Little-hiiown Victorian Fossils. 119 



niicula in lists of Australian fossils. A careful examination of 

 a large number of valves from the Deep Creek section and 

 elsewhere has convinced me that they differ in essential 

 characters from the well-known British species, and the form will 

 I think most appropriately be designated by associating with it 

 the name of its first discoverer. 



Localities and Horizons.— CoWected. by the Geological Survey 

 of Victoria, Bb 29 [198 — 9] Newham ; associated with Didy- 

 mograptus extensus, Tetragraptus quadribrachiatus, Clonograptus 

 rigidus var. tenellus, Diplograptus sp., Lasiograptus sp., and 

 Phyllograptus typus. Lower Ordovician. 



Geological Survey of Victoria, Ba 62 [232-5J and 64 [219 

 -31], Deep Creek, Saltwater River, north-west of Bulla; asso- 

 ciated with Stephanograptus gracilis, Dicranograptus ramosus, 

 Dicellograptus furcatus, Diplograptus sp., and Climacograptus 

 bicornis. Upper Ordovician. 



Order PTEROPODA. 



Genus Hyolithes, Eichwald, 1840. 



Hyolithes leptus, sp. nov. (PI. XVIIL, Fig. 15). 



Descriptio7i. — Shell straight, conical, and attenuate, tapering 

 very gradually. (Apex missing.) Aperture opening obliquely 

 towards the extended margin of the dorsal side. Surface of shell 

 convex, but somewhat crushed in the present specimen ; marked 

 transversely with convex lines near the apex, but becoming 

 sinuous nearer the apertural end. Sides of shell with a narrow- 

 sunken border possibly indicating a lateral angulation. Length 

 when complete, about 50 mm.; length of specimen, 41 mm. ; width 

 at aperture, 7.5 mm. ; width at broken proximal end, 3 mm. 



Observatio7ts. — This species shows some affinity with certain 

 forms of Hyolithes described by Billings and Walcott from the 

 Lower Cambrian (Olenellus zone) of Newfoundland, Canada, and 

 the United States, and especially with H. communis, Billings, var. 

 emmonsi, Ford.^ Our specimen, however, is more attenuate, and 

 the surface strise are not so fine, the area between them often 

 forming superficial ridges. The specimen figured by Tate from 



1 Bull. U.S. Geol. Survey, No. 30, 1886, p. 137 ; Walcott, U.S. Geol. Surv. Tenth Ann. 

 Rep. (1888-9) 1890, p. 621, PI. Ixxvii. fig. 4, 4a, 6. 



3 



