far as can be made out its outer lip is simple. 



Subgenus Eudolium, Dall, 1889. 



(= Doliopsis, Monterosato, 1872, non Conrad). 



According to the interpretation here proposed, the subgenus Eudolium includes 



those forms in which, throughout the greater part or the whole of the life of the 



shell, the aperture is somewhat channelled posteriorly, the columella rugose, and the 



outer lip internally denticulate. 



4th Division. 



The shells of this division, which may be distinguished as the group of Dolium 

 tessellatum, include umbilicated shells in which the primary ribs are wide-spaced. In 

 Dolium tessellatum itself, the only form of this group in which the development of 



