OAVM. 



Har.olia. I 



description.. l\ -tin-part which relates to the absence of a slit and dorsalband, 



we place the genus near Otctnella and rrotomirtlii-i, and consider it as well dis- 

 tmpiishfd from those genera by the trilobate character of its shells. Kokin </.. 

 without -utliciciit \\arrant considers Meek's diagnosis as incorrect and proposes 

 to extend the limits of the genus so that it will include, beside the species placed 

 here by Meek and which Koken admits he has not seen, two other groups of 

 species, one falling under our Telr-modi, the other, having revolving surface 

 marking, probably under Hnr,ini>i>xix. For further discussions see remarks specially 

 devoted to the genera named. 



Family BUCANM1' 1 . 



:iinetric. involute shells; whorls rather numerous, merely in contact, or 

 embracing slightly, all visible in the umbilicus; aperture often expanded abruptly; 

 dorsal slit-band di-tinct, the slit itself generally very long and narrow, some- 

 times represented by a row of openings; surface with transverse lamella- or lines, 

 n-nally crossed at right angles by short ribs. 



TKTKANOTA, n. gen. (Hucunia [part] of Hall and other authors; Bucanella 

 .\. K uken, not Meek.) Shell thin; aperture moderately expanded, laterally 

 chiefly; inner lip without callosity; sinus more or less deep, terminating in a short 

 -lit; whorls generally compressed so that the transverse diameter greatly exceeds 

 the vertical; umbilicus open, large or of moderate size; dorsal band very wide, 

 margined on each side by a strong ridge; about midway between these ridges and 

 the narrowly rounded or angular sides of the volutions there is another ridge 

 on each side, making in all four constant revolving ridges; aside from these the 

 surface markings consist of rather delicate, sublamellose, regular lines of growth, 

 each crossed at right angles by its own set of minute ribs. The revolving ridges, 

 the lateral ones especially, are best developed on the inner whorls and may become 

 indistinguishable near the aperture. Type, Bucania bidorsatu Hall. 



<'<r r ofontMJieMM Whittled sp. ] 



T. MMTMMia U. & 8. / Wdonwta Hall p. 



..;- r .v> 



KOKKNIA, n. gen. (liucanelln [part.]. Koken, 1889, not Meek, 1870.) Volution- 

 depressed; slit-band wide. Hat, elevated, with a broad concave space on each side; 

 umbilicus open, rather lar^e: a^rture not expanded, lips thin, the outer one deeply 

 emarginated. Surface with straight, uninterrupted revolving ribs, strong on the 

 lateral parts of the dorsum, fine on the slit-band: growth lines very delicate. Type, 

 Buranelln tsthonn \\ Nrues .lahrbucli fur Mint-ralo^it-. etc.. Itfilagebainl \ i. p. 



389; 1889). Ix>wer Silurian drift, Berlin. One American A'. rw/u//.s- I'. A 



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