BRYOZOA. 333 



The theory which is suggested in the foregoing paragraph is 

 corroborated by similar comparisons between early Palaeozoic 

 and more recent representatives of perhaps every class of the 

 Invertebrata. It is well shown in the Mollusca and is especially 

 apparent in those classes that are largely represented in recent 

 seas. The student of Palaeozoic fossils is continually beset with 

 obstacles in his endeavor to classify his species, finding over 

 and over again that the rules which serve so well arrange 

 recent material, do not apply to the Palaeozoic faunas. To this 

 is attributable much of the confusion which pertains to palaeo- 

 zoology, since, according as the student emphasizes one or the 

 other character, the fossil is removed from one family to another. 

 Is there no remedy for this deplorable state of affairs? The 

 remedy will be at hand when palaeontologists generally will 

 have come to realize the vastness of their science, and the im- 

 portance of accurate and discriminative observation of the min- 

 ute details of structure. This is the pressing necessity, a min- 

 ute inquiry into the morphology of Paloeozoic life, and the in- 

 evitable result, a better idea of Palaeozoic geneaology, can- 

 not fail to produce harmony w T here we now have utter confu- 

 sion. A superficial observer determines the affinities of a fossil 

 very quickly; not so the careful student. He has learned to 

 esteem caution, because he sees how very easy it is to misin- 

 terpret a character, and how extremely difficult the task of cor- 

 relating the ancient types with the living. A full appreciation 

 of this difficulty may have led me to propose and adopt divi- 

 sions that workers on recent Bryozoa may object to in the be- 

 ginning. Thus the suborder CRYPTOSTOMATA lately proposed 

 by Mr. Vine, includes forms which there can be little doubt are 

 to be regarded as the ancestral types of a large proportion of 

 the CHEILOSTOMATA. In fact, the CRYPTOSTOMATA really repre- 

 sented that suborder in Palaeozoic times, and we might with 

 with much propriety unite the two groups. Still, as all the 

 Palaeozoic forms have certain peculiarities in common in which 

 they differ from the true CHEILOSTOMATA, the better course, at 

 any rate now, is to keep them separate. 



The order GYMNOLJSMATA includes, so far as known, all the 

 fossil Bryozoa. The bulk of those in the Palaeozoic rocks I 



