CLASS GASTROPODA 
235 
antiquum var. beringiana found their place on Plate II, figs. 3, 4, and 
Plate V, fig. 1 of my “Beitrage.” Among several shells of the variety 
beringiana that came from Kamchatka the Museum possesses one with 
especially high aperture a" (long., 90; last whorl, length, 56y 2 -%. The 
flattening of the whorl decreases on some specimens in that below the 
middle of each whorl a more or less distinct step shows itself, so that 
through this the whorls become like those of Fits, perversus Lamarck. On 
one specimen from Kamchatka with very short and strongly bent canal, 
distinguished by the complete flattening of the whorl, the indication 
of the step cannot be overlooked, and there runs also and parallel with 
that at some distance below it, a scarcely perceptible keel. This thus- 
described variation gives the transition to an unusually large and thick 
specimen (total length, 120; whorl, 4) from Bering Sea, which belongs to 
the form normalis A, and in its dimensions corresponds perfectly to the 
normal form of my variety beringiana; however, the next before the 
last and the third before the last whorl not only show the step distinctly, 
but also show on each whorl weak and irregular indications of 6 to 7 
varicose ridges. This specimen, which I here figured on Plate V, fig. 1, 
of the second half of my “Beitrage,” indicates that it is possible that 
a locality might be found where the variety beringiana might occur with 
keeled sculpture B'. This would be a significant approach to my var. 
communis and angulato carinata of T. antiquum L., and in such a case 
only the more depressed form and slender and more greatly bent canal 
would give means of distinguishing them. At the same time in the case 
discussed, transitions to Fusus bulbosus Val. would be attained, which I 
am acquainted with up to this time only in the textless illustration ( Voyage 
de la Venus; Atlas d'histoire naturelle; Mollusque, PI. V, figs. 2a, 2b, 2c) 
but which as to the measurements -comes quite near to the more depressed 
varieties of my var. beringiana . (Translation.) 
Type in Academy, St. Petersburg. Type locality, Bering Sea. 
Range. Norton Sound, south to Unalaska, Alaska. 
Chrysodomus saturus communis Middendorff, 1848 
Beitrage zu einer Malacologia Rossica, 2:131; PI. 5, figs. 5, 6. 
Testa rufescente, medilis anfractibus omnibus angulato carinatis; 
anfractibus duobus aut tribus, nobis (in quoque anfractu 8 ad 10) eodem 
sensu magitudine auctis. 
Es ist dieses nach meiner Erfahrung die haufigste Varietat, welche 
auch den grossten Verbreitungskreis einnimmt. Fur gewohnlich sind 
die Kiele und Knoten als aussere Sculptur nur undeutlich ausgesprochen, 
[ 235 1 
