AM \c\ LAND SNAILS FROM HAWAII, CHRISTMAS ISLAND, AND SAMOA Bv HENRY A. PILSBRY, C. MONTAGUE COOKE, JR., AND MARIE C. NEAL Bernige p. Bishop Museum BtJLLETIN 47 HoNOLuiu, Hawaii PtjBUSHEP BY THE MuSEUM /o 3 LAND SNAILS FROM HAWAII, CHRISTMAS ISLAND, AND SAMOA BY HENRY A. PILSBRY, C. MONTAGUE COOKE, JR., AND MARIE C. NEAL Bernice p. Bishop Museum Bulletin 47 Honolulu, Hawaii Published by ths Museum 1928 A^. 101 ,««- t , /d 5 1 CONTENTS Pag« Georissa, a land snail genus new to the Hawaiian islands, by Henry A. Pilsbry 3 Food habits of Partula zebrina Gould, by C. Montague Cooke, Jr 5 Introduction 5 Food of Partula 7 Anatomy 11 Summary 12 Three Endodonta from Oahu, by C. Montague Cooke, Jr 13 Introduction 13 Habits 14 Endodonta lamellosa 14 Shell characters 16 Soft anatomy 19 Conclusion 21 Endodonta marsupialis 21 Shell characters 22 Soft anatomy 22 Conclusion 24 Endodonta fricki 24 Shell characters 24 Soft anatomy 25 Conclusion 27 Bibliography 27 Distribution and anatomy of Pupoidopsis hawaiiensis, by C. Montague Cooke, Jr., and Marie C. Neal 28 Distribution 28 Anatomy 29 General 29 Jaw and teeth 30 Kidney 31 Genitalia 31 Summary ^^ Anatomical studies of Achatinellidae, by Marie C. Neal 34 Comparison of representative species of the family 34 Development of genitalia in Achatinella viridans 44 ILLUSTRATIONS Figure 1. Three new species of Georissa 4 2. Mouth parts of Partula zebrina and shells swallowed 11 3. Anatomy of Endodonta lamellosa 18 4. Free muscles and teeth of Endodonta lamellosa 19 5. Reproductive organs of Endodonta lamellosa 20 6. Reproductive organs and teeth of Endodonta marsupialis 23 7. Reproductive organs and tooth of Endodonta fricki 26 8. Expanded animal, pallial organs, and alimentary tract of Pupoidopsis hawaiiensis 28 9. Reproductive organs of Pupoidopsis hawaiiensis 30 10. Reproductive organs, teeth, jaw, and position of tentacles of Pupoidopsis . hawaiiensis 32 11. Pallial organs and alimentary tract of Partulina redfieldii, P. horneri, P. virgulata, and P. mauiensis 35 12. Pallial organs and alimentary tract of Newcombia canaliculata and Achatinella lehuiensis var. meineckei 36 13. Genitalia of Partulina redfieldii 36 14. Genitalia of Achatinella lehuiensis var. meineckei, Partulina virgulata, and P. rufa 38 15. Genitalia of Partulina mauiensis, P, horneri, P. dubia, and Newcombia cumingi 39 16. Nerve collar of Partulina redfieldii 42 17. Genitalia of Achatinella viridans 44 18. Genitalia of Achatinella viridans 45 19. Genitalia of Achatinella viridans 46 20. Genitalia of Achatinella viridans 47 21. Genitalia of Achatinella viridans 47 22. Genitalia of Achatinella viridans 48 Land Snails from Hawaii, Christmas Island, and Samoa By He;nry a. Pilsbry, C. Montague: Cooke:, Jr., and Marie: C. Neai. GEORISSA, A LAND SNAIL GENUS NEW TO THE HAWAIIAN ISLANDS By he:nry a. pii^sbry In the course of a trip to Kauai, Marie C. Neal, Assistant Malacologist, Bernice P. Bishop Museum, had the good fortune to collect specimens of three species of Georissa, forming the subject of this paper. The special interest of this discovery lies in the fact that it adds a genus and a family new to the Hawaiian fauna. It is, moreover, a group of purely terrestrial station, not a seashore or atoll dweller such as Trun- catella; therefore the less likely to be transported by natural rafts or other means of oversea drift. The nearest known neighbors of these Kauaian Georissa are in Guam and in the Society Islands. The species here described appear to be more closely related to those of the Society Islands than to species of Guam. On the western borders of the Pacific, the genus Georissa is known from Japan, China, the Philippines, and southward to tropical Queensland. Eastward it is spread through the Cook and Society islands to the Marquesas. All of the species were taken on a ridge between Hanalei and Wailua, Kauai, on the Pole Line Trail between Kualapa and the summit camp, elevation about 2,000 feet, in moss collected on fallen logs. The moss was subsequently dried, and the shells were found in the finest si f tings, the only other shells occurring with them being young specimens of Tornatellina and Leptachatina and a single specimen of an undescribed species of Punctum, Georissa