oo Le een m ree) ces oes ei ales “< ann ay os ‘ tas, ar yas =} athe Lae a ohne LA Ser Ta ewan ee eet Penh ms %. La Lane are nae es Py sae ”s AS ee Pn a er eae Sy ety wee ee ek ALBERT R. MANN LIBRARY AT CORNELL UNIVERSITY history of Crustacea; recent Malacostra Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924003415902 THE INTERNATIONAL SCIENTIFIC SERIES VOLUME LXXxI THE INTERNATIONAL SCIENTIFIC SERIES. Each book complete in One Volume, 12mo, and bound in Cloth. 1. FORMS OF WATER: A Familiar Exposition of the Origin and Phenomena of Glaciers. By J. Tynpaut, LL. D., F.R.S. With 25 Illustrations. $1.50. 2, PHYSICS AND POLITICS; Or, Thoughts on the Application of the Prin- ciples of ‘‘ Natural Selection”? and ‘Inheritance’ to Political Society. By WALTER BaGEHoT. $1.50. 3. FOODS. By Epwanrp Smitu, M.D., LL. B., F.R.S. With numerous Illus- trations. $1.75. 4, MIND AND BODY: The Theories of their Relation. By ALEXANDER BAIN, LL.D. With 4 Illustrations. $1.50, 56. THE STUDY OF SOCIOLOGY. By HERBERT SPENCER. $1.50. . THE NEW CHEMISTRY. By Professor J. P. Cooke, of Harvard Univer- sity. With 31 Dlustrations. $2.00. ON THE CONSERVATION OF ENERGY. By Batrovur STEWaRT, M.A., LL.D., F.R.S. With 14 Illustrations. $1.50. 8. ANIMAL LOCOMOTION; or, Walking, Swimming, and Flying. By J. B. Prerticrew, M.D., F.R.S., etc. With 130 Ilustrations. $1.75. . RESPONSIBILITY IN MENTAL DISEASE. By Henry Maovns ey, M.D. $1.50. 10. THE SCLENCE OF LAW. By Professor SHELDON Amos. $1.75. c=) a) =) 11. ANIMAL MECHANISM: A Treatise on Terrestrial and Aérial Locomotion. By Proressor E. J. Maney. With 117 Illustrations. $1.75. 12. THE HISTORY OF THE CONFLICT BETWEEN RELIGION AND SCI. ENCE. By J. W. Draper, M.D., LL.D. $1.75. 23. THE DOCTRINE OF DESCENT AND DARWINISM. By Professor Oscar Scumipt (Surasburg University). With 26 Illustrations. $1.50. 14. THE CHEMICAL EFFECTS OF LIGHT AND PHOTOGRAPHY. By Dr. HERMANN VoGEL (Polytechnic Academy of Berlin). Translation thoroughly revised. With 100 Illustrations. $2.00. 15. FUNGI: Their Nature, Influences. Uses, etc. By M. C. Cooxn, M.A., LL. vu. Edited by the dev. M. J. Berkeley, M.A., F.L S. With 109 Illustrations, $1.50. 146. THE LIFE AND GROWTH OF LANGUAGE. By Professor WiLLIAM Dwient WurenEY, of Yale College. $1.50. New York, D. APPLETON & CO., 1,3, & 5 Bund Street. 2 The International Scientific Sertes—(Continued.) 1%. MONEY AND THE MECHANISM OF EXCHANGE. By W. STANLEY Jevons, M.A., F.R.S. $1.75. 18, THE NATURE OF LIGHT, with a General Account of Physical Optics. By Dr. Evcene Lommen. With 18d Llustrations and a Table of Spectra in Chromo-lithography. $2.00, 19. ANIMAL PARASITES AND MESSMATES. By Monsieur Van BENEDEN. With 83 Illustrations. $1.50. 20. FERMENTATION. By Professor ScoUTZENBERGER. With 28 Illustrations. $1.50. 21. THE FIVE SENSES OF MAN. By Professor BernsTEIN. With 91 [llus- trations. $1.75. 22, THE THEORY OF SOUND IN ITS RELATION TO MUSIC. By Pro- fessor PreTro BLASERNA. With numerous Illustrations. $1.50. 23. STUDIES IN SPECTRUM ANALYSIS. By J. Norman Lockyer, F.R.8. With 6 Photographic lustrations of Spectra, and numerous Engraviugs on Wood. $2.50. 4. A HISTORY OF THE GROWTH OF THE STEAM-ENGINE. By Pro- fessor R. H. Taurston. With 163 Illustrations, $2.50. 25. EDUCATION AS A SCIENCE. By ALEXANDER Bsrn, LL.D. $1.75. 26. STUDENTS’ TEXT-BOOK OF COLOR; Or, Modern Chromatics. With Applications to Art and Industry. By Professor OGDEN N. Roop, Colum- bia College. New edition. With 130 Illustrations. $2.00. 27. THE HUMAN SPECIES. By Professor A DE QUATREFAGES, Membre de l'Institut, $2.00. 28. THE CRAYFISH: An Introduction to the Study of Zodlogy. By T. H. Hoxiey, F.R.S. With 82 Ulustrations. $1.75. 29, THE ATOMIC THEORY. By Professor A. Wurtz. Translated by E. Cleminshaw, F.C.S. $1.50. 80. ANIMAL LIFE AS AFFECTED BY THE NATURAL CONDITIONS OF EXISTENCE. By Karu SEMPER. With 2 Maps and 106 Woodcuts. £2.00. 81. SIGHT: An Exposition of the Principles of Monocular and Binocular Vision. By Josrra Le Conte, LL.D. With 132 Illustrations. $1.50. 82. GENERAL PHYSIOLOGY OF MUSCLES AND NERVES. By Professor J. RosenTsaL. With 75 llustrationa. $1.50. 83. ILLUSIONS : A Psychological Study. By James Suuty, $1.50. 34. THE SUN. By C., A. Younes. Professor of Astronomy in the College of New Jersey. With numerous INustrations. $2.00. New York: D. APPLETON & Cv.,, 1,8, & 5 Bond Street, The International Scientific Series—(Continued.) 8 85. VOLCANOES: What they Are and what they Teach. Ey Joun W. Jupp, F.R.S8., Professor of Geology in the Royal School of Mines, With 96 Il. lustrations. $2.00. 36, SUICIDE: An Essay in Comparative Moral Statistics. By Henry Mor- SELLI, M.D., Professor of Psychological Medicine, Royal University, Turin. $1.75. 3%. THE FORMATION OF VEGETABLE MOULD, THROUGH THE AC- TION OF WORMS. With Observations on their Habits. By Caar.es Darwin, LL. D., F.R.S. With Illustrations. $1.50. 38. THE CONCEPTS AND THEORIES OF MODERN PHYSICS. By J.B. STALLO. $1.75. 39, THE BRAIN AND ITS FUNCTIONS. By J. Luys. $1.50. 40. MYTH AND SCIENCE. By Tito Vienou. $1.50. fi. DISEASES OF MEMORY: An Essay in the Positive Psychology. By Ta. Rrsot, author of “ Heredity.’” $1.50. 42. ANTS, BEES, AND WASPS. A Record of Observations of the Habits of the Social Hymenoptera. By Sir Joun Luszock, Bart., F, R.S., D.C. L., LL. D., ete. $2.00. 43. SCIENCE OF POLITICS. By SHetpon Amos. $1.75. 44, ANIMAL INTELLIGENCE. By Grorce J. Romanes. $1.75. 45. MAN BEFORE METALS. By N. Joy, Correspondent of the Institute. With 148 Illustrations. $1.75. 46. THE ORGANS OF SPEECH AND THEIR APPLICATION IN THE FORMATION OF ARTICULATE SOUNDS. By G. H. von Muyenr, Pro- fessor in Ordinary of Anatomy at the University of Ziirich. With 47 Woodcuts. $1.75. 47. FALLACIES: A View of Logic from the Practical Side. By ALFRED Siwewics, B.A., Oxon. $1.75. 48. ORIGIN OF CULTIVATED PLANTS. By ALPHONSE DECANDOLLE. $2.00. 49. JELLY-FISH, STAR-FISH, AND SEA-URCHINS. Being a Research on Primitive Nervous Systems. By Groree J. Romanes. $1.75. 50. THE COMMON SENSE OF THE EXACT SCIENCES. By the late Wit1- 1am KINGDON CLIFFoRD. $1.50. 51. PHYSICAL EXPRESSION: Its Modes and Princivles. By Francis WaR- NER, M.D., Assistant Physician, and Lecturer on Botany to the Londor Hospital, etc. With 51 IJustrations. $1.75. 52, ANTHROPOID APES. By Ropert Hartmann, Professor in the University of Berlin. With 63 Illustrations. $1.75. New York: D. APPLETON & CO., 1, 3, & 5 Bond Street. The International Scientific Sertes.—(Continued.) 53. 62. 63. 68. 69. 70. a THE MAMMALIA IN THEIR RELATION TO PRIMEVAL TIMES. By Oscar ScumipT. $1.50. COMPARATIVE LITERATURE. By Hurcueson MacauLay PosNETT, M.A., UL. D., F.L.8., Barrister-at-Law ; Professor of Classics and English Literature, University College, Auckland, New Zealand, ete. $1.45. . EARTHQUAKES AND OTHER EARTH MOVEMENTS. By Joun Miiez, Professor of Mining and Geology in the Imperial College of Engineering, Tokio, Japan. With 38 Figures. $1.75. . MICROBES, FERMENTS, AND MOULDS. By E. L. Trovzssart. With 107 Ilustrations. $1.50. . THE GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION OF ANT- MALS. By ANGELO HEILPRIN. $2.00. . WEATHER. A Popular Exposition of the Nature of Weather Changes from Day to Day. With Diagrams. By Hon. Raupu ABERCROMBY. $1.75. . ANIMAL MAGNETISM. By AtFrep BINET and CHarR_eEs FERE, Assistant Physician at the Salpétriére. $1.50. . INTERNATIONAL LAW, with Materials for a Code of International Law. By Leone Lev1, Professor of Common Law, King’s College, $1.50. . THE GEOLOGICAL HISTORY OF PLANTS. With Llustrations. By Sir J. Wirt1am Dawson, LL.D., F.R.8. $1.75. ANTHROPOLOGY. An Introduction to the Study of Man and Civilization. By Epwarp B. Trtor, D.C.L., F.R.S. Illustrated. $2.00. THE ORIGIN OF FLORAL STRUCTURES, THROUGH INSECT AND OTHER AGENCIES. By the Rev. GzoreE HENsLow, M.A., F.L.S., F.G.S. With 88 Illustrations. $1.75. . ON THE SENSES, INSTINCTS, AND INTELLIGENCE OF ANIMALS, WITH SPECIAL REFERENCE TO INSECTS. By Sir Joun Lupgocr. With over 100 Illustrations. $1.75. . THE PRIMITIVE FAMILY IN ITS ORIGIN AND DEVELOPMENT. By Dr. C. N. Starck, of the University of Copenhagen. $1.75. . PHYSIOLOGY OF BODILY EXERCISE. By F. Lacrance, M.D. $1.75. . THE COLOURS OF ANIMALS: Their Meaning and Use. By Epwarp Bacnauu Poutton, F.R.S. $1.75. SOCIALISM: New and Old. By Wru1aMm Gravam, M.A., Professor of Political Economy and Jurisprudence, Queen's College, Belfast. $1.75. MAN AND THE GLACIAL PERIOD. By G. Freperick Wrieat, D.D., LL. D., F.G.8.A. With Maps and Illustrations. $1.75. HANDBOOK OF GREEK AND LATIN PALASOGRAPHY. By EpwarD MavunveE Tuompson, D.C.L., LL.D., F.S.A. $2.00. .A HISTORY OF CRUSTACEA. Recent Malacostraca, f By the Rev. Tuomas R. R. STespine, M.A. With numerous Illustrations, THE INTERNATIONAL SCIENTIFIC SERIES & EIS TORY <6 CRUSTA OCHA RECENT MALACOSTRACA BY THE Rev. THOMAS R. R. STEBBING, M. A. FORMERLY FELLOW AND TUTOR OF WORCESTER COLLEGE, OXFORD AUTHOR OF ) THE NATURALIST OF CUMLRAE, THE CHALLENGER AMPIIIPODA, ETC, WITH NUMEROUS ILLUSTRATIONS NEW YORK D. APPLETON AND COMPANY 1893 +) Authorized Edition. PREFACE —++-_—_—- THE ambition of this volume is that it shall be one to which beginners in the subject will naturally have re- course, and one which experienced observers may willingly keep at hand for refreshment of the memory and ready reference. An attempt has been made in it to bring the reader face to face with the vastness of the theme, to show him how variously it may engage the human mind, and to give him a groundwork of information as to the objects to be examined, with a side glance at the literature that has discussed them. It is not very generally known that the species of Crustacea extend to a number of several thousands, and that some of these species people parts of the ocean in enormous swarms. Of some of the groups the general character is familiar to every one, but there are also groups of which most persons either know nothing or have not the least idea that they belong to the Crustacea. The beginner, therefore, will have provinces of a new world opened to his exploration. There is curiosity to be gratified. The sporting instinct will discover many an unexhausted territory. In the manners and customs vi PREFACE of the creatures there is much to afford entertainment, and almost every new observer finds something singular to relate. In examining the structure both external and internal, whether in new species or in those that have been long established, the acutest powers of observation may be trained and profitably employed. Moreover, the highest ingenuity is excited and finds scope in the effort to explain the meaning of the facts observed. For, judging by dis- coveries already made, we are warranted in supposing that, down to the finest hair, every detail of every organism has its motive and meaning. Nor need man despair of finding out something for his private and personal benefit while investigating the physiology of a shrimp. It is needless to insist that a hundred volumes such as the present would not suffice to discuss the subject in all its bearings, since a hundred volumes would be but a small fraction of what has been already written upon it, and the incessant stream of publications widens and deepens as it flows. By the references made to some of the most recent and to some of the most important authorities, the student will be guided in general to adequate lists of literature. In consulting these bibliographical notices he will be perhaps as much amazed by the multitude of writers and writings as at first by the multitude of the genera and species of the Crustacea themselves. He will be led to consider it not unreasonable that the present yolume should have been content to deal with one half of the entire class, leaving the other half for a future occasion. PREFACE vil He will recognise by a perusal of the mere titles of what has been written, that no manual of this size could cope with all the branches of the subject, without the certainty of becoming a dry and repulsive catalogue. Even in what has been here laboriously put together the gentle reader is requested to remember that definitions are like the sermon which the preacher was forced to deliver, but to which, he reminded his hearers, they were under no sort of compulsion to listen. A time comes to the student when he scans every word of a definition with eager interest, but till then it will do him no harm to pass it over with cursory eyes and a light heart. In a volume of the International Series it would have been inappropriate to devote to the British fauna more than its proportional space, but I have thought that it would be neither unfair nor uninteresting to mention at least the names of all the British species, so far as it has been possible for me to collect them from and correct them by the latest and best authorities. One personal matter remains to be noticed. It was long the intention of Dr. Henry Woodward, of the British Museum, to publish in this Series a ‘ History of Recent and Fossil Crustacea.’ The continual pressure of other engage- ments has prevented him from accomplishing the con- genial task. That, nevertheless, the results of his un- rivalled knowledge of the extinct forms will sooner or later be gathered into a compendium for general use should be taken for granted. The other materials which he had collected for his purposed work, relating principally to the characters of the living organism, are still in reserve Vill PREFACE for the service of a future volume. In the meantime the production of the present book was entrusted to my hands at his express desire. A circumstance so honourable to myself and so well fitted to inspire an initial confidence in my readers, it would, I think, be false modesty to con- ceal, My best thanks are due to Dr. Woodward for his friendly and favourable opinion of my capacity; they will be best paid if my performance has succeeded in de- serving it. THOMAS R. R. STEBBING TuNBRIDGE WELLS, February 17, 1892, CONTENTS ses Sei Chapter I. Classification of Crustacea in outline . > II. Where to find specimens. ‘ 3 : III. On giants and dwarfs . IV. On thé Crustacean segments and hele en VY. Crabs; their tribes, legions, and families VI. The great eatable crab and its allies VII. The land-ecrabs, and others of the same tribe VIII. On the ‘sharp-snouted’ crabs, and some of their manners and customs ‘ é TX. On the tribe called Oxystomata or Leucoslidea X. The anomalous crabs XI. Hermit-crabs, lobsters, and fittings _— aes legions, and families XII. Burrowers, and their kindred XIII, The warty Scyllarus and the spiny chet, or crawfish XTV. The Norway lobster, the common aig soni is crayfish XV_ Small tribe of the Sicnapiden XVI. Branchial system, developmcnt, and range io iis Peneidea XVII. A surprising multitude of eee aid prawns XVIII. The Schizopoda; their branching feet; their fami- lies ; their luminosity XIX. The burrowing Squillide, and their paling 5 pelagic larvee ‘ : XX. A concise history of ne Gavan 104 123 133 146 180 191 199 211 213 224 256 279 291 x Chapter x XXII. XXIII. XXIV. XXYV. XSVI. XXVILI. XXVIII. CONTENTS . » 156 Tylaspis anomala, Henderson. Challenger Anomura - 166 Pylocheles spinosus, Henderson. Challenger Anomura . 169 Porcellana longicornis (Linneus). Early larval form. Sars 172 Uroptychus insignis, Henderson. Challenger Anomura - 178 Third maxilliped of Uroptychus insignis Under surface of Uroptychus insignis, showing the pleon folded naturally Uroptychus gracilimanus, Henderson. Challenger Anomura 178 Ptychogaster Milne-Edwardsi, Henderson. Chall. Anomura 178 PLATE VIII. To face p. 178. Lithodes maia (Linneus) * Eupagurus Bernhardus (Linneus) Porcellana longicornis (Linneus) Galathea intermedia, Lilljeborg Munida rugosa (Fabricius) End of pleon in the last larval stage. Sarg LIST OF ILLUSTRATIONS PLATE IX. To face p. 186. Upogebia littoralis (Risso). First post-larval stage. Sars Palinurus vulgaris, Latreille. Earliest larval form. Bate Nephrops norvegicus (Linneus). Second larval stage. Sars Peteinura gubernata, Sp. Bate. Challenger Macrura Elaphocaris Dohrni, Sp. Bate. Challenger Macrura PLATE X. To face p. 190. Cheiroplatea cenobita, Sp. Bate. Challenger Macrura Telson and uropods of Cheiroplatea cenobita Thaumastocheles zaleucus (v. Willemoes Suhm). Bate Platybema rugosum, Sp. Bate. Challenger Macrura Atya suleatipes, Newport. Bate . First trunk-leg of Atya sulcatipes Telson and uropods of Atya sulcatipes . ; Nematocarcinus undulatipes, Sp. Bate. Challenger Macrura PLATE XI. To face p. 211. Stenopus hispidus (Olivier). With separate figures show- ing the maxille, maxillipeds, first and second pleopods, and plan of the branchial arrangements and proportions. Bate ; PLATE XII. To face p. 219. Hepomadus glacialis, Sp. Bate. Challenger Macrura Pereon from below, showing the thelycum Epistome, mandible, lower lip, first maxilliped, and branchial plume in section 2 xiii Page 186 198 202 220 221 170 47 189 235 240 240 240 250 xiv LIST OF ILLUSTRATIONS PLATE XIII. To face p. 272. Notostomus perlatus, Sp. Bate. Challenger Macrura Eretmocaris longicaulis, Sp. Bate. Challenger Macrura Mysis relicta, Lovén. A female specimen in lateral view. Sars ” ” ” Ventral view of the cephalo-thorax ” ” “ Ventral view of telson, with inner branch of each uropod ” ay » ‘Theeye, and a section of the upper part of it Squilla scabricauda, Lamarck. Desmarest . : : In both the dorsal and ventral view the first maxilli- peds are drawn back behind the large second maxilli- peds, as otherwise they could not be seen Squilla empusa, Say. Late larval stage. S. I. Smith PLATE XIV. To face p. 338. Euneognathia gigas (Beddard). Challenger Isopoda. : The male, the female, and the first gnathopod of the male Neasellus kerguelenensis, Beddard. Challenger Isopoda Ischnosoma spinosum, Beddard. Challenger Isopoda PLATE XV. To face p. 352. Cirolana borealis, Lilljeborg. The adult male. Hansen Head from below, and mandible Nerocila Lovéni, Bovallius. Bovallius Dorsal and ventral view . . Ceratothoa auritus (Bovallius). Bovallius : : Dorsal and lateral view of female ; dorsal view of male PLATE XVI. ‘To face p. 389, Phreatoicus typicus, Chilton. Chilton . Second maxilla, second pleopod, telson, and uropod of Phreatoicus typicus Phreatoicus australis, Chilton. Chilton Page 246 255 272 284 290 338 381 383 342 342 352 352 354 354 389 3889 LIST OF ILLUSTRATIONS PLATE XVII. To face p. 897. Microniseus calani, Sars. Sars. . - ‘ Cyproniscus cypriding (Sars). A female (with a male in the normal position) affixed to the body of a Cypri- dina norvegica. The right valve of the host has been removed. Sars Adult ovigerous female of hs Caanendeene, detached, ae viewed from above d. Younger female, not yet ovigerous, in lateral view ce. Male, probably adult, with the anterior extremity carrying two root-like processes, and embedded in the skin of the Cypridina f. Larva in the last stage of development, seen from above 8 S PLATE XVIII. To face p. 414. Portunion meznadis, Giard, on Carcinus menas (Pennant). Giard and Bonnier : : _ ‘ Portunion Kossmanni, Giard and Bonnier. Gard and Bonnier ‘ ‘ é Cancricepon elegans, Gina sal Bonwion Lateral view of female; dorsal view of male and female. Giard and Bonnier Gigantione Moebii, Raine, Doossel and central: view of female. Kossmann PLATE XIX. To face p. 425. Helleria brevicornis, von Ebner The head from above, the head and pleon from below ; the antenna; mandible, lower lip; first maxilla, second maxilla, maxilliped; first leg; rudimentary first pleopod with opercular plate of the “pocout; stilet of the second pleopod, fourth pleopod showing the opercular plate broadside and edgeways, and the peduncle with the bran- chial plate; uropod. Von Ebner xv 397 407 408 413 414 Xvi LIST OF ILLUSTRATIONS on Fr WO DO e = So @ 18. 19. 20. 21. 22. ILLUSTRATIONS IN THE TEXT . ‘The lady in the chair.’ [Herbst] . . Ethusa mascarone (Herbst). [Herbst] . . . Corystes cassivelaunus (Pennant). [Herbst] . . Gelasimus arcuatus, de Haan. [de Haan| . Huenia proteus, de Haan, adult male. [de Haan] . Huenia proteus, de Haan, young male. [de Haan] . Huenia proteus, de Haan, female. [de Haan] . Chorinus aculeatus, Milne-Edwards. [Aurivillius] . Myra fugax (Fabricius). [de Haan] 10. 11. 12. 138. 14. 15. 16. 17. Dorippe japonica, von Siebold. [de Haan] Ranina scabra (Fabricius). [de Haan] Zanclifer caribensis (de Freminville). [Henderson] Lomis dentata (de Haan). [de Haan] Spiropagurus spiriger (de Haan). [de Haan] Porcellana longicornis (Linn.), young form. [Stebbing] . Ibacus incisus (Péron). [Desmarest] Astacus americanus (Milne-Edwards), 1urval form. Smith] Astacus americanus (Milne-Edwards), larval form. [S. I. Smith] Astacus americanus (Milne-Edwards), larval form. eons & Smith] Sergestes atlanticus, Milne-Edwards, [Spence Bate] ; Procletes biangulatus, Spence Bate. [Spence Bate] Mysis relicta, Lovén. First maxilla. cE. 0. Sars] The petasmata Page 272 LIST OF ILLUSTRATIONS XVil Page 23. Mysis relicta, Lovén. Second maxilla. [G.O. Sars] . 272 24. Diastylis stygia, Sars. First maxilliped. [G. 0. Sars] . 297 25. Diastylis Goodsiri (Bell). Second maxilliped. [Hansen] 298 26. Diastylis Goodsiri (Bell). Female. [Hansen] . - 310 27. Diastylis Goodsiri (Bell). Female. [Hansen] . . 810 28. Eisothistos vermiformis, Haswell. Male. [Haswell] . 334 29. Hisothistos vermiformis, Haswell. Female. [Haswell]. 334 80. Gnathia asciaferus (Hesse). [Hesse] ; . - 338 31. Ceratocephalus Grayanus, Woodward. [Haswell] - 364 82. Eurycope gigantea, Sars. [Hansen] 5 5 - 385 The names in italics indicate the sources from which the figures have been copied or adapted. The Brachyura of the Challenger were described by Mr. E. J. Miers, the Anomura by Dr. J. R. Henderson, the Macrura by the late Mr. C. Spence Bate, the Cumacea by Professor G. O. Sars, the Isopoda by Mr. I’. E. Beddard. The other pictorial authorities are Gesner’s ‘ Historia Animalium,’ Herbst’s ‘ Naturgeschichte der Krabben und Krebse,’ Desmarest’s ‘ Considérations générales sur la classe des Crustacés,’ de Haan’s ‘Crustacea’ in von Siebold’s‘ Fauna Japonica,’ and various papers of modern date by G. O. Sars, 8. I. Smith, C. W. 8. Aurivillius, H. J. Hansen, C. Bovallius, C. Chilton, MM. Giard and Bonnier, R. Kossmann, W. A. Haswell, and Victor von Ebner. For the text, as distinct from the illustrations, many other authorities would have to be named, but the text will speak for itself. As to the reproduction, on a scale suitable to these pages, of figures so numerous and so diversified from originals neither equal in merit nor uniform in style, I am indebted to Mr. James D. Cooper for the care and skill exhibited in carrying out a task of no mean difficulty. A. BiIsvony OF RECENT CRUSTACEA THE MALACOSTRACA CHAPTER I OUTLINE OF CLASSIFICATION IT is conceivable that by origin all the animals of the globe belong to a single family. They now exhibit very great divergence. Between a star-fish and a crocodile, for ex- ample, the cousinship is obscure and remote. Yet almost all species may be included within a few principal clans, and these are united one to another by a small number of intermediate forms of life. For the whole series the de- tails of classification will vary with the increase of know- ledge. No system has yet been accepted as final. One, which is sufficiently good for our present purpose, dis- tributes animals among nine leading divisions. These are (1) the Protozoa, primitive animals, such as the Foramini- fera and Infusoria ; (2) the Ccelenterata, in which the body- cavity serves alike for circulation and digestion, a tribe which includes sponges, corals, and jelly-fish; (8) the Echinodermata or prickly-skinned animals, embracing the sea-lilies, star-fishes, sea-urchins, sea-cucumbers, and a 2 A HISTORY OF RECENT CRUSTACEA wormlike genus called Balanoglossus ; (4) the Vermes or Worms; (5) the Arthropoda; (6) the Mollusca, among which are the well-known oyster, snail, and cuttle-fish ; (7) the Molluscoidea, containing the mollusc-like lantern-shells, and the grouped animals of the Polyzoa, in some of which the so-called ‘ bird’s-head’ organs amuse the observer; (8) the Tunicata, the tunic-clad or mantled animals, com- prising the Ascidians, whether tough-coated or gelatinous, and the Salpz which roam the sea in alternate genera- tions solitary or connected in a chain; (9) the Vertebrata, with the important classes of fish, amphibians, reptiles, birds, and mammals. It is with the central group of these nine that we are here concerned. So far as the name goes the Arthropoda are animals with jointed limbs. So far as the name goes, therefore, cats and dogs and vertebrates in general might belong to this division. But the name was given with reference not to the vertebrates, but to the vermes, for originally the worms and arthropods were included in a division called the Annulosa, animals of which the bodies contain several annuli, rings, metameres, somites, zonites, arthromeres, or segments, as they are variously called. These two sections of the Annulosa are now severed, and are distinguished by the circumstance that the one is, and the other is not, provided with jointed limbs. The Arthropoda are defined as animals which have bodies composed of variously shaped segments; which have jointed appendages attached to some at least of the segments; which have (in general) a brain united to a ventral nerve-cord, or ganglionic chain, and which exhibit bilateral symmetry. None of the other divisions will be found to possess all these characters combined. For example, in the verte- brata the nerve-cord is dorsal, in the mollusca the body is unsegmented, in the vermes there are no jointed appen- dages. Instances, it is true, are to be met with of arthro- pods which do not themselves answer the requirements of the definition, instances in which the bod ‘ ; 1 y is unsymme- trical or unsegmented, and in which there ae are no articu- DEFINITION OF THE CLASS 3 lated limbs. But in all these instances there is a period of life when the creature possesses, though it subsequently loses, the characters which determine its place in classifi- cation. Under the Arthropoda are included five classes, two of which are of very prominent importance in the economy of the world. The five classes are the Crustacea, Pycno- gonida, Arachnida, Myriapoda, and Insecta. A sixth class, the Onychophora, is sometimes added for the sake of the peculiar genus Peripdtus, but for the present it may be as well to give this the rank of an order among the myria- pods, a class represented by the familiar but unfavoured centipede. The Arachnida contain spiders, scorpions, mites, as well as some other less commonly known groups. The Pycnogonida (or Pantopoda), the sea-spiders, at one time included in the Crustacea and at another time in the Arachnida, have some remarkable peculiarities, inas- much as the ovaries of the female are found as a rule not in the trunk of the body, but in the thighs of the legs, and when the eggs are laid they are usually carried about not by the mother but in packets upon the oviferous feet of the male. The Insecta are so strikingly distinguished by the special number of their legs that this class sometimes receives the name Hexapoda, the six-footed animals. Beetles, bees, bugs, flies, fleas, moths, spring-tails, ear- wigs, grasshoppers, and gnats, in countless profusion people the globe, sometimes disputing possession with man him- self or rendering his life a burden, at other times offering him service direct or indirect of no mean value. It is in this class, and in this class only, that the present state of science reckons the number of species not only by scores of thousands but by hundreds of thousands, and even by millions. The class which stands nearest to the Insecta in the multitude of known species is that of the Crus- tacea, but the interval is so vast that, properly speaking, the Insecta are in this respect first with no second. Of the numerous definitions which have been given of the Crustacea, it will be s ifficient to quote two. According 4 A HISTORY OF RECENT CRUSTACEA to one of these, they are ‘ AquaticArthropoda, which breathe by means of gills. They have two pairs of antenna, numerous paired legs on the thorax, and usually also on the abdomen.’ This is compendious and useful. The statements clearly exclude all the other classes of the Arthropoda. They are also widely applicable among crus- taceans ; yet of these animals there are some which are not aquatic, some which have no gills, some which have not two pairs of antenna, and some in which the ‘ paired legs on the thorax’ are not numerous. A different definition was given by Professor Alphonse Milne-Edwards in 1860, according to which the class of Crustacea comprises ‘ all the segmented animals with bran- chial or cutaneous respiration, in which the body is pro- vided with jointed limbs, whether permanent or transitory.’ The Insecta and Myriapoda breathe by means of the air- tubes called tracheze; most of the Arachnida by means either of tracheze or pulmonary sacs known as fan trachee. From all these, therefore, the definition separates the Crustacea in a satisfactory manner, even though some terrestrial Crus- tacea combine tracheate with branchial respiration. There are, however, some subordinate members of the Arachnida, and the whole class Pycnogonida, in which the respiration is dependent on the surface of the body and not on any special organs. Asit is only in recent years that the Pycnogonida*: have been constituted an independent class, it was no fault of a detinition framed in 1860, that it included them among the Crustacea, to which they were then supposed to belong. They are in fact separated by many characters, on9 of which is the possession of a proboscis, which is supposed to have originated in the coalescence of the upper lip and the mandibles. So far as is known, they are all marine animals. On the other hand, those Arachnida which have surface-respiration are apparently all air-breathers. To meet all existing requirements, then, the definition of the Crustacea may be framed in the following manner :— They are Arthropoda without terminal proboscis, with respiration branchial or cutaneous, the latter only aquatic. It is not to be expected that any legitimate definition ORIGIN OF THE NAME 5 of an extensive class will be largely descriptive, because many features of wide range and great prominence are likely to be missing in outlying and erratic members of the group, and these consequently have to be passed over unnoticed, in favour of less conspicuous, and of alternative, or even of negative characters. The name Crustacea is a Latin word of old standing. Another and probably the original form of it is Crustata. The animals clothed in a crust, a covering of more or less flexibility, were distinguished by the ancients from the Testacea, in which the test, as in the example of an oyster- shell, is hard and rocky, and like a potsherd more ready to break than to bend. Dr. Johnson was of opinion that if the terms of natural knowledge were extracted from Lord Bacon’s works, few ideas in that branch of learning would be lost to mankind for want of English words in which they might be expressed.' Modern science would be much hampered by such a limitation of its verbal resources. Johnson’s own dictionary during the last century does not recognise the substantive, a crustacean. The adjective, crustaceous, it thus defines: ‘ Shelly, with joints; not tes- taceous; not with one continued, uninterrupted shell. Lobster is crustaceous, oyster testaceous.’ The same dic- tionary defines and illustrates the word crab as follows: ‘ A crustaceous fish. ‘Those that cast their shell are, the lobster, the crab, the crawfish, the hodmandod or dodman, and the tortoise. The old shells are never found, so as it is like they scale off and crumble away by degrees. —Bacon’s Natural History. ‘ The fox catches crab fish with his tail, which Olaus Magnus saith he himself was an eye-witness of —Derham.’ Shellfish, crayfish, and crawfish, are expressions still in use, although the term crab-fish is no longer in fashion. The uncritical ages had a tendency to regard as fish most animals which came out of the sea, and a story is told of a cook who persuaded her Hebrew mistress that a sucking pig became for all practical purposes a fish by being made 1 See A Dictionary of the English Language. Preface. Eighth Fdition, 1799. 