Cooper.] ^O"* (May it;, 



nected by intermediate forms, even that retained by Mr. Binney in genua 

 Euparypha {Tryoni), the difference in this being merely the result of a 

 greater abundance! of lime in its food, and therefore in the shell. It is 

 also noi improbable that the species called Euparypha from southern Eu- 

 rope, etc., are merely Arionta developed under similar conditions. In 

 our species, however, I see no reason for allowing more than specific dif- 

 ferences. Specimens of II. kellettii, and of var. crebristriata may be 

 selected, and are more common fossil, that have just as much claim to 

 be considered Euparypha (or of other genera) as Tryoni. No single char- 

 acter, external or internal, will suffice to distinguish genera in this family 

 or order of animals. 



A. redimita W. G. Binn. The author of this name now calls it "proba- 

 bly a variety of A. rameutosa," relying upon a resemblance in sculpture. 

 But this file-like surface is characteristic of many forms in the young state, 

 and of these species, the island variety first named redimita, show's in 

 its form a much nearer approach to A. kellettii than any other, and much 

 the same sculpture. The jaws and Unguals are also nearer. A variety of 

 californiensis, however, comes very near it in form, and was formerly 

 mistaken for it on this coast. 



I have before discussed the close gradations between the other southern 

 species of Arionta. 



Sub-genus Campyl^ea? 



Retaining this name provisionally, I merely refer to my previous writ- 

 ings for the distinguishing characters between it and Arionta. The re- 

 markable differences in the geographical distribution of the species, shown 

 in the maps referred to, is among the most striking of their characters. It 

 is quite probable that more thorough search in intermediate localities will 

 tend to increase the number of connecting links, but as now known the spe- 

 cies are more distinct than in Arionta, though a regular gradation in char- 

 acters corresponding with their distribution has been already referred to.* 



* With his characteristic devotion to European precedents, even where plainly 

 wrong, Mr. Binney retains the name Aglaia now as a genus) though long ago 

 shown to he preoccupied twice in Mollnsca. Besides it was used first for a South 

 American snail of apparently distinct generic characters from ours. But be- 

 cause Albers long ago placed H.fidelis in this group, it is retained, with the sub- 

 species or southern race infumata, and because the latter lias a form like that of 

 II. hillebrandi, Mr. Binney has put this also with them, ignoring the fact that 

 this species bears exactly the same relation to 77. mormonum as II. infumala 

 to fi'ldis, and that intermediate specimens are even more common between 

 the two first. II. mormonum, however, is an "Arionta" according to Mr. 

 Binney ! 



Now any one with the shells before him can see a regular gradation from //. 

 hillebrandi through mormonum, sequoicola, dupetilhouarsi, traskii, carpenteri, 

 diabloensis, ruftciiicta, to i/nhhi and facia. If our is an Aglaia, all are, the differ- 

 ences between this genus and Arionta being in the shells, though Binney's de- 

 scription does not make- it at all clear. Having before pointed out the distinc- 

 tive characters (Amer. Jour, of Conch., V, 201), I merely wish here to amend 

 them by stating that I placed H. carpenteri \u Arionta from misapprehension 

 of its true characters, and that diabloensis as well as this, is probably a variety 

 of traskii, although the form described by Kinney as diabloensis appears tobea 

 variety of ramentosa, of which he docs not figure a type. The types, however, 

 show an approach to Arionta as I stated in description. 