cookei, new species (figure 1, a). The shell is conic, orange-cinnamon colored, composed of 3^ strongly convex whorls. The first whorl appears to be smooth or very minutely punctate; the last two whorls are encircled with low spiral cords about as wide as their intervals. At Bernice P. Bishop Museum — Bulletin 47 the beginning of the last whorl are about 5 or 6 cords between lip and suture; on the base the spirals are smaller and weaker. The oblique aperture is somewhat wider than semicircular. Columellar margin straight, heavily calloused. Length i mm., diam. o.8 mm., height of aperture, 0.5 mm. Figure 1. — Georissa: a, Georissa cookei, new species; b, Georissa neali, new species ; c, Georissa kauaiensis, new species. Type, 131432, Academy of Natural Sciences of Philadelphia; paratype, 59188, Bishop Museum. Georissa neali, new species (figure 1, &). The shell is decidedly shorter than G. cookei, of 2^2 strongly convex whorls. The embryonic shell is inflated, hemispherical, deeply and closely striate across (Trivia-like, as seen from above). Subsequent whorls have a few low, wide, somewhat uneven spiral cords. The aperture is strongly oblique, semicircular, the straight columellar margin heavily calloused. Color white, but probably bleached. Length 0.85 mm., diam. 0.75 mm. Type, 131433, Academy of Natural Sciences of Philadelphia; paratype, 59189, Bishop Museum. Georissa kauaiensis, new species (figure 1, c). The shell is light pinkish cinnamon, somewhat more globose than G. neali, with the first whorl of more regular shape, not striate, but showing a faint, close microscopic punctation; 2^ whorls, the last having faint traces of spiral sculpture. Length 0.9 mm., diam. 0.8 mm. Type, 131431, Academy of Natural Sciences of Philadelphia; paratype, 59187, Bishop Museum. The type of this species is evidently not adult, but it differs from its fellows so much in sculpture that it must represent another species. The embryonic whorl appears to be larger than in G, cookei, and subsequent whorls are far less strongly sculptured. Very few specimens of these tiny shells have been examined, and their limits of variation are unknown. They are the smallest species yet known in the genus. Pilsbry, Cooke, Ned — Snails from Hawaii, Christmas, Samoa 5 FOOD HABITS OF PARTULA ZEBRINA GOULDi BY C. MONTAGUE COOKK, JR. INTRODUCTION The family Partulidae contains but the single genus Partida. This family is confined to high islands of the Pacific and has no near relatives on any of the continents bordering this ocean. The eastern limits are Rapa and the Marquesas islands, the western the Pelew, Talauer, and Admiralty islands. It does not occur in the Hawaiian islands to the north, and its southernmost representative is on the island of Rapa. Most of the literature on the genus Partula is taxonomic. While little is devoted to distribution, still less has been written on the habits of the snails. Crampton is the only writer who has closely studied the habits of the genus. 2 Other than that certain species are arboreal or terrestrial I can find nothing else that has been published. Crampton found that ... the greater number of species in Tahiti, in the Society Islands, and elsewhere, whose representatives are arboreal during the day time . . . [remain] sealed up on the under sides of leaves less than 10 to 15 feet from the ground; at night, however, they resume activity and crawl to the earth to feed upon decaying vegetation. . . . Under normal conditions . . . Partulae resume activity at night and become quiet in bright light, in practically 95 per cent of the cases as observed in the laboratory, and in ex- periments in the field where snails were placed on suitable plants at the coast for determination of this point. But if the atmosphere is very dry, they are apt to remain sealed up all night, while, on the other hand, if the sky becomes clouded and the light is reduced, they will crawl about even in the day time. When rain falls and humidity increases greatly, they move about with celerity, crawl to the ground, and resume feeding. As far as I can learn the only observations in regard to their food have been made by the same author. To quote again: The character of the food of Partulae is a