6 A HISTORY OF RECENT CRUSTACEA to run a few steps into the ocean and out again. With a similar effort of the scientific imagination, the illustrious Erasmus Darwin, when a schoolboy, excused himself for eating roast goose during Lent by the scriptural axiom that ‘all flesh is grass,’ and the goose therefore a species of vegetable. ; So far as the name Crustacea implies a covering of any considerable toughness, it is little applicable to some of the parasitic members of the class, but in general much more confusion than advantage follows from the dis- placing of long-established names in the effort after absolute accuracy. If we are never to use the scientific designation of a group unless it exactly applies to all the members of it, then what is to be done, one writer rather maliciously asks, in the case of the species called Homo sapiens ? A general though not a complete agreement prevails in regard to the externa) boundaries of the crustacean class. The proper mode of subdividing it and the arrangement of the subdivisions are subjects still open to much dis- cussion and dispute. Any final decision depends upon questions of genealogy which have yet to be answered. In the mean time four sub-classes may be accepted, under the names Gigantostraca, Malacostraca, Entomostraca, and Thyrostraca. The Gigantostraca, or giant-shells, are the oldest in known lineage, and, as the name implies, fore- most in the average of magnitude. They seem to be tending to speedy extinction. The Malacostraca include forms highest in development and of most direct value to mankind. The Entomostraca probably surpass the rest in multitude of individuals, if not also of species, but are the smallest in average size. The Thyrostraca, commonly. called Cirripedia, though they fall short of the Entomostraca in numbers, excel them in bulk, and are even more remote in outward appearance from any general idea of a crusta- cean, such as the better known malacostracan lobster, or ; the crab fish, might suggest. _The Greek word Malacostraca, meaning softshell animals, is practically equivalent in sense to the Latin’ MALACOSTRACA 7 word Crustacea. Like that, it was originally adopted to distinguish such creatures as crabs and crawfish and prawns from such others as oysters and clams; not be- cause of the absolute, but because of the comparative softness of their shells. Were reasons wanted for dis- placing the name, they would not be difficult to find. Many of the Malacostraca have shells harder instead of softer than those of some Mollusca. In some Malacostraca the integument has ceased to be of the nature of a shell, a parasitic habit having cancelled the need for such a defence. Moreover, the term suggests a false contrast with the neighbouring sub-class of the Entomostraca, in which as a rule the shells or skin-coverings are still softer. The name Thoracipoda, not open to any of these objec- tions, has been proposed by Dr. Henry Woodward. But against this it may be urged that, by many students of the Crustacea, the word thorax is not admitted as a proper technical term, and among others it is disputed whether the word, if admitted, should apply to three, to seven, to eight, or even to nine, of the crustacean segments. Retaining, therefore, the ancient, familiar, and suffi- ciently euphonious word Malacostraca, the subdivisions of this sub-class may next be considered. Two orders have been formed, named respectively the Podophthalma, or stalk-eyed, and Edriophthalma, or sessile-eyed, crusta- ceans. In the former the eyes are mounted upon stalks or peduncles, which are almost invariably movable ; in the latter they are in continuity with the general surface of the head, or, if raised above it, the ocular prominences are unjointed and immovable. That some species in both orders are blind, gives a certain vantage-ground for the disturbers of accepted names to follow their bent. These may also allege that the terms just explained have not been at any time in undisputed possession. The Podoph- thalma have also been called Decapéda, ten-footed, while the Edriophthalma have been called Tetradecapdda, or fourteen-footed, Crustacea. The second of these names has found but little favour, and the first has the dis- advantage that it would apply to some Crustacea that are 8 A HISTORY OF RECENT CRUSTACEA not podophthalmous, and does not apply to others that are. Instead of Podophthalma or Decapoda, Burmeister proposed Thoracostraca. To this, however, the objectiong already urged against Thoracipoda will apply, with the additional one, that the word has a termination which had been already employed in two, and has since been em- ployed in the third and fourth of the higher groups. Some purists correct the word Edriophthalma, in accord- ance with its derivation, into Hedriophthalma, They may correct on the printed page, but who can guarantee that they will have their cherished aspirate pronounced ? The stalk-eyed Crustacea are portioned out into four sub-orders: 1. The Brachyira, or short-tails, such as the edible crab; 2. The Macrira, or long-tails, such as the common lobster, prawn, and shrimp; 3. The Schizopéda, or cleft-footed crustaceans, in certain points of structure so near to the prawns and shrimps that at least one author of eminence classes them among the Macrira; and 4. The Stomatopéda, with feet converging about the mouth, crea- tures abundant in some waters, but rare in those that wash the shores of Great Britain. A fifth sub-order, the Anomira, or irregular-tails, has long been accepted, but modern classification is disposed to distribute its members, which include the hermit crabs and others of very curious habits, between the Brachyiira and the Macrira, from which they may be supposed to have respectively diverged, yet without losing all trace of family connection. The sessile-eyed Crustacea are at present divided into three sub-orders, the Cumacea, Isopédda, and Amphipéda. The Cumacea seem to have entirely escaped the notice of the ancients, and among the moderns an accurate know- ledge of their singular structure is not too widely diffused. One of the genera earliest brought into notice received the name of Cuma, a wave, and from this was formed the de- signation Cumacea for the whole sub-order, which is exclu- sively marine. The Amphipoda, which are common in fresh as well as in salt water, were so named by the French naturalist Latreille, as having feet extending in all direc- tions, their limbs at the same time having much diversity: ENTOMOSTRACA 9 of form in correspondence with diversity of function. The Isopoda, or equal-footed animals, besides being found both in fresh and salt water, have more decidedly than the Amphipoda extended their range to the dry land. The name was invented by Latreille in ignorance of the great number of species since investigated in which the feet are strikingly unlike and unequal. Nevertheless the name may stand, just as a rose remains a rose even when it is not rose-coloured. To these three sub-orders some authors are disposed to add a fourth, the Tanaidea, while others, though agreeing to withdraw these animals from their old position among the Isopoda, would prefer to place them among the Amphipods. The need for the change in either direction has not yet been established. The Entomostraca, by their name, which literally means testaceous insects, bear witness to an era in classification when not only they but all other crustaceans were arranged among the Aptera or insects without wings. As the forms are multitudinous and very frequently microscopic, and as moreover crowds of the species have only been made known within recent years, it is not to be wondered at that the internal arrangement of this sub-class, like that of the preceding one, is still open on some points to discussion, although there is a fair amount of agreement as to the main lines of division. The method here followed dis- tinguishes three orders, the Branchiopéda, Ostracoda, and Copépidda. By Latreille the name Branchiopoda was ap- plied to the Entomostraca at large. It signifies branchial- footed, or animals in which the feet are in one way or another adapted to serve the purpose of respiration. This order is subdivided into four sub-orders. 1. The Phyllo- carida, literally leaf-shrimps, derive their name from the laminar or leaflike expansions with which their legs are provided. 2. The Phyllopéda, the leaf-footed ones, owe their name to the same characteristic, although by other features they are distinguished from the Phyllocarida. None of the Phyllopods are marine, although a few inhabit brackish water or strong brine. 3. The Cladocéra, which are so called from their branched antennz, occur chiefly 10 A HISTORY OF RECENT CRUSTACEA in fresh water, where they are common, but inconspicuous, and to the ordinary observer little suggestive of the crus- tacean type. 4. The Branchiira, represented by the carp- lice, are so designated from having a branchial tail which actively assists in the function of respiration. The Ostracéda, a title which might be interpreted as the testaceous Crustacea, may be easily mistaken for minute bivalve mollusca. Like the Branchiopéda they are divided into four sub-orders, the Podocépa, Myodocépa, Cladocipa, and Platycopa, in which names words meaning feet, mus- cles, branch, and broad, are respectively compounded with the Greek word signifying an oar. The Copepoda point at once to a connection with the preceding order, inasmuch as there one of the sub-orders derived its name from words signifying a foot and an oar, while the Copepoda are indebted to the very same compo- nents, in the inverse order of an oar and a foot. The actual structure of the animals to some extent justifies this similarity of names, but in general appearance the Copepoda, not being shut up in two-valved shells, are widely different both from the Podocopa and the rest of the Ostracoda. Three sub-orders are formed: (1) the Gnathostdma, having the mouth well provided with jaws; (2) the Poecilostéma, in which the mouth varies; (8) the Siphonostéma, having the mouth produced into a siphon or tube. The Gigantostraca are as rare as the Entomostraca are common, ‘They are divided into three orders, the Mero- stomata, Xiphosira, and Trilobita. Of these, the first and third are entirely extinct, so that the knowledge of them is derived only from fossil remains. The Merostomata have a name derived from two words, meaning a thigh and a mouth, this singular combination alluding to the no less singular fact that in these animals the mouth is surrounded by a group of limbs which are not only ‘locomotive and prehensile, but also subservient to mastication. This peculiarity belongs likewise to the Xiphosura, or sword-tails, which are named from the long and sharp piece at the end of the body, their characteristic THYROSTRACA 11 tail-spine. Some authorities hold that this order should be removed from the crustacean class to that of the Arach- nida. The name of the third order, the Trilobita, refers to the circumstance that they usually have the body divided by two longitudinal dorsal grooves into three lobes. They were extremely abundant in bygone ages, and the natu- ralists of the Challenger were continually in hopes that they might obtain a living specimen or two from hitherto unexplored abysses of ocean. But extinction appears to have done its work with great thoroughness upon this order. The last of the sub-classes consists of the Cirripedia or curl-footed animals. The alternative name Thyrostraca, meaning ‘ valve-shells,’ has the merit of agreeing in ter- mination with the names of the other three sub-classes. But it must be admitted that if it is objectionable to call the whole group cirripedes when some have no cirri, it is equally inappropriate to call them all ‘ valve-shells’ when some have no valves. It is a triumph of the present cen- tury in minute investigation and comparative anatomy, that has withdrawn the Cirripedes from the zoophytes, worms, and molluscs, among which, at various times, the older naturalists placed them, and that has given them henceforth an undoubted position among the Crustacea. They may be divided into five orders, or the first two, the Pedunculata and the Operculata, may be grouped together as divisions of an order hitherto designated Thoracica, in which the part called the thorax is provided with cirri. The Abdominalia have the cirri only on the so-called abdomen. The Apoda are without cirri, being, as their name implies, footless. Lastly, the Rhizocephala are a parasitic set, which send rootlike filaments into the bodies of their hosts, 12 A HISTORY OF RECENT CRUSTACEA CHAPTER II SPECIMENS Collecting To study adequately any branch of natural history, it is essential to have specimens. Many exemplary forms of Crustacea are not difficult to obtain. Representatives of the two highest orders in the group, the crab, the lobster, the prawn, the shrimp, are exceedingly familiar, as these. creatures lie on the fishmonger’s board, or are brought to. table for food. When the eatable parts have been con- sumed or otherwise removed, the débris is still of value for mental nourishment. This refuse may be made to yield more profit and pleasure than many a costly collec- tion which can only be viewed intact. By carefully separating the constituent parts of the head, the trunk, and the tail, in each of the crustaceans above mentioned, and comparing them piece by piece, the beginner will be able to give himself a cheap but invaluable lesson. He will be surprised at first to detect likenesses in the corre- sponding parts of animals externally very distinct, and afterwards he will be surprised at the differences in the corresponding parts of animals which he has learned to regard as closely connected. As his range of study widens, he will find relationships established between forms which, to any one unacquainted with the intermediate links, must seem to have absolutely nothing incommon. For instance, while examining the gills of a lobster, he may chance to observe some small orange-coloured specks, and may rightly conjecture that these are parasitic animals. But it is scarcely conceivable that any amount of genius would BREAKFAST-TABLE ZOOLOGY 13 enable a man to discern, from a comparison of the lobster alone with its entomostracan parasite, that they are alike crustaceans, which is, nevertheless, known to be the case. In a dishful of prawns it may often be noticed that one or two of the finest have the head swollen on one side, as if the creature were suffering from a face-ache. There is no special reason to suppose that the prawn thus affected is suffering any great inconvenience. Itis merely lending the shelter of its carapace to a family of isopod crustaceans. Comfortably ensconced in the bulging cheek-piece will be found a misshapen animal of no inconsiderable size, in general laden with innumerable eggs, and accompanied by a far smaller partner, the father of the brood, symmetrical in form, and retaining some of the freedom of movement which belongs to the young when first hatched, but which the mother has entirely resigned. Thus the zoology of the breakfast table will supply examples of three very dis- tinct orders. These examples are none the less curious because they happen to be common. Any one who is content to examine them with care will thereby lay a simple and solid foundation for all subsequent study in the realm of carcinology. The novice, however, need not be dependent on the fishmonger for specimens. In cellars, gardens, hedges and ditches, under flat stones, in dry moss, among moist dead leaves, in the loosened decaying bark of trees, crusta- ceans are to be met with almost everywhere. These are the so-called wood-lice, including those known by the trivial names of Pill-bugs and Slaters, Millepedes, and Carpenters. One species, small and white and slow in movement, is frequently to be found in ants’ nests, and seemingly never elsewhere. All this set of animals, though air-breathing and living on land and often possess- ing great agility, belong to the Isopoda in common with the marine species above mentioned that leads its apathetic life within the carapace of the prawn. From almost every little brook and pond in England the amphipod, Gammarus pulex, and the isopod, Asellus aquaticus, may be fished without difficulty and without 14 A HISTORY OF RECENT CRUSTACEA any stint of numbers. Less commonly the innocent well- shrimps, which are also amphipod crustaceans, may be obtained from wells. It may be proper to mention that the well-shrimp is not poisonous, and that it flourishes in water which is perfectly wholesome. A different view of its character is probably entertained by many owners of wells, who are on that account unwilling to mention or acknowledge its presence. From stagnant ponds various species of Entomostraca may be obtained in vast abund- ance. Some of the Phyllopoda are found only in brine pools. The brine shrimp, Artemia, breeds in vast num- bers in the mud of the great Salt Lake of Utah. In South America one of the Ostraccda very singularly dwells on the leaves of a plant. The river crayfish and crusta- ceans parasitic on freshwater fish are pretty widely dis- tributed. Highest in known range of all the Crustacea are the Isopods and Amphipods taken by Mr. Whymper at a height of 13,300 feet on the Great Andes of the Equator. In many parts of the world there are land-crabs, but none of these live in the British Isles. This is referred to as follows in the ‘ Narrative of the Cruise of the Challenger.’ . In describing the visit to Ascension Island in the South Atlantic Ocean, the writer says :— ‘Land-crabs swarm all over this barren and parched volcanic islet. They go down to the sea in the breeding season; they climb up to the top of Green Mountain, and the larger ones steal the young rabbits from their holes and devour them. It always seems strange to an English naturalist to see crabs walking about at their ease high up in the mountains, although the occurrence is common enough and not confined to the tropics. In Japan a crab is to be met with walking about on the mountain high roads far inland, at a height of several thousand feet, as much at home there as a beetle or a spider, and crabs of the same genus (T’helphusa) live inland on the borders of streams in Greece and Italy.’ France and Germany, as well as England, have reason to regret that the sunny south should have a monopoly of these land or river crabs, for they are delicate eating, and, SPECIMENS ON THE SHORE 15 as writers of the sixteenth century inform us, they are much sought after for the tables of the Pope and cardinals. From what has been said it will be seen that those who live inland enjoy no inconsiderable opportunities of ob- serving crustaceans of various kinds, dead or living. The common and easily obtainable specimens will, as a rule, - not be of the same species in different parts of the world, but they will often belong to the same or closely allied genera, and they will in any case afford similar facilities tor study. The traveller would do well to remember that kinds easy to collect abroad or cheap to buy in foreign markets will probably be rare in his own country, and that therefore preserved specimens may be of future value to himself or acceptable to his friends at home. Passing, however, from inland resources to those of the sea coast, the student will find an enormously greater and an almost bewildering variety of forms to engage his at- tention. Shore-crabs and hermit-crabs are often obtru- sively conspicuous, as also are the operculate cirripedes with their sharp-edged shells coating large surfaces of rock. When a flat stone is lifted, not unfrequently a small specimen of the edible crab may be seen nestling in the mud. If the position is chosen in order to gratify the sense of smell, one would be inclined to adapt the words of the poet to the situation, and say that crabs want but little here below, but want that little strong. Cling- ing to the under surface of a stone, a group of the broad- clawed Porcelluna, the hairy porcelain crab, will often be found. They try to look as if they were not there, or they endeavour to slidder rapidly away. If one is seized by the claw, it will adhere as tenaciously as it can to the rock, and sometimes end the unequal contest by relin- quishing the claw and running off without it. The lobster- like Galathea, under similar circumstances, is ready either to fight or run, a very Achilles for courage and speed. Specimens of the masked crab and of various spider crabs, and of others not commonly found alive upon the shore, are often to be met with upon it when an obliging gale of wind has thrown their carcases landward. The common 16 A HISTORY OF RECENT CRUSTACEA shrimp will sometimes attract attention by oe an abrupt spring, after which it sinks softly into the moist sand, from which its imitative colouring makes it barely distinguishable. The stretches of sand on the shore, which to unobservant or inexperienced eyes might seem quite barren and deserted, are often teeming with crusta- cean life. The upper and driest zone will be riddled with the burrows of the sand-hopper. Lower down several other species of amphipods lie at a very small depth beneath the surface. Little biting carnivorous isopods are there, and occasionally others that are vegetarians. In some localities Cumacea can be found, but never very far from the waves, nor, when they are present, must it be expected that these animals will make a striking feature in the landscape. They are remarkably unobtrusive. Where rocks and rock-pools and various kinds of seaweed abound, and especially on sheltered coasts, a very large number of species of amphipods and isopods may be obtained, these being in most instances distinct from those found in the sand. Here is to be seen Orchestia, the shore-hopper, a near ally of the sand-hopper, Talitrus. Here are two of the marine species of Gammarus, and examples of their cousins Melitu and Mara, all of which, when on land, slip or wriggle along on their sides, and have in consequence been irreverently spoken of as ‘scuds.’ Many other forms, including some of the Caprellide or skeleton-shrimps, can be obtained by examining tufts of the finely branched sea- weeds. At the lowest ebb of the spring tides, a day or two after new moon or full moon, species may be obtained which are rarely or never procurable higher up on the shore. Several of the isopods, however, may be taken, indepen- dently of the lowness of the tide, roaming among the coarser weeds, and mimicking in various ways the colours around them. The rocks which look least interesting, having no vegetation except the short black crumbling foliage of the Lichina pygmea, supply the curious Cam- pecopea hirsuta, an isopod easily to be confounded with the leaves of the tiny plant which shelters it. Found among cirripedes at low tide, however, it displays much brighter « VARIOUS LODGINGS 17 colouring. Where wooden piles have been driven into the shore within tide-marks, the part which the water reaches is almost sure to be very soon attacked and taken posses- sion of by two or three very distinct crustaceans, the two constant companions being the strange amphipod Chelura terebrans, with a name signifying the boring claw-tail, and a perhaps equally mischievous isopod, known as Limnoria lignorum, or the Gribble. With these is frequently asso- ciated one of the cheliferous isopods, the species Tanais vittatus in England, and Tanais filum in America, not cun- cerned, it may be, in making the excavations, but only using them when made. Some Amphipoda and Isopoda shelter themselves in sponges and some in the branchial sacs of Ascidians. Many free-living Copepoda may be obtained in rock- pools and by washing seaweeds, others from various Asci- dians. ‘Those parasitic Copepoda, which are commonly known as fish-lice, may often be procured by examining fishes when first brought to shore, and before they have been prepared for display on the fishmonger’s board. New species of Crustacea have sometimes been discovered by the examination of the contents of a fish’s stomach. This same repository will also occasionally yield good specimens of already known species. The Cirripedes are all marine, most of them impatient even of brackish water, although one species, Baldnus improvisus, Darwin, will live contentedly for some time in water that is quite fresh. Several species are obtainable between tide-marks. Many attach themselves to the sub- merged sides of ships, and to other floating objects. Some make their home in sponges, corals, or shells, and in con- - sequence specimens not sought for their own sake are frequently distributed by the commerce of which their dwelling-places are the more direct object. For the Gigantostraca collectors in England must content themselves either with fossil or with imported species. In New England, the horseshoe crab, Limulus polyphemus, may be had at or just below low water. By availing himself, then, of those Crustacea which 18 A HISTORY OF RECENT CRUSTACEA live on tand or in shallow waters, or on the coast, and of those specimens which are brought to shore either as or in connection with articles of food, the student may obtain a thoroughly representative collection. Closely as all the easily accessible localities and resources have been already searched and examined, even from among them he will find it still possible to add new species to the long roll of those hitherto known. In many of the forms that are common and abundant, and that have long been familiar to science, he may, by diligent observation, find features of great interest that have heretofore escaped notice. One discovery he will almost certainly make, that the objects of his study do not deserve the epithets of contempt and disgust so freely lavished upon them by the ignorant. At every step he will be increasingly charmed by the striking characters which different species exhibit, by the delicate grace or the intricate mechanism of the separate parts, and by the marvellously varied adaptation of the different or- ganisms to their diverse modes of life. It is, however, in the waters of the ocean, from the surface down to the abyssal depths, that the vast majority of the Crustacea are to be found. Of the lower limits of the so-called bathymetrical distribution a good general idea may be formed from the results of the dredging and trawling carried on by the Challenger, during a voyage of nearly seventy thousand miles. Of the Brachyura indeed, only a single specimen of a single species was taken so low down as 1,875 fathoms. Mr. Miers, who named it Lthusa (Ethusina) challengeri, says: ‘This is the greatest depth at which any Brachyurous crustacean was taken by the expedition, and also, I believe, the greatest hitherto recorded for any species of crab.’ It was not, perhaps, to be expected that members of the highest order in the class would either need or condescend to penetrate into the very lowest regions, where light and heat and vegetation, not to speak of cheerful society, must at the best be very scanty and extremely scarce. The very genus Lthusa, with its sub-genus or neighbouring genus Ethu- sma, seems to apologise for frequenting levels beneath its SPECIMENS IN THE DEEP SEA 19 natural rank by including the forms which, as Mr. Miers observes, ‘ evince the greatest degree of degradation from the Brachyuran type.’ It approaches in fact the group which till recently held-a distinct position under the name of the Anomura. Of these Dr. Henderson observes that they occupy an intermediate position between the Macrura and the Brachyura, in regard to the limit of depth at which they are found, the more highly specialised forms being, like the Brachyura, found in shallow water and at moderate depths, whereas the more primitive macruran types extend to the abysses of the ocean. The single and singular specimen on which the species T'ylaspis anomala, Henderson (see Plate VII.), was established, ‘came from the greatest depth at| which any anomurous crustacean was taken by the Challenger, the depth in question being 2,375 fathoms. In the Macruratwo genera, Benthesicimus and Gennddus, instituted by the late Mr. Spence Bate, descend to 3,050 fathoms, and have nowhere been found dwelling with less than 300 fathoms of water above them. It is not perhaps surprising that most of the specimens were brought up ‘in a soft, pulpy, and collapsed condi- tion,’ for it is calculated that each perpendicular mile, that is, each 880 fathoms of water, exercises a pressure of a ton upon each square inch of an animal’s surface. As long as the fluids within correspond with those outside the body, there is a state of comfort and efficiency, but when this equilibrium is suddenly destroyed, uot only a crus- tacean but any other creature is likely to feel weak and discomposed. Of the Schizopoda Boreomysis obtusata, Sars, was taken from a depth of 2,740 fathoms. On the other hand the Stomatopoda are content with far less profound explora- tions. Mr. W. K. Brooks reports that ‘they are usually found in very shallow water, and with the exception of the specimen of Squilla leptosquilla, taken in the trawl by the Challenger in the Celebes Seas from a depth of 115 fathoms, and a specimen of Lysiosquilla armata, which Mr.8. I. Smith found in the stomach of a Lopholatilus from 120 fathoms, they are all from very moderate depths.’ The Challenger 20 A HISTORY OF RECENT CRUSTACEA found a cumacean as low down as 2,050 fathoms, put some years earlier the Swedish Spitzbergen expedition obtained the appropriately named Diastylis stygiu from the still lower deep Mr 2,600 = heme. The Teanete extend down to 2,740 fathoms, the Amphipoda possibly, but by no means cer- tainly, to 2,500. Among the Entomostracans, a Phyllo- earid species came from 2,550 fathoms, Ostracoda from 2,750, the strange copepod, Pontostratidtes abyssicéla, Brady, from 2,200, and a parasitic copepod, Lernaa abys- sicola, was attached to a deep-sea fish brought by the trawl from 2,400 fathoms. Lastly, of the Cirripedes the great Scalpellum regium was dredged from a depth of 2,800 fathoms, the character of these animals giving more cer- tainty than can be had with free-swimming Crustacea, that the specimens actually came from the depth assigned. In the use of trawls and dredges with open mouths, there is always a chance that specimens may be captured in the course of lowering or hauling in the instrument, instead of while it is being dragged along the ocean floor. By this means the record of the occurrence of specimens at as- touishing depths is left open to some question. Yet on the whole there is fair reason to believe that most of the principal groups of Crustacea have representatives capable of supporting existence in regions of dense gloom, with a temperature icily cold, and under a column of water from two to three miles in height. Many species, indeed, of the Crustacea show a preference for a frigid climate, since where this condition prevails their swarms are far vaster and their bodies more bulky and solid than in waters less cold. These Polar forms, therefore, find no inconvenience, but the reverse, in the unheated tempera- ture of the great depths, and though probably many of them could not possibly pass the tropical waters at or near the surface, far down there is a suitable water-way for them from one pole of the earth to the other. It is rather the task of national expeditions than of any private collector to procure the exceptional forms which the remotest abysses of the sea have yielded and may be expected still from time to time to yield. There a Bee METHODS OF CAPTURE 21 are, however, unstinted riches of natural history which the ordinary student may obtain with comparatively simple means. By the use of the towing-net from a boat, espe- cially after sunset in warm and calm weather, numerous larval forms of Crustacea are to be obtained, as well as adult forms of various orders. By dredging in a few fathoms, or even in a few feet, of water, species enough to occupy weeks and months of study may often readily be secured. For this work sheltered bays and inlets are favourable. When the dredge brings up apparently nothing but rugged pebbles and the worn shells of departed molluscs, these are not to be despised. Among them may be found the little crabs of the genus Ebalia, at the first glance perhaps rejected as if pebbles themselves. Rare Tanaids may come creeping out of the crevices of an old oyster shell. When gea-weeds are brought up in the dredge, they are not to be cast aside after a hasty exami- nation as unproductive. They should be placed in a vessel of shallow water, and, though the crafty inhabitants lie close, they will eventually come forth. Sand and muddy ooze scraped from the bottom requires to be passed through a sieve or stirred about in a pailful of sea-water. After the stirring, and before the animals have time to regain the sand, the water must be poured off through a muslin bag which will retain the desired specimens. Some species, besides the edible ones, may be obtained by a sort of systematic fishing. A dead crab, for instance, let down in a lobster-pot, will attract one species or another accord- ing to the locality, the clan trooping to the feast in hun- dreds and thousands till they have consumed every par: ticle of the dainty repast. The voracity, indeed, of some among the smaller Crustacea is such, and their numbers in some places so enormous, that they have been known in a single night to clear all the flesh off a dead seal. To such appetites almost any carrion is a sufficiently alluring bait. There is little need for surprise, under the circumstances, at the label on certain museum specimens, irtimating that they were ‘pulled off the head of a bear let down to the bottom to be cleaned.’ Some of the Amphipoda attack the 22 A HISTORY OF RECENT CRUSTACEA head and other parts of the whale while the monster is still alive. On the other hand, whales and seals, and fishes large and small, swallow down the Crustacea in a truly wholesale manner, and so prevent these prodigiously prolific animals from producing a complete block in the cooler parts of the ocean. Independently of this interest- ing exchange of courtesies, which consists In alternately eating and being eaten, there is another kind of associa- tion between crustaceans and other animals, known as commensalism. In this the one creature lives, not at the expense of the other, but merely in companionship with it. Thus, on the common starfish there is found a thread- like minute species of the Caprellida. Though the star- fish is very frequently to be met with on the shores, its companion Pariambus typicus (Kréyer)!is only seen on dredged specimens, so that apparently this tiny animal has the sense to disengage itself when its host is being driven into an unsuitable or dangerous position. Someof the Amphipoda Hyperidea are very frequently to be found upon jelly-fishes. One of the Gammaridea, Iswa Montagui, Milne-Edwards, appears never to have been found except upon the Spinous Spider Crab, Maia syuinado, for clinging to which its feet, with their serrate widened extremities, are peculiarly adapted. A French zoologist, M. Edouard Chevreux, some five or six years ago, was searching this interesting crab for its already well-known commensal, when to his surprise, among the alge and hydrozoa, with which the carapace is usually decked, he found not only the species he was in search of, but no less than twenty- two other species of Amphipoda into the bargain. Maia syuinady is not found far to the northward. On the other hand a very distinct crab, but with some external re- semblance to it, Inthodes mata, is not found far to the southward. Such facts of distribution are often of scien- tific importance. For instance, with regard to the com- paratively narrow strip of land which separates North from South America, the geologist will desire to know how far the crustacean fauna of the sea on one side of the ‘Formerly Podalirius typicus. DISTRIBUTION 23 isthmus corresponds with that on the other. A close agreement would dispose him to consider that not so very long ago, in the large measurements of geological time, the Atlantic and Pacific may have been connected by a natural canal. From great divergence, such as is known to exist in the molluscan fauna, he would infer that the passage existed, if ever, only at a very remote period. In the large freshwater lakes of Southern Sweden, it was dis- covered some thirty years back, that a remarkable marine fauna existed, and the inference ingeniously drawn from a review of all the connected facts has been, that these sheets of water were at one time part of the sea, but have been cut off from it by the gradual elevation of the land. Upon this supposition, while the water was gradually losing its saltness, its marine inhabitants, with equal steps, were becoming habituated to a freshwater existence. But it must not be forgotten that the transfer of marine animals to brackish and fresh waters may take place by various modes of migration quite independently of geological changes. It has been noticed as curious, that shells, insects, and plants, inhabiting fresh water, are of comparatively few species, but those few very widely distributed. Mr. Belt ingeni- ously remarks that, in the oscillations of sea and land, the oceanic and continental domains, though shifting, are con- tinuous, whereas every freshwater area is liable to be again and again completely overwhelmed. By this means the freshwater species of narrow range may be entirely de- stroyed, and only families of wide distribution will survive. The application of this theory to the Crustacea is worthy of study, but the facts which it is designed to explain do not embrace the whole of the globe. The Isopod Asellus aquaticus and the Amphipod Gammarus pulex are obvious instances of freshwater species with an enormous range. Yet from the fresh waters of the Malay archipelago the Asellidee and Gammaride are said to be entirely wanting. On the other hand, Professor Max Weber has recently observed that, while Europe can show but seven species of freshwater decapods, the Indian archipelago can boast of more than eighty. ok A HISTORY OF RECENT CRUSTACEA CHAPTER IIL MAGNITUDE In zoology, size attracts attention in comparison with two standards. Man contrasts the bulk of an animal either with the average in his own order or with that of the group to which the particular animal belongs. An elephant is a huge beast, not in competition with a whale, but with a human being. A hornet less than a man’s little finger is a monster beside a house-fly or a gnat. As in all classes the majority of individuals conform pretty closely to the average magnitude, the mind becomes trained to regard the exceptional extremes with wonder, often not unmingled with admiration when the mass is not smaller but greater than common. Among the Crustacea there are forms, not indeed surpassing all others in diminutiveness, but at any rate so exceedingly small that the sharpest eyes could perhaps never have found out that they were crustaceans without the aid of the microscope. Here it is that the philosophical naturalist sometimes finds chief reason to marvel, in perceiving the whole machinery of life, enabling active locomotion, nutrition, and repro- duction, with senses, a power of choice, and the capacity for feeling pleasure and pain, all packed away as neatly and conveniently as possible in so extraordinarily small a casket. For preliminary studies creatures of more con- siderable compass hold an obvious advantage, and with most observers it is rather the giants of an order than the dwarfs that are deemed especially remarkable and worthy of the notice which they are fitted readily to engage. Some of the old writers probably understood ASTACI MARINI,QV EM HV MER vocant Germani , ex defersptione Scptentrionalium regionum Olat Ma Lotefigies. Ingentem effe [ertbit,(inter Orchades F H ebrides infulas, ): €F tam validura ut hominem natantem chelis apprehen{uim fief cet. Sednon probe, quod pedes omnes bifculcos pinxit: €9 caudamtabellis tam multis con- firuxit, Fe. JN EADEM TABVLA MAGNYP dcpingit aftacum xu. pedum, quidenoratur amonftromari~ no fimilt rhinocerote, OLD STORIES 25 that their readers would take more interest in a large crustacean than in a small one. For this reason, no doubt, Olaus Magnus declares that between the Orkneys and the Hebrides there lives a kind of lobster so large and strong that it can catch a swimmer in its claws. and squeeze him to death. His picture, as will be seen, repre- sents a bearded man as a mere plaything in the lobster’s arms. The human race is avenged in the companion picture, where a lobster twelve feet long is itself being ruthlessly devoured by a ‘rhinoceros whale.’ Though these myths are many centuries old, they still have an amusing interest to the Anglo-Saxon from having been localised in British waters. It is, however, very extraordinary that at the beginning of the present century a travelled French naturalist of eminence should have accepted a statement little differing from that of Olaus. L.A. G. Bosc in 1802 published his ‘ Natural History of the Crustacea, contain- ing a Description of them and their Manners,’ in the In- troduction to which he says :— ‘It is related that on the coasts of the isles of America, where the crabs are in great profusion, they engage during the pairing season in desperate conflicts, which often result in the death of numerous individuals, and always in the loss of a great many of their limbs. It does not appear that the Crustacea of Europe have this custom; but their small numbers, and the perpetual hunting after them, do not permit so easy an observation of their habits, as in warm countries, where it is said that they are of a size so monstrous, that they attack men, and have eaten several, amongst others the famous sea captain Francis Drake (Francois Drack), who, although armed, could not avoid this fate.’ } This passage is still retained in the revision of 1830, edited by the well-informed Desmarest. The story ap- pears to have been derived from De Paw’s ‘ Recherches Philosophiques sur les Américains’ (t. i. p. 245), a work which describes the death of Drake as follows: 1 Histoire Naturelle des Crustacés, contenant leur Description et leurs Meeurs, p. 149. 4 26 A HISTORY OF RECENT CRUSTACEA ‘This navigator having landed on the Isle of Crabs in America, he was there immediately surrounded by these animals; although he was armed, although he made a stout resistance, he had to succumb. These monstrous crustaceans, the largest known in the world, cut in pieces with their claws his legs, his arms, and his head, and enawed his carcase to the very bones.’ There are some elements of truth in this blood-curdling story. It is true that Drake died in the West Indies. It is true that he landed on Crab Island. It is true that he met with huge crabs. But he died on board his own ship of a sickness brought on by disappointment, and his body wrapped in a leaden shroud was buried in the sea. The Crab Island on which he once landed was in the Eastern not the Western Main, nor did he lose his life upon it. The land- ing was in the course of his successful voyage round the world, and it was not the crabs that ate Drake, but Drake and his people that ate the crabs, of which a single one, they afterwards said, was sufficient to make a meal for four men. That might well be, if the crabs at all resembled the giant crab of Australia, Pseudocarcinus gigas (Lamarck),? in which the carapace is said to be sometimes two feet in breadth, and in which one of the claws of the front pair attains a vast bulk. Such crabs as these may be thought to justify a statement in Linschotten’s ‘ Voyage to Goa,’ according to which, ‘To the South of Goa, at a place called St. Peter’s Sand, there are Crabs so great and numerous, that Men are forced to keep a good Watch to defend themselves, for if they get one in their Claws it costs him his life.’ No crustaceans, however, either extinct or extant, can compete in size and power with those fabled by Olaus and De Paw. In the far distant Silurian age the fossil genus Pterygotus among the Merostomata is supposed to afford the largest specimens of the whole crustacean class. 1 Nouvelle Biographie générale, edited by Hoefer, t.14, p. 737. 1856. ? An author’s name appended in parentheses by custom signifies. °- that he is responsible only for the species, and that thi er stands in the genus to which he had assigned it. Eevee aoe A WIDE STRETCH 27 The remains make it probable that some of them attained a length of six feet and a breadth at the widest part of the body of nearly two feet. The sculpture on the carapace, like conventional feathers drawn by some old Assyrian artist, is thought to have led the Scotch quarrymen to call these giant fossils by the quaint name of Seraphim.! Great as their size was, their organisation would have little fitted them to cope with an armed knight. Their nearest living allies belong to the genus Limulus, in which the eastern King Crab, Limulus moluccanus, attains a breadth of a foot by a length of two feet, although, to be sure, nearly one half of the length consists only of a great caudal spine. Among the Brachyura, Japan possesses a species which is certainly from one point of view a rival in size to the largest Pterygotus, and may almost seem to justify the old mythical narratives, for Macrocheira Kdmpferi, de Haan, as a specimen in the British Museum shows, can span eight feet, and it is said that sometimes even eleven feet are within the compass of the outstretched arms ot the male. But portentous as we must allow these dimen- sions to be, the animal is after all only a spider crab, with comparatively weak and spindly legs, and a carapace which seldom if ever exceeds twelve inches in either length or breadth. The fossil Trilobites, which compose the third order of the Gigantostraca, include indeed many species of incon- siderable size, but they are also represented by forms such as Asaphus tyrannus, Murchison, about a foot long, and others in the genus Parudowides, measuring twenty-one inches. Among the spiny lobsters or crawfish, a New Zealand species, Palinurus tumidus, has recently been described by Mr. T. W. Kirk as measuring twenty-four inches from the tip of the beak to the end of the tail, and as having the carapace very much swollen, and measuring 213 inches in circumference. The European Palinurus vulgaris attains a length of 18 inches, also without including the antenne, 1H. Woodward, Transactions of the Palaontographical Socicty, 1866, p. 42. 28 A HISTORY OF RECENT CRUSTACEA which are sometimes considerably longer than the animal’s body. The common lobster, though less bulky in the trunk and with more slender antenna, attains an equal length, or by inclusion of its long and powerful claws might claim in this respect far to exceed the weak-limbed Palinurus. There ig an Australian crayfish, Astacopsis serratus (Shaw), from ten to twenty inches long, and weighing some pounds, which makes a fine show when compared with the much more modest dimensions of the English crayfish. In the same way Leander serratus (Pen- nant), the common prawn of British markets, is humbled by contrest with Palemon carcinus, the river prawn of the West Indies and Guatemala, of Surinam and the Ganges, with its lobster-like size of twelve inches long. Palemon lur, from the Pacific Islands and India, exaggerates one of the characteristics of the genus to which it belongs, inas- much as a male specimen five inches in length will have the second pair of legs nearly eight inches long—much longer, therefore, than the body which carries them. The Her- mit Crabs appear to attain their maximum at about eight inches, a length not inconsiderable, seeing that it has to be accommodated to the vacant shell of a univalve mollusc. One, however, of their near kindred, Lithodes camschatica (Tilesius), has sometimes a span of four feet. This makes its hermitage not in the shell of a mollusc, but in some cranny of the rocks. From this fastness it takes vengeance on the crab-eating octopus, and is itself so firmly lodged that it cannot easily be dragged out, except in fragments. Of shrimps, Pasiphea princeps (S. I. Smith), dredged by the Albatross in 1883, may be accepted as the leader, seeing that it is not only far larger than any of its own genus hitherto known, but by its length of more than eight inches and a half, it exceeds all examples of kindred geneia. Among the Schizopoda the more familiar species are quite the reverse of bulky. A specimen of Gnathophausia ingens (Dohrn), measuring from the tip of the rostrum to the extremity of the telson or tail 157 millimatres, or G4 inches, is spoken of as possessing ‘a truly gigantic size A ROYAL GIFT 29 for a Schizopod.’ It is also said that ‘this form ranks, therefore, as the largest by far of all hitherto known Schizopods,’ although in truth an allied species in the same genus, Gnathophausia gigas, v. Willemoes Suhm, obtained by the Challenger from a depth of 2,200 fathoms, measures 142 mm., or 52 inches. Both of these species, with one or two others in the same genus, such as Gnathophausia Goliath, A. Milne-Edwards, far surpass most of those in the sub-order, the length usually ranging from half an inch to two inches. Of the Stomatopoda, some are no more than three- quarters of an inch in length, but of the species Lysio- squilla maculata (Fabricius), a male specimen, presented to the naturalists of the Challenger by the King of Amboina, fell short only by three-sixteenths of an inch of measuring a whole foot. The Cumacea are a feeble folk. In some species the slender frame, with trunk and tail and tail appendages all told, does not exceed, or even equal, a twelfth of an inch. Only the arctic Diastylis Goodsiri (Bell), occasionally yields a Goliath of an inch and two-fifths. In the Isopoda there is a far greater range of size. Within a single genus, Hurycdpe mutica, Sars, which measures about one milli- métre and a third, is contrasted with Hurycope gigantéa, Sars, which reaches 33 millimetres, or about an inch and a third. Anilocra gigantea (Herklots), measuring three inches and a third, would seem a veritable monster in this sub-order, were it not far surpassed by the ex- tremely exceptional Buthyndmus giganteus of Alphonse Milne-Edwards, which is nine inches long by four inches broad.!. This prize was fished up by the United States Survey steamer Bluke, under the supervision of Alex, Agassiz, from a depth of 955 fathoms, in the region of the Gulf Stream, to the north-east of the bank of Yucatan to the north of the Tortugas. Among the Amphipoda, none yet discovered reach more than about half the dimen- sions of this great Isopod. At the other end of the scale 1 Il mesure, en effet, prés de 0™, 23 de long sur 0™ 10 de large. 30 A HISTORY OF RECENT CRUSTACEA there are Gammarids, Hyperids, and Caprellids, of micro scopic proportions, but for colossal species each Amphipod division must be content to compare its members one with another, rather than with the outside world. In the threadlike Caprellidea, some of which might be regarded as creatures of only one dimension, the Challenger species, Dodecas elongata, by help of its antennz and hind legs, can stretch over a space of three inches. In the Hyperidea, Rhabdosima armatum is not quite so thin, but its length is greater, since the tip of its rostrum is sometimes nearly five inches distant from the extremity of its caudal appen- dages. In the same section the remarkable genus Cystisoma has species which combine a length of four or five inches with the respectable breadth and depth of an inch in the amplest part of the head. The chief boast of the Gam- maridea is Hurythénes gryllus (Lichtenstein in Mandt). The first specimen observed of this full-bodied animal was three inches long and two inches and a quarter round the waist. It was disgorged in the far north by a wounded arctic petrel. Twenty-seven years later it again attracted scientific attention, singularly enough the specimen this time coming from the far south, for it was taken from the stomach of a fish canght off Cape Horn. Its body was nine centimétres long and three deep—in other words, more than three and a half inches in length and more than one inch in depth. In recent years the apparent anomaly of its occurrence both in arctic and sub-antarctic waters has been explained by evidence that it can make itself at home in the intervening expanse, since in 1883 the American steamer Albatross captured a specimen over four and a half inches long, in deep water off the middle Atlantic coast of the United States. This must be regarded as the bulkiest of the Amphipoda yet known. The Entomostracans make their position in the world’s 1 It is doubtful whether the change of this name to Niphocephalus armatus, as proposed by Dr. Bovallius, can be justified, since the name Xyphicéphale was only given by Eydoux and Souleyet on Guérin’s authority in trivial not in scientific form, an ill-spelt French name for a genus rather hinted at than established or defined, the name more- over not being definitely given but only contingently suggested. A DIMINUTIVE GIANT 31 economy remarkable far more by their incalculable num- bers than by their individual measurements. In regard to the Phyllocarida, Dr. Packard remarks that the palao- zoic species were gigantic in size, some being about a foot or more in length, while our recent Nebalia is less than an inch. The new species, Nebaliopsis typica, Sars, however, may extend the magnitude of modern examples to an inch and three-fifths. The Phyllopoda can exhibit Hstheria californica, Packard, in a shell 16 millimétres long, ten broad, and four thick, and Apus Newberryi, Packard, with the carapace, the abdomen behind the carapace, and the slender caudal appendages, each an inch long. But the amplitude more usual in the sub-class may be estimated by the respect paid to such a species as Bythotrephes crassicauda, Jilljeborg, 5 mm. long, one of the Cladocera. This is a colossal species of a fifth of an inch! Among the Ostracoda, Crossophdrus imperator, G. 8. Brady, is one third of an inch long, and with good reason Dr. Brady cannot restrain his admiration of ‘this noble species, cer- tainly the largest of the known Cypridinide.’ In the Thyrostraca or Cirripedia a total length of two or three inches will deserve and earn the lordly epithets of eximium, regium, and gigas, but the Patagonian Balanus psittacus (Molina), which grows rapidly and is ‘ universally esteemed ag a delicious article of food,’ attains six inches in length by three and a half in diameter, and a specimen has been found no less than nine inches in length, though only two and a half in diameter. Of the pedunculate species, Lepas anatifera, the common Goose Barnacle, can grow a stalk more than a foot long. Darwin says: ‘ The largest specimen which I have seen had a capitulum two inches in length ; the longest, including the peduncle, was sixteen inches.’ 32 A HISTORY OF RECENT CRUSTACEA CHAPTER IV ON STRUCTURE TuE body of a crustacean is externally divided into a theo- retically constant number of segments and paired append- ages. In the Malacostraca, it generally exhibits a more or less clear partition into head, trunk, and tail, or, as these parts are sometimes called, cephalon, thorax, and abdomen. There is indeed a rather bewildering supply of alternative names, which it is needless for the moment to discuss. The objections to the use of the word thoram have been already mentioned. Throughout the sub-class, however, the head is found to be united to some portion of the trunk, and to denote this variable combination the convenient word cephalo-thorae is very frequently employed for the region covered by the carapace. It is a matter of opinion whether the full number of true segments should be reckoned as twenty or twenty-one, since that which is called the telson, and which is regarded by many authors as the terminal segment, is considered by others not to be a true twenty-first segment, but a median outgrowth of the twentieth. Scarcely ever can the whole number be dis- tinguished in one and the same animal. As the Entomos- traca always have more or fewer than the theoretical num- ber, there is some need for the eye of faith to include them in the reckoning. The foundation of the integument which forms the external skeleton of a crustacean is a tolerably flexible substance called chitin. This is hardened and consolidated by being impregnated with calcareous salts, and the absence of these leaves the skin the requisite flexibility for acting as a joint between one hardened part WHAT IS A HEAD? 33 and another. But the joints themselves are sometimes consolidated, and then it is said that two or more segments have coalesced. This is not a merely arbitrary statement, for, comparing the Malacostraca one with another, the conclusion cannot be avoided that a single segment is limited to a single pair of appendages. Segments which are not independent in one of the families will be found well articulated in another, and those which can least boast of freedom nevertheless frequently point to an origi- nal independence by some suture or groove, if not by the actual separateness of the segmental ring in some small part of its circuit. No rigid definition is possible of a head. It is bound to contain the animal’s mouth, and may be expected to include the brain and organs of the senses of sight and hearing, smell and taste. In birds and in mammals its limits are conveniently defined by the neck, but in the Crustacea there is no such obvious constriction separating it from the trunk. Consequently its true limits here are still a subject of dispute, which cannot be settled offhand by an appeal to the cervical groove, even when that is con- spicuous. By various authorities the first five, six, or seven seements have been assigned to the head, and in the higher crustacea it might not unreasonably be regarded as comprehending the first nine. This will be understood from a consideration of the form and functions assumed by the several appendages, only thos> in front of the mouth- opening or directly contiguous to it being accepted without dispute as cephalic, although others in variable number are concerned in the operation of feeding. Glancing along the whole line of limbs, as the out- growths from the segments have some right to be called, twenty pairs in uumber, we find them successively devoted to seeing; feeling and otherwise perceiving, feeding and presumably tasting, grasping and striking, walking and digging, swimming and leaping. But although the order in which they act may thus be generally stated, there is not unfrequently a transfer of function from one part of the line to another. The feelers may be employed to assist 34 A HISTORY OF RECENT CRUSTACEA in swimming or climbing or clasping. The mouth-organs of one group are the grasping weapons of another. The walking legs of one set are elsewhere adapted for swim- ming. There are also other functions conjugal or maternal in which the swimming legs or the walking legs may take part, while the breathing apparatus, simple or complicated, may be connected with the mouth-organs or limbs of the trunk or both, or else with the swimming organs of the tail-part, commonly called the pleon. These and other curious modifications are largely made use of in classifying the Crustacea, and to understand the unavoidable intrica- cies of any system of arrangement, the outgrowth of each segment should be studied, in some form the less abnormal the better. 1, The first segment is known as the ocular or ophth- almic. This is clearly articulated in the Squillide, but only occasionally in other groups, as in the macruran Plesi- onika uniproductu, Sp. Bate. Its individuality is in no way indicated in the sessile-eyed Crustacea, in some of which the eyes pretty well cover the whole dorsal surface ofthe head. In the Brachyura and Macrura its original independence can often be traced, but it is in these chiefly attested by the pair of movable appendages which it almost invariably carries. Now, just as it is thought that all the segments represent a common original type variously modified, a similar view is applied to all the appendages that arise from the segments. The resemblance, in fact, is often very obvious between the antennee and the swimming feet ; between the laminar maxillee near the mouth and the opercular and breathing plates in the tail; between the maxillipeds, which are in- struments of nutrition, and the ambulatory legs of the trunk ; so that a connection, at first sight very improbable, is satisfactorily established between them all, when the comparison has been sufficiently extended. Yet it de- mands some exercise of faith on the part of a novice to accept the declaration that this homology holds between the claw of a lobster and its eye. No two parts of an animal could well be more unlike in appearance and func OPTICAL INSTRUMENTS 35 tion. It is unusual to think of a creature’s eye as one of its limbs, for only by a figure of speech do we describe a person as grasping the whole situation at a glance, Never- theless, there are very few inclined to dispute that the eyes of the Podophthalma have really been developed upon appendages by nature equivalent to the rest of the series. Any one acquainted only with the extremely short-stalked eyes of some of the crabs might be excused for thinking this view extravagant, but its improbability is lessened when we observe the long-stalked eyes of the Angular Crab, Gonoplaa rhomboides (Linn.), or those of the macruran Leucifer Reynaudii, Milne-Edwards, or those, again, of Eretmocaris longicaulis (see Plate XITI.), a shrimp in;which the eye is projected on a support actually longer than the animal. Moreover, the ocular appendage, besides being articulated to the head, is itself composed of two or three articulations. In the fast-running Ocypdde cursor (Linn.), the peduncle is extended beyond the cornea of the eye, and terminates like an antenna in a pencil of long hairs. There is one instance on record in which the eye of a kind of lobster, Panulirus penicillatus (Olivier), has been obgerved to develop a jointed antenna-like lash, while the com- panion eye remained normal. This evidence is parallel to that on which a botanist infers that the petals of a flower are by origin modified leaves when he sees them occasionally assuming the form of the unmodified leaf. 2. The second segment carries the first pair of an- tennze, sometimes called the inner or upper, or, without epithet, the antennules. In the Malacostraca normally these appendages consist each of a three-jointed peduncle and two flagella or lashes, composed of many joints or few, the inner or secondary flagellum being not unfre- quently absent altogether or rudimentary. In some in- stances, and in the Amphipoda Caprellidea and in the Entomostracan Copepoda not as an exception but as the rule, the first antenn are larger than the second, from which it results that the diminutive name antennules is _.-rather convenient than appropriate. The superior size, however, is no indication of higher rank, but rather the 36 A HISTORY OF RECENT CRUSTACEA reverse. These organs are sometimes most dwindled in families which can claim a decided precedence over others in which these appendages are well developed. ‘Thus they are short in the crabs, but long in the lobsters and shrimps, and short in the normal Isopods, but long or large as a rule in the Amphipoda, and within the Amphipoda they are short in the Orchestidz, a family that claims superiority by its tendency to terrestrial habits. Those who have made themselves acquainted with Professor Huxley’s volume, ‘The Crayfish, in the Inter- national Scientific Series, will be aware that in describing a crustacean appendage he names the first two joints the protopodite, which bears at its extremity on the inner side the endopodite, and on the outer side the exopodite. For these terms the shortened forms exopod and endopod will here be preferred—exopod for exopodite, endopod for endopodite and protopodite combined—and peduncle will be used for a variable number of basal joints. In the first antennee the peduncle consists, as already stated, of three joints, and by this circumstance the rule which widely prevails elsewhere that the so-called protopodite ends with the second joint of an appendage is broken without any obvious cause. Moreover, that which by its function and in general by its superior size appears to be the main branch is here the outer one, and not as usual the inner. It is conceivable that the exopod is wanting, that the main branch or principal flagellum is the true endopod, and that the secondary flagellum is an independent outgrowth. For the reasons mentioned, and some others, Dr. J. H. V. Boas considers that the first antenng are not homologous with the following limbs, but that both they and the stalked eyes ought to be regarded as limb-like sense organs. That besides being organs of touch, they are frequently organs of other senses, seems to be beyond doubt. In the Macrura at large the first joint contains an auditory apparatus. Sometimes the cavity is provided with a well-formed otolith or ear-stone. In the lobster and crayfish, Mr. Spence Bate says, ‘ the perforation is long, narrow, and slit-like, the aperture being scarcely AN ACOUSTIC TAIL 37 appreciable, and opens into a calcified chamber, more or less filled with particles of sand, which are voluntarily placed in position by the animal soon after casting its exuvium.’ But while the higher Podophthalma have the organ of hearing thus placed, there are some—the Mysidee—which, extraordinary to relate, carry it in the tail (see Plate XIII.). In some of the Amphipoda otoliths have been detected in connection with the brain, notin, but behind the antenne. In general, the antenne are fur- nished with delicate plumose hairs, the vibrations of which assist in the conveyance of sound to tbe auditory nerves. Similar hairs in the Mysidz are connected with the caudal otoliths. The principal flagellum of the upper antennz is frequently furnished with a number of smooth setze or filaments, which were at one time described as auditory cilia, though there was nothing to support this guess at their function, and though the term ciliwm was inappro- priate to the shape of these rod-like membranous filaments. It was noticed by various naturalists of eminence that the sete of this form were much more abundant in the adult males than in the young males or in the females. Leydig supposed them to be not auditory but olfactory organs, and Fritz Miiller independently came to the same conclu- sion, adducing in support of it their stronger development in the males, as in other cases male animals are guided by the scent in pursuit of the females. It can scarcely be said that their olfactory function is as yet absolutely proved, but they are evidently not well placed to serve the sense of taste, and for the senses of sight, hearing, and touch, there are other organs much better adapted, so that these glassy filaments, to be sensory organs at all, are in a manner forced back upon the sense of smell. The secondary or inner flagellum, according to Dr. Boas, is wanting in all genuine Nauplii—that is, in the earliest larval stage of the crustacean. Its after develop- ment conforms to no known rule, since in some species 16 is not found at all, in others it is only rudimentary, whereas, on the other hand, among the Macrura it is not unfrequently much longer than the outer flagellum. Mr. 38 A HISTORY OF RECENT CRUSTACEA Spence Bate suggests that its function may consist in pto« tecting and keeping clean the mass of cilia and filaments attached to the outer branch. In some genera of the Macrura, for example Paleemon and Alpheus, the principal flagellum divides at some distance from its base into two branches. In the Squillide, also, there are three flagella, 8. The third segment carries the outer, under, or second antenna, sometimes called simply the antennz in distinc- tion from ‘antennules.’ They are rarely absent, as in the females of some Amphipoda. More often they are strongly developed, in some instances exceeding in length all the rest of the animal which carries them, the joints of the flagellum or lash being then very numerous. In the Malacostraca the peduncular portion embraces the first five joints. The exopod, when developed, as it gene- rally is in the Macrura, very commonly has the form of a thin plate known as the antennal scale, in Latin sguama, while those who love long words are privileged to call it the scaphocerite. When laterally extended this broad scale must assist in keeping the animal upright in the water, a position which would otherwise with difficulty be maintained by long-bodied forms. In some Crustacea, the scale, though present, has not a laminar character, and it is then spoken of as the acicle. The first, or basal joint of the peduncle, is not unfrequently soldered to the wall of the head, and very often carries a tubercle in con- nection with the ‘green gland,’ of which the function is supposed to be renal, though it has not been with certainty determined. That this tubercle is of some importance may be inferred from the fact that in some cases where the antenna itself is obsolete the tubercle persists. It is not a little singular that up to thirty years ago or later, many naturalists of eminence regarded this tuber- cle as connected with the auditory apparatus, which they assigned to the base not of the first but of the second antennee. Milne-Edwards in 1834 refers to the researches of M. Savart, who had discovered that the stretching of a fine elastic membrane over an opening was one of the circumstances best adapted to promote the appreciation of THE MANDIBLES 39 sound. Just such a membrane Milne-Edwards considers to exist at the base of the antenne now under discussion, and in some of the Brachyura he and his colleague Audouin had investigated an inner apparatus capable of increasing the tension of the disk at the will of the animal, an arrangement which he compares with that of the auditory ossicles and the tympanic membrane of the human ear. It is only with reluctance that this description of a natural telephone can be relinquished. In some species, such as the common rock lobster, Palinurus vulgaris, there is a stridulating apparatus in the basal joints of the second antennee, and it is obviously unlikely that a sound-pro- ducing organ should have been developed in an animal’s ear. 4, The fourth or mandibular segment is of great im- portance, since from this, or from it in conjunction with the preceding segment, the carapace is developed. Its appendages also, the mandibles, yield in value to very few of the other organs. In form they vary extremely, but are for the most part of powerful structure. Their edges meet over the mouth-opening between the upper lip and the lower. The trunk of the mandible is frequently massive, with a projecting, finely denticulate, grinding surface called the molar tubercle, and a thick or thin dentate cutting edge, often having also a variety of spines between these two processes. It is not seldom surmounted by a narrow piece, commonly called its palp, which never in the Malacostraca consists of more than three joints. Very rarely, and only among the Entomostraca, one of the joints of the palp has an outgrowth supposed to represent the exopod. Since theoretically the exopod always arises from the second joint of an appendage, it is argued that the trunk of the mandible must represent the first joint. But to this it may be answered that the exceptional out- growth just mentioned is perhaps not an exopod, and that at any rate in the first antenna there is a similar out- growth from the third joint. In Huchet« glaciahs, Hansen, and some other Entomostraca, the mandibular palp divides into two branches from its second joint. Seeing that the first joint of a crustacean appendage is very rarely of large 40 A HISTORY OF RECENT CRUSTACEA size, it is a question whether the trunk of the mandible may not represent a coalescence of the first and second joints, or even of the first three or four joints. The latter supposition would explain the circumstance above noticed that its ‘palp’ or terminal portion in the Malacostraca never exceeds the number of three joints, though it may le reduced to two or one, or may vanish altogether (see Plates XII., XV., XIX.). On the inner side of the man- dible there is sometimes, adjoining the cutting edge, a plate which more or less closely imitates that edge in its character. It has now been made probable that this secondary plate is a modification of one of the spines above noticed, and, as if to show the plasticity of nature, some- times the series of spines mimic the secondary plate. The upper and lower lip seem best to be regarded as modifications of the integument, where it is turned in to form the alimentary canal, commencing with the cesopha- gus or gullet. An American lady, Miss J. M. Arms, however, in her very clever little work on Crustacea, in Alpheus Hyatt’s ‘(yuides for Science-teaching,’ maintains that the leaves of the lower lip ‘are independent outgrowths or buds from the integument, as much as any other pair of appendages; and the fact that the parts of the segment to which they must have belonged have disappeared, or cannot be readily found, is, in her opinion, ‘an argument of doubtful weight.’ The theory that all the appendages of a crustacean are either legs or modified legs will strike a casual observer as rather strained in its application to the mandibles. That a crab should adapt the basal joints of a pair of limbs for masticating its food may seem as unlikely and absurd as that a man should have teeth on his elbows, and should draw them up in front of his lips for the purpose of biting and chewing whatever he wished to put into his mouth. To prevent all cavilling, however, on this point of the theory, the King Crab, Limulus, is so obliging as to ignore the ordinary mouth organs, and to use the bases of its actual walking legs as mandibles. THE MAXILLARY FAN 41 5. Close up to the lower lip, and as little leg-like as any of the appendages, are placed the first maxille. ‘They are almost always thin and foliaceous, with few joints, and those few not easy to distinguish. The pattern is ex- tremely variable. The functions are obscure. There are sometimes strong fringing spines which may assist in dividing the food. There are plumose hairs, some of which may be connected with the sense of taste. The position of these organs has also suggested that they may ‘be useful in preventing the escape of food from the lateral angles of the mouth.’ It is with these that some authors close the number of true cephalic appendages. Of those which follow some are frequently, but none with the same constancy, developed into mouth-organs. 6. The second maxilla, when present, have generally the same thin flattened. character as the first, but their structure is often more complicated. Among other pecu- liarities they have in some of the higher groups a mem- branous expansion or large lamina on the outer side, frequently termed the flabellum or fan, and compared by Milne-Edwards to a ventilating register (see Plate XI.). This species of valve is in constant and rapid vibration, in most cases forcing the water which has aerated the gills to pass out in front, so that a new supply may be introduced from behind; but in some crabs (as Dorippe, Ranina, Leu- cosia) according to de Haan the water is introduced in front, and passes out behind. Huxley supposes that this valve may represent the epipod, that is to say, the branch which is given off by the first joint of an appendage, or else that it may be a combination of the epipod of the first joint with the exopod of the second.!_ Professor Sars re- gards it as the exopod,? while Dr. Hansen considers that it springs from the third joint.2 In those Crustacea which have the branchi either not enclosed in a chamber or in one remote from the head, this part of the maxilla is either absent or rudimentary (see Plates XVI., XIX.). 