No. 89.J 25 



companion to Prof. C. B. Adams's extremely valuable Catalogue of 

 the Shells of Panama, which belong to the same great Tropical 

 Fauna of Western America. 



An estimate of the value of the Reigen Collection as a geographi- 

 cal authority, and a comparison of it with other neighbouring 

 faunas, will be found in the " Report of the present state of our 

 knowledge of the Mollusca of the West Coast of North America," 

 presented to the British Association in September 1856, and pu- 

 blished in its Transactions, pp. 159 et seq. The only account of the 

 Shells of Mazatlan previously known, is Dr. Menke's list of the 

 species brought by Mr. H. Melchers, published in the Zeitschrift 

 fur Malacozcologie^ 1847 - 51. An analysis of these is given in the 

 Erit. Assoc. Reports, pp. 235 - 239. 



The species of Bryozoa* (now first, I believe, included in a cata- 

 logue of Mollusca, although generally acknowledged by naturalists 

 to belong to that Subkingdom), have been described by G. Busk, 

 esquire, with his usual kindness. The class is named as in Dr. W. 

 B. Carpenter's "Principles of Comparative Physiology, 1854." The 

 name Polyzoa is believed to have precedence : but while the names 

 of genera and species are proper names, and therefore ought to fol- 

 low the law of priority, the arrangement of classes and orders is a 

 matter of opinion; and it appears allowable to make use of those 

 names, whenever given, which best express the leading characteri- 

 stics of the division. For this reason, Palliohranchiata and Lamelli- 

 hranchiata are used instead of the older names Conchifera and (or 

 rather, including) Brachiopoda; Prohoscidifera, for Zoop/iaga, &c. In 

 the present case, when the names of a supposed order (of polypes) 

 becomes entitled to rank as a class (of molluscs), and as such has 

 to be learned in common, schools, it appeared very important to 

 select a name that could not easily be confounded with others of 

 similar sound. 



In the Bivalves, the order of Prof. E. Forbes, adopted by Mr. 

 Woodward in his invaluable " Manual of the Mollusca," has been 

 mainly followed; in the Univalves, that of Dr. Gray, who obliging- 

 ly lent me the proofsheets of liis " Systematic Arrangement of the 

 Mollusca," now passing through the press. 



Having found considerable difficulty in the identification of spe- 

 cies, when Lamarckian genera are retained without division, al- 



\ 



* The Crustacea, Cirripedes, Annelids, Radiata, &c. found in the Reigen Collection, are de- 

 posited in the "Warrington Museum; which has the honour of being the first Free Museum and 

 Library established in the manufacturing districts. Duplicate series of the shells can be obtained 

 through the Curator. 



[Senate^No. 89.] 4 



