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



pillar is thicker and more defined. H. 0*31 in. B. 0-09. Penultimate whorl, height 0*04. 

 Mouth, height 0'066, breadth 0-05. 



The sculpture of this species always tends to become obsolete on the last whorl, but in some 

 specimens the whole sculpture on all the whorls is so feeble as greatly to alter the whole appearance 

 of the shell. 



12. Bittium pupiforme, Watson (PI. XL1. fig. 3). 



Cerithium {Bittium) pupiforme, Watson, Prelim. Report, pt. 5, Journ. Linn. Soc. ;Lond., vol. xv. p. 114, 



sp. 15. 



Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E. Wednesday 

 Island, Cape York. 8 fathoms. Coral mud. 



Shell. — Small, narrow, conical, blunt, with convex outlines, contracted both toward 

 the apex and the point of the base, reticulated, tubercled, solid, translucent, glossy, white. 

 Sculpture : Longitudinals — there are on the last whorl about 25 rows of small, rounded, 

 adjacent tubercles ; they are parted by mere lines, and run pretty straight, but with a 

 slight sinistral turn down the spire. On the upper part of the spire the rows are straight, 

 but in the penultimate whorl, where the shell begins to contract toward the base, the rows 

 have a slight concave and dextral curve. Spirals — on each whorl there are three equal 

 spiral threads, which form the tubercles as they cross the longitudinal rows ; they are 

 parted by two narrow and shallow furrows ; there is a strong deep sutural furrow. Besides 

 these there are quite inconspicuous microscopic longitudinal and spiral lines on the sur- 

 face. The very narrow base is encircled by a strong rounded prominent thread, within 

 which a deep furrow surrounds the pillar. Colour translucent white. Spire high and 

 narrow, with convex outlines. Apex extremely abruptly truncate, rounded. The 

 smooth embryonic shell consists of 1^ whorls, and the tip of it scarcely rises into 

 sight. Whorls 9, contracted upwards, flat on the sides. The base is extremely con- 

 tracted ; and as the contraction begins in the penultimate whorl, the form of the shell 

 resembles the pupa of an insect. Suture only defined by the deep furrow in which it lies. 

 Mouth oval, with a very small channel in front. Outer lip broken. Pillar very short, 

 strong, but not broad ; the point is in the only specimen slightly broken. H. 0'1 in. 

 B. 0-037. Penultimate whorl, height 0*02. 



In general form, but in that alone, this is very like some of the ill-thriven-looking forms of 

 Cerithiopsis minima (Brusina), but is obviously very different. 



13. Bittium oosimense, Watson (PI. XXXIX. fig. 1). 



Cerithium (Bittium) oosimense, Watson, Prelim. Report, pt. 5, Journ. Linn. Soc Lond., vol. xv. p. 117, 



sp. 17. 



May 14, 1875. Oosima, Japan. 