1 The Crayfish, p. 170. (The scaphognathite.) 2 The Norwegian North Atlantic Expedition Crustacea, p. 21. 3 Oversigt over de paa Dijmphna-Togvet indsamlede Krebsdy7, p. 193 note, and p. 252. 5 42 A HISTORY OF RECENT CRUSTACEA 7. The appendages of the seventh segment are dis- tinguished from the two preceding pairs by the name maxillipeds, meaning maxillary feet or jaw-feet, because they often conspicuously combine the function of a mouth- organ with the general appearance of a crustacean leg. This is very much the case in the Amphipoda, where they conclude the series of cephalic appendages, having here something of the opercular function which they exercise still more conspicuously in the Isopoda. In the Copepoda, which are content with one pair of maxilla, there are two pairs of ‘ foot-jaws,’ in regard to which the singular dis- covery has been made that they belong to a single segment, and yet do not violate the rule that a single segment is limited to a single pair of appendages. By tracing the process of development Dr. Claus made it clear that they were in fact the exopods and endopods of a single pair of limbs, which had separated so as to wear the appearance of two distinct pairs, which is much as if the radius and ulna in the human arm were to become independent and produce a four-handed man. In the higher Crustacea these appendages, without being divided, are only the first of a series of three pairs of maxillipeds. Their forms vary exceedingly in the different groups. Sometimes the endopod is seven-jointed like an ordinary limb, at others the terminal part is reduced to insignificance. Often the epipod and exopod are important both in size and function. 8. In regard to the eighth segment, a difficulty arises as to how the appendages should best be designated. In some groups, such as the Amphipoda and Isopoda, they belong not only in theory but in fact to the trunk, and they have in these groups been called gnathopods, a word which, like maxillipeds, means jaw feet, and which was chosen to indicate that they grasped the food in a jaw-like manner. But in the higher Crustacea these appendages practically belong to the mouth and not to the trunk, their general appearance and functions allying them closely to the preceding pair. Under these circumstances it seems best to call them the second maxillipeds. For, A CENSUS OF LEG-JOINTS 43 though it has been strongly urged that one and the same term ought to be applied to homologous parts throughout the whole crustacean class, either nature has opposed the rigid application of such a system, or the wit of man has not yet been able to devise appropriate terms. It may here be mentioned that the full number of joints for a malacostracan trunk-leg is seven. With aview to uniformity of nomenclature, the afflicted naturalist has for many years had to deal with these seven under the following names :—Coxa, basis, ischium, merus, carpus, propodus, dactylus, which respectively signify hip, foot, socket of thigh joint, thigh joint, wrist, forefoot, and finger or toe. Originally the names were longer, all being podites, from coxopodite to dactylopodite, to the use of which the philosophic French still adhere, though the time-saving Anglo-Saxon has for the most part rejected them. Among other difficulties in this terminology under either form, it has to be remembered that the basis is the second, not the basal joint of the limb. The more reason- able plan is now being widely followed of naming these joints simply according to their numerical order, the coxa being called the first joint, and the dactylus the seventh. But the older names have still to be borne in mind by those who study the older literature. Even the numbers are attended by a very unfortunate element of confusion. The late Axel Boeck, when introducing the use of num- bered joints, was studying the Amphipoda, in which the first joint of a leg is seldom, if ever, free. Taking into account, therefore, only the six free joints, he called the second joint the first, and made the finger the sixth, instead of seventh. In treating separately of the Amphipoda or Isopoda, many naturalists have followed Boeck’s usage as reasonable and convenient. But when other Crustacea are considered in which an appendage has the first joint or perhaps all the seven joints free, they must be numbered from one to seven, and whenever a comparison is needed between the limbs of the Edriophthalma and those in other groups, two different systems of numbering the joints cannot fail to be highly embarrassing. It must 44, A HISTORY OF RECENT CRUSTACEA further be noticed that there are Crustacea in which one or other of the joints, most often the fifth, is itself multi- articulate, thus adding to the normal number, which on the other hand is still more frequently diminished by coalescence, absorption, or complete failure of develop- ment, affecting various parts of the limb. 9. The ninth segment carries a very important and, at the same time, very variable pair of appendages, which, as the third maxillipeds, have in the higher Crustacea the same kind of opercular character that has been noticed as pertaining to the appendages of the seventh segment in some of the lower groups of the Malacostraca. In his celebrated and valuable work on the Crustacea of Japan, de Haan made great use of these third maxillipeds for classifying the Malacostracan group in respect to families and genera. The various joints of the endopod by their shapes, relative size, number, and mode of articulation one with another, have yielded a multitude of characters. Ju the Amphipoda, where the appendages of the ninth segment are not mouth-organs, but constitute the second gnathopods, they are commonly the most powerful limbs of the trunk, being, no doubt in general, the animal’s most efficient weapons for holding its prey. In the Isopoda, on the other hand, they are to be called gnathopods only by courtesy, being in general little distinguishable from the following pair of limbs. 10, 11, 12, 18, 14. The appendages of the five follow- ing segments have been and may sometimes conveniently be called perasopods, which means walking-feet. Among the Amphipods and Isopods they are usually adapted for walking, and in those groups the trunk, to which they are attached, is often called the peraeon, intended to signify the ambulatory part. Among the crabs and lobsters, and various other crustaceans, however, the first of these pairs is by no means adapted for walking, but ends in large claws or nippers, on account of which they are known as the chelipeds, and Mr. J. E. Ives proposes to call the four following pairs cruripeds, which means leg-feet, while Dr. A. 8. Packard, unaware of what was intended by APPENDAGES OF TRUNK AND TAIL 45 perzeon, has proposed to substitute for it ‘banosome,’ a word of precisely the same sense. The epithets chelate and sub-chelate are of constant occurrence in descriptions of Crustacea. A limb is chelate when it has joints that will act together like a pair of tongs. Generally this character is produced by the hingeing of the seventh joint a considerable way down on the side of the sixth. When the seventh joint or finger can be folded back upon the sixth, although the latter is not produced into any thumb- like process to oppose it, the limb is then said to be sub- chelate, the claw being in that case partial, though often extremely efficient. ‘he possession of chelee is not con- fined to the first pair of so-called peraeopods, although it is seldom elsewhere that they attain a monstrous develop- ment. They may occuron any of the pairs, and on several in the same animal. In connection both with the maxilli- peds and the pereeopods there are developed in great variety of form the branchiz or gills, also the plates of the marsupium, wherein, in some groups, the eggs are retained for a time after their discharge from the ovaries; and again, in some groups, the exopods are developed as swim- ming organs. ‘The vulve, or uterine openings of the female, belong to the sternal, that is the ventral, side of the tweltth segment, while the genital openings of the male occupy a similar position in the fourteenth segment. In those Crustacea which have the basal joints of each pair of legs brought close together, the openings in ques- tion have been transferred from the wall of the trunk to the first joint in each of the last pair of legs in the male, and of the antepenultimate pair in the female. 15, 16,17, 18,19, 20. The remaining segments belong to the tail or caudal portion of the animal, which has been termed the pleon or swimming-part, a convenient and often a very appropriate name, although on the other hand there are plenty of crustaceans which do not and cannot use the pleon to swim with. ‘The first five of these segments frequently have appendages that are really natatory and may properly be called pleopods, swimming- feet. But some or all may be wanting, or rudimentary, 46 A HISTORY OF RECENT CRUSTACEA or devoted to other purposes. They may be partially or entirely branchial. Among the Stalk-eyed Crustacea they are often used in the female for retaining the eggs during an early period of development or hatching. In the Amphipoda the fourth and fifth pairs are more or less adapted for springing, and bear the name of uropods, or tail-feet. This name is also given to the appendages of the twentieth segment whenever they are present. ‘These are prominent features in the Cumacea and most other Edriopbthalma, and in the Macrura they combine with the telson to form the powerful tail-fan, for which Mr. Spence Bate has proposed the Greek name rhipidura (see Plate X.), In the Copepoda there is a ‘ caudal furca,’ homologous with the caudal rami in the Nebaliide, which must be distin- guished from the terminal uropods of the higher Crustacea, as ‘ being not true limbs, but more properly representing a bipartite terminal segment.’ } 21. The telson is extremely variable in form and relative size, and sometimes by coalescence with the pre- ceding segment shows little trace of independent exist- ence. The intestinal canal opens on its under side. It is sometimes deeply cleft, as though the two terga, or dorsal plates, of a body-ring had come apart. To prove its claim to be regarded as a segment, the most effective argument would be to show that it sometimes carries appendages after the fashion of all the other segments. Bell, in the ‘ British Stalk-eyed Crustacea,’ says that he has frequently observed appendages to the telson of the common prawn, Leander serratus (Pennant), ‘in the form of extremely minute points attached to the very extremity of the segment, and moveable.’ Spence Bate says, ‘In some genera, or even families, the telson is posteriorly rounded, as in the Astacideze; in others it is anteriorly hard and calcareous, and posteriorly soft and membranous, as in the Synaxidea, a circumstance that is suggestive of a distinct relationship of the two parts, the anterior which carries the anus belonging to the normal somite, ' Sars. Iteport on the Phyllocarida collected by H.M.S. Challenger, p. 35. INTERNAL DIFFERENCES 47 while the posterior portion represents its appendages. This idea is still more strongly suggested in the genus Cheiroplatea, where the separation of the posterior from the anterior division is clearly defined by a distinct mem- branous articulation, and the posterivr portion is divided into two lateral lobes.’! The older genus Porcellana is even more to the purpose than Cheiroplatea, and Miss J. M. Arms, in the Manual before referred to, considers that it settles the question. Comparing a species of it with the lobster, ‘This curious little crab,’ she says, ‘ possesses a telson with an unmistakable pair of appendages attached to it, proving that this part is really a ring whose appen- dages are wanting in the lobster.’ It must, however, be remarked that neither in the Porcellanide nor in the Gala- theidee do these apparent appendages of the telson ever become freely articulated with it, and as they are the last to put in any appearance at all, and then only in a late stage of the animal’s development, it remains a question whether they may not be dividing lines of the telson rather than appendages arising from it. In the internal organs of crustaceans the differences are as great as in the external. One writer has even undertaken to classify the Brachyura according to the structure of their stomachs. Unless this part of the organism were tolerably complicated, it will be easily under- stood that it would not afford sufficient variations for such a purpose. But though, for establishing a really natural system, every stage of an animal’s development and all its parts ought to be studied and taken into account, surely a systematist ought to aim at founding his classification as far as possible on the most accessible stages and the parts most easily observed. At any rate the general student will have little inclination to arrange his collec- tion by investigating in the different specimens the walls of the stomach and the teeth and hairs within it, although he may occasionally be pleased to observe in that of the lobster the three horny-looking grinders, the central one 1 Spence Bate. Report on the Macrura collected by H.M.S. Chal- lenger, p. Xlviii. 48 A HISTORY OF RECENT CRUSTACEA of which has from of old been fancifully called ‘the lady in the chair.’ The character of all the internal organs of Fic. 1—A lobster’s stomach opened to show the teeth, the central one of which has been supplied with eyes, nose, and mouth, to represent ‘the lady in the chair.’ [Herbst] a crustacean, as exemplified in the crayfish, has been already discussed in detail by Professor Huxley in a pre- vious volume of this series. It may here, therefore, suffice to recall that in a crustacean the heart is dorsal, the nerve- chain, with the exception of the brain, ventral, and the alimentary canal central, having in proximity the hepatic lobes or liver, and the testes and ovaries. Some of the more or less striking peculiarities which prevail in different groups in regard to these organs are reserved for mention as occasion offers in the description of the several sub- orders and their families. The following table supplies a synopsis of all the leading groups of the Crustacea. The literal meaning of the various names has been explained in the first chapter :— A TABULAR VIEW Class. CRUSTACEA, Sub-classes. Malacostraca. Entomostraca. Gigantostraca. Thyrostraca (or Cirripedia), MALacostTraca. Orders. Podophthalma. Edriophthalma. Sub-orders. Sub-orders. Brachyura. Cumacea. Macrura. Isopoda. Schizopoda. Amphipoda, Stomatopcda, ENTOMOSTRACA. Orders. Branchiopoda. Ostracoda. Copepoda. | Sub-orders. Sub-orders. Sub-orders. Phyllocarida. Podocopa. Gnathostoma. Phyllopoda. Myodocopa. Peecilostoma. Cladocera, Cladocopa. Siphonost. ma. Branchiura. Platycopa. GIGANTOSTRACA. Orders. Merostomata. Xiphosura. Trilobita. THYRUSTRACA (CIRRIPEDIA). Orders. Thoracica. Abdominalia. Apoda. Rhizocephala. Sub-orders. Pedunculata, Operculata. 49 50 A HISTURY OF RECENT CRUSTACEA CHAPTER V THE SUB-CLASS MALACOSTRACA Tur head and trunk are together composed of thirteen, or, if an ophthalmic ring be included, of fourteen seg- ments. The caudal part or pleon is composed of six seg- ments and a telson. The trunk is clearly distinguished from the pleon, but some part of it is always more or less closely united with the head. To every segment normally belongs a pair of jointed appendages. The eyes are either pedunculate, and limited to two in number, with rarely a pair of accessory ocelli, or they are sessile, and then gene- rally two, but sometimes four, or with the components variously distributed. There are two pairs of antenna, a pair of mandibles, and two pairs of maxille. Of the next eight pairs of appendages, from one to three are mazxilli- peds, organs of the mouth, the remainder, from seven to five in number, being prehensile or locomotive. All these are typically seven-jointed. Like the second antenne and second maxille they may either have or be without an exopod on the second joint, and they may also have or be without an epipod on the first. The six pairs of appen- dages of the pleon, when present, generally have an exopod. The last pair almost always differs in character from the rest. The paired appendages of the mouth work from the sides, the oral aperture itself being fringed by the labrum or upper lip above, and the bifid labium or lower lip below. A short cesophagus leads up into the stomach. The intestinal tube terminates in the under side of the telson. The heart which is dorsally placed has lateral openings for the entrance of the blood that has been oxygenated in the branchia. These slits are in one, two, SHORT TAILS 51 or three pairs, only in the Squillide exceeding that num- ber. The ganglia of the same pair are situated close to one another, though the commissures may stand a little apart. By the dorsal and lateral extension backwards and generally also forwards of one (or two) of the cephalic segments a shield or carapace is formed covering at least some part of the trunk and sometimes all of it. The above characters will suffice for a descriptive defi- nition of the Malacostraca, but it may be proper to remind the reader that the segments are sometimes so intimately coalesced that their separate identity is entirely obscured, and that moreover almost any pair of the appendages, even one so seemingly indispensable as the mandibles, may in certain cases be missing. Absence of eyes is by no means infrequent, and the telson, though perhaps never properly speaking absent, is often, by its close union with the pre- ceding segment, so withdrawn from recognition, that in practice it is spoken of as absent. Order 1.—Podophthalma. In this order there is normally a pair of compound eyes on movable stalks, the eyes being sometimes absent but never sessile; the dorsal shield or carapace extends back over the ninth segment or further. Sub-order 1.—Brachyura, The carapace extends over the whole head and trunk, with occasional exception of the trunk’s ultimate and pen- ultimate segments, and is longer than the pleon. In the carapace are excavated orbits and fossettes, hollows respec- tively adapted to receive the stalked eyes and the short first antenne. The third maxillipeds have some of the joints broad and flat, and they form a more or less com- plete operculum to the well-defined mouth cavity. The following pair of appendages are perfectly chelate limbs, commonly called the chelipeds. The next four pairs are adapted for walking or swimming, or rarely may have a prehensile character. In the sternal plastron, or breast- 52 A HISTORY OF RECENT CRUSTACEA plate, the coalesced ventral plates of the last five seg- ments of the trunk are distinguishable, and three earlier segments are obscurely represented. It is never entirely linear. The vulve of the females are generally placed upon it, but in some groups are transferred to the basal joints of the ante-penultimate legs. ‘The pleon is of sub- ordinate size, usually reflexed against the concavity of the plastron, in the male generally narrow and pointed, with only one or two pairs of pleopods, in the female broad, with four pairs of pleopods. ‘The basal joint of the first antenne contains auditory hairs but no otoliths. In this definition the Anomura apterura are included. To the dry bones of definition must be added an even less appetising explanation of terms in common use for the description of genera and species. The orbital regions of the carapace speak for themselves as being those which contain the eyes. The ‘ front’ lies between them. Behind it on the under surface are the fossettes of the first an- tennee, followed in the median line by the epistome, the buccal or oral frame, and the sternal plastron. The second antenne are placed outside of and a little behind the first. The ‘hind margin’ of the carapace separates the trunk from the pleon, and lies between the first joints of the last pair of trunk-feet. Between it and the orbits are the lateral margins, each of which is subdivided into an antero-lateral and a postero-lateral portion forming, when not continuous, the epibranchial angle. The dorsal sur- face of the carapace is marked by several grooves cor- responding with the insertions of muscles underneath, and also forming the boundary lines of regions which roughly coincide with the positions of important internal organs. Along the centre lie the gastric, cardiac, and intestinal regions, respectively over the stomach, heart, and intes- tine. The hepatic regions over the liver flank the gastric region on either side in front, and behind these lie the two branchial regions, the ‘ cervical groove’ being that which separates the gastric and hepatic regions from the cardiac and branchial. On the under side the pterygostomian re- gions, ‘the wings of the mouth,’ lie between the antero- MASKS AND FACES 53 lateral margins of the carapace and the buccal frame. Milne-Edwards remarks that the grooves are often em- phasised about the middle of the carapace, so as to pro- duce the appearance of the capital letter H, the transverse Fie. 2.—Ethusa mascarone (Herbst). [Herbst] line being the upper boundary of the cardiac region. In some cases the grooves are so arranged as to represent very strikingly a human countenance or the caricature of one, as in the Masked Crab of Great Britain and the grimac- ing Ethusa mascarone of the Mediterranean, which is here shown as depicted by Herbst. Such likenesses the old writers were not at all disinclined to accentuate. The Brachyura are divided into tribes, in regard to which, however, there is not at present any absolute agree- ment among naturalists. We shall here arrange them under the uames Cyclometopa, Catometopa, Oxyrrhyncha, Oxystomata, Anomala. It is melancholy, but scarcely avoidable, that an alternative list of names should have to be mentioned, for these tribes in the same succession may be called—-Cancroidea, Ocypodiidea, Maividea, Leucosiidea, and Anomura apterura. The subjoined table will be use- ful for reference. 54 A HISTORY OF RECENT CRUSTACEA BRACHYURA. Tribes. Legions. Families. Cyclometopa . Cancrinea . Cancride, Trapeziide, Portunidm, Podophthalmidz. Cyclinea . Cyclidee. Corystinea . Corystide. Thelphusinea. Thelphusidee. Catometopa : Gecarcinide. Ocypodidz. Grapside. Pinnotheride. Oxyrrhyncha , Maiinea. . Inachide, Maiide, Pericerida, Parthenopinea Parthenopide. Oxystomata ‘ Calappide. Matutide. Leucosiide. Dorippide. Anomala . « Drominea . Dromide#, Homolide, Ranininea . Raninide. ROUNDHEADS 55 CHAPTER VI TRIBE I.—CYCLOMETOPA THE name literally means ‘those of a circular forehead.’ In these Crustacea the carapace is often of a breadth greater than the length, wide and regularly arched in front, more rarely quadrate or suborbicular, but not rostrate. The epistome is short, transverse. The first antenne are in general transversely folded. ‘The third maxillipeds have the fifth joint articulated at the apex or the inner front angle of the fourth (except in Pirimelu). There are nine pairs of branchie, with their efferent channels opening at the sides of the endostome or palate. The verges of the male are inserted at the bases of the last legs of the trunk. Milne-Edwards states that the different ganglia of the trunk form a sort of circular ring, of which it is often easy to distinguish the constituent elements, and that the two halves of the liver remain distinct without a median lobe. The tribe has been subdivided into four legions— Cancrinea, Cyclinea, Corystinea, Thelphusinea, in de- fining which I shall follow the safe guidance of Mr. E. J. Miers, as afforded in his report on the Brachyura collected by the Challenger. Legion 1.—Cancrinea. The buccal cavity is usually well defined. The flagella of the second antennz are not greatly elongated. The seventh joint in the walking-legs is generally unarmed. It is either stiliform or in the last pair expanded into an 56 A HISTORY OF RECENT CRUSTACEA ovate swimming organ. The species are marine or littoral. This legion contains four families—Cancride, Trape- ziide, Portunide, Podophthalmide. Family 1.—Cuneride. The carapace is commonly transverse and convex, with the antero-lateral margins arcuate, and armed with several lobes, teeth, or spines. The ‘front’ is of moderate width, in general not projecting over the first antenne and the bases of the second, the latter being seldom excluded from the inner hiatus of the orbits. Jn this family are included about half a hundred genera, some widely and conspicuously distinct, others separated by fine and almost inappreciable differences. Thus Mr. Miers observes of Xantho (Leach, 1813), that ‘it is connected by almost insensible gradations on the one hand with Lophoxanthus and Xanthodes, on the other with Panopeus and Eurypanopeus.’ Quite recently the genus Panopeus, H. Milne-Edwards, 1834, has been re- viewed by James Benedict and Mary Rathbun. They recognise in it thirty-eight species, and re-include within its boundaries Eurytium, Stimpson, 1859, and Hurypano- peus, A. Milne-Edwards, 1880, considering that they have been separated from the parent genus on grounds in- sufficient or untenable. It will, however, be quite be- yond the range of such a mannal as this to enter into all the minutize of generic distinctions. Far less can the characters of innumerable species be discussed. Only the specially typical or the specially anomalous forms may court a passing attention. Here and there a comparison, a description, a comment, may indicate the variety of details upon which classification is founded, or may sug- gest the endless opportunities for the exercise of keen eyes and acute minds, which the subject provides. Those whose scientific zeal is limited to the desire of having the specimens in a cabinet rightly arranged and ticketed with their proper names are often puzzled and HOW GENERA ARE GENERATED 57 exasperated to find that there is practically no finality in these matters. It is important to remember that this cannot be helped, so long as knowledge is in the stage of growth, the stage in which it is most acceptable to the human intel- lect, by continually holding out the invigorating hope of new acquisitions. In the progress of science some animal hitherto unknown or little noticed attracts the attention of a naturalist. Describing some of its salient features, he makes it the typical species of a new genus. In course of time many other animals are found to have characters almost identical, and they constitute the various species of the same genus, till the number of them becomes so large that they are perhaps at first grouped in lettered or num- bered sections, to which presently names are given as sub- genera, and these in turn are raised to the rank of genera, and sometimes eventually to higher grades in the system. At each successive improvement there comes a displace- ment of the old names, and for the accurate designation of specimens the unskilled are placed at greater and greater disadvantage. There was a time when all the Crustacea were included among insects, but to call a lobster an in- sect would now be regarded as a proof of ludicrous igno- rance. The existing genus Cancer is an absurd little remnant of that which was originally established by Linnzeus, and which has been gradually subdivided into a long array of genera, and families, and legions, and sub-orders, and orders. Bell, in 1853, in his ‘ British Stalk-eyed Crustacea,’ says, ‘There is but one species of this genus, as now restricted, native of the shores of this country, or indeed of Europe, all the others being South American.’ He refers, however, to the species discovered by Say, which belong to the East Coast of North America. The great eatable crab of our own shores is well known. Dr. Leach remarks that ‘at low tide they are often found in holes of rocks, in pairs, male and female, and if the male be taken away, another will be found in the hole at the next recess of the tide. By knowing this fact, an experienced fisherman may twice a day take with little trouble a vast number of specimens, after having once 6 58 A HISTORY OF RECENT CRUSTACEA discovered their haunts. Mr. Couch found that this referred to the mating time, which occurs just after the female has cast her coat, her new shell being still soft. It is easy to understand why the exuviation of the male takes place at a different period, as otherwise the pair would be defenceless together. Of this Cancer pagqurus, Linn., small specimens are often sheltered in considerable numbers in cavities wrought in the vast masses of the sand-tubes of the marine worm Sabellaria alveolata. Cancer irroratus, Say, is the commonest species of the genus in America. It is exceedingly like the European species, but smaller, with the chelipeds less bulky, and dis- tinguished by a strong tooth on the fifth joint. It is said to be common under the large rocks near low-water mark, often lying nearly buried in the sand and gravel beneath them. It is also frequent on sandy shores, and occurs in the tidal pools, where, according to Professor Verrill, ‘ the comical combats of the males may sometimes be witnessed.’ Miss J. M. Arms founds upon it the following description of a crab’s method of walking :— ‘The legs of one side are used to push with, and those of the other to pull with, when the crab is in motion. Those of the same side do not, however, all move together, but alternately, so that there is no halting in their gait; some of the legs are always in the act of taking new steps, and by shoving and pulling in unison a continuous motion is kept up. This crawling by means of jointed appen- dages can be imitated after having once seen a live crab. Cross the two wrists side by side, placing the fingers down on a level table; bind the wrists by an elastic band, hold them well up from the table, so as to show the fingers. Then let one set crawl while the other pushes, so as to keep up a continuous motion sidewise without assistance from the arms. The terminal sections of the legs show wear only on the points where these are inserted in the ground.’ It will subsequently be seen that there are some crabs which are by no means limited to the slow progression denoted by the word crawling. FACT AND FICTION 59 Say established the species Cancer irroratus in 1817, but in 1859 Stimpson discovered that under one name Say had combined two species, having been misled into matching the male of Cancer irroratus with the female ot Cancer borealis. The differences between the sexes which often exist in Crustacea have more commonly led naturalists into the opposite mistake of instituting a separate species for each sex. Cancer borealis, Stimpson, occurs in the same localities as Cancer trroratus, only being a heavier and more massive species it does not equally court shelter and retirement, but will rest entirely exposed on bare rocks and ledges, or clinging to weeds amid the onset of the waves. Yet the strength of its shell does not save it from the gulls and crows which take advantage of its venturesome position to carry it off for their own con- sumption. It is not only the sexes of the adult crustaceans that often differ considerably in appearance, but in many in- stances between the egg and maturity there are stages to be passed through in which the forms of the young are so startlingly different from those of their parents that they have been placed in different genera, until the relationship was eventually proved or made probable. To these lar- val stages various names have been given, some of them borrowed from the names of the supposed genera to which the young animals had been at first assigned. The Dutch naturalist, Martin Slabber, in 1769, was the first to publish an account of a crustacean metamorphosis so striking that, as he says, had he not himself witnessed it, he should have placed the two forms in different genera. Yet this singular observation was left barren, until in 1823 Mr. Vaughan Thompson was induced to follow it up, with results that have since been far-reaching. One very curious circumstance in this history is that the two forms which Slabber figures evidently do belong to perfectly dis- tinct groups, the first or Zoéa form to the Brachyura, and the second to the Macrura. Bell, in the Introduction to his ‘British Stalk-eyed Crustacea,’ reproaches Thompson tor coming to the conclusion ‘that Slabber lost his Zoéa, in 60 A IfISTORY OF RECENT CRUSTACEA changing the sea-water, and that the new form came from the added portion.’ The second form has been shown to correspond very exactly with the larval stage of a prawn, and from this Bell weakly argues that the observation of Slabber was correct, although the first form, as Bell had reason to know, was the larval stage of a crab, and in this Slabber correctly observed the gradual dwindling of the horns of the carapace. The minuteness and transparency of these infants and the readiness with which they perish will account for the confusion in regard to the principal change into which he appears undoubtedly to have fallen, but it is remarkable that such an error should have been in close agreement with the real facts of the case, that a discovery apparently so full of interest should have been neglected for half a century, and that then, when at length it was placed upon a solid foundation, the facts should have been hotly and stoutly disputed for a long series of years. In 1837 Milne-Edwards was still undecided on many of the details of the question, but as to the state- ment made by Vaughan Thompson in 1835 that the great French naturalist had been deputed by the Academy of Science to investigate the development of the Crustacea, that he had passed a sammer in the Isle of Ré for that’ purpose, and had come to the conclusion that the Crustacea are born in their permanent forms, in all that, Milne- Edwards retorts, there is not a word of truth. He had never been in the Isle of Ré, he had never denied that some Crustacea underwent considerable changes, and he could only hope that Thompson was more careful in his observations than in his quotations. Notwithstanding this sharp denial, Bell in 1853 still sends Milne-Hdwards to the Isle of Ré, and wonders that observations which he never made should have led him to conclusions which he did not entertain. The larval stages of the American Cancer irroratus have been studied by Professor S. I. Smith. As might have been expected, they agree very nearly with those of the European Cuncer pagurus. In its latest stage the Zoéa still has a frontal and a dorsal spine that are WATER-BABIES 61 very conspicuous, but at an earlier period it has much longer spines on the carapace, and as yet no rudiments of the legs of the trunk or pleon. After many months they attain the final Zoéa stage, in which the terminal segment of the pleon is very broad, and divided nearly to the base by a broad sinus, formed by long spiniform diverging processes, at the base of which the sinus is armed with six to eight spines on each side. Shortly before the change into the second or Megalopa form, ‘ they were not quite so active as previously, but stiil continued to swim about until they appeared to be seized by violent convulsions, and after a moment began to wriggle rapidly out of the old zoéa skin, and at once appeared in the full megalops form. The new integument seems to stiffen at once, for in a very few moments after freeing itself from the old skin the new megalops was awimming about as actively as the oldest individuals. In this megalops stage the animal begins to resemble the adult. The five pairs of cephalothoracic legs are much like those of the adult, and the mouth-organs have assumed nearly their final form. The eyes, however, are still enormous in size, the carapace is elongated and has a slender rostrum and a long spine projecting from the cardiac region far over the posterior border, and the abdomen is carried extended, and is furnished with powerful swimming legs as in the Macroura.’ Professor Smith observed a few instances of the change from the megalops or Megalopa stage to the young crab. ‘The little crab worked himself out of the megalops skin quite slowly. For a short time after their appearance the young crabs were soft and inactive, but the integument very soon stiffened, and in the course of two or three hours they acquired all the pugnacity of the adult. They swam about with ease, and were constantly attacking each other and their companions in the earlier stages.’ Professor Smith has remarked that in ‘The Crayfish,’ fig. 74 represents the Zota and Megalopa stages of Carcinus meenas, not, as stated by a misprint, those of Cancer pagurus. 62 A HISTORY OF RECENT CRUSTACEA If the tiny young of the Crustacea attack and destroy one another, it is not for want of innumerable other enemies fitted to keep their numbers in check. As far as the timidity of human experience can decide, the Crustacea in general, though by no means particular as to the food they consume, invite rapacity by the agreeable quality of the food they supply. The enormous spines of the very young and the strong armature of the adults have probably becn called into existence in consequence. Where these are wanting or inadequate, the life of the species has been protected by extreme fertility. In Geryon quinquedens, Smith, for example, it has been computed that one speci- men was carrying no less than forty-seven thousand eggs, and there are other species reckoned to be at least twice ag prolific. To the extensive genus Xantho Bell assigns three British species, naming them florida, rivulosa, and tuber- culata. But, Montagu’s floridus having lapsed as a syn- onym, the first of the three should be named Xantho inetsus, Leach. The second, on Bell’s own showing, ought to be called Xantho hydrophilus (Herbst), and of this Couch’s tuberculata is now held to be a variety. Ozius, Milne-Edwards, 1834, was a genus established to receive certain species found in the Indian and Austra- lian waters. The name had been given much earlier by Dr. Leach, but without published description. It presents a peculiarity by help of which the large family of the Cancride is divided into two sections. The space between the front margin of the buccal frame and the mouth itself was called by Milne-Edwards the prelabial space. By English writers it is called the endostome or palate. In Cancer, Xantho, and many other genera, this endostome is without distinct longitudinal ridges defining the apertures of the efferent branchial channels, whereas in Ozius, Pilum- nus, Hriphia, and others, it has these ridges. Pseudozius, Dana, 1851, is, as the name implies, a genus that might be mistaken for Ozius, but the crests of the endostome do not quite reach the upper margin of the buccal frame. In 1881 the species Pseudozius Mellissi MUCH LEARNING 63 from St. Helena was carefully described by Mr. Miers, who pointed out its resemblance to and differences from Xantho Bouviert, A. Milne-Edwards, a species from the Cape Verd Islands. In 1886 Mr. Miers re-described it, and gave a figure of it in his ‘ Challenger Report,’ but he then placed it in a new sub-genus Luryozius, entitling it ‘ Pseudozius bouvieri, var. mellissti, in a hesitating manner identifying it with the species Xantho Bouviert of A. Milne-Edwards. In 1888 Professor Th. Barrois, in his catalogue of the marine Crustacea of the Azores, once more describes this species, and gives a beautiful figure of it in its natural colour of bright orange-red, with black tips to the cheli- peds. He and Mr. Miers are in exact agreement in their descriptions, as two such excellent naturalists were likely to be. But Professor Barrois calls the species Ozius Ediwardsi, and explains that he had submitted it to the highly competent judgment of M. Alphonse Milne-Edwards, who pronounced it to be a new Ozius, of which he had himself obtained a specimen at the Canaries during the expedition of the Tulisman. It will be consoling to the beginner and the amateur, when involved in perplexity amid species that they cannot name or can only name at random, to find the past masters of the science thus en- tangled as it were in their own web. For it must not be forgotten that Alphonse Milne-Edwards is acknowledged to be ‘the highest authority on the Brachyura,’! and yet he leads Barrois to make a new species of that which had been twice described and twice named by Miers, and which had probably been already named and described by Pro- fessor Milne-Edwards himself. The instance is significant of the stress, to which the highest powers must sometimes prove unequal, of keeping in mind each individual species of the vast multitude now known, and each individual chapter of the vast literature which records them. Barrois mentions an interesting peculiarity in this ele- gant crab. The carapace along the antero-lateral margins is obliquely striated on the under side with fine parallel grooves, in correspondence with which the fifth joint or » Miers, Challenger Keport, p. 146. 64 A HISTORY OF RECENT CRUSTACEA wrist of the chelipeds has a long sharp crest, and the rapid rubbing of this crest against the strize produces a shrill sort of stridulating noise such as a grasshopper makes by drawing the thighs of its hind legs over the salient nervures of its wing-cases. Pilumnus, Leach, 1815, is represented in Great Britain by the single species Pilumnus hirtellus (Linn.), but for the world at large more than eighty forms have been described under separate specific names, and still await the discriminating criticism of some future monograph. In this genus, as at present defined, the antero-lateral margins are normally armed with spines instead of the usual teeth, and the pleon is seven-jointed in both sexes, But when the description and figures of Pilumnus wan- thoides, Krauss, 1843, are examined, they exhibit not spines but rounded teeth or lobes on the antero-lateral border, and a five-jointed pleon in the male. Thus there is primd facie reason to suppose that this species ought to be removed to some other genus. Otherwise the boun- daries of the existing genus must be enlarged, whereas for convenience they rather require to be narrowed. Pirimela, Leach, 1815, like Pilumnus, is represented in Great Britain only by a single species, Pirimela denticulata (Montagu), which occurs also in the Mediterranean, but, unlike Pilumnus, it is not represented by any other species elsewhere. In this genus the pleon of the female is seven- jointed, but that of the male five-jointed, the three middle joints being coalesced into a single piece. It differs from all the rest of the Cyclometopa in the character of the third maxillipeds, for here the fourth joint receives the articula- tion of the fifth on its inner instead of on its apical margin. Family 2.—Trapezude. ‘Carapace depressed and nearly quadrilateral, smooth, with the postero-lateral angles truncated, the dorsal regions not defined; the antero-lateral margins are straight, form aright angle with the front, and are entire or have but one tooth (tbe lateral epi-branchial tooth) developed. The THE COMMON SHORE CRAB 65 front is horizontal, broad, lamellate, and projects over the antennules and bases of the antenna, which are widely excluded from the orbits.’ The genera are Trapezia, Latreille, 1825, Tetralia, Dana, 1851, and Quadrella, Dana, 1851, names indicative of the prevailing shape. The species in general are small and confined to the warm seas. According to the Russian writer, Paulson, 1875, the lower antennz of Tetralia re- quire that the last clause of the above-quoted definition should be cancelled. Family 3.—Portunide. The carapace is depressed, moderately transverse, and usually widest at the last antero-lateral marginal spine. The ‘front’ is horizontal and not spatuliform (see p. 71). The orbits and eye-stalks are of moderate length. The spine or tooth at the outer angle of the orbit does not project laterally beyond the teeth of the antero-lateral margin, of which more than one, usually from five to nine, are developed. The last legs of the trunk are commonly adapted for swimming, with the seventh joint ovate, flatly expanded, The Portunide include about half as many genera as the Cancridee. Carcinus, Leach, 1813, has the seventh joint of the fifth legs narrowly lanceolate. The species Carcinus maenas (Pennant) is the most obtrusive of all the British Brachyura. Its numbers justify its English designation as the Common Shore Crab; its extremely vivacious movements and its reckless audacity when brought to bay justify its scientific title and the corresponding French name for it of Crabe enragé. Inthe early part of this century Leach stated that it was sent to London in immense quantities and eaten by the poor. Professor Stalio says that at the present day it is a considerable source of food-supply to the humbler classes on the shores of the Adriatic, that in the soft state, just after the shedding of the skin, it is welcome at the tables of the rich, and that the Istrian fisherinen pound it up and use itas a most attractive bait tothe sardines. On 66 A HISTORY OF RECENT CRUSTACEA the other hand, complaints are made by English writers of the mischief which it does to fish already captured, and Dr. Hoek accuses it of the truly detestable crime of in- vading the oyster beds, and eating the young oysters while their shells are still soft and easy to break. In attacking the adults, it is itself sometimes caught by the snapping down of the powerfully hinged valves. The only other species of this genus known is the American Curcinus granulatus (Say), and even this may not be really distinct from the European form. Portunus, Fabricius, 1798, has the last two joints of the fifth legs dilated and compressed, and the last joint ovate. It is by this formation that many of the Portu- nidee are qualified as swimming crabs. In the Caribbean Sea, and among the gulf weed in the tropical Atlantic, Mr. Gosse observed them shooting through the water almost like a fish, ‘ with the feet on the side that happens to be the front all tucked close up, and those on the oppo: site side stretched away behind, so as to hold no water, as a seaman would say, and thus offer no impediment to the way. Our British species swim with less facility, and are often called fiddler crabs, because, as Mr. Gosse explains, ‘the see-saw motion of the bent and flattened joints of the oar- feet is so much like that of a fiddler’s elbow.’ The beauti- ful Velvet Crab, Portunus uber (Linn.), called in the Channel Islands the Lady Crab, is for ordinary purposes sufficiently described by Bell in the ‘ British Stalk-eyed Crustacea,’ together with six other species of the genus that have been obtained in the waters of Great Britain, namely depurator (Linn.), corrugatus (Pennant), arcuatus and pusillus, Leach, holsatus, Fabricius, and its near ally marmoreus, Leach. To these Canon Norman has added Portunus tuberculatus, Roux, from the Shetland Isles. He remarks on the singularity of the circumstance that this and many other southern forms should be found in the deep Shetland waters, though they are not known from localities between those waters and the Mediterranean. Portumnus, Leach, 1814, both by name and structure, closely approaches the preceding genus, but it has the THE AMERICAN LADY-CRAB 67 last joint of the fifth legs lanceolate. The British species which Bell names Portumnus variegatus, Leach, he ought in accordance with the rules of priority to have called Portumnus latipes (Pennant). In distinguishing Por- tumnus from the closely allied HMatyonichus, Latreille, 1818, Bell or his printer has made a confusing mistake by attributing to Platyonichus the acutely lanceolate ter- minal joint in the fifth pair of legs, and the broad oval, very much rounded joint to Portumnus, instead of putting the contrast the other way round (see Plate II.). He men- tions that in Portwmnus, as in many other Portunide, the pleon of the male is five-jointed, whereas in Platyonichus it is seven-jointed. Unfortunately this distinction, which would have been so convenient, only applies to two out of the three species which are now allotted to the latter genus, namely to Platyonichus bipustulatus, Milne-Edwards, and to Platyonichus iridescens, Miers, a species in which the legs are said to be beautifully iridescent. Platyonichus ocellatus was first described in 1799 by Herbst, who records its habitat in the words, ‘ Das Vater- land ist Long-Hiland bey Newyorck.’ Both New York and the ‘Lady Crab’ of America have come to be better known than they were in the time of Herbst. Verrill and Smith, in their valuable report on the inverte- brate animals of Vineyard Sound, give a figure of the crab and many interesting particulars. It is, they say, perfectly at home among the loose sands at low-water mark, and also abundant on sandy bottoms off shore. It is a rapid swimmer, and was not unfrequently taken on the surface of the sea. ‘When living at low-water mark on the sand beaches it generally buries itself up to its eyes and antenne in the sand, watching for prey or on the look-out for enemies. If disturbed, it quickly glides backward and downward into the sand, and disappears instantly. This power of quickly burrowing deeply into the sand it pos- sesses in common with all the other marine animals of every class which inhabit the exposed beaches of loose sand, for upon this habit their very existence depends during stcrms. By burying themselves sufficiently deep 63 A HISTORY OF RECENT CRUSTACEA they are beyond the reach of the breakers.’ ‘ The lady- crab is predacious in its habits, feeding upon various smaller creatures, but like most of the crabs it is also fond of dead fishes or any other dead animals. In some localities they are so abundant that a dead fish or shark will in a short time be completely covered with them, but if a person should approach they will all suddenly slip off backwards and quickly disappear in every direction be- neath the sand ; after a short time, if everything be quiet, immense numbers of eyes and antennz will be gradually and cautiously protruded from beneath the sand, and after their owners have satisfied themselves that all is well, the army of crabs will soon appear above the sand again, and continue their operations. The colour of this crab is quite bright, and does not imitate the sand, probably owing to its mode of concealment. The ground-colour is white, but the back is covered with annular spots formed by specks of red and purple. It is devoured in great numbers by many of the larger fishes.’ Polybius, Leach, 1820, is closely related to the three preceding genera, and like the last has the capacity for swimming highly developed. The single species, Polyhius Henslowii, Leach, is European, and is distinguished by having much compressed joints not only in the last pair of legs, but also in the three preceding pairs. It is said to pursue fishes so active as the mackerel, to fasten upon them with its sharp pincers, and to hold on till they succumb. The fishermen in consequence call it the nipper crab. Probably it is only fish that are terrified or hampered by the proximity of the fishing-net that fall vie- tims to its agility. The Prince of Monaco records that on one occasion, off the coast of Spain, his bursting trawl-net brought up from a censiderable depth at a single haul about five thousand fine specimens, which produced an animated scene on board his yacht by nimbly fastening with their cat-like talons on to the bare toes and fingers of the crew. Scylla, de Haan, 1833, belongs to a group of genera in which the carapace is very broad, and the antero-lateral margins are armed with nine or more teeth. Some of the SCYLLA AND CHARYBDIS 69 species are strikingly handsome, both in shape and colour. Scylla serrata (Forsk&l), a widely distributed Indo-Pacific species, is said by Krauss to be the largest and strongest of the South African Crustacea. The chelipeds of the male are much larger and more powerful than those of the female, and colossal in relation to the carapace. The damaged limbs and bodies covered with scars, uniformly exhibited by male specimens, are adduced in support of the inference that their combats one with another are not a little intemperate. On the muddy coasts of the Bay of Natal, Krauss says, this species lives in great deep holes, and wears the dingy earthy colour of its residence. They sit at the openings of their holes when the tide is coming in to snap up the food which it brings them, and to sun themselves when the tide is going out. At any one’s approach they vanish into their holes in a moment, or, if their escape is cut off, they raise themselves up on their hind legs, and by clashing together their powerful claws endeavour to scare away the intruder. By driving a spade into their slanting tunnels their retreat may be cut off, or they will clutch at the proffered point of a stick and may so be drawn out, but the Caffres, who consider them dainty food, capture them by spear-throwing. Charybdis, de Haan, 1833, belongs to a group of genera in which the carapace is said to be only moderately broad, and the antero-lateral margins have seven teeth or fewer. However, in Charybdis cruciatus (Herbst), the carapace is of very considerable breadth. The colouring of this species is highly remarkable. Herbst in 1796 gives a fine picture and a glowing description of one of the specimens which he received from the Kast Indies. The colours in the plate are vivid, but it cannot be said that they tally in all respects with the verbal account. According to the latter, the carapace from the front to beyond the middle of the field is of blood-red hue upon a yellowish ground, and marked with the figure of a great yellowish white cross. Down the sides run broad stripes of greenish red, shading off into grey. The upper surface of the chelipeds is marbled with yellow and red, the hands 70 A HISTORY OF RECENT CRUSTACEA having deep red patches and interlacing lines. The following pairs of feet are yellowish with faint red lines, the last pair being marbled with red, its joints very broad, and the last of them thin and membranous. By some writers this species is called Gontosoma eruciferum (Fabri- cius). They would displace de Haan’s Charybdis, not because of any pre-occupation of that name, which would have afforded a just reason, but because a different name Charybdea had been previously employed, which is no reason at all for cancelling Charyhdis. Again, they would displace the earliest specific name cruciatus as inappro- priate, whereas, they argue, the name cruciferum, given by Fabricius, is in accordance with the great pale cross marked upon the carapace. It is true that Herbst pro- bably tortured the meaning of cruciatus, but it is quite clear that he intended it to bear the sense of cruciferum, and even if he had chosen to regard his crab as fixed to a cross instead of regarding the cross as fixed on the crab, it would not have justified any tampering with the name and the rights of priority. It is perhaps this species that suggested the story found in the old writers that on one occasion, to calm the sea, Xavier threw a crucifix into it, and that this was afterwards restored to him by a crab. Bathynectes, Stimpson, 1871, with a name that means ‘the deep swimmer,’ is closely akin to Charybdis, but its antero-lateral margins have only five teeth, the hinder- most of which is very prominent, being twice as long as those which precede it. Thranites velox, of which in 1876 and 1881 Professor Carl Bovallius gave a detailed description, illustrated by numerous excellent figures, has since been found to belong to Stimpson’s Bathynectes. The detailed description is in Swedish, the excellent figures are in a language which all but the blind can read with ease. The species has been identified with Stimpson’s Bathynectes longispina, 1871, but Canon Norman has recently made it probable that the priority rests with Portunus superbus, O. G. Costa, and that the name will, therefore, be Bathynectes superbus, the species having ‘a range apparently co-extensive with the North Atlantic, A BATTLEDORE FRONT vi and belonging to the British fauna as well as the Nearoli- tan in which it first was named. Another Mediterranean species, Portunus longipes, Risso, which is also found on British coasts, and which is figured and described by Bell in the ‘ British Stalk-eyed Crustacea,’ p. 361, is now called Bathynectes longipes. Family 4.—Podophthalmide. The carapace is widest anteriorly, with the ‘front’ very narrow, spatuliform, and inflexed. The orbits are extremely large, and the eye-stalks greatly elongated, occu- pying nearly the whole width of the carapace. Podophthalmus, Lamarck, 1801, contains but one recent species, the widely distributed Indo-Pacific Podoph- thalmus vigil, Fabricius. The long eye-stalks almost meet at their bases, and consequently the ‘front’ is there almost linear, but it is prolonged for a short distance below and transversely dilated, so that, if straightened out, it might be compared to a battledore, or a broad-bladed knife, a spatula, whence the expression spatuliform has been applied to it. The great breadth of the short cara- pace, the very large denticulate chelipeds, and the unusual though not unparalleled length of the eye-stalks, make this a conspicuous and attractive species. According to Miers (1886) the only other genus that can claim a place in this family is Huphijlax, Stimpson, 1860, the name of which, meaning a good watchman, corresponds with the family character. Legion 2.—COyelinea. The carapace is more or less orbiculate. Acanthocyclus, Milne-Edwards and Lucas, 1843, has for its type species Acanthocyclus Gayt, which occurs com- monly on the shores of Chili and Patagonia, and in the Straits of Magellan. In this the eye-peduncles are short ; no longitudinal ridges are developed upon the endostome ; the ‘front’ is rather narrow, with a prominent median lobe; in the third maxillipeds the third joint is much longer than the small fourth one; the pleon of the male is narrow 72 A ILISTORY OF RECENT CRUSTACEA and five-jointed. Mr. Miers says, ‘The nearest ally to Acanthocyclus is, I think, Bellia [Milne-Edwards, 1860], which resembles Acanthocyclus in the more or less orbicu- late carapace, in the form of the front, chelipedes, and ambulatory legs, but is distinguished by the narrower, more elongated merus [fourth joint] of the exterior maxil- lipedes, by the broader post-abdomen [pleon] of the male, and the less distinctly defined buccal cavity.’ The legion Cyclinea, which cannot boast with certainty of more than a single genus and single species, may hope to have its ranks filled up in the course of time. At present it does not make a very good show, even on paper. Legion 3.—Oorystinea. The second antenne have elongate flagella. The third maxillipeds usually do not make a complete closure of the mouth-cavity and are extended over the anterior margin of its frame. The sternal plastron is narrow. The single family Corystidz: does not require a separate defini- tion. It does not appear to contain more than eight genera, three of which are included in the fauna of Great Britain. Corystes, Latreille, 1803, has a very distinguishing charac- ter as compared with the forms previously discussed, in that the carapace is not transverse, but much longer than it is broad. Corystes cassivelaunus (Pennant) has fre- quently attracted attention by the amusing resemblance of the carapace to a human countenance, which Herbst com- pares to the broad-nosed Kalmuck type. It is in Great Britain a convenient species for study, from the number of dead specimens that are often cast up on sandy shores. The sexes are easily distinguished. In the male the cheli- peds are enormously elongated, and the pleon is very small and has only five joints, although it is quite plain that the central one of the five is in reality a compound of three that have coalesced. In the female the pleon, though small, is broader than in the male, and has the seven joints distinct ; the openings of the vulve can without difficulty be observed on the plastron between the third pair of legs; ARTISTIC TOUCHES 73 the chelipeds are of no unusual length. The very long external antennz are a special feature of this crab. When Fic. 3.—Corystes casstvelaunus (Pennant), a female specimen, with the features on the carapace slightly accentuated. [Herbst.] the animal is burrowing in the sand according to its wont, the flagella of these antennz are brought close together, and the tips alone project from the funnel of the burrow. They are provided with stiff hairs on the inner margin, which no doubt assist: in maintaining the funnel-opening of a due width. The joints of the peduncle can be strongly bent, and by this means, as Mr. Couch observed, the hairy fringes of the flagella can be made to brush one another 7 74 A HISTORY OF RECENT CRUSTACEA down and clear away any clinging particles of sand. Mr. David Robertson had a female of this species alive in his possession for seven months, and, so far as his observation went, it would lie buried for weeks without seeking to change, the antennze clasping into each other to form the tube necessary for its breathing, by giving access to the water above. Through this tube he was also fortunate enough to see the ova sent up, and he infers that the animal at the proper time places them within the influence of the current which its breathing apparatus must con- stantly maintain. He notices that the pleon by its small size is less fitted to cover the ova than is generally the case among the Brachyura, but that this is compensated and accounted for by the burrowing habit. In a very young specimen, scarcely three tenths of an inch long, the ‘front’ quite differs from what is seen in the adult, being produced into a conspicuous rostrum as in the genus Galathea, and the telson, instead of being rounded, is broadly emarginate. As two genera, Nautilo- corystes and Pseudocorystes, were so named by Milne- Edwards in 1837, to indicate their great resemblance to the earlier genus Corysies, it may be interesting to point out some of the differences by which the three are dis- tinguished, and which in the early days of classification would probably have passed unnoticed. Corystes.—The third maxillipeds have the fourth joint longer than the third, with the fifth joint inserted in a deep notch of its inner margin considerably below the apex. In the fifth pair of legs the seventh joint is narrow. Nautilocorystes.—The third maxiliipeds have the fourth joint a little shorter than the third, with the fifth joint attached at its apex. In the fifth pair of legs the seventh joint is widened. Pseudvcorystes.—The third maxillipeds have’ the fourth joint much shorter than the third, small, triangu- lar, with the fifth joint attached near the apex. In the fifth pair of legs the seventh joint is widened. ‘HE GENDERS OF GENERA 75 The species Pseudocorystes armatus, Milne-Edwards, was found at Valparaiso, and Milne-Edwards supposes that it may be the same as the ‘Grass Crab,’ figured by Browne in his ‘ History of Jamaica,’ pl. 48, fig. 2. Atelecyclus, Leach, 1813, is a member of the family in which the third maxillipeds, contrary to the family custom, do make a complete closure of the mouth-cavity. The type species, Atelecyclus septemdentatus (Montagu), was first observed on the south coast of Devon. Its carapace is nearly circular. Leach says that to the fishermen it is well known by the name of old man’s face crab. The antero-lateral margin on each side is furnished with nine teeth, and probably for this reason Leach thought himself justified in changing the name to heterddon, in which he has been followed by Bell. Montagu perhaps did not think that the point at each extremity of the series ought to be counted in, and at any rate no one can be injured by the retention of the name which it was his privilege as the discoverer of the species to choose. Thia, Leach, 1815, is represented both in the Mediter- ranean and in British waters, probably by one and the same species, called Thia polita by Leach in 1815, in allu- sion to the polished surface of the carapace, but as there is no substantial reason for thinking it distinct from the species described and figured by Herbst as Cancer residuus in 1799, its name ought to be Thia residuus (Herbst), although some may prefer to call it Zhia residua, not re- flecting that the animals are both male and female, and ignoring the old rule of Latin grammar that the mascu- line gender is to be preferred to the feminine. In this species, which like Corystes is a sand-burrower, the pleon is very narrow in both sexes, and, though in the male it is only five-jointed, the transverse grooves of the composite joint are so strongly marked, that all the seven joints might at first glance be thought to be distinct, as they are in the female. To conclude the discussion of the names used in this family, it may be mentioned, first, that although de Haan rightly claims priority for Dicéra which he established 76 A HISTORY OF RECENT CRUSTACEA in 1833 ovér Naztilocorystes instituted by Milne-Edwards in 1837, yet Dictra must give way, having been already earlier used in other classes of zoology ; and secondly, that Ogidia, de Haan, 1833, a name meaning egg-like, must likewise be cancelled, having been found to be a synonym of Gomeza, Gray, 1831, a Corystid genus of the Japanese fauna. Legion 4.—Thelphusinea. The carapace is more or less dilated at tke branchial regions ; the third maxillipeds have the fifth joint articu- lated at or near the front inner angle of the fourth or at its apex. The fingers of the walking legs are usually spinuliferous; the verges of the male pass directly through the basal joint of the fifth pair. The species are fluviatile or live in damp ‘forests. Family Thelphusidee. This being the only family has the characters of the legion. Thelphusa, Latreille, 1819, contains numerous species, of which Mr. Miers observes that ‘ one, the com- mon Thelphusa fluviatilis, occurs not only on the shores of the Mediterranean, but also in Asia Minor, Syria, and Persia; the others are found in all the warmer temperate and tropical regions of the old world, extending southward to the Cape of Good Hope, Madagascar, and Australia, but not to New Zealand ; a species (Thelphusa chilensis) occurs in Chili’ Potamonautes, Macleay, and Geothelphusa, Stimpson, are so closely related to Thelphusa that their separation from it remains a matter of doubtful expedience. Krauss remarks that the Thelphuside are especially fond of clear running streams in which they shelter them- selves under stones and plants. They are easily scared, and in spite of their monstrous chelipeds their long pe- reopods carry them off at a great pace. ‘The pearly Thelphusa (Zhelphusa perlata, Milne-Edwards) has an earthy greenish colour, which matches its surroundings in the rivulets, whereas “helphusa depressa, ® species RIVER CRABS 77 which Krauss found at a waterfall in Natal, is yellowish and orange-coloured, in accordance with the cushions of moss among which it has its residence. Thelphusa dehaanit, White, occurs in the paddy fields of Japan, and has been taken at an elevation of 2,500 feet above the sea- level. It has been already mentioned that the river crab of Europe is good eating. Milne-Edwards supposes that it was to this crustacean that Aristotle referred under the name Carcinus Heracleoticus. Paratelphusa, Milne-Edwards, 1855, was at first sup- posed to be a marine genus, but has since been proved to be an Indo-Malayan genus of fresh-water crabs, several species of which have been described by Mr. Wood-Mason. They differ from the rest of the Thelphusidae in having the distal end of the fourth joint of the chelipeds armed with a sharp spine, and are also said to have a greater general resemblance to some of the Cancridz. Dr. de Man, in his elaborate Report on the Podoph- thalmous Crustacea of the Mergui Archipelago (‘ Journ. Linn. Soc.’ 1887, 1888), includes the genus Thelphusa in the next tribe, and the same arrangement is followed by Dr. Camil Heller in his ‘Crustacea of the Novara, 1865, the Thelphusinea being in fact intermediate in structure between the Cancride and the Gecarcinide. 78 A HISTORY OF RECENT CRUSLACEA CHAPTER VII TRIBE Il.—CATOMETOPA Tue ‘front’ is bent downward. The carapace is broad anteriorly, often subquadrate, sometimes subglobose, trun- cate or arcuate forwards, but not rostrate. The epistome is short, often almost linear. The pairs of branchiz are usually fewer than nine in number; the efferent channels open at the sides of the endostome. The third mazxilli- peds have the fifth joint articulated at the front outer angle of the fourth, or less frequently at its apex, or very rarely at the front inner angle. The male verges are inserted either in the sternal plastron, or in the basal joints of the last pair of legs, thence passing through channels in the sternum beneath the pleon. The tribe contains four families, the Gecarcinide, Ocypodidae; Grapside, and Pinnotheride. The liver is said by Milne-Edwards to be in general central, extend- ing little or not at all over the branchial cavities. Family 1.—Gecarcinide. The carapace is dorsally very convex, especially dilated over and in front of the branchial regions, with the antero- lateral margins usually entire and strongly arcuate. The ‘ front’ is of moderate width and strongly deflexed. The orbits and eye-stalks are of moderate size. The third maxillipeds have the fifth joint articulated at the front outer or near the front inner angle or at the apex of the fourth, which sometimes completely conceals it. The chelipeds in the adult male are powerful, usually unequal. The seventh joint in the walking legs is nearly always LAND CRABS 79 granulated and armed with longitudinal rows of spines. The pleon of the male usually covers the whole space between the bases of the last pair of walking legs. These land-crabs are called Toulowroux by the French. They inhabit the warm territories of both hemispheres. The third maxillipeds suffice without other details to dis- criminate the genera. Uca, Leach, 1817. The third maxillipeds have the fifth joint attached at the outer angle of the fourth; the inner edges of the third and fourth joints are in one line; along their outer edges the exopod is externally visible, and has a flagellum. Gecarcinucus, Milne-Edwards, 1842. The third maxilli+ peds have the fifth joint attached to the middle of the apical margin of the fourth ; the inner edges of the third and fourth joints are in one line; the exopod as in Uca. Cardisoma, Latreille, 1825. The third maxillipeds have the fifth joint attached at the outer angle of the fourth ; the inner edges of the third and fourth joints form a re-entering angle; the exopod as in Uea. Gecarcoidea, Milne-Edwards, 1837. The third maxil- lipeds have the fifth joint inserted in a deep groove of the apex of the fourth; the inner edges of the third and fourth form a re-entering angle; the exopod is without flagellum and concealed beneath the third joint. Gecarcinus, Leach, 1815. The third maxillipeds have the fifth joint attached on the inner margin of the fourth and completely concealed by it; the inner edges of the third and fourth joints form a re- entering angle; the exopod as in Gecarcoidea. Hyleocarcinus, Wood-Mason, 1874. The third max- illipeds have the fifth joint attached to the middle of the apex of the fourth ; the inner edges of the third and fourth form a re-entering angle; the exopod as in Gecarcoidea. 