25 



smooth, others are crenulated, and all are more or less arched 

 toward the mouth. The texture of the shell is horny, with lime- 

 phosphate. The phosphate is conspicuous, in the outler layer- 

 The phosphatic appearance is more strongly marked in some 

 groups of rocks than in others, which is likewise true concerning 

 the horny texture, which, sometims, as in C. greenei, re- 

 sembles the test of a crustacean. 



The genus Conularia is so distinct from all others that no other 

 genus has ever been confounded with it. It is the only genus in 

 the family Conulariidce. Any one having ordinary perceptive 

 faculties, after having carefully examined a specimen belonging to 

 any species of Conularia, can tell a Conularia wherever he sees 

 it, no matter to what species it belongs. This cannot be done 

 with any other fossil specimen from the palseozoic rocks except, 

 possibly, a Bellerophon or an Orthoceras. 



The genus made its appearance, in the Trenton period, repre- 

 sented by small and large species, as fully developed and pos- 

 sessed of as distinctive specific characters, as the genus ever ac- 

 quired. These it retained, throughout its life history, and closed 

 its career in the Coal Measures, by such large species as C. 

 roeperi and such small species as C. crustula. It came from some 

 quarter wholly unknown, and after having lived as long as any 

 other genus ever did upon the face of the earth, except, possibly, 

 Bellerophon, Pleuroiomaria, Murchisonia, Orthoceras and one or 

 two genera of the Brachiopoda, it disappeared as abruptly as it 

 came, without leaving a trace of its final course behind it. There 

 is no evidence of development or evolution connected with the 

 genus. It never showed any higher or lower stage of existence, 

 than it did when it first appeared. Some species had a wide geo- 

 graphical and geological range; for example, C. trentonensis from 

 New York and Kentucky, and C. subcarbonaria from the Keokuk 

 Group, at Crawfordsville, Indiana, and Hamilton, Illinois. We 

 have seen large specimens and small specimens belonging to the 

 same species, possessing exactly the same ornamentation and sur- 

 face characters. But we have never seen anything that indicated 

 advancement or decline in the genus or in any species, and fur- 

 ther, we have never seen any intermediate forms, that might be 

 said to represent a link connecting any two species. This may be 

 cold comfort, to those limited palseo-biologists, who claim to see, in 

 every fossil, a link from the lowest to the highest stages of ani- 

 mal existence. It is, nevertheless, true, that we do not even know 

 to what Class, in the animal kingdom, the family Conulariidaz, or 

 the Order, Conularida should be referred. 

 —4 



