590 



BEV. R. BOOG WATSON ON THE 



twisted tooth projecting at about three fourths of its length, 

 below which is a smaller sinus running out into a point at the 

 extreme end of the pillar. Umbilicus large, funnel-shaped, 

 deep, sharply defined by the edge of the base, the spiral of 

 which runs out to the point of the pillar-lip. "Within the um- 

 bilicus is a strongish undefined spiral furrow answering to the 

 pillar-tooth, and the lines of growth are strongly defined. 

 H. 0-18. B. 0-24 ; least breadth 0-21. Penultimate whorl 0-04. 

 This species diff'ers from S. carinata, Jefir., in being more 

 depressed and broader, much more angulated and more lirate 

 above, more tumid and lirate on the base, of which the carina is 

 less flanged, and the most prominent part is the edge of the um- 

 bilicus, not the centre ; here, too, the last whorl and the mouth 

 are larger. The young of this species look disproportionately small 

 and high. 



3. Seguenzia caeinata, Jeffr. 



St. 73. "West of Azores. June 30, 1873. Lat. 38° 30' N., long. 



31°14!'W. 1000 fms. Gloligerina-oozQ. 1 specimen. 



St. 78. San Miguel, Azores. July 10, 1873. Lat. 37° 24' N., 



long. 25° 13' W. 1000 fms. Gloligerina-oozQ. 1 specimen. 

 St. 85. Palma, Canaries. July 19, 1873. Lat. 28° 42' N., long. 



18° 6' W. 1125 fms. Volcanic sand. 4 specimens, young. 

 St. 120. Pernambuco. September 9, 1873. Lat. 8° 37' S., long. 



34°28'W. 675 fms. Mud. 2 specimens, young. 



J. Gwyn Jeffreys, Biol. Val. Cruise, Proc. Eoyal Soc. No. 173, 



1876, p. 201. N. Atlantic, 690 fms. ' Porcupine ' Expedition, 



1870, Bay of Biscay, off Spain and Portugal, 718-1095 fms. 



Shell— Small, broadly conical, rounded on the base, sharply an- 

 gulated, umbilicate, thin, polished, vitreous. Sculpture. There is 

 a sharp circumbasal carina, which on the spire sometimes projects 

 a little above the suture, and there is generally concealed by the 

 succeeding whorl. In the middle of the whorls is a slight spiral 

 thread, which on the earlier whorls is much stronger and some- 

 what lower in position than on the last ; it defines the inferior 

 edge of the generic sinus. The base is margined by a broad flat 

 flange, and the edge of the umbilicus is defined by a fine sharp 

 thread. Besides these there are some faint traces of microscopic 

 spirals on the whole surface, especially on the base ; and the basal 

 sinus has on its outer edge more or less traces of a fine spiral 

 thread. Longitudinals — there are many hair-like flexuous lines 

 of growth. Colour glassy when freehand young, in older shells 



