EEPORT ON THE GASTEROPODA. 557 



6, besides those of the embryonic shell ; they are conical aud flat on the sides, contracted 

 below, short, of regular rather rapid increase ; the body-whorl is a little large, and has a 

 short rounded base. Suture has its position very strongly defined by the contraction at 

 the base of each whorl, but is really all but invisible. Mouth gibbously and tumidly fusi- 

 form, being sharp pointed above, and also at the canal in front. Outer lip arched through- 

 out. Pillar is longish, thin-edged, twisted, truncate in front, rich chestnut, with a very 

 distinct small oblique canal at its point. Inner lip thin, concave. H. - 112 in. B. 0'041. 

 Mouth, height 0-032, breadth 0*022. 



This is much smaller than the young of Bittium granarium, Kiener, and the whole sculpture is 

 different. It is not unlike Bittium reticulation, Da Costa, but the sculpture is quite distinct. The 

 specimens are not full grown, so that the outer lip cannot be satisfactorily described. 



21. Bittium xanthum, 1 n. sp. (PI. XXXVIII. fig. 6). 



September 7, 1874. Torres Strait, North-east Australia. 3 to 11 fathoms. 



Shell. — Small, narrow, conical, very slightly constricted at the suture, fine-tipped, 

 feebly tubercled, with four spiral threads on the penultimate whorl, and a longish base. 

 Sculpture: Longitudinals — there are on the last whorl about 18 small narrow riblets, on 

 the earlier whorls they are fewer, and so far as their increasing number allows they run 

 continuously and straight down the spire from whorl to whorl ; the parting furrows are 

 open and shallow, and a little wider than the ribs ; one or two are swollen into slight 

 varices ; they entirely disappear on the base, and do not exist on the first regular whorl. 

 Spirals — there are on the penultimate whorl four small threads, which rise into little 

 rounded tubercles as they cross the riblets ; on the first two whorls there are but two, on 

 the middle whorls three of these threads ; below these in the contraction of the suture, 

 but on the upper side of the suture itself, is another excessively minute threadlet not 

 tubercled ; this threadlet is seen beyond the lip insertion to be the exposed edge of the 

 first basal thread, which is pretty strong, and lies just below the periphery ; within this 

 are four other very similar threads, while one very small one coils round the pillar ; all the 

 parting furrows are shallow and small, but rather wider than the threads ; there are no 

 microscopic spirals. Colour ochry yellow throughout, only the tip is paler. Spire high, 

 narrow, conical, with slightly convex outlines. Apex small, but blunt ; it consists of three 

 smooth whorls, of which the latter two are subcylindrical, while the first is sub-immersed, 

 the extreme tip being barely raised. Whorls 8, exclusive of those of the embryonic 

 shell ; they are rather short, conical, feebly contracted at the suture, barely convex-sided, 

 of slow and regular increase, the body-whorl is slightly contracted, and has a longish 



1 %a.M$, yellow, so called from the colour. 



