WEST AMERICAN PYRAMIDELLID MOLLUSKS. 75 



Base with spiral sciilpture^Continued. 



Axial I'ihs passing feel^ly over the periphery, but evanescing before they reach 

 the middle of the base — Continued. 

 Shell broadly conic — Continued. 



Incised spirals between the sutures not of uniform strength. 

 Incised lines between the sutures all strong. 



Incised spirals between the sutures 8 ireldi, p. 86. 



Incised spirals between the sutures 9 nereia, p. 86. 



Incised lines between the sutures partly strong and partly fine. 



Base with 11 well-incised spiral lines antestriata, j). 87. 



Base with 9 slender and numerous micro- 

 scopic lines antemunda, p. 88. 



Shell elongate-conic. 



Incised spiral lines between the sutures of uniform strength. 

 Spiral striations between the sutures more than 10. 



Whorls well rounded fiavescens, p. 89. 



\\Tiorls flattened. 



Spiral striations between the sutures 15 macbridei, p. 90. 



Spiral striations between the sutures 30 nuttulU, p. 90. 



Spiral striations between the sutures less than 10. 



Spiral striations between the sutures 5 macra, p. 91. 



Spiral striations between the sutures 6 angusta, p. 91. 



Incised spiral lines between the sutures not of uniform strength. 

 Incised spiral lines between the sutures all strong. 



Summits of the whorls excurved tenuicula, p. 92. 



Summits of the whorls not excurved. 

 Spacing regular. 



Incised spirals 6 strong and 1 fine virgo, p. 93. 



Incised spirals 7 strong and 3 fine marshaUi, p. 94. 



Spacing irregular. 



Whorls flattened canfieldi, p. 95. 



Whorls well rounded almo, p. 95. 



Incised spirals between the sutures consisting of well-impressed pits or 

 lines and fine striations. 



Spiral markings consisting of two strong series of pits, one the pe- 

 ripheral, the other the sub or supra-median and many fine striations. 

 Whorls strongly shouldered. 



Incised spiral lines bet ween the two pits 18. ra/Zipfp/iH/f, p. 96. 

 Incised spirnl lines between the two pits 12. . . .dina, p. 96. 

 Whorls not shouldered. 



Whorls exserted at the summit shimeki, p. 97. 



Whorls not exserted at the summit sanctorum, p. 98. 



Spiral markings consisting of more than two series of strong pits or 

 lines and wavy fine striations. 



Whorls exserted at the summit tenuicula, p. 92. 



Whorls not exserted at the summit. 



Shell large, adult more than 11 mm eucosmobasis, p. 98. 



Shell smaller, adult less than 7 mm halidoma, p. 99. 



Axial ribs extend over the base to the umbilical area. 

 Base of the last whorl very decidedly inflated. 



Adult shell less than 8 mm. long auricoma, p. 100. 



Adult shell more than 10 mm. long castanea, p. 101. 



