MAZATLAN UNIVALVES 399 



*17 by *07. It has a very broad, excavated infrasutural area, 



with a faint keel above, and one row of small tubercles below, 



shewing on the spire, and other smaller tubercular spiral lines 



beneath. 



Hob. Mazatlan ; 2 sp. off Chama and Spondylus ; IS pool Col. 



Tablet 1910 contains an imperfect operculum, which may 

 belong to a large Drillia ; of a rich, dark brown colour, rather 

 undulated, with very faint marks of growth ; inside with a 

 large, nearly smooth scar bounded by a ridge. 



Tablet 1911 contains a very small operculum of somewhat 

 concentric elements ; very thin ; not unlike that of Clavatula 

 bimarginata, figured in H. fy A. Ad. Gen. vol. i. pi. 10, f. 5a. 



GENUS CLATHCHELLA.* 



Defrancia, Millet, Ann. Soc. Linn. Par. 1826. Gray, Fig. 



Moll. An.^. 73. Phil, Handb. Conch, p. 137. H. ^ A. Ad. 



Gen. vol. i. p. 95, (ISTon Defrancia, Mull. Ind. Moll. Groenl. 



p. 12, = Bela, Leach : nee Defrancia, Bronn. 1825.) 

 Clavatula, pars, Hinds. The Lamarckian genus is restricted 



by Gray to the species which have a Purpuroid operculum. 



These shells are said to have none. 



471. CLATHUEELLA EAVA, Hinds. 



Clavatula rava, Hinds, Proc. Zool. Soc. 1843, p. 39: Voy. 



Sulph. Moll. p. 17, no. 53, pi. 5, f. 18. 

 Defrancia rana, H. fy A. Ad. Gen. i. 96. 

 ?Non Pleurotoma rava, Eve. Conch. Ic. pi. 28, sp. 250. (Isl. 



Mindanao, Philippines, Cuming.) 



Two beautiful specimens were found, exactly agreeing with 

 the accurate figure and description in the Voy. Sulph. Moll. 

 As Reeve's shell is from the Philippines, and differs in some 

 particulars from this, it is probably a distinct species. Shell 

 orange, with two purple brown bands ; one in the infrasutural 

 channel, which is ornamented with very fine undulated spiral 

 striulae ; the other continuing the suture round the base, and 

 staining the inside of the aperture. Labrum and labium armed 



* This name is proposed for a convenient group of the Mangelia tribe j the 

 name Defrancia, previously in use, being preoccupied, v. supra, p. 6. 



