dall: mollusc a and brachiopoda. 311 



The operculum is typically Columbelloid, having an ovate margin of polished 

 callus with a narrow ray of callus projecting across the centre of the scar of adhe- 

 sion. The animal is whitish with a reddish-brown margin to the mantle; the 

 tentacles are rather short and stout, witli the eyes on short, separate pedicels just 

 outside the tentacles ; the proboscis wholly retractile, the foot large, voluminous, 

 solid, with wrinkled surface aud au apparently rather blunt posterior extremity. 



Muricidae. 



PURPURINAE. 



THAIS BOLTEN. 



(= Purpura Lamarck, 1799, not Martyn, 1784.) 



Thais nesiotes Dall, n. sp. 



Shell small, purple-brown, bleaching to a purplish-white, with four smooth, 

 minute dark brown nuclear whorls and about four subsequent whorls; suture 

 appressed with a slight ridge, followed by a slight constriction, in front of it ; 

 aperture longer than the spire, which is acute; whorls moderately rounded ; spiral 

 sculpture of numerous flattish major spiral ridges, sometimes striated or even 

 duplex, with narrower chaunelled interspaces usually with a small intercalary 

 thread; on the penultimate whorl there are five or six major spirals between the 

 sutures aud on the last whorl about fourteen ; these are crossed by very numer- 

 ous slightly elevated lamellae, which in well preserved specimens imbricate the 

 interspaces and rise a little iiighcr at the suture; aperture semilunatc, narrow 

 behind; outer lip more or less thickened, white, and obscurely dentate within; 

 columella broad with a flattened white callosity; pillar short, straiglit; canal 

 very short and narrow, but having a strong siphonal fasciole with a closed chink 

 behind the columellar callus. Lon. of shell, 18 ; of last whorl, 15 ; of aperture, 

 11 ; max. diam. 10.5 mm. 



Collected on the shore at Easter Island by the "Albatross" jiarty. U. S. N. 

 Mus. 110,700. 



A thorough search has failed to reveal this little species anywhere among the 

 described species of Purpura. The specimens are possibly not quite mature. 



MURICIXAE. 

 TROPIION MOXTFORT. 



Trophon (Pascxila) citricus Pall, n. sp. 



Shell small, fusiform, acute, the spire longer than the aperture, livid flesh color 

 with orange knobs and aperture, aud about six whorls; apex rather acute, but \i\ 

 all the specimens overgrown with uullipore, etc., or eroded so as to be iuaccessi- 



