512 MOLLUSCA OF MAST HEAD REEF, QUEENSLAND, II., 



Cylichna doliaria, n.sp. 

 (Plate xviii., fig.39.) 



Shell small, solid, cask-shaped, perforate at either end. 

 Colour milk-white zoned with alternate opaque and semitrans- 

 parent, spiral bands. Sculpture : nineteen sharp, narrow, deep, 

 spiral grooves are interposed between broad flat-topped ribs. 

 Under a high magnification the ribs are seen to be set with fine 

 lonc^itudinal grains, whose ends undulate the grooves. Summit 

 flat, excavate within, spirally descending to a narrow perforation. 

 Base with a comparatively large umbilicus, which at the penulti- 

 mate whorl contracts to a similar narrow hole. Aperture regularly 

 arched. Columella subdentate below. Height 2-35 mm.; breadth 

 1-55 mm. 



The novelty is related to C. granosa Brazier { = reticulata 

 Watson), C. pulchra Brazier ( = suhreticulata Watson), and C. 

 hizona A. Ad. From this group it is distinguished by broader 

 form and absence of colour. 



Plentiful in 17-20 fathoms. A smaller form was taken near 

 the Hope Islands, North Queensland, in 5-10 fathoms. 



EXPLANATION OF PLATES. 



Plate xvi. 



Figs. 1, 2.— Interior and exterior of Gena ungida Hedley. 



Pig, 3. — Calliostoma trepidum Hedley. 



Figs.4, 5, 6, 7. — Adult and growth-stages of Macrosrhisma madreporaria 



Hedley. 

 Fig. 8. — Cydostrenia cubitale Hedley. 

 Fig. 9. — Mathilda oppia Hedley. 

 Fig. 10. — Mitra capricornea Hedley. 

 Fig. 11. — Liotia latehrosa Hedley. 

 Fig. 12. — Monilea tropicalis Hedley. 

 Figs. 13, 14-. — Emargimda convexa Hedley. 



Plate xvii. 

 Fig. 15. — Crossea inverta Hedley. 

 Fig. lQ,—Plesiotrochus pagodiforniis Hedley. 