matter of considerable interest, in view of the theoretical possibility that differences in the vegetation of separated valleys might be adduced to account for the diverse characteristics of the snails in such dif- ferent localities. When the facts are examined, however, this possibility is ruled out. Confining our attention to the low arboreal species, and disregarding those of the ground and of the highest tree-tops, we have several independent series of data that justify the statement given. In the first place, it is clear that the snails do not feed on the living tissue of the plants upon which they are found, because the organisms may be present in numbers on a perfect unmutilated leaf, and because no leaves occur that display alterations saving such as are made by insect larvae. Secondly, the animals go to the ground to feed, as described in the foregoing paragraphs. Thirdly, the stomach-contents of active and newly killed snails comprise no fresh vegetable material, » Read at the second annual meeting of the Hawaiian Academy of Science. ^^^^ J. 1927. » Crampton, H. E., Studies on the variation, distribution, and evolution of the genus I'artula. Carnegie Inst. Washington, Pub. 228, pp. 24-26, 1916. 6 Bernice P. Bishop Museum — Bulletin 47 but only the rasped fragments of decaying woody and fleshy plant tissues. Again, animals that were feeding under observation in nature avoided the living parts of plants and restricted themselves to decaying leaves and wood. Finally, the specimens that were brought back to the laboratory ate moist dead leaves with avidity ; only when very hungry did they eat the whiter and firmer portions of lettuce and cabbage leaves. In transporting them from the field, they consumed great quantities of wet paper, which to all intents and purposes, is wood pulp. Dall has suggested that in the case of Achatinellidae decaying vegetation is eaten for the sake of the fungi that grow in and upon it. Whether or not the same is true for Partulae, the fact remains that the nurse-plants upon which Partulae are found during the day do not seem to have any effect upon the specific or varietal characters displayed by these animals. We would scarcely expect that this would be so, when representatives of three distinct species may be sealed up on a single leaf of caladium, plantain, or Dracaena, Last year in company v^ith Mr. A. F. Judd and Mr. Theodore T. Dranga, I spent six weeks in American Samoa. On the Island of Tutuila three species of Partula were taken. These three species were found associated in diflferent proportions, in some localities, but in many localities only the most common species, Partula zehrina Gould, was found. The habitats of two of the species, Partula conica Gould, and Partula abbreviata Mousson, were also slightly different from those of P. sebrina. The first two species were usually taken on the trunks and branches of trees and shrubs but sometimes on the leaves, while P. zebrina was taken under almost all conditions, usually on the leaves of shrubs and trees, sometimes on trunks and branches of trees. A considerable per cent were also found on and under dead leaves on the ground and a very few on stones. No obser- vations were made by any of us as to whether they were nocturnal in their habits, but it was very noticeable that a large number of specimens were active and crawling during rain and shortly after. Nearly all our material was expanded by drowning and brought back to Honolulu in alcohol. During the early stages of the process of extracting animals from shells. Miss Neal found a specimen of Aphanoconia in the body of a young specimen of P. zebrina, which led to a tentative examina- tion of every specimen of Partula that was cleaned in the laboratory. All animals in the stomachs of which shells were found were isolated for fur- ther study, and some of them served as the material on which this paper is based. I have used only a portion of the data collected and have examined critically the stomachs of about 200 specimens. The catalog numbers of the specimens referred to in this paper are as follows: AmouH, 84173-84185, 84228, 84234, and 84238-84243; Pago Pago, 83779-83789 and 83821-83831; Fagasa (arboreal), 83919-83933 and 83937- 