28 THE SPECIES OF 



by the olive-green epidermis, variegated with purplish- 

 brown patches. I find the number of laminsB in the 

 aperture very variable, but the two prominent ones on the 

 labium are constant in all the individuals I have had the 

 opportunity of examining. 



Mr. Carpenter (1. c.) says that M. Mork has labelled this 

 in Mr. Cuming's collection " Melampus bidentatus Say," 

 and justly adds that it is much more nearly allied to 

 Melampus coffeus Lin. It seems to me, however, to be a 

 peculiarly well marked species. 



The figure is taken from a specimen in the cabinet 

 of the Boston Society of Natural History, labelled by Mr. 

 Carpenter. 



I am indebted to the kindness of Prof. S. F. Baird for 

 specimens of this species. 



FAMILY ACICULACEA. 



Genus TRUNCATELLA Risso. 



TRUNCATELLrA CALIFORNICA Pfeiffer. 



Plate LXXIX. Figures 20, 22. 



T. non-rimata, turrito-cylindracea, truncata, tenuiscula, leviter stri- 

 ata, parum nitens, pallide rubellocornea ; spira sursum vix attenuata ; 

 sutura simpliciter marginata ; anfr. superst. 4 convex!, sensim accres- 

 centes, ultimus basi non compressus ; apertura verticalis, ovalis, superue 

 vIx angulata ; perist. simplex, continuum, margine dextro expanso, 

 superne sub-repando, columellari adnato. [Pf-] 



SYNONYMS AND REFERENCES. 



Triincatella Califwnica Pfeiffer, Proc. Zool. Soc. London, May, 1857, p. Ill; 

 Mon. Pneum, Viv. ii. p. 7. 



DESCRIPTION. 



Animal not observed. 



Shell imperforate, cylindrical, truncated at tip, thin and 

 translucent with light striae, shining, amber-colored ; 

 spire in the perfect state of the shell composed of about 



