. Bulletin - United States National Museum. Science. 350 A MANUAL OF AMERICAN LAND SHELLS. the oviduct. The vagina is moderately broad. The cloaca is short. The exterior generative orifice is on the right side of the head, consid- erably posterior to the tentacles. (See Terr. Moll. U. S., I, Plates XIV, XVI.) Jaw absent. Lingual dentition as described above. There are about 34-1-34 teeth in each row. I have shown in Fig. 375 the central and various marginals from the first to the last tooth. The figures show the teeth as seen from below, thus giving a perfect view of the bases of attachment. T
. Bulletin - United States National Museum. Science. 350 A MANUAL OF AMERICAN LAND SHELLS. the oviduct. The vagina is moderately broad. The cloaca is short. The exterior generative orifice is on the right side of the head, consid- erably posterior to the tentacles. (See Terr. Moll. U. S., I, Plates XIV, XVI.) Jaw absent. Lingual dentition as described above. There are about 34-1-34 teeth in each row. I have shown in Fig. 375 the central and various marginals from the first to the last tooth. The figures show the teeth as seen from below, thus giving a perfect view of the bases of attachment. The eighth tooth seems to be the largest, in an- other the sixth. The central tooth I find great difficulty in studying. It appears to have a loug, slender base of attachment, truncated and ' emarginate above and below, with slightly expanded lateral angles. [ The sides are somewhat incurved, giving the tooth the appearance of a simple modification of the base of attachment of the marginals. There is a single median cusp, with obsolete side cusps and a long, pointed median cutting point. (See the enlarged figure.) There are no lateral teeth. The marginal teeth are all of purely aculeate type. i The shell is a very variable one, as shown by the figures in Vols. Ill and IV, Terr. Moll. The form from Key West, figured in Plate LXI, Fig. 2, is a well-marked variety, but surely is not a variety of G. Tex- asiana, as I formerly supposed it might be. After further opportuni- ties of judging by the study of more numerous specimens. I am led to J change my opinion as to the specific distinction of the form I formerly ' called G. imvaUela. (See outline figure of Terr. Moll., III.) The rose-color of the living shell soon fades. Cirlaiidiiia. bullata, Gould. Shell elongate ovate, ventricose, widest a little behind the middle, Fio HTs. very light and thin, and so translucent as to show the whole of the pillar by transmitted light, very pale horn- <;olor, tinged with rusty brown towards th
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