80 A HISTORY OF RECENT CRUSTACEA In the last four genera it will be perceived that tho maxillipeds do not form a complete operculum, but by the arrangement of the inner edges of their third and fourth joints they leave a lozenge-shaped space over the mouth- opening uncovered, while in Uca and Gecarcinucus the straight inner edges from either side can be brought exactly together so as to close the cavity completely. Mr. Wood- Mason points out that the character of the exopod distin- guishes Gecarcinus, Gecarcoidea (which he calls Pelocar-’ emus), and Hyleocarcinus from the three preceding genera, and that they are distinguished from one another by a further character of the maxillipeds, for in Gecareinus the three terminal joints are completely hidden, in Hyleocar- cinus they are partially visible, and in Gecarcoidea com- pletely so. None of the Crustacea have more attracted the atten- tion and excited the wonder of travellers than some of those belonging to this group. Like the twin snakes that came over the sea and deliberately landed at Troy to slay Laocoon and his two sons, these crabs have, contrary to nature, forsaken the ample waters of the ocean, scorned all the brooks and rivers and lakes, and carried out a portentous invasion of the dry land. Still they are by no means indifferent to moisture. The vaulted part of the carapace over the branchial regions is lined with a very spongy membrane, and sometimes a fold of the membrane along the lower edge of the cavity forms a kind of tube in which water may be held as in a reservoir. But their form and structure are not so surprising as their manners and customs. Under the heading Oancer ruricola, a species of Gecar- cinus, Herbst brings together many curious particulars, depending largely upon Patrick Browne’s ‘History of Jamaica.’ In the Bahamas, he says, and in tropical regions these land-crabs are so numerous that when they creep out of their holes the ground seems to be in motion. One little island is so full of them that it has been called Crab Island. They are just as frequent in certain districts of Jamaica and in some of the Caribbee islands. Thesame REMARKABLE BEHAVIOUR 81 was the case at St. Croix, but since the cutting down of the forests and destruction of thousands of the crabs, their number has diminished. They generally take up their abode on the hills, not less than one mile nor more than three miles from the coast. It is in the morning and evening that they are to be found in greatest numbers under the trees. Go away then without a stick in hand, and they will approach with uplifted claws as if threatening an assault. But if they are themselves assailed with a stick or a switch, they retreat, yet still facing the foe, and ever and anon clashing their claws together to strike terror into him. Thus they withdraw to their holes in the rock or the rotten tree or deep burrows in the ground. They are capital eating, and are one of the principal food resources of the natives, who improve the flavour by fattening them up for three or four days in a potato field. But a warning is given that they do not always suit the stomach of Euro- peans, since they are apt to produce cold hypochondriac humours, whereby some explain the slow melancholy nature of the Caribbee islanders. Whenseized bya leg or a claw these crabs relinquish it so readily as to produce the im- pression that their limbs are only stuck on. The lost appendage would be renewed at the next change of skin, but it often happens that the sacrifice which has saved the crab from its human foes exposes it as a defenceless victim to those of its own race. The pairing season is said to be in March and April. Tn May, the rainy period, they march in great hosts towards the sea, to bathe and lay their eggs in it. ‘Then all roads and brooks are filled with them, and it is indeed a very wonderful instinct, which the Creator has given them, to go direct to that part of the island where there are stretches of sand and slopes from which they can most easily arrive at the sea. Nothing can hinder them from going the straight road towards the sea, for they go over everything that comes in their way, be it hedges, houses, churches, hills or cliffs, straight over everything they go, and rather clamber up at the peril of their lives, than make a circuit. In the night, for example, they will creep in at a window, and 82 A HISTORY OF RECENT CRUSTACEA come on to the beds, causing the unwary occupants no small alarm by their clatter. If one has the misfortune to tumble down and damage its limbs, it is immediately eaten up by the rest. It must be a wonderful sight, to see them come down the hills. Everywhere they issue from hollow trees, rotten stems, from under the rocks, and out of innumerable holes. The fields are so covered with them, that unless they are chivied away, there is no setting foot to ground without treading upon them. What with the infinite variety of their markings, their brilliant colours, tueir sideways gait, their celerity, I know of scarcely any sight comparable with this one. Unless the description of their march has been embellished by the force of imagination, the journey is conducted with as much order as if they had a very experienced commander.’ The vanguard, consisting of none but males, starts some days in advance. Then follows the main army, composed chiefly of females, their battalions often covering a space of a mile and a half long by forty or fifty paces broad, and covering it so closely as almost to hide the ground. Some days after, the rear-guard, containing both males and females, closes the vast procession. Sometimes all the divisions are brought to a halt several days by the want of rain, a want which makes prolonged land-travel impossible to a crustacean. But when Herbst says that these hosts follow the line of the rivers and water- courses, the statement, though highly probable in itself, is scarcely consistent with the miraculous bee-line which he had previously described. If anyone approaches the army and puts it into alarm, these martial crabs draw back facing him, with their claws uplifted and open to be constantly ready for defence. The nip of one of them, it is said, can tear out a piece of flesh, and the claw, even after it has been thrown off by its owner, will continue for a minute to pinch with incredible force. The noise of their march is compared to the rattling of the armour of a regiment of Cuirassiers. Having arrived on the coast, they bathe once in the sea, and then creep into some shelter to rest. The females enter the sea a second time and there deposit their SEASIDE LODGINGS 83 eggs. These are cast up by the waves upon the sand, and in due course out creep the young crabs, which then cling to the rocks in thousands, but presently quit the water for any suitable places of protection on land, there acquiring strength to follow their mothers up the country. Patrick Browne says: ‘The eggs are discharged from the body through two small round holes situated at the sides, and about the middle of the under shell; these are only large enough to admit one at a time, and, as they pass, they are entangled in the branched capillaments, with which the outer side of the apron is copiously supplied, to which they stick by means of their proper gluten, until the creatures reach the surf, where they wash ’em all off, and then they begin to return back again to the mountains. It is re- markable that the bag or stomach of this creature changes its juices with the state of the body; and, while poor, is full of a black, bitter, disagreeable fluid, which diminishes as it fattens, and, at length, acquires a delicate rich flavour. About the month of July or August the crabs fatten again, and prepare for mouldering, filling up their burrow with dry grass, leaves, and abundance of other materials; when the proper period comes, each retires to his hole, shuts up the passage, and remains quite inactive, until he gets rid of his old shell, and is fully provided with anew one. How long they continue im this state is un- certain, but the shell is first observed to burst both at the back and sides, to give a passage to the body, and it ex- tracts its limbs from all the other parts gradually after- ward. At this time the fish is in the richest state, and covered only by a tender membranous skin variegated with a multitude of reddish veins, but this hardens gradually after, and becomes soon a perfect shell like the former; it is, however, remarkable that during this change there are some stony concretions always found in the bag, which waste and dissolve gradually, as the creature forms and perfects its new crust. A wonderful mechanism!’ A footnote remarks that the concretions, which are the well- known gastroliths or crab’s eyes, ‘are seldom under two or more than four.’ 84 A HISTORY OF RECENT CRUSTACEA Since it is during this period of ‘ mouldering’ that the crabs are fattest and best flavoured, Herbst finds it easy to suppose that greedy man will not leave them safe in their repose. On the contrary, he busily digs them out with a spade. Considering how readily under some cir- cumstances these crustaceans shed their limbs, it is singu- lar that in exuviation they are able to cast off their whole caparison so uninjured and complete that it might be mis- taken for the living animal. Careful inspection is required to perceive near the insertions of the limbs the ventral slit through which the animal has made its escape. It was in a West Indian species of Gecarcinus that Professor Westwood observed that the young issued from the egg in a form not materially different from that of their parents. This experience, combined with Rathke’s similar observation in regard to the European crayfish, led him at first to throw doubt upon Vaughan Thompson’s theory of crustacean metamorphoses. But it was soon brought to light that the examples of the land-crab and the freshwater crayfish were interesting exceptions to a still more interesting rule, and there are few who would now deny that these exceptions are to be explained as modifications in the life-history of the animals concerned, acquired late in the course of time to suit the new condi- tions of existence encountered by creatures emerging from the sea to a life in fresh water or on dry ground. That no crustaceans have been able to cut themselves loose from some dependence upon moisture is not very wonderful, since in that respect man himself is still an aquatic animal. ‘ Gecarcinus lagostoma, Milne-Edwards, represented on Plate II, is a widely distributed species. Hylaocarcinus Humei, Wood-Mason, occurs in ‘the dark dense damp forests of the Nicobar Islands.’ Uca una (Linn.), the crab of the mangrove swamps of Brazil, may be mentioned as a rare instance of one that has been allowed to possess the names by which it was figured and described centuries ago. In this genus the last joints of the walking legs are compressed and un- Platyonichus iridescens RACERS 85 armed. M. Jobert, in examining the breathing apparatus of land-crabs, has found that of Uca wna to be the most complete. There is a regular movement of inspiration and exspiration to keep the air from stagnating in the breathing chamber, and between the third and fourth and the fourth and fifth limbs there are small supplemental inspiratory orifices coated externally with long hairs (sée Sp. Bate, ‘ Brit. Assoc. Report,’ 1880). Family 2.—Ocypodide. The carapace is in general moderately convex, cancroid or trapezoidal, with the antero-lateral margins straight or arcuate, the branchial regions not greatly dilated. The ‘front’ is of moderate width or very narrow. ‘The orbits and eye-stulks are of moderate size or greatly developed. The third maxillipeds have the fifth joint articulated at the front inner or rarely at the front outer angle. The chelipeds in the adulfi males are in general of moderate size, sometimes slender and elongate. The seventh joint in the walking legs is stiliform, without strong spines. The pleon does not always cover the whole width of the sternum between the last pair of legs. The species are generally small, littoral, or inhabitants of shallow water, but are not unknown from considerable depths. There are nearly forty genera assigned to the various subdivisions of this family. Ocypodé, Fabricius, 1798, has the orbits very large and open, extending all along the anterior margin on either side of the narrow and deflexed ‘front.’ The eye-stalks are large, with a short basal joint, the terminal part often prolonged distally as a spine or tubercle, the large corner covering much of the lower surface of this terminal joint. The chelipeds in the adult male are unequal and well de- veloped, and usually the palm has a vertical series of short raised lines or tubercles on the inner surface, which form a stridulating ridge. As the name swift-of-foot implies, these Crustacea are especially noted for their rapidity of movement. They are just the opposite of some of the strong-armed, thick- 86 A HISTORY OF RECENT CRUSTACEA shelled, slow-moving Cancridee. On wind-swept stretches of sandy beach, and coloured like the sand, they some- times seem rather to be borne on the wings of the wind than to run. Also with their compressed lancet-like fingers they are extremely dexterous in digging into the sand. They burrow holes an ell deep, generally perpen- dicular, and from these they wander far, when the tide is out, in search of food. Krauss observed in South Africa the species Ocypode ceratophthalmus (Pallas), and others. and he says that while they are busy hunting, every now and then they look carefully round, raising their stalked- eyes upright, and standing on tiptoe. At the slightest movement towards them they run with uncommon rapidity to the nearest hole, or, if the danger is too close, press themselves flat on the sand, till an attempt is made to seize them, and then off they dart. In running they carry their bodies high, doubling and dodging with‘such speed and cunning that it is a difficult matter to lay hold of them. When the tide comes up, they are enclosed in their flooded burrows, and as soon as the waves retreat, they are busily employed in clearing them, shovelling out the wet sand and heaping it at some little distance off. The American species, Ocypode arenuria (Catesby), is de- scribed by Professor 8. I. Smith as having precisely similar habits. According to his observation it lives largely upon the Amphipods of the genus Talorchestia, known as “ beach-fleas,’ which inhabit the same localities. ‘It will lie in wait,’ he says, ‘and suddenly spring upon them, very much as a cat catches mice. It also feeds upon dead fishes and other animals that are thrown on the shore by the waves.’ It is of this species, under the synonym of Ocypoda rhombea, Fabricius, that Fritz Miller speaks in his memor- able work ‘ For Darwin.’ ‘In the swift-footed Sand-crabs (Ocypoda),’ he says, ‘—which are exclusively land animals, that can scarcely live in water for a single day, and which in far less time than that are reduced to a state of com- plete collapse in which all voluntary movements cease— there has long been known a peculiar arrangement con- Mls CROSS-EXAMINING A CRAB 87 nected with the third and fourth pairs of legs, but that these had anything to do with the branchial cavity was not suspected. These two pairs are pressed more closely together than the rest. The opposed surfaces of their basal joints, that is, the hinder surface in the third, and the front surface in the fourth pair, are flat and smooth, and their margins are clos:ly fringed with long, sheeny, peculiarly formed hairs. Milne-Edwards, who compares them to articular surfaces, as their appearance warrants, thinks that they serve to diminish the friction between the two legs. On this supposition the question arises why precisely in these crabs and only between these two pairs of legs such a provision for diminishing friction is neces- sary, not to mention that it leaves unexplained the singular hairs, which must augment instead of diminishing friction. While, then, I was bending to and fro in ever so many directions the legs of a large Sand-crab, in order to see in what movements of the animal friction occurred at the place in question, and whether perhaps these were move- ments often recurring and of special importance to it, I observed, when I had stretched the legs far apart, a round opening of considerable size between their bases, through which air could easily be blown into the branchial cavity or even a slender probe be introduced. The aperture opens into the branchial cavity behind a conical tubercle, which stands above the third foot at the place of a bran- chia which is wanting in Ocypoda. It is laterally bounded by ridges which rise above the articulation of the legs and to which the lower edge of the carapace is applied. Also outwardly it is overarched by these ridges with the ex- ception of a narrow slit. Over this slit extends the cara- pace, which just at this point projects further downwards than elsewhere, and so a complete tube is formed. While Grapsus always admits water to its branchize only from in front, in Ocypoda I saw it also streaming in through the just described aperture.’ For its details about one particular crustacean such a passage is interesting, but it is far more important as a lesson in scientific observation. ‘There are numbers of 8 90 A HISTORY OF RECENT CRUSTACEA is frequently found in great numbers, either running actively about over the sand, or peering cautiously from their holes, which are often thickly scattered over con- siderable areas. These holes are mostly from half an inch to an inch in diameter, and a foot or more in depth, the upper part nearly perpendicular, becoming horizontal below, with a chamber at the end. Mr. Smith, by lying perfectly still for some time on the sand, succeeded in witnessing their mode of digging. In doing this they dug up pellets of moist sand, which they carry under the three anterior ambulatory legs that are on the rear side, climb- ing out of their burrows by means of the legs of the side in front, aided by the posterior leg of the other side. After arriving at the mouth of their burrows and taking a cautious survey of the landscape, they run quickly to the distance often of four or five feet from the burrow before dropping their load, using the same legs as before and carrying the dirt inthe same manner. They then take another careful survey of the surroundings, run nimbly back to the hole, and after again turning their pedunculated eyes in every direction, suddenly disappear, soon to reappear with another load. They work in this way both in the night and in the brightest sunshine, whenever the tide is out and the weather is suitable. In coming out or going into their burrows either side may go in advance, but the male more commonly comes ont with the large claw for- ward. According to Mr. Smith’s observations this species is a vegetarian, feeding upon the minute algze which grow upon the moist sand. In feeding, the males use only the small claw with which they pick up the bits of alge very daintily ; the females use indifferently either of their small claws for this purpose. They always swallow more or less sand with their food. Mr. Smith also saw these crabs engaged in scraping up the surface of the sand where covered with their favourite alge, which they formed into pellets and carried into their holes, in the same way that they bring sand out, doubtless stowing it until needed for food, for he often found large quantities stored in the terminal chamber.’ ARCHITECTURAL EFFORT 9] An earlier observer, Bosc, who studied this same species in Carolina, declares that these crabs were tv be seen in thousands and even in millions on the margin of the sea or of tidal rivers. He remarks that, if a man or any animal comes among them, they lift up the large claw, and holding it forward, as if challenging their opponent to fight, in that attitude they scurry off sideways. They bave, he says, a great number of enemies among the otters, bears, birds, turtles, alligators, and the like, but they are so prolific that the devastation made among them by these foes is imperceptible. He occasionally saw the ‘calling crabs’ swarming over a carcase on the shore and disputing with the vultures for strips of the carrion. He was very anxious to see them make their burrows, but they never would work in his presence, doubtless not from shyness, but from some prudential motive. Gelusimus minaz, Leconte, the largest of the American ‘fiddler-crabs,’ lives in salt marshes or fresh water. Over the mouth of its burrow Mr. T. M. Prudden ascertained that this crab often constructs a regular ovenlike arch of mud, and that it sits in this doorway on the look out for whatever may befall. Professor Smith kept a large male of this species in a glass jar containing nothing but a little siliceous sand, moistened with pure fresh water, for over six months. It was for ever pacing round the jar and trying to climb out, was never observed to rest or show fatigue, ‘and after months of confinement and starvation was just as pugnacious as ever.’ The species Gelasimus arcuatus, de Haan, already mentioned, was observed by Krauss in South Africa as occupying muddy ground, and having a bluish-grey colour suitable to its residence. The appropriateness of the generic name will be appreciated in the light of his in- cidental remark that ‘it is truly comical to see these crabs with uplifted arms in countless numbers scampering over the dark mud.’ Gonoplax (originally spelt Goneplat and Goneplaz), Leach, 1814, is a North-Atlantic and European genus, which till lately contained only one species, Gonoplas 92 A HISTORY OF RECENT CRUSTACEA rhomboides (Linn.), called in Bell’s ‘History of the British Crustacea’ Gonoplax angulata (Fabricius), the angular crab, the specific name obviously, and the generic name probably, alluding to the angular character of the carapace. A second species, closely resembling the first, and named Gonoplax sinuatifrons, Miers, was obtained by the Challenger at Amboina. The elongated orbits and eye-stalks cannot fail to attract attention, and the latter especially when they are suddenly erected from a position of rest within the former. The male has the chelipeds of a remarkable length, and these, at least when in confine- ment, he is fond of clashing together in a noisy and perhaps threatening manner. The joints of these limbs are, so proportioned that while they are able to seize food at a great distance, they can also convey it to the mouth. The pleon is seven-jointed in both sexes. Ommatocarcinus, White, 1852, is distinguished from its near neighbour Gonoplaw by a still narrower ‘front,’ a great development of the antero-lateral spine on each side of the carapace, and still more elongate eye-stalks, to which reference is made in the generic name, meaning ‘the crab with the eyes.’ There is but one species, Ommu- tocarcinus Macgqillivray:, White. This is found in Austra- lian and New Zealand waters. Macrophthalmus, Latreille, 1829, with a name mean- ing ‘long-eye,’ surpasses the two preceding genera in the length of the orbits, and the eye-stalks are exorbitant in the literal sense in certain species, in which they are pro- longed laterally beyond the orbit’s outer angle. The species are numerous, occurring ‘in the littoral or shallow waters of all parts of the Indo-Pacific region.’ In some of the species, as also in the genera Helice, de Haan, 1835, and Metaplaw, Milne-Edwards, 1852, the males have on the arms of the chelipeds a short horny ridge, which Dr. de Man calls ‘the musical crest,’ on the supposition that the crab produces musical sounds by rubbing this crest against a row of granules below the orbit. Naturally this crab-music must only be judged by a crustacean standard. THE GRAPSIDZ 93 A certain amount of uniformity, especially as regards the flatness of the carapace, may be inferred to exist in this family from the number of genera with names all alike ending in -plax, as Acanthoplax, Ilyoplax, Hemiplax, Camp- toplax, Bathyplax, with many others. The genus Geryon, Kréyer, 1837, may claim a passing notice as one of those instances in which systematic arrangement finds itself at fault. It is sometimes placed among the Cyclometopa and sometimes among the Cato- metopa. Mr. Miers says that it is very nearly allied to Pseudorhombila and Pilumnoplaw in the latter, and to Galene in the former group. ‘That, on the theory of the evolution of different groups from a common stem, such inosculant forms are almost sure to occur, has long been recognised. Darwin himself humorously admits that while as a theorist he delighted in coming across them, as a naturalist engaged in classification he found them an un- mitigated nuisance. Family 3.—Grapside. The carapace is depressed or moderately convex, more or less quadrilateral, with the lateral margins straight or slightly arcuate. The ‘front’ is never very narrow, in geueral decidedly broad. The orbits and eye-stalks are of moderate size. The third maxillipeds have the fifth joint articulated at the apex or the front outer angle of the fourth. The chelipeds in the aduit male are usually subequal, moderately developed. In the walking legs the seventh joint is stiliform, compressed, and either smooth or spiniferous. The pleon at the base usually covers the whole width of the sternum between the last pair of legs. The species are almost always littoral or shallow-water forms, with a rare exception in deep water. In this family there are about twenty-four genera. Grapsus, Lamarck, 1801, is a wide-ranging genus which was brought to the notice of Europeans a century and a half ago in the species Grapsus maculatus (Catesby, 1743 and 1771), to which Bosc in 1802 applied the better 94 A HISTORY OF RECENT CRUSTACEA known name of Grapsus pictus. Professor Th. Barrois, in his account of the Crustacea of the Azores, speaks of this and two companion species as running with astonishing velocity among the rocks near the sea. The brilliantly coloured Grupsus, with its limbs of a marvellous red, he culls a superb species. As it occupies by preference the sides of the perpendicular cliffs, it is easy to believe the statement that prodigies of agility and cunning are re- quired for capturing uninjured specimens. In Charleston Bay Bosc had a much easier task. There he noticed that these crabs almost always kept themselves concealed under stones or pieces of wood, and, as these objects are rare in that locality, every day on the retreat of the tide he was sure to find fresh specimens of Grapsus under the hiding-places from which he had taken other specimens on the previous day. Darwin, in ‘A Naturalist’s Voyage,’ when speaking of the nests of the tern at St. Paul’s Rocks in the Atlantic, says, ‘It was amusing to watch how quickly a large and active crab (Grapsus), which inhabits the crevices of the rock, stole the fish from the side of the nest, as soon as we had disturbed the parent birds. Sir W. Symonds, one of the few persons who have landed here, informs me that he saw the crabs dragging even the young birds out of their nests and devouring them.’ The voracity and audacity, the cunning and speed and jumping powers of these crabs of St. Paul’s Rocks are amusingly described in the ‘ Log Letters of the Challenger, by Lord George Campbell, who however, saw no proof that they ate the young birds. About a dozen other genera have been formed with names in which Grapsus is part of the compound, as Geograpsus, Paragrapsus, Platygrupsis, and the like. Several of these contain species which were at one time included in the genus Grapsus, and which are by no means very remote from it. The Cancer marmoratus of Fabricius has been trans- ferred from Grapsus to Pachygrapsus, Randall, by Stimpson, and to Goniograpsus, Dana, by Miers. It is a European species, common among chinks of the rocks in the Adriatic. It prowls about on the shore by night to feed on dead Eriocheir japonicus, de Haan. THE GULF-WEED CRAB 95 animals cast up by the waves. It is said to be timid, running off with great speed if scared, but if stopped it shows temper and nips hard. It is also very common, according to Lucas, in Algeria, where it is eaten by the poor. Fine specimens for a naturalist’s collection are not easy to catch because of their extreme readiness on the least alarm to ensconce themselves deep in rifts of the rock. If in their headlong haste they sometimes slip into a hole too shallow to contain them entirely, the pursuer will still be likely only to obtain their cast-off legs, since they readily relinquish them all rather than be captured. Nautilograpsus, Milne-Edwards, 1837, like some of the genera previously described, has third maxillipeds which do not form a complete operculum. In 1825, in Bowdich’s ‘Excursion to Madeira and Porto Santo,’ Leach gave to this genus the name Planes, a wanderer, but from want of a sufficient accompanying description this has been re- garded as technically only a manuscript name, not entitled to priority. It may, however, be doubted whether this is aright decision, since a figure of the type species, Planes minutus (Linn.), was appended, and there appears to be but a single species in the genus. The name of wanderer is very appropriate, since this, the common Gulf-weed Crab, is said to occur nearly everywhere on floating weed in the temperate and tropical seas of the globe. If, as is probable, it was the presence of this little crab on the Sargassum bacciferum that Colambus adduced as an argu- ment to prove to his despairing sailors the proximity of land, it was not quite so much to the point as the sailors appear to have thought it. Columbus himself had other and more satisfactory reasons for his own confidence. Patrick Browne calls it the Turtle-Crab, remarking, ‘I found this insect on the back of a turtle, near the western islands.’ Eriocheir, de Haan, 1835, meaning ‘ woolly-hand,’ contains a species, Hriocheir japonicus, of very singular appearance, the great claws looking as if they were muffled up in cuffs of long fur. Itis represented in the accom- panying plate, which is reduced from de Haan’s work. 96 A HISTORY OF RECENT CRUSTACEA The detached figures show the chele of the young male and the female, and the pleon respectively of male and female. By the Japanese this species is called the moun- tain savage or the hairy crab. It occupies brackish waters, passing from them into fresh-water streams, by means of which it ascends the mountains, where it is often observed on dry land. Varuna, Milne-Edwards, 1830, has the single species Varuna litterata (Fabricius), common in the Indo-Pacific region, and attracting attention by the marking on the carapace to which the specific name refers. The capital letter H is here considered to be formed with more than usual distinctness by the longitudinal grooves that sepa- rate the lateral from the median regions, and the trans- verse groove which appears to form the upper boundary of the cardiac region. Sesarma, Say, 1818, includes a large number of species found in the shallow waters of all the warm regions of the globe. In this genus the ‘front’ is broad; the third maxillipeds, when closed, still leave open a lozenge-shaped space, and have the large fourth joint traversed by a ridge from the front inner angle to the outer angle behind ; the pterygostomian regions have a granular or reticulated sur- face, which in general is divided into little squares of extreme regularity. Reference has been already made to Fritz Miiller’s in- vestigation of the breathing arrangements in land-crabs. He was anxious to put the theory of evolution to a test. The resemblances which prevail among all crabs point, on that theory, to their derivation from a common ancestral form, but the differences which prevail in the numerous genera of land-crabs point to a divergence that must have begun long before they assumed terrestrial habits. That, at least, is what Fritz Miiller assumes, and few evolution- ists will be inclined to deny it. If, then, several different forms of water-breathers at various times and places have independently developed into air-breathers, it is unlikely that the necessary changes will all be of the same pattern. It is so unlikely that, had it proved to be the case, Fritz DARWIN'S THEORY TESTED 97 Miiller was prepared to regard it as a very damaging blow to the theory of evolution. The result was just the oppo- site, as will be seen by a comparison of his observations on several species and genera. Those on Ocypode have been already quoted. In the family Grapside he describes, under the name Aratus Pisoni, the species which Milne-Edwards calls Sesarma Pisoni, a sweet little vivacious crab, which climbs the mangrove-bushes and feeds upon their leaves. Its short sharp claws are well fitted for climbing, but they prick like pins when the creature runs over a bare hand. Once, when he had one of these seated on his hand, Fritz Miller noticed that it raised up the hinder part of its carapace, and that by this means a wide slit was opened upon each side over the last pair of feet, affording a view into the bran- chial cavity. When studying this phenomenon in another species, which he took to be a true Grapsus, he observed that with the formation of the slit behind, the anterior part of the carapace seems to sink so as partly or entirely to close the anterior afferent opening. As the lifting of the carapace never takes place under water, he infers that the animal opens its branchial cavity in front or behind accord- ing as it requires to breathe water or air. He had noticed the elevation of the carapace, also, in species of Sesarma and Cyclograpsus, which burrow deep in swampy ground, and often scamper about on the wet mud, or sit watch- fully before their burrows. But to observe the action in these is a work of patience, since they can continue to breathe water long after they have quitted the source of supply. That reticulation of the shell between the afferent and efferent branchial orifices, which has been mentioned in the character of the genus Sesarma, has a special purpose. The squared meshes of network are due partly to fine tuberculation and partly to curious geniculate hairs form- ing over the surface a sort of fine hair-sieve. When the water issues from the branchial cavity it spreads through this network, and can take up fresh oxygen, whereupon the appendages ot the third maxillipeds, working in the 98 A HISTORY OF RECENT CRUSTACEA afferent opening on either side, by their powerful move- ments bring it back to the branchial cavity. ‘The two ridges on the maxillipeds, which are often densely fringed with hairs, meet in front and form a triangular break- water which prevents the streams intended for the bran- chiee from entering the mouth-opening. Of the rock-haunting species of the genera Plagusia, Latreille, 1806, and Goniopsis, de Haan, 1835, Krauss speaks with a sort of admiration. At low tide they come bustling out of their crannies in ho.ts. By help of their soft elastic bodies, and their limbs cut out for the very purpose, they clamber over rough blocks and steep sides of rock, jump from one crag to another, and creep into the most inaccessible crevices. They are not very swift, but very canny, so that on their own ground, in spite of their multitude, it is almost impossible to catch any of them. In the fear of pursuit they will let themselves drop several feet from one ledge on to another, or plunge a fathom down into the sea and paddle off to the nearest rock. Acanthipus clavimdnus, de Haan, is a tiny species nearly allied to Plagusia, but with different habits. It lurks under stones, and it may seem a light matter to turn over a stone and catch it, but before the stone is well over the crab will have whisked to the other side, and when at length it has been pinned fast, it is no easy task to drag away its thin body and clinging talon-like claws without breaking them. The name of this genus having been pre- occupied, it has been changed by Miers to Leicléphus. Plagusia contains species that come from the Atlantic and Pacific, and some of these have been taken in the Medi- terranean under circumstances worthy of note. In the winter of 1873 an iron vessel entered the port of Mar- seilles. It had come from Pondichéry, by way of the Cape of Good Hope, having had a long and stormy voyage in the most rigorous season of the year. To the iron plates of this ship had become attached a little forest of alge and barnacles; and living among these were a number of higher Crustacea of exotic origin. Two of the specimens were found by Professor Catta to belong to a new species FRIEND OR FOE 99 which in 1876 he named Pachygrapsus qdvina; one was a Nautilograpsus (or Planes) minutus, a species scarcely ever found in the Mediterranean; the remainder belonged to two species, which M. Catta speaks of as Plagusia squa- mosa and Plagusia tomentosa. The latter,a South African species, should rather, it seems, be designated Plagusia chabrus (Linn.), and the former Plagusia depressa (Fa- bricius). It was this last-mentioned one that was the most numerous, being present in hundreds. As an Atlantic species, it might not have had far to come. The point of special interest, however, lies, as Catta explains, in showing the effects on distribution that may be produced by unconscious human agency. Family 4.