60 bartsch: subspecies of obba marginata 



closely allied to that genus, in which the anthers are borne on 

 long filaments. By the sessile anthers blepharidium is easily 

 distinguished from all the genera of the Cinchoneae with imbri- 

 cate corolla lobes. 



ZOOLOGY. — A key to the Philippine subspecies of Obba mar- 

 ginata with notes on their distribution.^ Paul Bartsch, 

 U. S. National Museum. 



The preparation of a report on the Philippine Island land 

 shells reveals so many distributional gaps in the material avail- 

 able for study that it seems wise to publish a series of synopses 

 in the form of keys to the various groups as the work progresses, 

 together with a brief account of the zoogeographic facts pre- 

 sented by the data at hand 



It is hoped that these sketches may serve to stimulate collec- 

 tors to bestow their efforts upon localities from which material 

 is sadly needed to render the monographic reports complete. 



Obba marginata Miiller 



In this species the shell varies from broadly conic (066a ■marginata 

 mearnsi), to almost lenticular {Obba Jiiarginata samarensis) . The 

 range in size is also great. 066a marginata saranganica attains a 

 greater diameter of 35 mm., while in 066a marginata mearnsi it does 

 not exceed 19 mm. All the races have a narrow acute peripheral keel 

 to which the summit of the succeeding turn is appressed. The ground 

 color varies from pale buff (066a marginata griseola and 066a marginata 

 tnearnsi), to pale brownish (Obba marginata marginata). In all the 

 subspecies known, the peripheral keel and the extreme summit are 

 edged by a very narrow white or whitish zone, while the rest of the 

 upper surface of the turns is marked by three bands of brown of which 

 one adjoins the peripheral white zone while another bounds the white 

 line at the summit and the third occupies a space almost midway 

 between them. The width of these brown bands varies in the differ- 

 ent races. In some they equal the light areas that separate them 

 (066a marginata balidensis), while in others some of them are repre- 

 sented by mere hair lines. The intensity of the color may be the same 

 or may vary in the different bands on the same whorl, the band at 

 the summit being usually much paler than the rest. Two bands are 

 present on the basal sides of all the members of this species, one adjoin- 



* Published by permission of the Secreta;-y of the Smithsonian Institution. 



