1020 THE PALEONTOLOGY OF MINNESOTA. 
(Ccelocaulus cehlerti. 
Species whose known characters are in accord with this diagnosis of Celocaulus 
occur in most of the principal formations from the Calciferous on to well up into 
the Devonian system. Of these Murchisonia linearis Billings, is the oldest. Then 
followed our C. whlerti and C. neglectus, both Trenton forms, M. compressa Lindstrom, 
from Upper Silurian strata in Gothland, M. bivittata, M. longispira, M. logani and 
M. turritiformis, four Guelph species described by Hall, and C. davidsoni, C. barroisi 
and C. procerus, three species described from the Devonian of France by (hblert. 
And there are others which probably belong here, but they are as yet too little 
known to justify their removal to Cwlocaulus. However, without them, the ten 
species mentioned make a sufficiently respectable showing to establish the genus in 
the classification of the Paleozoic Gastropoda. 
C@LocauLus (2HLERTI, ”. Sp. 
PLATE LXX, FIGS. 61—63, 
This species is known only from fragmentary casts of the interior, but as it is an interesting and 
striking form we deem it well worth a description. The apical angle is about 12°, and, if the taper of the. 
spire is uniform an entire specimen must consist of at least thirty whorls, and have a length of about 
60mm. The largest specimen, having a maximum diameter of 12 mm., has eight whorls in a length of 
30 mm.; another, 9 mm. in diameter, has twelve whorls in the same distance. The hight of the whorls is 
to their wiith as 2is to5or3to&. The whorls are very little separated and decidedly convex in casts 
but in the shell itself, which evidently was very thin except at the sutures, the convexity must be consid- 
erably less. Transverse section of whorls rounded quadranglar. Band and surface markings not observed, 
probably obscure, since no trace of them is visible on a mould of the exterior. 
We know of no other shell in the Lower Silurian deposits of the Mississippi valley that could fora 
moment be confounded with C. whlerti. The next species is smaller and has a much wider apical angle, 
with fewer whorls. 
Formation and locality.—A rare fossil of the Trenton group (Galena limestone), and so far known 
only from Jo Daviess county, Illinois. 
Collection —EK. O. Ulrich. 
C@LOCAULUS NEGLECTUS, ”%. Sp. 
PLATE LXXXII, FIGS. 29—31. 
Hight about 18 mm., apical angle about 25°. Theonly specimen seen is a slightly distorted cast of 
the interior, consisting of only four whorls, the uppermost of which has an obtusely rounded termination, 
indicating that the apical whorls were filled with an organic deposit. These four whorls have a hight of 
about 12 mm., the last a diameter of 7 mm., the first of about 3mm. The whorls are rounded in trans- 
verse section, the sutures deep, the umbilical perforation small, yet very obvious. 
This small species might be confused with Hormotoma subangulata or with certain varieties of H. 
gracilis, but if the observer will bear in mind that the umbilicus is very small and quite inconspicuous in 
casts even of those shells, that their whorls are not so much depressed nor subcircular in section, and that 
the upper turns are never lacking except through accident, he should not have much trouble in disting 
uishing the Coelocaulus. 
Formation and locality.—Clitambonites bed of the Trenton group, near Cannon Falls, Minnesota, 
Collection.—E. O. Ulrich. 
