202 Christmas Island. 



Tectus pyramis, Bom. 



G. "W. Knorr: Vergniigen Sammlung Muscheln, 1757, vol. i, pi. xii, fig. 4. 

 Trochus pyramis, Born: Testacea Musei Csesarei Vindobonensis, 1780, p. 333; 



Chemnitz, Conchylien - Cabinet, 1781, vol. v, pi. 160, figs. 



1510-1512, p. 19. 

 Trochus oheliscus, GmeHn : Systema Naturae, 1790, 13th ed., vol. i, pt. 6, p. 3579. 

 Tectus oheliscus, G. W. Tryon : Manual of Conchology, 1889, vol. xi, p. 19, 



pi. ii, figs. 13, 14. 



Description. — Born's original diagnosis of this Troehiform shell 

 expresses very clearly the salient characters of the species. It is 

 as follows : ^^ Testa conica, acuminata, anfractihus imbricatis, seriatim 

 granulosis, columella torta, imperforata." 



Remarks. — An undoubted specimen of this species has been 

 obtained from the limestone reefs of Christmas Island. It is a tall, 

 conical form, with about twelve or more somewhat flattened whorls, 

 the upper ones being tuberculate or undulating at the suture. 

 The surface of the whorls is ornamented with a regular series of 

 spiral granulations, which on the last whorl are arranged in eight 

 or nine rows ; the periphery is obtusely acute. The base of the 

 shell is flat, wide, and sculptured with concentric lirations, which 

 become obsolete near the outer margin. The shell possesses a 

 shallow, subtriangular aperture and a short twisted columella. No 

 internal characters of the mouth are visible, being hidden by matrix. 



Limemions. — Length 80, diameter 80 mm. 



Tryon's illustration (fig. 14, see Synonymy) gives an excellent 

 idea of the specimen from Christmas Island. 



Bistrihution.—ln&mn. and Pacific Oceans; Samoan, Yiti, and 

 Philippine Islands, New Caledonia ; North Australia, etc. ; 

 Singapore. (Tryon.) 



Locality. — Flying Fish Cove ; found in the lowest raised reef. 



Number on specimeti : 609. 



JSxamples : 1. 



Tectus ? 



Remarks. — A fragmentary cast, probably of this genus, occurs 

 embedded in a pink-coloured limestone associated with remains of 

 corals, etc. It is not specifically determinable. 



Locality.— To^ of first inland cliff, about 300 feet above sea-level. 



Number on specimen : 951. 



Examples: 1. 



Genus TUTUFA, Jousseaume, 1881. 



Bull. Soc. Zool. France, 1881, vol. vi, pp. 172, 175. 



Type. — Murex lampas, Linnaeus. 



Synonyms. — Lampas, Schumacher, 1817, nee Meuschen, 1787 

 (Brachiopod), nee De Montfort, 1808 (Foraminifer). 



