TECHNIQUE 



tology impossible. The conception of species held 

 by a specialist must differ from that held by an 

 elementary student. For the latter, specific terminology 

 greater latitude, so that forms similar in all 

 characters will be grouped under a single 

 [en so, systematic difficulties are bound to 

 fertile source of confusion has been indicated 

 Derations of students have been taught that 

 \emisulcatus is a characteristic fossil of the 

 (olite, while P. umbrella is restricted to the 

 But it is now established that the name 

 ts belongs by right of priority to the Corallian 

 it from the Inferior Oolite having the specific 

 tus, while P. umbrella is a name with no 

 Inificance. The same fate has befallen other 

 Echinoid names, such as Ananchytes ovatus 

 Echinocorys vulgaris) and Galerites albo" 

 tich, after a temporary sojourn in Echinoconus, 

 ;d to Conulus. These irritating changes of 

 ire are not gratuitous pitfalls dug in the 

 path, but represent attempts to apply to 

 Jies and genera the names given them at their 

 ,innaean description. It is unfortunate, but 



