356 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
have been able to identify is that of Chenu in his manual, and even 
this is not entirely characteristic. Lahille figures no typical ancilla, 
so far as one can judge from his figures, which represent only the 
backs of the shells; the figures he gives Which come nearest to true 
ancilla I have cited in the synonymy, but with doubt. It may be 
that the veritable ancilla does not extend to the upper Argentine 
coast. The specimens in the National Museum? agree exactly with 
the figures of D’Avila and Lamarck, and come from the Straits of 
Magellan. 
There are reasons why the name magellanica should be placed in 
the synonymy of V. ancilla, but the fact that Chemnitz covered more 
that one species under the name, and figured one which was not 
ancilla, led subsequent writers in several cases to retain the name 
magellanica for the principal form erroneously united with ancilla. 
This seems to be a variable shell, but is heavier; on the whole more 
slender, with a longer spire, and shorter body whorl than ancilla. 
It is dangerous to put forward dogmatic opinions on such a subject 
without large supplies of material for comparison, but the aspect 
of the two forms is distinct, though they are doubtless closely re- 
lated. Strebel’s figures from specimens do not seem to include 
any which represent the typical ancilla of Solander, though he copies 
in a reduced form the figure given by D’ Avila. 
ADELOMELON SUBNODOSA Leach 
Voluta subnodosa Lracu, Zool. Miscel., 1, pl. vim, 1814; Sowerrsy, Thes. 
Conch., Voluta, p. 203, pl. xiv, fig. 24, 1847. 
V oluta ancilla Sowrrsy, Thes. Conch., Voluta, p. 203, pl. Liv, fig. tor, 1847 
(not V. ancilla Sot. or LAm.); Hanley’s Wood’s Ind. Test., Suppl., 
p. 209, pl. 11, Voluta, fig. 1, 1856; KrENER, Icon. Cog. Viv., Voluta, 
Pp. 39, pl. 52, 1839. 
Voluta magellanica K1ENER, loc. cit., p. 40, according to the description. 
Voluta magellanica Reeve, Conch. Icon., Voluta, pl. xiv, figs. 33a, 330, 
1849; not of Lamarck. 
Voluta magellanica Tryon, Man. Conch., tv, p. 97, pl. xx1x, figs. 107, 
108 (copied from Sowerby figs. tor and 24), 1882. 
Voluta ambigua LAHILLE, Revista Mus., La Plata, vi, p. 317 (27 of 
extras) pl. vi, figs. 163-6, pl. x1, figs. 6, 9, 11; pl. x1, figs. 17—16; 
1895. Not V. ambigua (Sol.) Sowerby, Min. Conch., 1v, p. 135, pl. 
300, fig. 1, 1823, or of Maron, Lin. Trans., 1807, or LAmarcK, Ann. 
du Mus., xvi, p. 77, 1811. 
Voluta ambigua vars. constricta, pseudotuberculata, subnodosa and typica, 
LAHILLE, /. cit., pp. 27-20. 
* Nos. 9732 and 87542. 
