i44 Bulletin 29 308 



Genus Pyramidella Lamarck 

 Pyramidell-a canaliculata Gabb 



Plate 25, Figure 5 

 Obeliscus canaliculatus Gabb, (in part) Trans. Amer. Phil. Soc," vol. 



15- P- 225, 1873. 

 Obeliscus canaliculatus Dall, Trans. Wagner Inst. Sci., vol 3, pt. 2, p. 



247, 1892. 



Gabb's description of O. canaliculahis comprises a^number of 

 different forms, some of which we also collected. Dr. Dall's re- 

 mark concerning the type corresponds. He says, (Trans. Wag- 

 ner Inst. Sci., vol. 3, pt. 2, p. 247, 1892) "The supposed types 

 at Philadelphia comprise three or four species belonging to several 

 distinct genera, all loose in one tray together." T have here re- 

 stricted the species canaliculata to the following form, chosen 

 from its possessing the more striking of the characters enumer- 

 ated by Gabb. 



Shell elongate- conic, slender, nuclear whorls two, subsequent 

 whorls thirteen, flattened, shouldered at the summit which is 

 minutely crenulated ; suture deeply channeled, the center of the 

 channel being occupied by a fine sutural thread ; periphery of last 

 whorl sulcate; base rounded; perforation minute, surrounded by 

 a stout fasciole; aperture oval; columella slender, with one trans- 

 verse, lamellar, posterior plication and two oblique folds below, 

 the anterior of which borders the canal; outer lip thin, with two 

 or three denticles, a varying distance within. Length 1 1 , diam- 

 eter 4 mm. This species somewhat resembles the recent P. pana- 

 mensis Bartsch, dredged off Panama. 



Sowerby described as canaliculatus an entirely different 

 species from the Sandwich Islands (Proc. Zool. Soc, London, 

 for 1873) but apparently this was not published until early in 

 1874, so that Gabb's name has priority. 



Locality. — (Exp'd '16) Bluff 3, Cercado de Mao. 



Pyramidella semicanalicalatas , n. sp, 

 Plate 25, Figure 6 

 Shell resembling P. canaliculata but differing markedly in 



