14 PEOCBEDINGS OF THE MALACOLOGICAL SOCIETY. 



102 rows of teeth, and one of the lateral cusps of the rhachidian is 

 split throughout the series (See III below). Another radula of 

 the same species from a specimen recently presented to the national 

 collection by Mr. A. V. Insole agrees in the arrangement of the 

 teeth, but exhibits a small denticle half way up one side of the 

 centre cusp of the rhachidian. 



Though the radula is not typically muricid, I have no hesitation 

 in forming an opinion that the true position of Columbarium is in 

 the Ehachiglossa near the Muricidce. On the evidence of shell and 

 operculum Columbarium would undoubtedly come near the ternispina 

 group. I am unable to find any trace of a pleurotomid groove in 

 the shell. Chinks exist at the base of spines such as are found 

 equally in M. ternispina and its allies. 



Pending further evidence one can only surmise that the peculiar 

 objects figured by Schacko are limbs of Crustacea or some such 

 remains associated with the body of his mollusc which was, 

 admittedly, badly preserved. They do not resemble the teeth of 

 any turrid radula known to me. 



II. Some Turrid^. 



From examination of the series in the Gwatkin collection it is 

 evident that if the radulse be considered in classification some 

 changes will have to be made in the ascription of species to genera. 

 Unfortunately, among the multitude of species, the radula. is known 

 in comparatively few. 



One of the most remarkable radulae, differing widely from the 

 other forms already known, is that of Spirotropis as figured by 

 Dr. Cooke in the Cambridge Natural History, vol. iii, p. 219, fig. 114. 

 As far as I know it has hitherto been considered peculiar to this 

 northern genus. Pending further research it is worthy of record 

 now that almost identical radulae are found in two species ascribed 

 to Drillia, viz. D. fucata (Reeve), from Mauritius, and D. persica, 

 Smith, from Karachi. No close affinity between these species and 

 Spirotropis would be deduced from shell characters. 



III. Abnormal Radula. 



Any malformation or want of symmetry in a radula is displayed 

 throughout its whole length and evidently depends on some peculiar 

 condition obtaining in the radula sac. This is well shown in simple 

 radulas such as those of Marginellidce, where the single tooth often 

 has more cusps on one side than on the other as well as small 

 subsidiary cusps adjoining the others here and there. Examples of 

 a malformation and of a subsidiary cusp have been given above in 

 the radulse of Columbarium. 



A most surprising asymmetry is shown in the radula of a specimen 

 of Cyprma caput- serpentis, L., here figured from the Grwatkin 

 collection. Compared with a normal specimen the following 

 peculiarities are found (Fig. 2, a and b) : — 