83942; Fagasa (terrestrial), 83970-83975; Mount Tau, 84457; Logotala, 84783. Pilsbry, Cooke, Ned — Snails from Hawaii, Christmas, Samoa FOOD OF PARTULA Judging from the type of the teeth of Partula, the genus is herbivorous. As shown by Crampton, the stomach contents of Tahitian species is made up of decayed vegetable matter, which was found also in some of the Samoan snails. To determine this point, the stomachs of 50 P. sebrina were examined. Of these, nine were empty or nearly so, and one or two were found to contain matter that could be classed strictly as decayed vege- table matter, as it was very black. In most specimens the vegetable material consists of very fine brownish particles, which appeared to be made up of rather newly dead vegetable matter. In addition to this material, 21 speci- mens had the stomachs crowded with or partly full of a compact white mass. Dr. Brown has made a careful microscopic study of this material and has come to the conclusion that it is the undigested remains of vegetable matter. In the stomach of one specimen, in addition to the white mass already mentioned. Dr. Brown was able to recognize partly digested, newly dead leaf cells and fibers, diatoms, Protococcus, fern sori, bacteria, pollen grains, etc. Of the 50 specimens examined, only three contained the remains of shell animals. As the shells had been completely dissolved and the animals crowded in with vegetable matter, none of the genera was recognizable. Of the three species of Partula occurring on the Island of Tutuila, only P. zehrina was found to have acquired the habit of swallowing other land shells. Of the many hundreds of specimens of P. conica and P. abbreviata that were tentatively examined, not a single stomach was found to contain a shell. This is probably due to the relatively thicker shell of P. zebrina, and, as I will try to show later, shells are swallowed merely to procure lime for the formation of new shell material. The frequency of this habit is illustrated by Table 1, for which I have selected specimens from five somewhat separated colonies. TABI.E: 1. I^RKQUE:nCY Ot THE SHElvI.-SWAI.I.OWING HABIT IN PARTUI^A ZKBRINA Colony Amouli Pago Pago Fagasa (arb.) Fagasa (ter.) Mount Tau ... Logotala Totals ADULT u en 1 CO X! OS 5 ^^^ 138 22 116 16 72 22 50 30 120 21 99 17 6 2 4 33 50 13 37 26 137 9 128 6 523 89 434 17 YOUNG W5 u ^ (U . i^ O 1 t 7 CO CM fO 00 CO CO oj 213 *^0 en en C G oo CO c4 a CTJ J3 §15 C/iPs ^3 *^S 23 oS nJTJ Ui<43 COPh C/3Ph 03 0, a o o 3 2 t 3 I 1" 00 mmm tii m m m m m lam CO I J! CO .S CO CM CM 00 1 .s , >. >» ^^ >;i CO CO -no :2;0 kJ CO .2 O GM p O-M t^ r-H to 3 3 2 1 "T T I CX3 to CT) Csi r-; ^ CM to CO t^ VC) 1-H 1—1 tA r6 06 fO HiiitiAiii! 3 I J 3 T 7 t "T T 1 10 to 10 CO to eg r-l CMr-l .5 c C3 CMt-I ^ !s ^ i§ 2 ;o '3 ^ ^ 'o "o rt '0 § § s § § as n! j5 .2 ^ rt g ci a* 1 s *co 'a; 6 II m CO .s 1 c 1 g g §1 .55 Ss •*-' 'jn 5 3 n :3 3 ^ rt •^ <*•» OS CO co-g fi< a, A^ A. P^ < 3 3 3 X! J3 J=! rt rt rt S 3 u'u u CA js s ^ .s Jm* 1 g 13 a .S rt j2 rs CtJ ^ bo a u Si i-i X o-fi 3 *-:« u <: "JS ^ *~4 Q4 1 13 . 13 3 »2 3 •^S *^ •s -s 1) M ^ r^ 00 lis Die •2 o\ o. 'f i^^- wi <^ ^ ic 3 O rl- bO.rT TfPO X* tS Tf 'T tv a-^ ^^ .. C ^ «- t^ " • • .^ »-. ^ \o "» ^ L^;;o6 .^ "o 2 -"too -5 *+^ 3^ -Hvo iJ a c - -^ (u ctf 5.2 nj*i3 .5 «J w a jj o 1 M^ !^A- d ^ ^ !> n '^ §^< ctf .^.j> ^^ ttfP^ « « < < < 42 Bernice P. Bishop Museum — Bulletin 47 In the Manual of Conchology^^ the statement is made Borcherding tentatively suggests the view that P. rufa is "not a pure species, but a bastard form between P. tessellata Newc. on the one side, and P. proxima Pse. on the other." While this seems rather doubtful, and probably could be proved only by breeding experiments, rufa certainly unites characters of the two species. The embryo has protractive stripes as in P. proxima. Some very rare color forms closely resemble proxima in the later stages; but it differs from that species by the dull surface, deeply sculptured spirally; proxima being glossy, with weak spirals and very slight trace of the minute, wavy, spiral lineolation of the full Partulinas. This, of course, deals with the shells only. Anatomically P. rufa and P. proxima were found to be closer to each other than