DISTRIBUTION AND VARIATION OF ACHATINELLA MUSTELINA MIGHELS IN THE WAIANAE MOUNTAINS, OAHU BY D'ALTE A. WELCH BERNICE P. BISHOP MUSEUM BULLETIN 152 HONOLULU, HAWAII PUBLISHED BY THE MUSSUM 1938 TABLE OF CONTENTS PACE Introduction ·······························-······················ ............ -··-······················-·····················-·····-········ 3 Historical ........ - .................. - ........................................................ - .....................................- ..... 3 Scope of the work.................................... ...... ·-·--··-·················--·--.. _ ................ -..................... 5 Plac::e ruunes ·······-·········-······--··--············-·---·················-········-········-·-············--···········-··--·-- 6 Climatological data ···--·······-······--··-····--···········-···········-···-··--........... _........... -... -·······-······ 7 Methods ··-····-··-····- .. ·····-··············· .. ·---·······-···········-··-········-·-····-·-·- ·-··-········-······ 11 Explanation of maps ........................ - ..... ·-······-············-···-··-·- ···--··-············-···-··-········· 13 Species concept ·-··-····-·······-······-······· .. ........................................ -··-··-········-··-··-··-······ 14 Taxonomy ················-··-····-·-···-··-·····-·--· .. ···-··-·-··-···-····················---··· .. ·-·-··-·-·-·····-···· 15 Species and subspecies included. ..... _ ...... - ·-··-···········-··-········· .. -···--·······-··-·······-··-···· 15 1. Achatinella mustelina subspecies of the northern section of the Waianae Mountains-........................ ·- ················-····················-···········-··- ·····---···· 16 2. Achatinella mustelina subspecies of the central section of the Waianae Mountains························-·······- ············-····················-·-·-·······-··-·-·· 96 3. Achatinella rnustelina subspecies of the southern section of the Waianae Mountains ................ -·-·····-·······-··-··-···············-·······-··-·-·······-····.. ·-·· 123 Sunuoa.ry and discussion.-······-···-··-····-···"'·····-·················-··-···-···-···-··-·······-··-···-··-··-·· 141 Literature cited ···----·--······-·······-············-·- ····-·--······-········-················-······-·-··-···-·· 154 Index ····-·················-················-·····------·.. ··---·-······-······-·-- ·············-·················-····-···-··-··· 155 Index to place names-....... _·······················-··············-.. -············································-··--·····-··-·· 156 Explanation of plates......... .... _ ............................... - .. ··········-····-···········-············· .. ·-·········----···· 159 Figure 1 in text. Maps A and 1-16 in text. Plates 1-13. 0~.._.... :z _ __,4 mi I e ~ Map A.-Island of Oahu with location of rain gauge stations plotted in the Waianae Mountain region. Distribution and Variation of Achatinella mustelina Mighels in the Waianae Mountains, Oahu* By D'AI,'tE A. WELCH INTRODUCTION H1STOIUCAI. A single valley on Oahu may contain a number of different color races of tree shells of the genus Achaiinella. A locality may contain shells of one particular pattern, while a neighboring locality in the same valley may have a mixture of one or more kinds. Do these color patterns occur in definite places at random, or are they arranged according to a definite plan? Is it possible to ascribe this variation to any probable cause? Early collectors and students of land shells up to 1850 were interested in new species rather than in the localities from which they came. They gave their specimens general place names such as "Sandwich Islands'', "Oahu", or "l\folokai." Pilsbry and Cooke have presented a very complete account of 1 the historical background of Achatinella (5) • About 1850, John Gulick made a great advance in the work by carefully noting the valleys from which his shells came, and in so doing, he noted that shells from different valleys varied in color pattern. Dr. C. M. Cooke, Jr. carried the work further by giving more detailed locality citations. Under his stimulus, a number of fine collections were built up, all carefully annotated, which formed the foundation for Pilsbry and Cooke's work on this genus (5). In this volume, Pilsbry states : In the typical group of Achatinella (Apex), a certain correlation seems to exist between pattern and elevation, banded forms occupying higher situations than streaked forms of the same species, at least in many cases. I believe that the relation is an indirect one. Banded patterns have been evolved from streaked, as stated on p. xx; evolution in more humid stations would naturally be more rapid than in lower, less abundantly watered places, .slnce resting periods would be shorter, and the succession of generations would be faster. A study of his discussion of A. ape~fulva (5, pp. 321~330, map, p. 277) shows that on one or more ridges in the Koolau Range, different color races occur on different parts of the ridge or at different elevations. Whether this • Submitted to the Board of Uni...,rsit;y Studi~ of Johns Hopkins University in C(lttfonnity wjth the n!