MOLLIISOA OF THE ' CHALLEKGEB ' EXPEDITION. 599 



spire is not unlike. In regard to the apex I am unable to speak 

 with certainty. A specimen of M. tribulus, which. Prof. v. Mar- 

 tens most obligingly sent me for examination from the Berlin 

 Museum, turned out to have suffered from the effects of cleaning 

 almost as much as those in the British Museum ; so far, however, 

 as the apex was recognizable, it seemed to have fewer whorls, 

 and to be somewhat more conical but more amorphous, and the 

 first regular whorls seem to have only one row of squamous 

 tubercles, as in M. ternispina, Lam. 



2. MuBES (Tribulus) acanthodes, n. sp. (JuKavQio^ris, prickly.) 

 Sept. 8, 1874. Cape York (Australia), off Albany Island. 

 3-12 fms. 



Shell. — Thinnish, pale rufous, globose, with a short scalar 

 spire, spinous whorls, a minute, regular, conically globose, glossy 

 chestnut apex, an oval mouth, a denticulated and, on the edge, 

 slightly crenulated" outer lip, a short rounded base, and a 

 long straightish snout. SculpUire. Longitudinals — there are 3 

 strongish corresponding varices on each whorl ; they are marked 

 by short stout diverging front-furrowed spines, whose numbers 

 are probably incomplete (as the specimens are young), but are 

 evidently few; these spinous varices run straight down the 

 snout ; between the varices are two tubercled ribs ; the first 2\ 

 regular whorls present no distinction between these varices and 

 ribs, but are crossed by about 10 tubercled ribs, on each of which 

 above is a single short hollow spine ; besides these are many, 

 faint, very slightly raised, rounded threads. Spirals — there are 

 on the last whorl about 20 narrow, rather raised, rounded, distant 

 threads ; others similar appear on the snout, but become obsolete 

 in front, the latter third being glossy and smooth ; the upper 

 whorls are bisected by an angular keel, besides which, on the 

 last whorl, there is a blunter keel where the basal contraction 

 begins : both of these keels are accentuated by the tubercles 

 into which they rise in crossing the longitudinal ribs and the 

 spines on the varices. Colour dead white with a rufous tinge, 

 which is stronger on the spire, on two faint bands corresponding 

 with the keels, on the spines, and on the glossy point of the 

 snout, where are some rich chestnut stains ; the apex is also 

 chestnut. Spire low, conical, scalar. Apex consists of 3 coni- 

 cally globose, rounded, glossy, chestnut whorls, of which the 

 extreme tip is minute, rounded, and a little bent down and 