to any other Par- tulina. Two sections of Achatinella, represented by Achatinella viridans, lehuien- sis var. meineckei, and stewartii var. pro duct a c. f. dunkeri, were not dis- tinguishable except in the smaller size, velvet-black mantle, and gray penis and appendix of A. I. meineckei. The section Eburnella, similar in many ways to Partulina redfieldii, was not found to be uniform. For P. mighelsiana and P. mighelsiana var Figure i6. — Partulina redfieldii (Newcomb), nerve collar, b. n. = buccal nerve, cer. g. = cerebral ganglion, ped. g. = pedal ganglion, sub. com. = subcerebral commis- sure, t. n. = tentacular nerve. Greatly magnified. bella though alike otherwise differed distinctly in the length of the first division of the appendix, that of the species ranging from 6 to 7 mm., of the variety from 3 to 4 mm. P. nattii differed even more widely. The first division of its appendix ranged from I/2 to 1 J4 nim., the second division and penis were shorter, and the kidney was distinctly wider than were corre- sponding parts of the preceding species and variety. The section Baldwinia showed even less uniformity than Eburnella. The three species in the section Perdicella showed fair uniformity, Par- tulina mauiensis differing from the other two in having a shorter third »5Pilsbry, H. A., and Cooke, C. M., Achatinellidae : Man. Conch., vol. 22, p. 30, 1912-1914. Pilshry, Cooke, Ned — Snails from Hawaii, Christmas, Samoa 43 division of the appendix and a shorter kidney. In length of penis, of branch of penial retractor, and of appendix they differed from Achatinella. This is true also of the three Newcomhia, which differed slightly among themselves. Perdicella and Newcomhia thus seem to be the only distinct groups in the family. Summary Though for the most part alike anatomically, according to data in Table 5 and figures 11 to 15, a few distinct differences were found in Achatinellidae, as follows : 1. All species of Newcomhia had comparatively shorter kidneys than Achatinella and Partulina. 2. Only in Partulina mighelsiana were the two free muscles, the ten- tacular and buccal, entirely disconnected from each other. In all other species the length and closeness of attachment varied, but not uniformly. 3. The penis varied in length, being proportionately shorter in the three Perdicella, in the three Newcomhia, and also, strangely, in large Par- tulina horneri than in the other Achatinellidae. 4. The location of the penial retractor muscle deviated little from slightly to one side of the tip of the penis. The shortened or webbed nature of the branch of the penial retractor in Perdicella is added proof of the primitiveness of that section. 5. The length of the appendix with its three divisions bears out in a general way the relationships designated in one or more other organs. 6. In proportion to the size of the animal the prostate gland was about the same size. 7. The spermatheca was oval or elliptical in all except Partulina horneri. 8. The place of origin of the spermatheca duct on the oviduct was not constant, even in one species. 9. Divisions of the family by shell characters and anatomical characters do not agree. Jud^-ing from the few specimens examined, some species had wide differences in measurements and in shape of some parts of their anatomy, greater proportional differences than between some of the different species. The overlapping of variations shows that anatomically Achatinella and Partulina cannot be differentiated, except in the section Perdicella and the genus Newcomhia. The consistent differences of the three Perdicella from other Achatinellidae suggest that the section^^ should be raised to generic rank. The decision that Newcomhia should have generic value^^ is confirmed. 1^ op. cit., p. 15. ^"^ op. cit. p. 1. 