REPORT ON THE GASTEROPODA. 501 



line of it runs very straight across the body and out nearly to the point of the pillar, 

 where it curves round to join the basal lip. Inner lip : a thinnish porcellanous glaze 

 crosses the body and spreads a little outside of the mouth and round the base of the pillar, 

 to which it also forms a very narrow, thin, and flatly patulous edge, which is angulated 

 both to the inside and the out. H. - 26 in. B. 0'09. Penultimate whorl, height 0"044. 

 Mouth, height 0'055, breadth 0'05. 



This very beautiful little shell has some features of resemblance to Fcnella clongata, Wats. The 

 twist on the pillar-lip, though very slight, is unmistakable ; and this feature makes the absence of 

 the extreme tip of the apex the more to be regretted, as its character would have determined 

 whether this species ought not more properly to have been classed among the Odostomias. 

 Dunkcria, however, has an elasticity which makes it very suitable for a doubtful classification. Dr 

 Philip Carpenter (Mazatlan Catalogue, p. 433), in establishing the subgenus, says that it " com- 

 bines the characters of Chemnitzia and Aclis, presenting the mouth of the former with the rounded 

 whorls of the latter. It agrees with all the other sections of the family in having its limits badly 

 defined." 



6. Aclis, Loven, 1846. 



Species. 



1. Aclis mizon, Wats. 3. Aclis sarissa, Wats. 



2. Aclis hyalina, Wats. 4. Aclis minutissima, n. sp. 



1. Aclis mizon, 1 Watson (PI. XXXIV. fig. 1). 



Aclis mizon, Watson, Prelim. Eeport, pt. 7, Jouxn. Linn. Soc. Lond., vol. xv. p. 245. 



Station VIIp. February 10, 1873. Lat. 28° 35' N., long. 16° 5' W. Tenerife. 78 

 fathoms. Volcanic sand. 



Shell. — Broadly subulate, high, conical, umbilicated, thin, glassy, feebly ribbed longi- 

 tudinally. Sculpture: Longitudinals— on the penultimate whorl there are about 40 feeble 

 unequal rounded riblets, which run obliquely from right to left across the whorl ; they die 

 out on the last whorl, which, towards the mouth, presents a slightly malleated surface ; 

 on the upper whorls these riblets are fewer but more equal and distinct, but gradually die 

 out towards the apex ; they are parted by furrows rather broader than themselves ; on the 

 base they are very feebly present ; the whole surface is further covered with faint irregular 

 hair-like lines of growth. Spirals — there are a few very feeble, flatly-rounded, barely 

 raised threads on the last whorl ; these are rather more distinct on the base. The edge of 

 the base is slightly and hesitatingly angulated ; the lip of the umbilicus is much more 

 distinctly and sharply so. Colour thin transparent white, so as to be almost glassy. Spire 

 conical, long and fine. Apex small, quite regular, and perfectly rounded, with a minute 



1 fiii^uv, rather large. 



MARINE 



Dint nr^inAi 