<juirements for the Ph.D. degree. 1 Numbers ln parenthese1 tefer to Literature Cited, p. 154. 4 Bernice P. Bishop Museum-Bulletin 152 was purely a random or a constant differentiation due to or occurring at different elevations could not then be determined due to lack of material. When my work began in 1931, little further advance had been made, because there were little or no accurately plotted data concerning these shells or their localities in any museum, to my knowledge, with the exception of a few lots from localities in the district of Mokuleia, plotted on rough out­ line maps by Dr. Cooke. Before 1931, no suitable map of Oahu was avail­ able to collectors on which to plot localities easily. In 1931, I procured a set of advanced sheets of the United States Geological Survey of Oahu through the kindness of Mr. C. S. Judd, Territorial Forester, to use in field work. Another set of maps, a gift of Mr. Robert King of the Territorial Survey Office to Bishop Museum, also proved invaluable to me. The first plotted collection of Achatinella was formed in 1932 by G. W. Russ, then Assistant Forester on Oahu. The collection is particularly rich in shells from the northern section of the Waianae Mountains and is the foundation of this paper. Soon after this collection was plotted, the W. Meinecke collection was received by Bishop Museum, and was plotted by Mr. Meinecke. Later, Dr. Cooke plotted his Waianae Mountain localities. Since the plotting of the Museum's three major collections still left the picture of the distribution of Achatinella incomplete as far as the Waia~ Mount:il.ins were concerned, efforts were made to increase the collections. Mr. G. W. Russ, Mr. W. Meinecke, Mr. H. Lemke, Mr. H. Lemke, Jr., Marshal and Mrs. 0. F. Heine, all collected large numbers of shells and gave many to Bishop Museum. Other collectors to whom I am indebted are Mr. C. S. Judd, Mr. G. P. Wilder, Mr. I. Spalding, Major and Mrs. Charles Steel, Mr. F. R. Fosberg, Mr. E. H. Bryan, Jr., Dr. Erling Chris­ tophersen, Mr. C. W. Isle, Mr. Otto Degener, Mr. E. J. Meadows, Miss Jane L. Wirme, and many others. All doubtfully plotted localities were personally checked as far as possible, and their work supplemented by my own weekly trips into the field. In addition to the highly localized material collected since 1931, the Musewn collections contained many Waianae shells collected by D. D. Bald­ win, E. D. Baldwin, E. Lyman, E. W. Thwing, C. M. Cooke, Jr., R. A. Cooke, W. D. Wilder, 0. H. Emerson, A. F. Judd, C. S. Judd, Henry Judd, L. A. Thurston, and others. The portion of the Gulick collection in Bishop Museum is one of the most valuable parts of the shell collection. According to Mr. Addison Gulick, it was originally divided into 20 separate collections. In 1913, Dr. Pilsbry and Dr. Cooke bought collections 5, 6, 7, 8, and 9, and divided each lot of a single species into equal halves, Dr. Cooke's portion going to Bishop Museum as a gift. Later, Mr. Addison Gulick presented Bishop Museum with collections 14 and 15. The J. S. Emerson collection also in Bishop W elch-Achatinella mustelina of the Waianae Mountains 5 M usewn is especially outstanding as it contains many shells collected at about the same time as many of Gulick's. Thus, many very rare shells now believed to be extinct are represented in the collection by large series. I wish to thank Mr. W. J. Clench of the Museum of Comparative Zoology at Cambridge for allowing me to study types of Achatinella and to have photographs made of type specimens. I am grateful to Mr. G. C. Robson and Mr. W. T. Calman of the British Museum for similar courtesy. I am also indebted to Mr. J. R. le B. Tomlin and Colonel A. J. Peile of the British Musewn for assistance they gave me while I worked there. Above all I wish to express my appreciation to Dr. C. M. Cooke, Jr. for the advice and encouragement he has given me. 1 am deeply indebted to Dr. H. A. Pilsbry and Dr. E. A. Andrews for advice and help towards the completion of this work. Dr. H. B. Baker, Dr. T. Sonneborn, and Dr. Gardner Lynn also aided me in completing the paper. Dr. Henry Crampton has given me many ideas concerning the value of biometrically treating distribution problems. Finally I wish to acknowledge the encouragement and support of the Trustees of Bernice P. Bishop Museum and of the Museum's successive Directors, Dr. H. E. Gregory and Dr.