44 Bernice P. Bishop Museum — Bulletin 47 DEVELOPMENT OF GENITALIA IN ACHATINELLA VIRIDANS While looking for differences in anatomy in different species, I noticed the disproportionate size of genitalia in comparison to the size of juvenile and adult animals, and this led to an investigation of the development of genitalia in one species. Descriptions and figures of adult genitalia of sev- eral species in the family Achatinellidae have already been published. (See page 34-) A series of the species of land mollusk, Achatinella viridans, was collected November 26, 1926, in Waialae Iki, Oahu, Hawaii, by William H. Meinecke for Bishop Museum for use in anatomical studies. The material, consisting of sixty specimens ranging in size from newly born infants to gravid adults, was divided into six groups according to number of whorls, which ranged from 3 to 6 1/4. In each group two or more animals were examined. (See figs. 17-22.) Group A The first animal examined (figure 17) was a gravid adult in the group having shells with from 5 3/4 to 6 1/4 whorls. All these snails were fully adult, as evidenced both by the animals and the shells, the shells having apertures with thickened lips. As was expected, each part of the genitalia was found to be fully developed. In a second specimen, the male organs Were about identical in size and length; the uterus was shorter above the embryo. FiGURie 17. — Achatinella viridans Mighels (No. 87423), genitalia, ephebic stage-— app. = appendix, h. d. = hermaphrodite duct, n. = nerve, o. = oviduct, p. = penis, pr. g. = prostate gland, r. p. = retractor penis, sp. = spermatheca, sp. d. = sperma- theca duct, ut. = uterus, v. d. = vas deferens. Pilshry, Cooke, Neal — Snails from Hawaii, Christmas, Samoa 45 Group B The second group consisted of adult snails (figure 18) with 5 3/4 to 61/4 whorls, the same number as in the first group. But these had no embryos, and the lip of the aperture was not thickened. Besides not being distended, the uterus was shorter, and the spermatheca seemed slightly smaller. Otherwise the organs were found to be as well developed as in Group A. As a matter of fact, in both of the two specimens examined the male organs were larger than in Group A; but whether this was due to individual variation or to some other cause was not discovered. In some other species examined, pregnancy did not aflfect the length of the penis. Figure 18. — Achatinella viridans Mighels (No. 87424), genitalia, ephebic stage, lettering as in figure 17. Group C In the third group (figure 19) a decided difference was evident, and varying stages of development were found, though the range in the number of whorls of the shells was only half of one whorl, being between 5 1/4 and 5 3/4, most being 5 1/2. This seemed to be a transitional period — an extremely short one — when the snails were half way between maturity and youth, that is, in phases of the neanic stage. ^^. One of the specimens I examined was quite undeveloped (in the metaneanic stage), the other close to maturity (in the paraneanic stage). The specimen in the paraneanic stage (fig. 19, a) had smaller and more slender genital organs than those in Group B. But evidently they were nearly ready to function. The uterus was as long but much narrower, and the spermatheca duct branched off from it slightly higher up. The prostate 1* op. cit., Appendix to Amastridae. Tornatellinidae, vol. 23, p. xi, 1915-1916. This and similar terms given in the following account were first used by Pilsbry and Cooke. 46 Bernice P. Bishop Museum — Bulletin 47 gland was greatly reduced, and the spermatheca smaller. The penial retractor muscle was slender. When the dissection was made, the appendix was lying out straight, following the penial retractor muscle. Near the proximal end of the free muscles, its tip was bent down, apparently only because the cavity was not long enough to allow it to lie straight throughout its length. In all maturer specimens the appendix was found lying curled around in the region of the penis. Figure ig.— Ac hatine I la viridans Mighels (No. 87425), «. genitalia, paraneanic stage, lettering as in figure 17; h, genitalia, metaneanic stage. The specimen in the metaneanic stage (fig. 19, b) had no genital orifice, and none was found in still younger animals. It was present in all the preceding groups. Both male and female organs were much reduced, com- pared to the paraneanic stage, and were flattened, as they also were in the younger animals. I found no spermatheca. Possibly it was too minute or else homogeneous with the soft undifferentiated material of the tiny prostate gland. The spermatheca duct branched ofif from the uterus distinctly