(9 bi 
400 
outer varix, and dentated within ; columella smooth, strongly arched ; 
aperture small, tortuous. 
15. SCALARIA MILLECOSTATA, Pease. 
Shell small, pyramidal, white, thin; whorls nine, contiguous, 
rapidly enlarging, rounded, the last one ventricose and perforated at 
the base; varices numerous, crowded, appearing like raised lines ; 
sutures deeply impressed ; aperture rounded. 
16. ScaLarta FUCATA, Pease. 
Shell elongate, imperforate, white, with a spiral brown band on 
the periphery of the whorls; whorls 8-9, rounded, separated and 
closely decussately striated with fine raised lines ; varices 7-8, distant, 
compressed, rather large, continuous and toothed above ; aperture ab- 
breviately oval. 
17. CrirsoTREMA ATTENUATUM, Pease. 
Shell small, elongate, solid, imperforate, slightly distorted; spire 
obtuse; whorls plano-convex, nodulous at the suture, encircled with 
fine, close spiral lines, upper whorls longitudinally ribbed ; varices 
few, irregular, suture faintly impressed; outer lip thickened by an 
external varix ; aperture oval. 
14. Review or THE Genus TENAGODUS, GUETTARD. , 
By Orro A. L. Mércu or CopENHAGEN. 
Worm-tubes, with a branchial slit, were figured by Aldrovandus, 
Buonanni, Rumphius, and Argenville; but this character, either 
overlooked or regarded as accidental, was first described by the ac- 
curate Lister in his ‘ Historia Conchyliorum,’ pl. 548. fig. 2: ‘* Ver- 
miculus fissura quadam secundum volutas insignitus.”” A porous slit 
was first described by Linnzus, although Rumphius first figured 
the same species. Guettard, 1776*, in his, for the time, admirable 
treatise on ‘ Worm-tubes,’ first recognized the generic value of the 
slit—a view adopted by Bruguiére, Lamarck, and most subsequent 
authors, under the new name Siliqguaria, preoccupied by Forskal for 
a genus of plants. 
Lamarck supposed Tenagodus to belong to the Annelides. Blain- 
ville brought it first, guided by conchological reasons, to the Mollusca, 
close to Vermetus; but erroneously imagined, from the median posi- 
tion of the branchial slit, that it had affinities with the animal of 
Fissurella. 
In the year 1829 Audouin+ set the question respecting the mol- 
luscous nature of the genus at rest ; but it was first im 1836 that Phi- 
lippi, in his ‘ Enumeratio,’ gave a clear description and figure of the 
animal and its operculum. 
Montfort, too, has given some account of the animal ; but one part 
* Guettard arranged the Tenagodus, figured by Davila, pl. 21. f. L, in the genus 
Tulaxodes, because he regarded the septa more important than the pores. 
+ Audouin, Société Philomatique, 1829 ; Annales des Sciences, 1829 ; et Rang, 
Manuel, p. 188. 
