. v '' 



IIW.1 



Hut thi> will not do, for it would he nothing le>s than ignoring mo-t palpahle 

 We mu-t return to the original t\pe. t\ ,,,-n<itt<s, and restrict the genus to 

 -p.-cie- p,.^e>MHK' essentially tli.- -aim- generic peculiarities. A Her lie character- 

 mentioned in tlie tir-t -entence of the preceding paragraph, which brings u- 

 d..wn in the ident ilicati.m of the genii- to four or live similarly constructed types, 

 these peculiarities con-i-t of il) the subquad i angular cross-section, of the whorls, 

 lie simple and sharp edged or minutely serrated character of the dorsal 

 .anna. <:'.' the total absence of a slit-hand and (4) the pattern of the surface 

 marking whieh. with a -ingle exception, differs from that of all other beller- 

 ophontid.-. The second and third of the features is shared by Oxydiscus, but as 

 the latter has more numerous and more compressed volutions, a much deeper 

 rural emargination and slit, and lines of growth only, there is little trouble 

 in M-paratiiijj it from Cyrtolites. Conradella is distinguished by its slit-band and 

 remarkably long apertural slit, by the rounded or cordate section of its whorls, 

 and hy its strongly imbricating and wavy surface lamellii-; I'orrelliti has a long 

 ulit like Conradella, rounded volutions, the inner ones unsymmetri. -ally coiled, and 

 different surface markings. For comparisons with Cyrtolifiim, which of all the 

 Hfller>,j,h<mti<{<r at present seems to be the nearest, see remarks on that genus 

 (some pages hence). 



Such strong resemblances are to be traced between casts of species of ('<n-i- 

 naropsis and Cyrtoliies, that, despite our strong assertion to the contrary on a later 

 page, we would really not be surprised if future discoveries should prove that the 

 are related genetically. At present, however, the origin of that genus 

 is enveloped in the greatest obscurity. As to Cyrtolites, it may have sprung from 

 Camhrian Slenothera. 



The species remaining under the genus as restricted are not many, and all (six) 

 about which there is no doubt are illustrated in this work. Four of the six are 

 described a-s new. Of the other American -pecies that have been referred to the 

 gem: ' mjiressus Conrad. C. </y<r; Hall. C. flri/mis Miller. <'. iinhrirtiftis Meek & 

 Worthfii. and < '. iinnosiis Hillings, belong to i 'nni-l- /l-i; C. maynu* Miller and C. 

 crisiatus Sall<>rd. to Osy-lisou; C. /////<> I'lrich, to Ci/iinlitiiin ; C. -nl><;irinnfus 

 Kninion-. pr-il-alily to Cnrinaropsit. C. filosux Kminons and C. crisis Conrad are 



halopoda; while the remaining forms, C. desidtrntns Billings, C. expansus Hall. C. 

 yill.tnu* White A- St. -iohn. Hall \ Whittield. and < '. >/>m...x-M.v Hall, are too 



little known to 1)6 placed with anything like certainty, "f Knropean -pecie- that 

 have heen referred to Cyrlni. iiap- none n-ally lelcniL r tin-re. <'. <lel<tnouei 



Khlert. and < '. itrhirulu* Lind>tr. .in doul>tless Itelong to (h-i/>lixi-ns, to which we are 

 inclined to reft > Lindstrom as well, although it ha- a di-tinct slit-band 



