THE MOLLU8CA HEDLEY. 



433 



Fig. 21. 



only a form of C. morus, Lamk." Tryon, ever ready to reduce 

 synonymy, agreed in this view. Whatever may be deemed the value 

 of C. breve, it cannot be adjudged an absolute synonym of C. morus. 

 The type of C. breve came from Tongatabu. The shell does 

 not seem to have been again observed. 



CERITHIUM SPICULUM, sp. nov. 

 (Fig. 21). 



Shell narrow, subulate, with a sharply-pointed 

 spire and a rounded base. Colour dull white, dis- 

 tantly, faintly, irregularly, and minutely spotted 

 with chestnut. Whorls eleven, slowly increasing, 

 somewhat turreted, flattened. Sculpture on the 

 uppermost whorls the spiral ridges are tuber- 

 culated by longitudinal plications which rapidly 

 diminish as the growth proceeds. On the last 

 whorl their influence is barely perceptible in faint, 

 shallow, longitudinal undulations. A stout varix 

 occurs a third of a whorl behind the aperture ; 

 from four to ten, raised, spiral cords encircle each 

 whorl, in the interstices of which are fine spiral 

 threads. Aperture perpendicular, oval ; outer lip 

 straight and sharp ; canal very short, turned 

 abruptly outwards. Length 11, breadth 4 mm. 



Two specimens were obtained in the outer beach of Nukulailai. 



This form appears allied to C. lacteum, Kiener,* from which it 

 differs by smaller size, narrower outline, and absence of granula- 

 tions. 



CERITHIUM STRICTUM, sp. nov. 

 (Pig. 22). 



Shell narrow, elongate, tapering in a slender spire 

 and blunt anteriorly. Colour white, irregularly 

 longitudinally splashed with chestnut. Whorls seven, 

 the upper angled, the last straight. Sculpture 

 round the angle of the upper whorls runs a line of 

 tubercles, of which eleven occur on the penultimate. 

 Very slight longitudinal undulations, hardly to be 

 called ribs, extend from these tubercles across the 

 whorl ; both vanish before attaining the last whorl. 

 This latter is girt with about twenty, sharp, revolv- 

 ing ridges, of which the central is largest and 

 corresponds to the tuberculated angle of the earlier 

 whorls ; the rest vary in size and spacing, the basal 

 ridges being least and closest ; the upper seven ascend 

 the spire. A large varix is behind the aperture, and a Fig. 22. 



* Kiener Coquilles Vivantes, Canaliferes i., (n.d.), p. 58, pi. vii., figs. 

 3, 3o. 



Do 



