.i.\>TK'l't>l'A 1'I.V.I 



DMdlftlr ] 



fr.mi the typical form of the speclM.a* above described, by having much floer surface mark- 

 Ing* ami th<- outer Mir fare ( the whorls almost constantly concave. The undulations of the surface, 

 .I) occurring wore commonly In this form than In any other, are not considered of much Importance. 

 A- ii. .Icately sculptured rarlety deserve* some recognition we propose to retain Mr. James' name 



In a reduced sense for It, so it may be known hereafter as O. Wttr rar. Jturiuntum. 



Heck's r. Mix var. Iota (Pal. Ohio, TO). I, p. 152) seems to rest on nothing more than an unusually 

 depressed and somewhat abnormally colled old shell of the typical form of the species. What I* calls the 



il form of the species Is something quite different, being one of the forms of our C. mediate, while the 

 high shell represented by his flg. fy on plate XIII, which Is the type of Miller's var. conieum, really belongs to 

 the species aa restricted by us. The spire In the last lx>lng higher than usual, the name oonieum might 

 be retained rr It. but after an exhaustive study of a large number of specimens we are forced to the con- 



11 th.it tli.- r.-latlve night of the spire Is a very unreliable character, each species and variety exhib- 

 iting great variability In this respect. The form of the whorls Is a better character, butof all the surface 

 markings have served us best In separating the various species. 



. In the great confusion prevailing among collectors and authors concerning the species of Cyclontma 

 occurring In the region about Cincinnati, we have found It no small task to select the particular form 

 which has the best right to bear Oonrad's original name, bilix. The significant points about Oonrmd's 

 bri.-r description are: (I) that the sides of the volutions are "suddenly contracted at th suture," (2) the 

 periphery Is abruptly rounded, (3) the bane flattened and (4) the locality, Richmond, Indiana.* 



We have a number of good specimen* (about sixty, exclusive of an even greater number of the var 

 JbedMtttm) from Richmond and Versailles In Indiana, and localities In Ohio exposing equivalent horizons, 

 freeing In all essential respects with the specimen Illustrated on plate LX X V III, and which, to the best 

 of <>ur knowledge, are of the same specie* as the one figured by Conrad. A rare variety with more convex 

 whorls occurs in the Lorraine group at Cincinnati, but this Is not the same as either of the two from that 

 locality which have been sent to all parts of the world as C. bilix. The typical form of the species was lost 

 sight of and the more easily obtained Cincinnati forms, which careless or Interested observers had said 

 were the same, took Its place. Excepting the variety mentioned, C. bilix Is restricted to the Richmond 

 group and, therefore, does not occur at Cincinnati. 



We cannot agree with the practice* of certain paleontologists who, either because they are Incapable 

 of separating the forms, or unwilling to take the trouble, would have us classify all the Cyelnnema of the 

 Cincinnati a ad Trenton periods as one species. The following forms are as good "species" as any, and as 

 each represents a recognizable and sufficiently permanent stage In the evolution of the genus, each with 

 Its own set of varieties or mutations, they deserve the notice of the systematise The more experienced 

 and careful collectors long ago separated the common forms, not only because they were different but 

 because they found them at different horizons. 



Formation and locality. Richmond group, Richmond, Versailles, and Madison, Indiana; Oxford 

 Waynesvllle, Blanchester and numerous other points In Ohio. Fragments apparently of this species were 

 seen at Sterling and Savannah, Illinois, and there is no reason known why It may not occur also In 

 southern Minnesota. 



-E. O. Ulrich. 



CTOLORKMA MIDI ALB, n. sp. (Ulrich.) 



PLATE LXXVIII. P108. !V .ad ft). 



WKr (part.) HALL, MEEK and other authors; not CON BAD. 



Distinguished from C. bOim Conrad, by Its more ventrlcose whorls and stronger revolving carlnss. 

 The under side of the whorls Is fuller and tho outer side (seen In the spire) Is always distinctly and 

 uniformly convex, there being no sign of a shoulder at the suture, nor of the median concavity, both of 



The orUlnml description r*4s w follow* :- 



P. Mir. PI. xvi. . W. flairs eonleal: volution* (oar: ttd ubrvctlllD.ear t (>. luddeoljr oontracUd tl tboutur*. 

 urfac* with plrl rmtood ttrbc Jlernattd In U; lr volution tbruptlr rounded In IU fr*lt clreumferwo*. bnM 

 SntlMMd ud (Mated. 



tut. IndlM. lnllmMtOMoribor ibcrocluof ItlmonKlrcr MrlM. Nw York. Lover Sllurlu 



