392 HYATT: GENEALOGY OF ACHATINELLID^E. 



The apertures vary from toothless to those with prominent 

 tooth-folds, but the shield on the columella and the structure 

 of the peristome occurs in almost all of these forms. A 

 marked characteristic is also the presence of bars or zigzag 

 lines of color in the early neanic stage or throughout life in 

 all the shells, as a rule except in extreme cases of albinism. 



The shells of the Partulinella marmorata series have a 

 peculiarly brown barred pattern either throughout life or in 

 the early neanic sub-stage. There are two sub-series ; the first 

 consisting of highly colored shells with elaborate marbled or 

 banded patterns that show affinity with Partulinella dubiot 

 in these colors and in their young; but as a rule these have 

 large columellar tooth-folds. The second sub-series consists 

 of shells that have lost these more highly colored patterns 

 in their later stages in different degrees and have remnants 

 of these only on their young and finally only in some individ- 

 uals in the most degenerate species. 



The sub-series of P. marmorata, shells with marbled or 

 banded pattern, is as follows: Partulinella proxima Pse., red- 

 fieldi Newc., tessellata Newc., rufa Newc., from Molokai; 

 Partulinella crassa Newc., P. perdix Rve., pyramidalis Gul., 

 splendida Newc., and several others from West Maui; Par- 

 tulinella marmorata Gould, plumbea Gul., grisea Newe. from 

 East Maui P. tessellata and rufa have either no tooth-fold 

 or a very slight one, and this condition is also found in 

 P. crassa* 



Marmorata series, Sub-series of P. horneri: These consists of 

 the species heretofore included in Partulina that occur on 

 Hawaii. They resemble the toothless forms of Oahu, Molokai, 

 and Lanai, and are especially similar to P. crassa of Lanai. 

 The spire, however, is more concave and more acute and in- 

 creases more rapidly and more regularly, and the last volution 

 flares out with a more even and regular form. The colu- 

 mella may be open or closed, but is always toothless and has 



* Partulinella is a new subdivision of Partulina proposed by Professor Hyatt 

 for species with the last embryonic whorl marked with protractive stripes ; the 

 shell otherwise like Partulina s. str. P. marmorata may be taken for type. 

 H. A. P. 



