352 



THETIS SCIENTIFIC RESULTS. 



Family MATHILDIID^. 



MATHILDA, Semper. 



MATHILDA DECORATA, sp. nov. 



(Fig. 75.) 



Station 49. 



Shell small, broad, turretted. Colour pale brown. Whorls 

 four and a half besides tlie protoconch. 

 Sculpture : a few fine spiral threads orna- 

 ment the otherwise smooth base, which is 

 bounded by a double smooth cord. On the 

 periphery are two projecting keels which 

 mount the spire ; above these are two minor 

 cords, and the suture is bordered by another 

 but plain cord. About twenty- five radial 

 riblets arise outside the basal border and 

 mount perpendicularly to the summit of the 

 shell ; they produce a bead at each point of 

 intersection with the four spirals and cut 

 their interstices into square meshes. The 

 protoconch is large, of more than one whorl, 

 and is set on edge at one side of the summit. 

 Aperture subquadrate, outer lip simple, 

 dentate by the sculpture. Columella ex- 

 panding anteriorlj', meeting the lip at an angle. Behind it is an 

 umbilical chink. Length, 4-25 mm. ; breadth, 2 mm. 



This species is closer to the type of the genus than other Aus- 

 tralian species which have been referred to Mathilda. The apex 

 suggests to me a relationship with Solarium. 



The " Thetis " took one specimen (the type) in 63 to 75 fathoms 

 off Port Kembla. Others were procured by Mr. G. H. HalHgan 

 and myself in 100 fathoms, sixteen miles east of Wollongong. 

 Mr. Halligan has lately taken a larger specimen than here de- 

 scribed in 111 fathoms, twelve and a half miles east of Cape 

 Byron. 



Fig. 75. 



Family LITIOPIDJE. 



D I A L A, A. Adams. 



DIAL A MONILE, A. Adams, sp. 

 Alahamonile, A. Adams, Ann. Mag. Nat. Hist., (3), x., 18G2,p.29C. 



