646 THE VOYAGE OF H.M.S. CHALLENGER. 



age. In the three specimens from Station 78 it is much more strongly marked than in the some- 

 what younger shells from Station 73. The young shells of Scaphander punctostriatus (Migh.), are 

 squatter, rounder, with a flatter crown, and have the outer lip less produced behind ; then- stippled 

 sculpture, which varies a good deal, is often coarser, and forms more continuous spirals ; the pillar- 

 lip, too, and shape of the body are very different. In one of the specimens, from Station 78 in par- 

 ticular, the slow wasting away of the surface has scarcely attacked the stippled pits of the spirals, 

 which accordingly remain projecting as flat round tubercles. 



4. Amphisphyra, Loven, 1846. 



I adopt this genus for some forms of which the Challenger obtained only two — one here described, 

 the other too young for differentiation. These forms differ from Aplustrum, Schum., in the absence 

 of all colour and in, the form of the pillar; from Utricuhts in the whole habit of the shell, in the 

 absence of any tooth or twist on the pillar, and in the inflated mamillary apex, a feature which exactly 

 corresponds with Loven's definition of Amphisphyra. G. 0. Sars rejects Loven's name of Amphisphyra 

 in favour of Diaphana of Brown, but this latter name was cancelled by its author in favour of 

 Utriculus, and it is obviously impossible to accept both of these as Professor Sars has done. 



Amphisphyra seguenza, n. sp. (PI. XLVIII. fig. 5). 



Bullina undata (as of Chiaje), Seguenza, Form. Terz. Calabria, p. 251, pi. xvi. fig. 9. 



Station 122. September 10, 1873. Lat. 9° 5' S., long. 34* 50' W. Off Pernambuco. 

 350 fathoms. Red mud. 



Habitat. — Stations 16, 17, 17a. of the "Porcupine" dredgings, North Atlantic (Jeffreys) ; 

 west of the Azores in 1000 fathoms (Watson). 



Fossil. — From the Middle Pliocene (Seguenza). 



Shell. — Small, oval, glossy, finely spirally stippled, with the large open mouth and 

 simple lips of a Bulla, but with a small prominent mamillate apex. Sculpture : Longitu- 

 dinals — there are over the whole surface fine close lines of growth. Spirals — there are 

 fine sharp lines made of minute round stippled dots ; above, these lines are crowded, in the 

 middle they are sparse, towards the point they are again closer. Colour semi-translucent 

 white, with a greyish surface. Spire very short and blunt, sometimes not raised at all. 

 Apex a small but coarse, slightly prominent, mamillate tip. Suture impressed. Mouth 

 resembling that of a Bulla, and shaped like a long bent pear. Outer Up rises slightly 

 above the body, sometimes to a level with the tip, retreats above and below, and is roundly 

 prominent in the middle, where it slightly bends inwards, elsewhere it is patulous ; its 

 sweep is very regular throughout. Inner lip roundly curved on the body, rather deeply 

 concave at the top of the pillar, along which it runs nearly straight : a broad pad with 

 defined edge spreads across the body, and is pretty broad and reverted on the pillar, with 



