214 



In the Palaeontology of California* Mr. Gabb describes a shell which 

 he refers with much doubt, first to the genus Ptychoceras or Hamites, 

 and finally to Ancyloceras under the name A. quadratus, which resem- 

 bles the present shell in its septation, as well as in the fact that its 

 surface is said to be marked with distant periodical constrictions. The 

 outline of a transverse section of A. quadratus, however, is described 

 as sub-quadrate and its sculpture is represented as consisting of " very 

 small rounded ribs." The specimens described above are so imperfect 

 that it is impossible to say whether they should be placed in the genus 

 Hamites, Ptychoceras, Hamulina, Ancyloceras, or Anisoceras, but their 

 sculpture, apart from the periodic constrictions, appears to have been 

 smooth, and they are certainly elliptic ovate in transverse section. 



GASTEROPODA. 



NERTNJEA MAUDENSIS. (N. Sp.) 

 Plate 27, figs. 2, 2a, 26, 2c, and 2d. 



Shellturreted, very long and slender : whorls exceedingly numerous, 

 the early ones obliquely flattened or slightly depressed, the later ones 

 concave in the middle and highest at the suture : suture very indis- 

 tinct, placed in the centre of a prominent and continuous spiral ridge, 

 which is rounded at the summit. Outline of aperture unknown. Sur- 

 face of the later whorls encircled by from six to seven fine and thread- 

 like spiral raised linos. Longitudinal sections show that a triangular 

 and acutely pointed spiral ridge or fold revolves around the inner sur- 

 face of the outer wall of all the volutions. 



East end of Maud Island, opposite Leading Island, in Skidegate 

 Inlet : not uncommon in brittle- and very friable shale. 



As the shale breaks readily in all directions when dry and as the 

 species is long, slender and fragile, the large specimens, which are 

 often much distorted, are invariably broken. The length of the largest 

 fragment collected (fig. 2), which consists of six of the lower volu- 

 tions, is forty-five millimetres, and its breadth is nine mm. at the 

 smallest end and seventeen mm. at the largest. A very young indi- 

 vidual (fig. 2ft), whose apex is unusually perfect and which measures 

 sixteen mm. (or five-eights of an inch) in length, and a little less 

 than five mm. in breadth at the larger end, has as many as fourteen 



Volume 1, pp. 74 and 75, pi. 14, fig. 21, pi. 15, fig. 21 : also volume 2, p. 213. 



