264 GASTROPODA. [Pectinibranchia. 



2. Siliquaria Weidii, T.-Woods, 1876. Plate 39, fig. 15. 



Siliquariu Weidii, T.-Woods, P.E.8. Tasm., 1875 (1876)44; Man. Conch. (1), 

 ix, 191, pi. 58, f. 28. Tenarjodes Weidii, T.-Woods, Index, 76. 



Shell graceful, smooth or very lightly longitudinally striated; 

 whitish, yellowish, or very light rosy ; first three whorls with the slit 

 filled below, afterwards it is open (Tyron), The first two or three 

 whorls are scalariform, disconnected ; the well-marked growth-lines 

 are very distinctly sigmoid on the outer side of the tube, and there 

 are numerous narrow and fine transverse fissures on the outer margin 

 of the slit, 



The longest specimen in my collection is 30 mm. 



Type in the Tasmanian Museum, Hobart. 



Hab. Chatham Islands (Dr. A. Bendy) ; Hauraki Gulf (H. S.) ; 

 off Waipapa Point, in 25 fathoms (E. R. Waite). 



Fam. C^EICID^B, Gray. 



Animal with a long flat rostrum ; tentacles cylindrical, with 

 sessile eyes at their outer base ; mantle thick, fleshy, circular, 

 closely embracing the neck ; a single branchial plume ; foot short, 

 narrow, truncated in front, attenuated and obtuse behind. Dentition 

 2+1 +2(?). 



Shell tubular, with a spiral plane nucleus, which is caducous or 

 persistent, then becoming cylindrical, curved, terminating in a simple 

 circular aperture, the posterior portion of the tube usually divided 

 by one or more septa. Operculum horny, multispiral, margin some- 

 times fimbriated. 



There are usually three stages of growth in the shell of Ccecum 

 first, the spiral or nuclear, soon lost by truncation, the end of the 

 remaining tube closed by a septum ; second, the adolescent stage, a 

 curved tube, also lost subsequently ; and, third, the adult tube, of 

 similar curved shape, and again closed behind by a septum. 



Distribution. Temperate and warm seas throughout the world, 

 but absent in cold water. About 200 nominal species have been 

 described. 



Fossil. Tertiary. 



Genus 1. CAECUM, Fleming, 1817. 



Ccecum, Fleming, Encycl. Eclinb., vii, 1817, 67. Cornuoides, Brown, 1827- 

 Brochus, Brown, 1829. Odontina, Zborzewsky, 1834. Odontidium, Philippi, 

 1836. CcecaMum, Macgillivray. Corniculina, .Minister. Dentaliopsis* 

 Clarke. Brochina, Gray, 1857. 



Shell when young discoidal, when adult decollated, tubular, cylin- 

 drical, arcuated ; aperture round, entire ; apex closed by a mamillated 

 septum, marking the point at which the original spire has been 

 cut off. 



Vernacular Name. Blind-shell. 



