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, tliat the mere finding 

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

 ment, whilst the limits of each species are daily more diflScult 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 MiNDOKOENSis. Bul. tcstd ovutd, ventrtcosd, subprond, 

 anfructibus sex, ultimo longe maximo, lineis incretnenti obliqtie 

 striatd, aperturd subrotundd, columelld laid, lubio expanso. 



Var. a. valde ventricosa, sordide brunnea strigis irregularihus longi- 

 tudincdibus varia; aperturd subalbidd ; labia nigro-brunnescente. 



Hab. ad Puerto Galero in insula Philippina Mindoro dicta. 



Legit H. Cuming in sylvis. 



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

 interruptu ; anfractu ultimo fascid brunned strigis longitudinali- 

 bus interriiptd cincto ; labii margine castaneo-rvfescente. 



Hab. ad Mansilai in insula Mindoro. 



Legit H. Cuming in sylvis. 



Var. c. Gracilior, longitudinaliter brunnea et flavo sordido striata. 



This comes very near in colouring, and approaches somewhat in 

 the shape of the aperture, to the two first varieties of Bul. 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 Buliwus instead of Buliwzus. Adanson's Bulin was a 

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

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



Q2 



