234 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



sulci, cue rather broad, shallow, and flat in the centre, and a 

 narrower one above. The number of whorls, and the ornamen- 

 tation, make it very beautiful and graceful. It has some faint 

 resemblances in size and number of whorls to Gerithium inversum, 

 Deshayes, of the Paris basin, but the differences are great. It 

 has no living congener at all like it. 



TURRITELLA TRANSENNA. PL 20, fig. 8. 



Testa parva, pyramidata, twrita, tenui, fragili, nitenie ; anfr. 

 medio angulatis, 5 carinis cinctis (2 magnis, ^ parvis alternant ibus) 

 et costulis numerosis declivibiis, supra carinas non transeuntihus 

 clathraiis ; peripheria angulata, marginata, et bilirata, basi plan- 

 aia, spiraliter lirata, tenuissime transverdm striata, margine, cos- 

 tata, granulata; apertura quadrata, antice conspicue producta et 

 angulata. Long. 8|, lat. 3. 



Shell small pyramidal, turretted, thin, fragile, shining, whorls 

 angular in the middle girdled with five keels (two large and three 

 small alternating), the interstices finely latticed with numerous 

 small somewhat sloping ribs which do not pass over the keels. 

 The periphery is angular, and margined with a double line of small 

 keels. The base is flattened, has spiral lirse crossed with very 

 fine stride, having a granular keel at its edge. The aperture is 

 quadrate, being very much produced and angular at its outer 



edge. 



I am not acquainted with any fossil Turritella latticed in the 

 peculiar manner seen in this species. Turitella tasmanica, Reeve, 

 is, however, like it, but the suture is not so strongly marked or 

 impressed, and the cancellation is not nearly so pronounced. The 

 latter is a species very common both in Tasmania and South 

 Australia. 



Turritella platyspira. PI. 20, fig. 13. 



Testa acute pyramidata, turrita, tenui, polita ; anjr. 12 — 15, 

 planatis, 3 carinis spiralibus inconspicuis, CBquidistantibus, et uno 

 sulco lato, haud profunda, antice, cinctis; lineis incrementi valde 

 ff.exiiosis, vix visibilibus, sutura angusta, parum impressa ; nucleo 2 

 anfr. rotundatis ; apertura sttbquadrata, columella marginata. 

 Long. 11, lat. 3. 



