Zoological Society, 227 



complete revolution in this department of the science, and has done 

 more towards giving us data for the geographical distribution of the 

 testaceous mollusca than any person who has yet lived. 



"Helicid^. 

 " When we consider what the genus Helix was when Linnaeus 

 wrote, and what it now is, we must be struck with the flood of new 

 species which has been poured in upon us of late years. Already 

 the vocabulary has been so drawn upon, that the mere finding 

 names for the new species is attended with no small embarrass- 

 ment, whilst the limits of each species are daily more difficult to fix. 

 When a few forms only in a great natural group are known, they 

 are easily defined. It is where multitudes are placed before the 

 zoologist, marked with every variation that food and temperature 

 and locality can impress upon them, that it becomes no longer easy 

 to solve the problem, * Which is a species and which is a variety?' 

 Then it is that the pregnant question * What is a species .'' ' comes 

 home to the mind. But our business now is to define, as well as 

 we can, those forms which have been laid before us, and which, to 

 us at least, are new. When the whole of the additions to this great 

 tribe existing in Mr. Cuming's collection have been studied, we shall 

 perhaps have materials for something like a complete natural ar- 

 rangement of the group." 



Genus Bulinus*. 

 BuLiNus MiNDOROENsis. Bul. tcstd ovutd, ventHcosd, subprond, 

 anfractibus sex, ultimo longe maximo, lineis incrementi obliquk 

 striatd, aperturd subrotundd, columelld latd, labio expanso. 

 Var. a. valde ventricosa, sordid e brunnea strigis irregularibus longi- 



tudinalibus varia ; aperturd subalbidd ; labio nigro-brunnescente. 

 Hab. ad Puerto Galero in insula Philippine Mindoro dicta. 

 Legit H. Cuming in sylvis. 



Var. b. Pallidior, coloribus distinctioribus , fascid suturali brunned 

 interruptd ; anfractu ultimo fascid brunned strigis longitudinali' 

 bus interruptd cincto ; labii margine castaneo-rufescente. 

 Hab. ad Mansilai in insuld Mindoro. 

 Legit H. Cuming in sylvis. 



Var. c. Gracilior, longitudinaliter brunneo et jiavo sordido striata. 

 This comes very near in colouring, and approaches somewhat in 

 the shape of the aperture, to the two first varieties of Bvl. chrysali- 

 diformis. The markings of the young shell remind the observer of 

 the eggs of some of the Plovers, and the shape assists the delusion. 

 Hab. ad Puerto Galero in insula Mindoro. 

 Legit H. Cuming in sylvis. 

 Var. d. Sordide flavescens creberrime longitudinaliter corrugata et 



strigata. 

 * " I have elsewhere (Zoological Journal, vol. iv. p. 222) given my 

 reasons for writing Buli/nis instead of Bulimus. Adanson's Bul'm was a 

 Physa, and the word, however written, is very inapplicable to the forms to 

 which Bruguiere> Lamarck and authors generally have applied it." 



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