higher up. The penial retractor muscle was not forked. It continued from the top of the penis down the side a short way and from there was free to a point near the base of the appendix. Group D Examples of the ananeanic stage (fig. 20) (4 3/4 to 5 whorls) were found to have quite inconspicuous genitalia. Besides being smaller than Pilsbry, Cooke, Ned — Snails from Hawaii, Christmas, Samoa 47 Group C, another difference was found in the penial retractor muscle. The base of the appendix was webbed by it closely to the penis, from the tip of which it extended upwards in a thin thread. The spermatheca duct branched off even farther up on the uterus. The prostate gland appeared to be a short wrinkled tube. Figure 20.— Achatinella viridans Mighels (No. 87426), genitalia, ananeanic stage, with details, lettering as in figure 17. Group E In the next smaller size (figs. 21, 22, h) (4 1/2 whorls), also an ananeanic stage, the appendix and penis were shorter, and a muscle con- nection between them could not be distinguished. The prostate gland seemed similar to that in the preceding stage. Figure 21. — Achatinella viridans Mighels (No. ^^7427), genitalia, ananeanic stage, with details, lettering as in figure 17. 48 Bernice P. Bishop Museum — Bitllctin 47 Group F As well-developed embryos of Achatinella viridans have three whorls the next stage examined (fig. 22, a) was evidently the youngest phase of the ananeanic, the shells having 3 to 3 1/4 whorls. The genitalia were minute and translucent, the uterus being almost transparent and also quite frail (two specimens breaking in the process of dissection at this point before a whole one could be obtained). The appendix was absent, and the penis had an enlarged tip, from which extended its retractor muscle as the finest of threads. Spermatheca duct and vas deferens had not developed, as the uterus appeared to be an unaccompanied tube. The part that would have developed into the prostate gland was not even enlarged, an angle at the tip of the uterus on one end and the narrower tube of the hermaphrodite duct on the other showing its position. It was embedded in soft clinging mate- rial, which it was necessary to remove before the outline of the tube could be seen. The uterus lay in the same position as at maturity and at its proximal end the oviduct was attached by a wide base to the wall of the animal behind the right tentacle, at the place where the genital orifice would later develop. p-^S- h.a. Figure 22. — Achatinella viridans Mighels (No. 87428) : a, genitalia, ananeanic stage, with details, lettering as in figure 17, ped. r. = pedal retractor, r. t. r. = right tentacular retractor; b, showing position of genitalia in specimen of same size as that shown in figure 21, t. = tentacle. At this stage an important feature was a connection near the base of the penis. It led from there shortly but indirectly to the right cerebral ganglion, being a thread-like nerve in a wide filmy sheath, which may also have served to conduct arteries in this region. The connection was noted in all the other five groups, but it grew constantly looser and slighter with age and was quite insignificant in mature animals. In the same region a short connection was noted with the tip of the pedal retractor muscle, which at this growth stage stopped near the proximal end of the genitalia. Pilsbry, Cooke, Ned — Snails from Hawaii, Christmas, Samoa 49 Summary Conclusions that may be drawn in regard to the genitalia of Achatinella viridans, a representative of the Achatinellidae, are as follows : 1. They develop to greater proportions during the growth of the animal than the body of the animal. 2. They are not ready formed with the embryo but develop from simple to complex structures. In the youngest examined, the organs offered slight suggestion of their condition at maturity, the hermaphrodite duct, prostate gland, and uterus seeming to form a continuous undifferentiated tube or thread. 3. Apparently male and female organs develop equally from the young- est stage to maturity and are ready to function at the same time. So far as observed they are present during the entire life of the animal. AUG28 1944 lilllAlHi 3 9015 02327 1805 Onh uB^^Rr^- Rimed by Preservation 1996