242 NATURAL SCIENCE [April 



trious American professor Daua rejects them on grounds which, I 

 think, Dr Faxon and Miss Eathbun cannot possibly accept ; but, 

 apart from those grounds, Dana declares that " Leach has undoubted 

 priority." 



Now, then, at last we may return to Latreille and his magic 

 volume of 1810. Latreille was not the author of the genus Astacus, 

 and he made no attempt to subdivide it, so that it is difficult to see 

 by what rule he could have any right to assign the type. But it 

 is superfluous to debate his right, if he never did or thought of 

 doing that which Dr Faxon so confidently affirms him to have 

 done. Observe, first, that the family to which Latreille assigns 

 Astacus as the initial genus, is called by him " Homardiens, Astacini," 

 and homard is not French for crayfish, but for lobster. Yes, but 

 then in that table of genera " avec I'indication de I'espece qui leur 

 sert du type," he gives " Ecrevisse, Astacus fluviatilis, Fab.," and to 

 anyone who urges that Latreille was only giving an example of the 

 g'enus, not the type in any technical sense, Dr Faxon makes 

 reply : — 



" As I understand it, the French word ' type ' means ' model,' 

 'type,' or 'standard,' not 'example' or 'illustration' (Gallic^ exemple). 

 I see no reason for going behind Latreille's plain words to indulge in 

 uncertain speculation concerning his possible meaning. If Mr 

 Stebbing is unwilling to allow Latreille the use of the word ' type ' 

 in its technical sense, by what ' statute of limitation ' will he fix 

 the year when the word acquired that meaning ? Even if it be 

 admitted that there is some doubt concerning the significance of the 

 word ' type ' as employed by Latreille, the benefit of the doubt 

 should, by a reasonable ruling applicable to all such cases, be given 

 to a long established terminology." 



" Some doubt," indeed ! Happily in this instance there is no 

 doubt. In spite of his great learning, Dr Faxon seems to speak 

 of Latreille as if he were a man of only one book. Latreille was 

 a voluminous writer. He can throw abundance of light upon him- 

 self. In 182-5 he published his "Families naturelles du Eegne 

 Animal," in which genera are mentioned for the most part only 

 under French names, and in which scarcely any species are men- 

 tioned at all. But of the very few which happen to be noticed 

 one is Astacus marinus, the lobster. Now, seeing that in this work 

 Latreille recognises three distinct genera, " Nephrops, Homard, 

 Ecrevisse" (p. 279), and that he calls the homard Astacus (p. 274), 

 he must have accepted a different generic name for the ecrevisse. 

 He evidently knows nothing about his own fine doings. It 

 would have amused him to learn that he was no longer at liberty 

 to speak of the lobster as Astacus, because already in 1810, in a 

 happy-go-lucky list of species, the river crayfish had been " speci- 



