30 MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
suture; aperture long and narrow, anteriorly rounded; labrum very thin, 
much advanced along the middle; columella terminating in a very robust 
spiral plait. Length, .28; breadth, .11; length of spire, .03 in. (C. B. 
Adams.) 
Type in Amherst College. Type locality, Panama. 
Range. Santa Monica, California, to Panama. 
Described as Bulla (Tornatina) infrequens . 
Acteocina carinata Carpenter, 1857 
Catalogue of the Collection of Masatlan Shells, 171. 
T. t. cylindracea, alba, laevi, infra suturam appressam acute carinata; 
inter suturam et carinam excavata; anfr. v. quarum duo primi discoidales, 
ad spiram verticaliter affixi; aspira plus minusve extante; apertura prae- 
longa, labro acuto, in medio producto, postice ad suturam vix canaliculato; 
labro tenui; pariete ad basim tumida; columella plica infra parietem robusta 
spiraliter munita. Largest specimen, long., .11; long, spir., .02; lat., .05. 
(Carpenter.) 
Shell cylindrical, white, smooth, acutely carinated below the appressed 
suture, between the suture and the carine excavated. Whorls 5, the two 
earlier discoidal and affixed vertically upon the spire, which is more or 
less apparent. Aperture elongate, the lip acute and produced in the middle, 
slightly sinused behind; inner lip thin, swollen above the junction with 
the columella proper. Columella provided with a stout spiral fold where 
it joins the parietal wall. (Carpenter.) (Tryon and Pilsbry, Manual of 
Conchology .) 
Known from T. infrequens (1) by the smaller size, and more irregular 
spire; (2) by the suture, which is not channeled; (3) by the shoulder, 
which is sharply carinated, with the space hollowed between the keel and 
suture; (4) by the swelling of the body whorl at the base; and (5) by 
the plait which runs more transversely, below the body whorl, instead of 
obliquely, almost on it, as in T. infrequens. (Carpenter.) 
Type in British Museum. Type locality, Mazatlan, Mexico. 
Range. San Diego, California, to Gulf of California. 
Acteocina planata Carpenter, 1865 
Journal de Conchylologie, 13: 139. 
C. t. parva, cylindracea, subelongata, alba, laevis, epidermide straminea 
induta; marginibus fere parallelis; spira planata, baud umbilicata, haud 
mamillata; anfractibus 4 convolutis, suturis parum impressis; basi modice 
effusa; labro tenui, in medio satis producto, antice late arcuato, postice 
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