BRONN ON PAL^ONTOLOGICAL STATICS. 41 



inserted between f and t in a peculiar column s. The head v is de- 

 signed for the Molasse, and contains the fossil remains from certain 

 rocks, of which it is uncertain whether they should be reckoned to 

 the middle or upper tertiary strata : whenever this question is de- 

 cided, the contents of this head will fall to be divided between the 

 two adjoining divisions. In like manner, if only formations of distinct 

 age were classed under separate heads, the head x, for freshwater 

 diluvial formations, should vanish and be conjoined with w, as in 

 reality several species of mammalia are common to both. We would 

 thus, on the whole, obtain only 21 to 22 instead of 24 formations. 



But irrespective of these difficulties, the complete enumeration of 

 fossil bodies has another class of hindrances to contend with. The 

 stratum in which many species, and hence even genera, occur, is mi- 

 known ; and whether we omit them altogether, or class them in all 

 possible formations, or in one period and formation selected arbi- 

 trarily, still the truth must suffer. A large number of organic re- 

 mains appear mider two or three synonyms, which for want of ac- 

 curate comparison cannot be conjoined, and hence must be numbered 

 two or three times over, although they occur only once. This hap- 

 pens especially in the polyparia and mollusca, the synonyms of which 

 have not yet been sifted and arranged in any monographical work ; 

 whereas the polygastrica and foraminifera by Ehrenberg and D'Or- 

 bigny, the Crustacea by Behrendt, Burmeister, and others, the echi- 

 noderms and fishes by Agassiz in special monographs, the plants and 

 the three higher classes of the vertebrata by Goppert and H. v. 

 Meyer for the ' History of Nature ' itself — have all been so carefully 

 wrought out, that in these parts but few synonyms now appear among 

 the true species. But among the polyparia and conchy lise the species 

 depending on mere synonyms may amount to 0*10 to 0*20. We 

 have also, with few exceptions, made it a rule, where fossils appear 

 under unsuitable specific or generic names, still in this catalogue to 

 form no new names, but to leave this to future monographs, and 

 were consequently compelled to quote many species under unappro- 

 priate genera, as has been occasionally pointed out in the Enumerator 

 itself; — there are likewise a number of genera wholly or partly syno- 

 nymous, which for the same reason we must allow to remain, although 

 this also, in the majority of cases, is indicated in the Enumerator : 

 such species consequently could not always be counted in the proper 

 place and under the right family ; and the number of the genera has 

 thus also turned out rather too large, although in the summing-up 

 attention was for the most part paid to these circumstances. If in 

 this manner a greater number of fossil species and genera appear 

 than were really before us, yet on the other hand the deduction to be 

 made on this account is more than compensated by the new disco- 

 veries made during the last two years since the completion of our 

 work, though these indeed extend over the whole system, and do not 

 exactly fall in those orders in which they were wanted to supply these 

 defects. Many insects and species of birds are only noticed under 

 the proper families and orders, since their genera were not deter- 

 mined, and consequently they could onlv be assumed as di^nded 



g2 



