234 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Family OVULIDAE 
Genus SIMNIA (Leach) Risso, 1826 (Ovula) 
The genus Simnia, is characterized by its sharp outer lip, and is still 
retained by authors, although as shown under favorable circumstances 
it sometimes completes its shell by the addition of a thickened lip, when 
the distinction from the typical group disappears. Ordinarily Simnia has 
the sharp lip and it may be considered a case of arrested growth, paralleled 
by that of Planorbis trivolvis —which only in northern waters takes on its 
expanded lip along with more vigorous growth and larger size. (Tryon, 
Manual of Conchology .) 
Distribution. Tropical and subtropical. Fossil, Tertiary. 
Simnia vidleri Sowerby, 1881 
Plate 32, figs. 8, 8a 
Proceedings, Zoological Society of London, 638; PI. 56, fig. 1. 
Testa elongata, utrinque acuminata, transversim striata, cerasina, ter- 
minibus vivide aurantiacis, dorso medio gibbosiuscula, lavissime angulato, 
laevigato vel obsolete costato; apertura angusta, antivelavior; labrum 
laeve, antice subangulatum; columella callosa, potice conspicue uniplicata. 
Long., 21; diameter, 7 mm. (Sowerby.) 
An Ovulum of an elongated form, of a cherry-red colour, with bright 
orange extremities. The back is nearly smooth; and the ends are trans¬ 
versely striated. Several of the specimens brought by Mr. Vidler are 
smaller, smoother, and more slender than the one I have chosen as type. 
Type in British Museum. Type locality, Monterey, California. 
Range. Monterey to San Diego, California. 
Described as Ovulum vidleri. 
Simnia acicularis Lamarck, 1811 
Paris Museum d’histoire naturelle, Annalcs, 16: 112. Mon. Cabinet List. Conch., t. 711, 
f. 66? 
O. Linaeris, perangusta, caereulescens; extremitibus subacutis; labro 
vix marginato. (Lamarck.) 
Habite Tocean americain. Espece petite, mais fort remarquable, rap- 
portee par Mauger, de son voyage aux Antilles. Elle paroit tres-distincte 
des deux suivantes, dont elle se rapproche par ses rapports. Cette coquille 
ressemble a un grain d’avoine allonge et peu renfle. Elle est subcylin- 
drique grele, d’un cendre bleuatre, et s’offre qu’un sinus leger et oblique 
sur sa columelle. Sa longueur est de 15 mm. L’individu figure dana Lister 
etoit probablement moins grele que ceus que je possede. (Lamarck.) 
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