—Pinnotheride. The carapace is usually more or less membranaceous, convex or depressed, with the antero-lateral margins entire or very slightly dentate. The ‘front, orbits, and eye- stalks are very small. The buccal frame is usually arcuate anteriorly. The third maxillipeds have the fourth joint well developed, and usually the third also, the fifth articu- lated at the apex, or at the front inner angle, or more rarely the front outer angle, of the fourth. The chelipeds in the adult male are small or moderately developed. The walking legs are slender and generally naked, with the seventh joint stiliform, unarmed. The pleon of the male in general does not cover the whole width of the sternum between the last pair of legs. The crabs of this family are small, and many of them live in the shells of bivalve molluscs, tests of Echini, tubes of annelids, and other borrowed habitations. Miers dis- tributes five-and-twenty genera over four sub-families. Pinnothéres, Vatreille (in Bosc), 1802, was known to the ancients under the same name, but more commonly under the name Pinnotéres. It is a great pity that Latreille did not adopt the latter, which is in all pro- bability the older form. Small as the difference in sound, the difference in sense is considerable. Pinnotheres means 100 A HISTORY OF RECENT CRUSTACEA one that hunts the Pinnw, and, in accordance with this designation of the genus, Oppian tells the story that when oysters open their valves to take in the mud and water on which they live, one of these crafty little crabs picks up a pebble and thrusts it in, so that the oyster is prevented from closing its shell again, and the crab enters and feeds upon its nutritious flesh. Gesner in the sixteenth century expressed his confidence that this was mythical, since you never find any bites upon the mussels, pectens, pinnas, and oysters that are attended by these crabs. The name Pinnoteres means one that watches or guards the Pinna, and there can be little doubt that it was the form used by Aristotle, seeing that he also speaks of it as Pinnophilux, a word of precisely the same meaning. Not only Aristotle, but many succeeding writers of renown, such as Cicero, Pliny, and seemingly Linnzus himself, accepted the opinion that there was a compact between the mollusc and the crustacean for their mutual benefit. Whenever little fishes swam in between the expanded valves of the mollusc, it was supposed that its companion gave it a little friendly nip, upon which the valves snapped together, the prey was secured, and shared between the confederates. A similar policy was pursued to exclude the intrusion of a dangerous foe. The great’ antiquity of the belief is at- tested by the fact that the Egyptians in their hieroglyphics made use of the pinna and crab to symbolise the helpless- ness of a man without friends. That the belief was un- tenable was pointed out by many naturalists from Gesner down to Cuvier, on the ground that molluscs do not feed on little fishes, and that the residence of the crabs within the valves was sufficiently explained by the prevailing sottness of the carapace in this family. This indeed ap- plies chiefly to the females, and it is the females: that appear to be most frequently found thus domiciled. It is so much the nature of crustaceans to take refuge in any sort of cleft or cranny that the first entrance of the Pinnotheres into any sort of bivalve can be easily under- stood. When the residence proved to be peculiarly secure, the shell of the crab would by degrees lose a hardness that THE OYSTER-CRAB 101 was no longer especially necessary. That the crab may be at times useful to the mollusc seems after all not so very improbable, for at the approach of an enemy so nervous a creature as a crab would no doubt begin to scuttle about and in this way communicate its terror to its more apathetic companion, which would then naturally close its doors against the danger. Dr. H. Woodward has recently recorded a remarkable instance of a Pinnotheres found encysted in a pearl-like formation of the pearl- oyster, Meleagrina margaritifera. Pinnotheres veterum, Bose, and Pinnotheres pisum (Linn.) are common European and British species. Giard and Bonnier suppose that under the latter name several distinct species have been confounded. Its Zoéa, long avo studied and drawn by Mr. Vaughan Thompson, is a singular-looking microscopic object. Among the names of other species some which indicate the animal’s resi- dence may be mentioned, as Pinnotheres ascidticola, Hesse, from the coast of France, the Japanese Pinnotheres pho- lidis, de Haan, and Pinnotheres lithoddmz, Smith, from the Pearl Islands and Lower California. A similar indication is given in the generic name, Holothuriaphilus, Nauck. In ‘The Civil and Natural History of Jamaica,’ when speaking of a Pinnotheres, which he calls the Oyster-Crab, Patrick Browne says: ‘This little species is generally found with the Mangrove oysters, in their shells, where they always live in plenty, and spawn at the regular seasons; and such as eat the oysters, do not think them a bit the worse for being accompanied with some of these crabs, which they swallow with the fish. They are very small and tender, and nearly of the same length and breadth, seldom exceeding a quarter of an inch either way.’ Tica Desmarest, 1823, was established under a name invented by Leach, and signifying a membrana- --ceous body. This is a character in which many members of the family partake. Hymenosoma orbiculare, Latreille and Desmarest, is a South African species. Lfalicarcinus, White, 1846, is closely allied to Hymenosoma, but courts 9 102 A HISTORY OF RECENT CRUSTACEA attention for the sake of the species Halicarcinus planatus (Fabricius), which is widely distributed over the Antarctic or Austral region, being the only Brachyurous Decapod, it is said, proper to that wide area of distribution. Mr. Haswell considers that the Elamene Mathei of Milne- Edwards is probably the young male of this species, and that it is quite distinct from the original Hymenosoma Mathei of Desmarest. Scopiméra, de Haan, 1833, was established for the single species, Scopimera globosa, in which the arm of the chelipeds and the corresponding fourth joint (the so- called merus) of the hinder legs has the outer margin cartilaginous instead of crustaceous, with a transparent membrane in the flat part. This peculiarity explains de Haan’s choice of a generic name, which means ‘thighs with windows in them.’ From the resemblance to the head of a drum these membranous pieces have been called ‘tympana.’ Dotilla, Stimpson, was substituted for Doto, de Haan, 1833, a pre-occupied name. In this genus Dotilla fenes- trata, Hilgendorf, from the Hast Coast of Africa, has the windows or tympana also in the sternum. Dotilla brevi- tarsis, de Man, is from the Mergui archipelago. Dr. de Man makes Scopimera a synonym of Dotilla, but, if the two genera are united, Scopimera as the older name must take precedence. Hexipus, de Haan, 1835, is entirely devoid of the last pair of walking legs, so that instead of decapods these crabs have become octopods, and if the chelipeds are excluded and only the walking legs counted they may be regarded as hexapods, or six-legged crabs, and to this view the name of the genus refers. Thaumastoplax, Miers, 1381, it is said, ‘is closely allied in all its characters and particularly in wanting the fifth pair of thoracic legs, to the genera Hewapus, de Haan, and Amorphopus, Bell, but is distinguished from the former by the much greater development of the second ambula- tory legs and the structure of the outer [third] maxilli- pedes, whose merus [fourth] joint is elongated and TRANSITIONAL FORMS 103 narrowed at its summit, where it is articulated with the next joint, and from the latter by the well-formed orbits and the entire absence of rudimentary fifth legs.’ Those who are always sceptically inquiring for links in the chain of evolution and for the fine gradations which the trans- mutation of species postulates, may be invited to observe in this family the genus Pinniwa, White, in which the fifth legs are often short, the genus Amorphdpus, in which they are rudimentary, and lastly Thaumastoplax and Hexa- pus, from which they have vanished altogether. Some curious facts relating to the organs of vision in certain members of this tribe are worthy of mention. In the family Ocypodidee the genus Bathyplax, A. Milne- Edwards, 1880, contains but a single species. Specimens taken by the U.S.S. Blake from depths between four and five hundred fathoms were found to have the eye-stalks very short, almost immovable, and with the cornez not developed. Accordingly the species was named typhlus, ‘the blind.’ But specimens taken from smaller depths by the Challenger agreed with the others in all respects except just this one, that they possessed small, distinct, terminal corneas. As these specimens were obviously not blind, Mr. Miers named them ‘var. oculiferus.’ In regard to another genus, also.but more doubtfully included in the Ocypodida, Professor Perrier cites the observation of A. Milne-Edwards, that in Geryon tridens, Kriéyer, a species which descends to great depths, the eyes are brilliantly luminous. 104 A HISTORY OF RECENT CRUSTACEA CHAPTER VIII TRIBE IJ.—OXYRRHYNCHA THE carapace is more or less narrowed anteriorly and usually rostrate, with the hepatic regions small, the bran- chial large. The epistome is generally large. The buccal frame is quadrate, with the anterior margin straight. There are nine pairs of branchize, with the efferent chan- nels opening at the sides of the endostome. In this, as in the two preceding tribes, the afferent channels open behind the pterygostomian regions, in front of the base of the chelipeds. The first antenne are longitu- dinally folded. The third maxillipeds have the fifth joint articulated at the apex or at the front inner angle of the fourth. The verges of the male are exserted through the bases of the last pair of walking legs. This tribe of the ‘sharp-snouted’ crabs is divided into two legions, the Maiinea and Parthenopinea. It has been observed in many cases that the two halves of the large liver are not separate, but united by a median lobe. The nervous system is said to attain a higher degree of cen- tralisation in this group of Crustacea than in any other, the ganglia of the trunk forming a single solid disk-like mass. Legion 1.—Maninea. The basal joint of the second antennz is well de- veloped, inserted beneath the eyes, and usually occupies a great part of the infra-ocular space. This legion contains three families, the Inachide, Maiide, and Periceride. Family 1.—Inachide. __ The eyes are non-retractile, or retractile against the sides of the carapace. In general the orbits are not de- SPIDER-CRABS 105 fined, but there is often a well-developed preocular and postocular spine. The basal joint of the second antenne is generally slender, sometimes moderately enlarged. The carapace varies in shape, being subtriangular, or trun- cately triangular or subpyriform, rarely suborbicular. The rostrum is simple or bifid, sometimes very short. The chelipeds never have the fingers excavate at the tips. The walking legs are sometimes very long. In both sexes the number of distinct segments of the pleon varies from four to seven. To this family belong nearly forty genera, three of which are included in the British fauna. Macropodia, Leach, 1814, meaning ‘long-foot,’ had been already called Macrépus by Latreille, but that form of the name was preoccupied. By Lamarck in 1818 it was named Stenorynchus, ‘narrow-snout, a very appro- priate name but without any title to supersede the earlier Macropodia of Leach. Just as the title of the tribe Oxyrhyncha ought in accordance with its Greek original to be spelt Oxyrrhyncha, so should Stenorynchus have been spelt Stenorrhynchus. Part of this correction has been adopted in the commonly used form Stenorhynchus, and naturalists have been so much tickled with the pleasing sound that, instead of leaving the monopoly of it to the Crustacea, they have employed it also among beetles, reptiles, birds, and mammals. The British species Macro- podia rostratus (Linn.) is described in Bell’s History under the name Stenorynchus Phalangium (Pennant). The specific name given by Pennant alludes to the resemblance which these crabs with long thin legs bear to the Pycno- gonids or Sea-spiders, and which has won for them the designation of spider-crabs. In spite of their long limbs they are a sluggish and slow-moving race, and in con- sequence are devoured in great numbers by other inhabi- tants of the sea. The fact that there are great’ numbers of them to be devoured shows that nature has not left them entirely without means of defence, of which some account will presently be given. Mucropodia longirostris (Fabricius), which Bell calls Stenorynchus tenuirostris 106 A HISTORY OF RECENT CRUSTACEA (Leach), is, like the preceding species, found both in British and Mediterranean waters, and is distinguished from the other species partly by the relatively greater length of the rostrum. Acheeus, Leach, 1815, is so near to Macropodia that ‘it is in fact only distinguished from it by the absence of rostral spines; the rostrum in Achceus being composed merely of two small acute or subacute lobes.’ Of ten species enumerated by Miers only the type, Acheus Cran- chii, Leach, belongs to the waters of Europe and Great Britain. Indchus, Fabricius, 1798, as at present restricted, con- tained in 1886 only six species, and these known only from European seas and the Western North-Atlantic. Three of these species are found in British waters, namely, Inachus dorsettensis (Pennant), Inachus dorynchus, Leach, and Inachus leptochirus, Leach. Leptopodia, Leach, 1815, has apparently but one species, Leptopodia sagittaria (Fabricius), with an extensive range in the warm waters of the Atlantic and of the West coast of America. Unlike the three preceding genera this has the rostrum not bifid, but simple. This beak is very long and serrate on the edges. The carapace is not spinous. The chelipeds in the male are rather slender and very elongate; the walking legs are very slender and extremely elongated, with the seventh joint stiliform. Next to this genus Leach placed one which he named Pactolus, with the species Pactolus Boscii, founded on a single female specimen in the British Museum from some unknown locality. Fabricius, he says, seems to have described it as the other sex of his Inachus suqittarius. Pactolus has a body exactly like Leptopodiu, but the legs are of moderate length, and of these the first three pairs have simple claws, while the last two pairs are didactyle, that is to say, chelate. In 1798 Fabricius said of his sagittarius that in one sex the feet were of moderate size and all chelate, in the other six times as long and simple. In 1798, without any distinction of sexes, he states that eight of the feet are unguiculate and the last four pre- A DECEPTION DETECTED 107 hensile, thus making six pairs of legs, with a structural arrangement as regards three of them that would be unique among the Brachyura. At each date the species is said to come from the Isle of Guadeloupe. Leach rightly per- ceived that error and confusion were lurking somewhere, if it should not rather be said that they are conspicuous on the face of the two discordant accounts. Milne- Edwards in 1837, though with a confession of great un- certainty, institutes for the single genus Pactolus the tribe of the Pactoliens, which he places among the Anomura. But soon after, in 1839, de Haan with great acuteness ob- served, ‘Pactolus, Leach, Zoological Miscellanies, vol. ii. tab. 63, seems to me to be made up of the thorax of a female Leptopodia sagittaria, to which the legs of some other animal have been united; for the thorax of Pactolus, just as also the rostrum and abdomen, agrees with the female Leptopodiu. The unlikeness in colour between the legs and the thorax in the figure referred to at once reveals the deception. Never are two alien forms found, agreeing exactly in the thorax, yet so disagreeing in the legs.’ The principle here enunciated is worth remembering, as in some parts of the world there are dealers who delight and find profit and have also great skill in fabricating mon- strosities, sometimes such as have deceived the very elect. Nearly related to Inachus is the gigantic Macrocheira Kampferi, de Haan, 1839, of which mention has been earlier made. In Japanese it is called the insular crab. Huenia is another genus of this family instituted by de Haan in 1839. The name refers to the acutely trian- gular form of the carapace, and is derived from the Greek word ives, a ploughshare, a derivation which would have been hard to guess, had not de Haan obligingly mentioned it himself. At the foot of his plate 23 he names the figures ‘4. Maga (Huenia) elongata n. 5. id. variet. 6. Masa (Huenia) heraldica n.’ But the species established in the text is Mja (Huenia) proteus. The double generic name results from the inconvenient practice, still some- times followed, of splitting a genus up into sub-genera. Sub-genera, if they are worth anything, are pretty sure to 108 A HISTORY OF RECENT CRUSTACEA Fic. 5.—Huenia proteus, de Haan, adult male, with separate figure of the pleon. Qi ag Fu. 7.—Huenta proteus, de Haan, female, with separate figures of the pleon in a sterilised and a healthy specimen. : PUZZLES OF PARASITISM 109 be regarded as genera later on, and might therefore just as well be called so at first. But for his change of the specific names de Haan had a reasonable though a rather singular excuse. After his plate had been engraved with the figures and names of two distinct species, based on the very great dissimilarity of the carapace in the male and female specimens at first available, he received a new series of specimens belonging to each form. These he found to agree in so many particulars tnat the protean form of the carapace no longer sufficed to separate them specitically, but had to be regarded as depending on the variations of age or sex. He here also observed that, as in several other Crustacea, there were what he supposed to be two forms of the female, the one ovigerous which he designates as genuine, the other sterile which he speaks of as spurious. In the present species he says that the pleon in the genuine females is of five segments, the fourth thick, very convex, with a longitudinal median impression, while in the spurious females it has seven segments, is lamellar and concave, with the fourth, fifth, and sixth segments dilated, the seventh narrower and truncate. The mystery of these so-called spurious females has been recently explained by Professor Giard. In studying the parasitic Crustacea, as well Isopoda as Rhizocephala, he was confronted by the statement which Rathke made in 1887, that of the many hundreds of Bopyrus which had passed through his hands he had never found one in any but a female Palemon, and also by the statement which Fraisse made in 1877, that the males of Inachus, so far as he had observed, were never attacked by parasites, which he thought might be the result of the unsuitable shape of the narrow pleon in that sex. The parasitic groups will be for after consideration, but it must here be mentioned that by careful investiga- tion Professor Giard arrived at the very interesting result that the specimens of the higher Crustacea infested by the parasites are as a rule more or less completely sterilised, and that the secondary sexual characters are considerably modified, so that the males acquire to some extent the 110 A HISTORY OF RECENT CRUSTACEA appearance of the females, especially in the widening of the pleon, which is the first characteristic of sex that would generally be looked for. It follows, therefore, that amorg the specimens which in old times have been regarded as spurious females many spurious males were beyond doubt included. It is also worth remembering that when the shape of the pleon leaves the sex of a crab ambiguous, that may be taken as an indication that some curious species of parasitic crustacean is likely to be found in some part of the organism. A large extension has been given to the family of the Inachidee by recent voyages of deep-sea exploration, and in some instances species which, when first discovered only a few years ago, were naturally supposed to be rare, have since proved to be cosmopolitan. Thus the little Lispognaithus Thomsoni (Norman), a delicate species with long slender limbs, taken at a depth of two or three hundred fathoms in the Faré Channel, and first described in 1878, has since then been taken at much greater depths and at places so wide apart as the Straits of Gibraltar, the neighbourhood of the Cape of Good Hope, and of Sydney in Australia. Ergasticus, A. Milne-Edwards, 1881, has two species —Ergasticus Clouei, A. Milne-Edwards, and Ergasticus Naresiit, Miers. The latter was taken near the Admiralty Isles in the Pacific, and recalls the name of the honoured captain of the Challenger; the former was found in the Mediterranean and the Atlantic, and the name of the genus founded for it signifies ‘a worker’ in remembrance of the French ship, the Travailleur, by which the type- specimen was dredged. Platymaia Wyville-thomsoni (see Plate IV.), Cyrtomaia Murrayt, Cyrtomaia Suhmi, Echi- noplax Moseleyi, represent new genera and species in this family instituted by Miers in 1886, in which the specific names have been chosen expressly to associate some of the finest of the Brachyura dredged by the Challenger with the names of its staff of naturalists. Platymaia and Oyrtomaia are also pointed out as of especial interest from their ‘ being Malayasian representatives of a section of the sub-family Pi. iv. Catapagurus Sharreri Housed J Te * Hippa talpoida TS aaa 4 Naxia hystrix H. talpoida Zoea, 2 “stage H talpoida.Zoca, last stage ae ua Lambrus intermedius A MOVING MUSEUM 111 Inachinze, hitherto represented only by types from Eastern America.’ Among those types the nearest to Platymaia is supposed to be Huprogndtha, Stimpson, 1870. In re- gard to Huprognatha rastellifera, Professor 8. I. Smith says: ‘This is apparently by far the most abundant of all the Brachyura along our whole eastern coast south of Cape Cod—in the belt from 50 to 200 fathoms depth. In the U.S. Fish Commission dredgings off Martha’s Vineyard, many thousands of specimens were often taken at a single haul of the trawl.’ Family 2.—Muatidee. The eyes are retractile within the orbits, which are distinctly defined, but often more or less incomplete below or marked with open fissures in their upper and lower margins. The basal joint of the second antenne is always more or less enlarged. The family includes about thirty genera, three of which are known in British localities. Maia, Lamarck, 1801, is a genus well known rather to the south than the north of Great Britain in the species Maia squinado (Herbst). It is a large, eatable, and, in the south-west of England, an extremely abundant species. Its great inflated carapace, covered with prickles and fur, gives it a ready place in the memory when once it has been noticed. A pretty little amphipod, called Iscea Montagut, Milne-Edwards, with the sixth joint of its legs much widened, seems to have been specially adapted for ranging about this hirsute and prickly crab, the only place in which it is found. The convenience of the residence may be in- ferred from the fact, previously noticed, that from time to time a score of other species of Amphipoda find it their interest to occupy the same station. The crab, according to Herbst, is known as Syuinado in Provence. In Corn- wall it is called the Corwich, and Bell was told that in those parts several dozens could be had for sixpence. But even this does not give so ample an idea of its abundance as is conveyed by Olivi in his ‘ Adriatic Zoology’ of a hundred years ago. He declares that in summer the crabs 112 A HISTORY OF RECENT CRUSTACEA are dispersed upon the shore, but that in winter the females collect on the deeper rocky ground in particular spots in a great crowd, and pile themselves up in such numbers that they form a sort of mound, which from the depth of eighty to a hundred feet ascends until the glimmer of it can be seen at the surface of the water, and that then the Istrian fishermen go out with two, four, or six boats, surround this living tower with their nets as easily as possible, and so make a speedy capture. Professor Stalio, in 1877, en- dorses this wonderful tale, except that in his account the boats employed are only two or four, and the instinct which leads these creatures to cling together and climb up one on another’s back only produces a great pile of several feet in height. Yet anything much less than Olivi’s submarine mountain of crabs would scarcely be visible from the sur- face at the depths which he mentions. The Mediterranean possesses another closely allied spe- cies, Maia verrucosa, Milne-Edwards, smaller in size, and covered with warts or tubercles, instead of spines or prickles. This little crab led the way in quite recent years to some observations that throw a new light upon the mental powers of the Crustacea. A great many of the Oxyrrhyncha have at all periods excited the surprise of collectors, when dealing for the first time with living specimens, by their often extreme un- tidiness. They are overgrown with alge and ever so many kinds of sedentary animals. They are undoubtedly them- selves slow-moving creatures, and it was not unnaturally supposed that these colonies with which they were encum- bered and disfigured were at once a proof and a result of their extreme sluggishness. Dr. Graeffe had once occasion to carry into the aquarium at Trieste a specimen of Maia verrucosa which had been stripped of most of its vegetable costume. He happened to place it in the same vessel with a large mass of the polyp known as Dead Man’s Fingers. The next day, to his astonishment, he found the whole back of the Spider-crab covered with pieces which had evidently been snicked out of the Alcyonium. To make sure, he kept watch, and at length had the sweet satis- HOW CRABS PUT THEIR CLOTHES ON 113 faction of seeing how the crab slowly stepped up to the polyp-mass, and with its claws tweaked off small points of the branches. At first it let them lie on the floor of the aquarium, but later on fished one of them up again with its claw, which it bent over the back of its carapace, and there among the fur it planted the fragment of the polyp with the severed surface downwards! Further experiments showed that not only in the species of Mata, but also in those of Pisa, Macropodia, Inachus, and other Oxyrrhyncha, the foreign organisms were fastened to the crabs’ bodies by the crabs themselves. That the object was concealment by the wearing of a mask was obvious, since the costuming was never at random, but always in strict agreement with the surroundings. Moreover, these marine zoologists know what sponges and polyps can be chopped up without causing mortality in the fragments. The pieces they plant are pieces that will live and thrive, and, as Dr. Graeffe observes, the keepers of aquaria have only to consult the crabs to learn what kinds of sea- animals will bear being thus transplanted piecemeal. Tor keeping on their living mask Dr. Graeffe found that the natural coats of these Crustacea were furnished with hairs varying in arrangement and shape in the different genera and species, some of the hairs being fish-hook-shaped, others clubbed, and others simply tapering, but all more or less serrate, the simple ones suflicing to detain a coating of slimy mud, while the others hold cape the living organisms. Dr. Graeffe published his observations in 1882, but already in 1878 Dr. Bisig had reported of a species of Inachus that he had seen it plucking Hydroids and plant- ing them on its spines and hairs, and Dr. C. Ph. Sluiter in 1880, when establishing the new species Chorinus algatec- tus, described its way of spitting little fragments of alge on the strongly bent hooklets of its body and legs, to mask itself from its enemies and its prey. Additional details of great interest were published in 1889 by the Swedish naturalist Dr. Carl W. 8. Aurivillins. Hyas, Leach, 1818, comprises but few species, two of 114 A HISTORY OF RECENT CRUSTAUFA which belong to Great Britain and are also extensively dis- tributed in the North Atlantic. These are yas araneus (Linn.) and Hyas coarctatus, Leach. In a tiny specimen of the latter species, taken from off the carapace of the mother, small spines or tubercles are observable on both sides of each of the two divisions of the rostrum, on the outer side of the second antennz, and on the eye-stalks. These minute characters do not reappear in the adult. The two species mentioned are very abundant on the coast of Sweden, and Aurivillius found that they were almost without exception dressed up either in pieces of different alge (almost always Floridece) or of shallow-water sponges, or with Hydroids, tubicolous Annelids, Polyzoa, Cirri- pedes, or Ascidians simple or compound. His experiments showed him that, if some of these settled rather by the crab’s permission than its active interference, yet they had been originally under its control, while in most cases the colonists had been actually planted and forced at the will of the crustacean to occupy their several stations. He found, just as Mr. David Robertson of Cumbrae had done, that his specimens of Hyas were capable not only of dress- ing but of undressing themselves. Of the effectiveness of their disguises he had often had practical experience, when upon visiting his aquarium in the morning he was unable to find specimens which he had placed there overnight, and which he at first thought must have escaped. Close inspection and the help of a magnifying glass, however, would always show that they were present, but that they had so decked themselves out with the vegetables and animals around them as to lose all invidious prominence. By transplanting into an environment of sponges some that had clothed themselves in bright-coloured alge, he ascertained how accurately they knew their business, for they laboriously picked off the gay colours, and stuck themselves over with fragments of sponge in their place. The chelipeds of these crabs are adapted by length and by the flexibility of the joints to reach to the different parts of the body which require dressing up. The hooks and hairs which hold on the tags and patches have been already A CAREFUL TOILETTE 115 considered. One curious point as to their distribution may be noticed. When the female is loaded with eggs, the basal segment or segments of the pleon are forced upwards so as to need concealment like the carapace. The result is, in some at least of the Oxyrrhyncha, that hooks for the attachment of foreign objects occur upon these segments in the females but not in the males. While dressing themselves the crabs invariably bring each portion of their intended coat to their mouths as if Fia. 8.—Chorinus aculeatus, Milne-Edwards [Aurivillius]. they were going to eat or at least to taste it. Aurivillius noticed that if a piece did not hold firm where the crab was seeking to plant it, recourse was had again to the mouth, and if the piece still proved intractable, it would be brought to the mouth a third time and then tried on a fresh spot. The object of this assiduous application to the mouth is, he thinks, that each piece may be well licked, a secretion from the mouth organs, especially the first pair of maxillipeds, bestowing the requisite adhesive 10 116 A HISTORY OF RECENT CRUSTACEA character. Considering the tolerably ruthless manner in which the crab gathers the constituents of its costume, one need not wonder at their needing a little emollient ointment. Under the circumstances their natural ten- dency to adhere might otherwise remain for some time dormant. Chorinus aculeatus, Milne-Edwards, as depicted on the preceding page, is suggestive of a wardrobe provided with a truly enviable number of pegs. In regard to a closely related species, Chorinus longispina, de Haan remarks that to the hooked sete of the thorax and legs marine odds and ends adhere so closely that they can scarcely be removed without damaging the sete. He is thinking only of man’s rude handling, for, however remorseless such a crab may be towards its surroundings, we may feel assured that its deft fingers will do no violence to the well-appointed furni- ture of its own carapace. Pisa, Leach, 1813, is open to the suspicion of being a synonym of Arctopsis, Lamarck, 1801. ‘There are several species of this genus in various parts of the world. The two known in English and Irish waters occur also in the Mediterranean and have a considerable range north and south. These are Pisa tetraodon (Pennant) and the species which Bell calls Pisa Gibbsii, Leach, a name which must be wrong, whatever other is right. Miers with some hesi- tation adopts for it the name Pisa (Arctopsis) tribiilus (Linn.). Nawia, Milne-Edwards, 1884, is narrowly distinguished from Pisa by the accessory spinules of the two-horned rostrum. Nawxia hystriz, Miers (see Plate IV.), was ob- tained by the Challenger at Amboina. Ivissa, Leach, 1815, is a genus apparently near to Pisa, but with a rostrum consisting of two truncate laminar horns side by side, which are somewhat wider at the ex- tremity than at the base. It was formed for the Mediter- ranean species Lissa chiragra (Fabricius), which is deep red in colour, and has the legs so covered with protuber- ances that its specific name, meaning ‘ gout in the hand,’ is not inappropriate, although it so happens that the hands PROTECTIVE PERIL 117 of the chelipeds are almost the only smooth part about it. It is said by Stalio to be sensitive to changes of tempera- ture, and at any increase of cold to crouch closely in the crevices of the rocks, but as he also says that its habitat is at a depth of thirty to forty fathoms, it is not easy to understand how this valetudinarian shrinking has been ascertained. The crab is only about two inches long, and according to Herbst is commonly covered with worm-tubes, corals, algee, and mud, to such an extent that it is scarcely to be recognised or to be taken for a living creature. Chioneecétes, Kroyer, 1838, is a northern genus, with a name meaning ‘the snow-dweller,’ founded for the Greenland species Chionecetes optlio, which, according to Professor 8. I. Smith, is taken rarely in the deep water off the New England coast. ‘It is,’ he says, ‘one of the largest arctic crabs, and occasionally attains gigantic pro- portions.’ In the largest specimen that he examined the span of the walking-legs was two feet eight inches. The specimen figured by Kroyer in Gaimard’s voyages was, he says, even somewhat larger, but though the figure occupies the whole extent of the folio plate, I do not find that even with the second pair of legs which are the longest or with the third pair which are inserted at the broadest part of the carapace could it span more than twenty-eight inches. Antilibinia Smithix, M‘Leay, is a South African species which Krauss observed in its native haunts on the per- pendicular wave-lashed cliffs of the headland at Natal. Its legs are powerful and have the terminal joint bent into a strong hook by which the crab can fasten on to the pores of the rock. Its body is rounded off and has a very hard horny shell well adapted to resist the continual beating upon it of the surf. Among the bright and dark green alge, and coloured like them, it sits almost completely motionless and lets its food be floated to it by the ever- moving sea. When Krauss wished to take some speci- mens away from their dangerous position, they clung so tight that he had to use considerable force to disengage them, and was in consequence several times overtaken by the returning waves before he could effect his purpose. It 118 A HISTORY OF RECENT CRUSTACEA is pleasant to see how creatures comparatively feeble may sometimes find security in stations the most unpromising and the most exposed. ‘The whole tribe of the Oxyrrhyn- cha are indeed often placed at the head of all the Crustacea in honour of the ready wit and resource which so many of them display. Scyramathia Carpentert (Norman) is a remarkable crab first observed on the Porcupine expedition in the Channel between the Faré and Shetland Isles. It was afterwards obtained abundantly by the Travailleur from great depths in the Bay of Biscay, and again the Norwegian North- Atlantic expedition trawled it from a depth of 220 fathoms about twenty miles off the west coast of Norway. According to the description of it by Professor Sars, ‘the whole surface of the body is invested, as it were, with a dense, felt-like covering, which, on closer inspection, is found to consist of two different kinds of cutaneous ap- pendages. Innermost, crowded together, are observed numerous small tuberculiform excrescences, which, at the first glance, may he readily taken for granulations on the skeleton of the skin, but, after a closer examination, are seen to be of a totally different character, since they have not only a soft consistence, but admit of being scraped off with the greatest facility. On treating these protuber- ances with a solution of potash, they are found to be true cutaneous vesicles or capsules, that, with a broad basis, are attached to the skeleton of the skin and sup- ported in the middle by a slender chitinous-like rod, of which the point projects more or less distinctly forward from the top. Between these peculiar cutaneous appen- dages, and projecting considerably beyond them, are short and comparatively stiff hairs, somewhat unguiform at the extremity, and crowded together, in particular on the anterior part of the dorsal surface of the carapace, which thus acquires a velvety appearance.’ The rostrum also is highly characteristic. It is divided from the base into two straight, stron gly divergent, branches, about half as long as the carapace. They are cylindrical at the base, but taper gradually to a dagger-like point, and SOME NAMES DISENTANGLED 119 are thickly covered with hair. There is, according to Sars, a possibility, which, however, S. I. Smith thinks an impro- bability, that the species may be the same as one earlier but all too briefly described by Stimpson, from the coast of Florida, under the name Scyra umbonatu. The speci- men taken by the Porcupine was first described as Amathia Carpentert, but the genus Amathia, Roux, has a pre-occu- pied name which has in consequence since been changed, by 8. I. Smith, to Anamathia, and Professor A. Milne- Edwards discovered that the species Carpentert could not be included in that genus. At the same time he noticed its likeness to Stimpson’s species above mentioned, and framed for it the new genus Scyramathia. From the fore- going remarks it will easily be understood what suggested the composition of this generic name, but it must not be forgotten that Scyramathia belongs to the family Maiidee, whereas Anamathia stands in the previously described Inachidee, and Scyra (though to the exclusion of Stimp- son’s species umbonata) is a genus belonging to the next family, the Periceride. Family 3.—Periceridee, The eyes are retractile within the small circular and well-defined orbits, which are not incomplete as in the Maiide. The basal joint of the second antennz is well developed, and constitutes a great part of the inferior wall of the orbit, the joint being in general much enlarged. The family contains about twenty genera. Pericéra, Latreille, 1829, of which the type is Pericera cornudo (Herbst), 1804, has been despoiled of many of its species by Miers, who has transferred them to Macro- celéma, a new genus which he instituted in 1879. Of the species Macroceloma trispinosa (Latreille) Mr. Ives says that Yucatan specimens when alive are of a bright scarlet colour. In the Challenger species, Macroceloma conciva, Miers, from Bahia and Fernando Noronha, the body and limbs are covered with a short close pubescence and with some longer curled hairs, Its colour in spirit is 120 A HISTORY OF RECENT CRUSTACEA yellowish-brown, but this is little or no guide to what its colour may have been when living. The specific names in this genus ought to have either masculine or else neuter terminations, but many naturalists seem to suppose that any generic name ending in -a is a feminine form, which is far from being the fact. In this family the genus Libinia, Leach, 1815, contains several species, aud Mithraw (Leach), Latreille, 1817, a very large group. Of Libinia emarginata, Leach, Miss Mary Rathbun, in her recent revision of the Periceridz, says that in Long Island Sound occasionally this species by its numbers ‘so interferes with the steam oyster dredgers that work is abandoned until the crabs (which are known to the oystermen as “ spiders”) have passed over.’ Legion 2.—Parthenopinea. The basal (or true second) joint of the second antenne is very small and embedded with the next joint in the narrow gap between the ‘front’ and the inner orbital angle, the infraocular space being mainly occupied by the inferior wall of the orbit. Lamily 4.—Parthenopide. The eyes are usually retractile within the small circular and well-defined orbits; the lower wall of the orbit is con- tinued to within a very short distance of the ‘front.’ The second antennee are very slender; the basal joint does not as in the Periceridee constitute a great part of the inferior orbital margin, but is very small, seldom reaching the ‘front,’ and with the next joint occupies the narrow gap intervening between the ‘front’ and the inner angle of the orbit. (In Ceratocarcinus the antenne are completely excluded from the orbits.) Some fifteen or twenty genera are reckoned in this family, of which only one is known in the waters of Great Britain. Hurynome, Leach, 1814, has not yet received many THE GREAT WARTY CRAB 121 additions to the type species Hurynome aspera (Pennant), for though the names scutellata and boletifera have been given to forms taken in the Mediterranean, it is probable that they are not distinct from, or at most are only varieties of, the species found on the British coasts. It is, as might be guessed from the names, a species rough with warts or tubercles. The walking-legs are short, but the chelipeds in the male are elongate, being nearly twice the length of the body according to Bell, but according to Leach three times its length. Hurynome tenuicornis, Malm, from Bohuslin, Guilmarsfjord, 1s there found to- gether with Hurynome aspera. Partherdpe, Fabricius, 1798, has in its type species, Parthenope horrida (Linn.), an animal of truly remarkable appearance. It is recorded from the West and Kast Indies, and has been called the great Warty Crab or stigmatised as the Lazy Crab. Its carapace is pentagonal, broader than long. While this and the legs are covered with warts and spines, the pleon is said to be full of pits, almost as if eaten through. The chelipeds are large and long. From the picture of it given by Herbst one might suppose that it was intended to look like a piece of light-red sand- stone overgrown here and there with green alge. Lambrus, Leach, 1815, unlike the two preceding genera, suffers from no paucity of species. So numerous indeed are they that in 1878 Professor A. Milne-Edwards deemed it expedient to subdivide Lambrus into ten genera, in- cluding in the number Solenolambrus, Stimpson, and Mesorhwea, Stimpson. The species are distributed over all the warmer seas of the world, and some occur.in the Medi- terranean. Of these Lambrus macrochélos (Herbst), mean- ing the Lambrus with long chelipeds, justifies its name, but almost puts its body out of countenance, seeing that the arms in question are nearly four times as long as either the length or breadth of the carapace. In Lambrus inter- medius, Miers (see Plate IV.), from the Corean Seas and Torres Strait, the disproportion between legs and trunk is less exaggerated. In the genus at large it is remarked that, apart from larval metamorphoses, so many variations 122 A HISTORY OF RECENT CRUSTACEA of form are undergone during progress to the adult con- dition, that, without a considerable series of specimens, young and old of the same species must often almost in- evitably be considered as distinct. Heterocrypta, Stimpson, 1871, contains but three species, and those of small size but singular appearance. One of these, Heteroorypta Maltzani, Miers, which has been taken at Goree Island, at the Azores, and off Senegambia, is also an ornament of the Mediterranean, having been taken by the Travailleur at a depth of about 250 fathoms off Toulon. The Mediterranean form was at first named Heterocrypta Marionis, after the distinguished French zoologist, but it has since been found to be the same species as Heteroerypta Malizant. THE POINT EXPLAINED 123 CHAPTER IX TRIBE IV.—OXYSTOMATA THE carapace is convex or depressed, with the antero- lateral margins arcuate or orbiculate ; or even subglobose ; or more or less oblong, with subparallel or slightly con- vergent margins (Dorippide). The epistome is very much reduced or rudimentary. The buccal frame is more or less triangular, nearly always produced and narrowed forwards with the margins anteriorly convergent. The. afferent channels to the branchie opén either behind the pterygostomian regions and in front of the chelipeds, or, more rarely, at the antero-lateral angles of the palate (Leucosiidee). The efferent channels open at the middle of the endostome which is produced forwards. There are six to nine pairs of branchie. The first antenne fold longitudinally or obliquely. The third maxillipeds have the fifth joint articulated at the inner or the outer front angle or at the apex of the fourth, beneath which it is often concealed. The verges of the male are exserted either from the surface of the sternal plastron or more usually from the bases of the fifth pair of legs, which are either adapted for walking or for swimming, or are feeble and raised upon the dorsal surface of the carapace. It is the narrowing anteriorly of the buccal frame or mouth-cavity ’ that gives the name of ‘sharp-mouths’ to this tribe, which is divided into four families, the Calap- pide, Matutida, Leucosiidee, and Dorippide. Family 1.—Calappide. The afferent channels to the branchia open bebind the pterygostomian regions and in front of the chelipeds. 124 A HISTORY OF RECENT CRUSTACEA The third maxillipeds have the fifth and following joints not wholly concealed by the fourth joint. The verges of the male are exserted from the bases of the fifth pair of legs. There are about ten genera included in this family. Calappa, Fabricius, 1798, contains some fifteen species, which are not a little remarkable in appearance. This is partly due to the form of the carapace, much narrowed in front where the short-stalked eyes twinkle cunningly, but widened behind with shield-like expansions over the bases of the legs. More singular, however, is the development of the chelipeds, which have a very flat crested hand of great size, yet the whole limb withal so arranged that the pair can be concealed beneath the body to which in that position they might be said to supply an operculum or in- complete ventral carapace. Of Calappa granulata (Linn.) Stalio says that, when it is compelled by fear of some enemy or by the force of the waves to leave its crevice in the rock, it draws together its walking-legs under the ex- panded parts of the carapace, makes its chelipeds meet, and, being thus reduced to the shape of a ball, launches itself into the deep. Unfortunately for it, the scouring of the waves often throws it up on to the shore, where con- tinuous rolling upon the pebbles puts an end to its exist- ence. This is a waste of what would otherwise form an agreeable morsel. It may be eaten with a good conscience, since it is itself very voracious, and when in pursuit of prey not to be intimidated. Judging from the contents of the stomachs of various Crustacea, de Haan was able to decide that Calappa, Matuta, and Dorippe feed on other Brachyura, Leucosia on species of Paleemon, Ranina on fishes and starfish. Calappa gallus (Herbst) is common to the Atlantic and the Pacific. The crested claws here carry to an almost comical extreme the resemblance to the head of a cock, which they exhibit more or less throughout this genus. Oalappa depressa, Miers (see Plate II.), from the South Australian coast; is one of the smaller species and a recent contribution to science. Paracyclois, Miers, 1886, is a genus in which the cheli- peds and walking-legs agree with those in Calappa and A QUESTION OF PRIORITY 125 Cryptosbma, and it is considered to connect Cryptosoma, Brullé, and Platyméra, Milne-Edwards, with Calappa through such forms as the above-mentioned Calappa gallus (Herbst), but Paracyclois is distinguished from the first two of these genera by the absence of any lateral spine on the margin of the carapace, and the broader basal joint of the second antenne, ‘and from Caluppu by the absence of the clypeiform prolongations of the carapace, which are represented by a slight protuberance of the postero-lateral margins in Paracyclois, which protuberance bears several strong spines.’ The type species of this curious genus, Paracyclois Milne-Edwardsti, Miers, was dredged north of the Admiralty Isles from a depth of 150 fathoms. Cryptosima cristatum, Brullé, was depicted in Webb and Berthelot’s ‘Hist. Nat. des Iles Canaries,’ and the genus was instituted at page 16 of that work, for which Miers gives the dates 1836-1814. Milne-Edwardsin 1837, while his own pages were passing through the press, refers to Brullé’s genus and species as about to be published. In the same year, 1837, de Haan published a new genus and species, Cycloés granulosa, from Japan. In 1841 he states that Brullé’s species is clearly the same as this, and in 1849 he repeats the remark as an example of wide distribution, the very same crab being found at the Canaries and in the waters of Japan. But he retains the name Cycloés, being evidently, aud perhaps rightly, under the impression that it had priority over Cryptosoma. Orithyia, Fabricius, 1798, is strongly distinguished from the other genera of this family by the natatorial character of the last three pairs of legs, which have an ovate terminal joint, as in the Portunide. The three preceding pairs of legs have also the terminal joints flat- tened, and the others more or less compressed, as is usual in species apt for swimming. There appears to be only one species, found in the Chinese Sea, and called bima- culatus by Herbst in 1790, and mammuillaris by Fabricius in 1793. Herbst, whose specific name must prevail, says that ‘ without dispute this crab is one of the most beautiful and most rare.’ 126 A HISTORY OF RECENT CRUSTACEA Family 2.—Matutide. The characters are the same as in the Calappida, ex- cept that the third maxillipeds have the three terminal joints concealed beneath the triangular acute fourth joint. The family contains four genera. Matita, Fabricius, 1798, is regarded as the genus among the Brachyura in which the adaptation for swim- ming attains its highest development. In the last pair of legs the oval terminal joint is supplemented by a very broad expansion of the preceding joint. Moreover, the other three pairs of legs are natatorial, having broad flat- tened joints, in particular the pair next the chelipeds evi- dently forming paddles of great power. Nevertheless, none of these limbs are fringed with hairs, the ordinary armature of swimming legs. The sufficient reason as- signed for this is that the crab’s safety often depends upon the extraordinary rapidity with which it can bury itself in the wef sand. Its flattened joints have sharp points and edges, with the digging powers of which any fringe of fur would seriously interfere. As it is, they can slip themselves under the sand in a moment, and before the troubled water has cleared over their departing footsteps the traces of them are smoothed and lost. Yet sometimes, itis said, their movements may be perceived under the feet of a person walking along the shore. Among the Japanese specimens of Matuta victor, Fabricius, de Haan observed some of what he calls ‘spurious females,’ but he mentions no peculiarities in them except their smaller size. If Paulson’s identification be right, the name of this species should become Matuta lunaris (Forsk&l.) Hepitus, Latreille, 1806, has, according to de Haan, the third joint much shorter than the fourth in the third maxillipeds, whereas in Matuta those two joints are equal in length. Hepatus princeps (Herbst) appears to be, the proper name of the type species, which occurs both in the Kast and West Indies. This genus, and with it Osachila, BEAUTIFUL COLOURING 127 Stimpson, and Actwomorpha, Miers, are distinguished from Matuta by having the terminal joints of the legs adapted, not for swimming, but for walking. Osachila and Actwo- morpha are, according to the author of tke latter genus, perhaps identical. Family 3.—Leucostide. The afferent channels to the branchie open at the antero-lateral angles of the endostome and not behind the pterygostomian regions. The third maxillipeds have the three terminal joints wholly concealed by the triangular fourth joint. The verges of the male are exserted from the sternal plastron. In this family twenty-nine genera are accepted by Miers in 1886. One of them is included in the fauna of Great Britain. Leucosia, Fabricius, 1798, contains numerous species, which occur in the littoral and shallow waters of the Indo- Pacific region. They are often remarkable for the beauty of their colouring, testimony to which is borne in the names of the species, Leucosia splendida, Haswell, and Leucosia pulcherrima, Miers. They have the frontal re- gion of the carapace narrowed and produced anteriorly, and in front of and above the bases of the chelipeds there is a pit defined by a series of granules. This, which is continued as a shallow excavation beneath the postero- lateral margins of the carapace, has received the name of the thoracic sinus. The walking-legs are small, succes- sively shorter from the front to the rear. The pleon of the male in some species has all the segments united ex- cept the first and last, in others the third coalesced with the fourth, and the fifth with the sixth. A figure of Leucosia australiensis, Miers, is given on Plate Il. The type species, scabriuscula, Fabricius, has been transferred to the next genus. Philjra, Leach, 1817, is a genus nearly allied to Leu- cosia, with a similar range, and also containing several species. But, among other distinctions, the ‘front’ is 128 A HISTORY OF RECENT CRUSTACEA broader and not at all prominent, and there is no ‘ thora- cic sinus.’ Philyra piswum, de Haan, is said to be infested, Fie. 9.— Myra fugax (Fabricius) [de Haan]. like Leander squilla and Leander serratus, by a Bopyrus, making the sides of the crab bulbous. De Haan remarks that he never saw the Bopyrus in true females, and that in males they occupy the right side, in spurious females SOMETHING ABOUT SUB-GENERA 129 the left side, of the crab. The parasite referred to would no doubt now stand under some other generic name. Myra, Leach, 1817, is another genus of common occur- rence throughout the Indo-Pacific region, of which the species Myra fugaw (Fabricius) has been frequently re- named. It is remarkable for the great length which the slender chelipeds sometimes attain, and which have caused the Japanese to call it the long-handed crab. Ebalia, Leach, 1817, has an extremely extended range, and includes numerous species, among which several occur in Kuropean seas, and four of them in the waters of Great Britain. These four are Khalia tuberosa (Pennant), Hhalia tumefacta (Montagu), Kbulia Cranchiti, Leach, and Hbalia nuz, Norman. It is curious that Bell, in his ‘ History of British Stalk-eyed Crustacea,’ should have thought it right to follow Leach in calling the first two of these respectively Ebalia Pennantii and Ebalia Bryerit, while he relegated the earlier names to the synonymy. The resemblance which these little creatures, with their legs all tucked up, assume to a rugged little fragment of stone has been already mentioned. Comparing Ebaliw with a genus Philyaia instituted by Bell in 1855, Mr. Miers says :—‘ The genera Ebalia and Phlyxia are now connected by so many intermediate species, that not one of the distinctive cha- racters mentioned by Bell can be regarded as constant. I propose, therefore, to unite these genera, but to separate the species under two primary sections or sub-genera (for which the names Hbalia and Phlyxia may conveniently be retained) as follows :— ‘I. Front slightly concave or truncated, not quadri- dentated (Hbalia).’ This is followed by a list of twenty- Six species. ‘II. Front with four distinct (usually tuberculiform) lobes or teeth, including the tooth at the interior angle of the orbit (Phlyzia).’ This is followed by a list of seven species, in regard to which it is pointed out that all are restricted to Australia. The convenience of having a generic name to indicate so small a mark of separation may well be questioned, but the inconvenience of the sub- 130 A HISTORY OF RECENT CRUSTACEA generic name scarcely admits of question, especially when it leads to the possibility of a creature being called ‘ Ebalia (Phlyxia) wndecimspinosa (Kinahan), var. orbi- cularis, a name which is even then incomplete without the addition of the names (Haswell) Miers, to show that Mr. Miers has made Haswell’s Phlyxia orbicularis a variety of Kinahan’s Hbalia wndecimspinosa. Iza, Leach, 1815, has perhaps, according to Mr. Miers, only one species, though five have been named. This one is the Iva cylindrus (Fabricius), called Iva canaliculata by Leach. It is widely distributed in the Indo-Pacific region, and has a very remarkably shaped carapace, transversely thomboidal or somewhat elliptical, and prolonged at either side into a cylindrical lobe, which is often as long as the width of the main portion of the carapace. Oreophirus, Riippell, 1830, ‘the hill-bearer,’ and Spelcophorus, A. Milne-Edwards, 1866, ‘ the cave-bearer,’ have names referring to the prominences and depressions in the carapace. Family 4.—Dorippide. The afferent channels to the branchie open behind the pterygostomian regions, and in front of the chelipeds. The three terminal joints of the third maxillipeds are not concealed by the fourth joint. The last pair or last two pairs of legs are short and feeble, and raised on the dorsal surface of the carapace. The verges of the male are ex- serted from the sternal plastron. The family includes eight or nine genera, the position of Cyclodorippe, A. Milne-Edwards, being rather doubtful, since in it there are no afferent openings to the branchie in front of the chelipeds. Dorippe, Fabricius, 1798, has a wide range, and in- cludes several species. One of them, Dorippe facchino (Herbst), is found both in the Mediterranean and at Hong Kong. The first two pairs of walking-legs are long, and enable the creature to run fast. The two following pairs are very slender and short. To account for their dorsal position various reasons have been suggested. Herbst LOOKING LIKE A BUFFOON 131 says that the crab can run either way up. Another view is that these hind legs lift foreign objects on to the carapace, male from the inner and outer sides, the left cheliped being the stouter [de Haan]. Fic. 10,—Dorippe japonica, von Siebold, a female specimen, with separate figures, showing the chelipeds of the and a third that they help to repel animals that might otherwise tread on the crab’s back. The specific name which Herbst gave it means a knave, and is its trivial name il 1382 A HISTORY OF RECENT CRUSTACEA among the Italians, in evident allusion to the resemblance it bears to a comic mask. Similarly, Dorippe dorsipes (Linn.) is not inappropriately named by the Japanese ‘ the demon-faced crab.’ Dorippe japonica, von Siebold, repre- sented on the preceding page, is closely allied to Herbst’s Dorippe facchino. Ethisa, Roux, 1828, unlike Dorippe, which usually has the carapace broader than long, in general has the carapace much longer than broad. Miers notices that the species of this genus are the forms which evince the greatest degree of degradation from the Brachyuran type. In other words, they make the nearest approach to the next tribe, which in Mr. Miers’ work is not in- cluded among the Brachyura. Ethusa mascarone, Roux, is a Mediterranean species. - Hihusina, 8. I. Smith, 1884, is closely allied to Ethusa, but distinguished by the form of the first antennz, the basal joints of which are very large and swollen, occupying the whole width of the ‘ front,’ and crowding back the eyes and second antennze into an almost transverse position. The type species, Ethusina abyssicéla, Smith, was dredged off the East Coast of the United States at a depth of about 1,500 fathoms, the members of this genus and Kthusa being those which descend to greater depths in the ocean than any of the Brachyura which we have been hitherto discussing. The species Ethusa granu- lata, Norman, has been transferred to a separate genus, Cymonimus, by Professor A. Milne-Edwards. Cymopolia, Roux, 1828, has for its type species, Cymo- polia Caronit, Roux, from the Mediterranean, but it includes twelve species in all, of which eight have been recently in- stituted by Professor A. Milne-Edwards from dredgings in the Gulf of Mexico and Straits of Florida. De Haan con- sidered that it ought to stand among the Maiacea, but his opinion has not been followed. CASHIERING THE ANOMURA 133 CHAPTER X TRIBE V.—ANOMALA Tue sternal plastron or breastplate is wide. The branchize lie obliquely, and may attain the number of fourteen pairs. The vulvee open-not on the breastplate, but in the bases of the third pair of legs. This tribe of Anomalous Brachyura has long been con- sidered a division of a separate sub-order called the Anomura, meaning Stalk-eyed Crustaceans ‘with un- symmetrical tails.’ To this division the name Apterira was given, to distinguish it from another division called Pterygira. The first name signifies those that have unwinged tails, the second those that have winged tails. The wings referred to are formed by the ap- pendages of the sixth segment of the pleon,; which in the Pterygura are expanded on either side of the telson, but which in the Apterura are not developed. By the transfer of the latter division to the Brachyura its old name becomes unsuitable, since all of that sub-order are apterurous. It contains two legions, the Drominea and Ranininea. Legion 1.—Drominea. The carapace is subglobose or subquadrate, the ‘front’ narrow. The third maxillipeds have the third and fourth joints subquadrangular. The lateral apode- mata! of the trunk are united in a common centre, form- ing a sternal canal. The last pair, and often the last two 1 The apodemata or apodemes are processes formed by an infolding of the cuticle and extending inwards to give surfaces of attachment for the muscles and to assist in protecting the internal organs. 134 A HISTORY OF RECENT CRUSTACEA pairs of legs, are subdorsal in position and of small size. The pleon folds under the trunk. In the female it has five pairs of appendages, of which the first is rudimentary, This legion is divided into two families, the Dromidz and Homolide, the characters of which are here accepted as laid down in Professor J. R. Henderson’s Report on the Anomura of the Challenger. Family 1.—Dromide. The carapace is subglobular, rarely flattened. The eyes are retractile into well-defined orbits. The first an- tenn fold in special fossettes. The fifth and usually also the fourth pair of legs are short, subdorsal in position, and in general prehensile. The vasa deferentia of the male pass through the bases of the fifth pair of legs and form tubular prolongations. The family contains some ten genera, one of which is British. The species, Dr. Henderson says, inhabit shallow water and moderate depths. The majority protect the body by an ascidian, a sponge, or by one of the shells of a bivalve mollusc. Milne-Edwards says that of the four- teen pairs of branchiee! the last two spring from the last two segments of the trunk, which in the Brachyura in general never carry any. He regards two little lateral pieces intercalated between the sixth and seventh seg- ments of the pleon in Dromia as rudiments of the appen- dages of the sixth segment, but that may be regarded rather as a pious opinion than an established fact. Dromia, Fabricius, 1798, almost monopolised the family until it was subdivided by Stimpson into six genera in 1858, this subdivision being grounded chiefly on the disposition of the sternal sulci in the female.? In ) Branchiw are called pleurobranchiss when attached to the pleura or sides of the segment, podobranchiz when attached to the first joint of the limb, arthrobranchiz when they spring from the interarticular membrane between the segment and the limb. * For the structure of these sulci and the correspondence of the ap- pendages on the pleon of the male, see the account in de Haan, Fawra Japonica, Crustacea, p. 105, A MISNOMER AND A MISAPPREHENSION 135 Dromia, as restricted by Stimpson, these sulci are ‘not approximated, only produced as far as the segment which bears the second pair of legs.’ The carapace in this genus is subglobose and usually hairy. Fabricius, in describing Dromia Rumphii as the type species from the East Indies, says that it hides in the sand holding the valve of a shell over its body with its hind feet, and so lies in wait for little fishes. It was called Cuncer dormiu by Linnzeus, perhaps in allusion to the widely prevailing idea that it is poisonous and narcotic. Herbst, for this reason, im- proved the Linnean name into Cancer dormitator, meaning the crab that sends you to sleep, for he rejected a previous improvement of the name into dromia, on the ground that to call it the running crab was to name it quite in contra- diction to its habits. In spite of, or in ignorance of, this criticism, Fabricius converted the specific name dromia into the name of the genus, which holds its ground not- withstanding the inappropriateness to a creature of espe- cially sluggish habits. Dromia vulgaris, Milne-Edwards, is sometimes taken in English waters. It is very common in the Adriatic, and according to Stalio the ancients were quite mistaken in attributing to it a poisonous character. Herbst seems to have thought the Dromia Rumphii ‘by the hand of nature marked, quoted and signed, to do a deed of shame,’ for, after describing its rough, brown, furry coat, its short, thick legs, and the last pair armed with sharp-pointed claw like a scorpion’s tail, he adds that ‘ everything con- tributes to give this crab a repulsive and horrible appear- ance, perhaps to scare men from eating it, since it is very poisonous.’ He subsequently noticed that when stripped of its fur it lost its grimness of aspect. The habit of concealment that runs through this family is referred to in several of the generic names, as in Cryptodromia, Stimpson, 1858, the concealed Dromia, in Hypoconcha, Guérin Méneville, 1854, the crab under a shell, in Concheecétes, Stimpson, 1858, the shell-dweller. Among the Crustacea collected a few years back by Surgeon-Major Archer on the sand and mud banks north 136 A HISTORY OF RECENT CRUSTACEA of Singapore, there were, he says, ‘two species with curved hooks on their hindmost claws, by means of which they hold on to a mangrove-leaf or a dead valve of a shell which conceals the animal from view; these leaves and dead valves may be seen apparently walking along on the shore.’ The species in question are supposed by Mr. A. O. Walker, in his account of the collection, to be Dorippe sima, Milne- Edwards, Dorippe astuta, Fabricius, and Concheecetes conchi- Jera (Haswell). Bell says of numerous young specimens of Dromia vulgaris, which he had received from Sicily, that every one had the carapace entirely covered with a sponge, which concealed the two hinder pairs of legs, and rendered them immovable. In Cryptodromia lateralis (Gray), a species which ranges from Australia and New Zealand to the coasts of Japan, the animal is said to have almost invariably a sponge fixed on the carapace, covering it completely. Hypoconcha sabulosa (Herbst), besides protecting itself with the shell of a Lamellibranch mollusc, perhaps wears an inner vest of sand, for the museum speci- men which Herbst examined was, he says, more like a lump of sand than a crab, and the carapace he found was extremely thin, delicate, and almost membranaceous. In this genus the sternal sulci of the female are widely separate, ‘each terminating in a tubercle opposite the basal joint of the second ambulatory leg.’ The terminal joints of the last two pairs of legs are described as Y- shaped, but 1t must be remembered that the two arms of the Y are by no means equal. Petaloméra pulchra, Miers, a Melanesian species of very small size, may be noticed as one member of this family which has obtained the epithet of beautiful, although in general figure it is not so very remote from the Dromia of which Herbst speaks so disrespectfully. Dynomene, Latreille, 1825, is distinguished from the rest of the family by having only the fifth pair of legs sub- dorsal in position. “Ad UuUeBH 2p ‘BPIIBA Bl] | edzpey APPEARANCES DECEPTIVE 137 Family 2.—Homolide. The carapace is quadrangular or subtriangular. The eye-stalks are usually slender and very long, the orbits very incomplete. The first antennz are not retractile into special fossettes. The last pair of legs are small, pre- hensile, subdorsal in position. The family may include five genera. The species ex- tend to moderate depths. Dicranodromia, A. Milne-Edwards, 1880, is what is called an inosculant genus. By the character of the last two pairs of legs it should belong to the Dromide, but the defective orbits and the want of fossettes for the first antenne place it among the Homolide. Homéla, Leach, 1815, has the carapace quadrilateral, of greater length than breadth. The eye-stalks have a long slender basal part and a shorter dilated corneal por- tion. The chelipeds are of moderate size, the three follow- ing pas of limbs are long and flattened, while the last pair are short and subchelate. Homola barbata (Herbst) and Homola Cuvieri, Risso, occur in the Mediterranean and Atlantic. Homola orientalis, Henderson, is a Pacific species. Latreillia, Roux, 1828, has a triangular carapace. The eye-stalks are very long and slender, cylindrical, turned forwards, and divergent. The legs are slender and cylin- drical, the three middle pairs being very long. The four species belonging to this genus are apportioned two to Japan, one to Australia, and one, Latreillia elegans, Roux, to the Mediterranean and Atlantic. The figures in Plate V. represent the Japanese Latreillia valida of de Haan, from whose work they are copied on a reduced scale. At the first glance any one would be tempted to place the genus among the spider-crabs in the tribe Oxyrrhyncha, but de Haan showed the impropriety ofthis. ‘The same struc- ture,’ he says, ‘which prevails in Dromia and Homola is found in the species of Lutretllia. They agree in the organs 138 A HISTORY OF RECENT CRUSTACEA of feeding, motion, and generation, and in the fabric of the trunk within. The vulve are not in the trunk, but in the bases of the third pair of legs. The sternum is deeply ex- cised between the last pair of legs; the turkish saddle! and median apodeme are wanting; the transverse septum of the apodemes forms in the middle a central yoke and central canal. Further, they show a peculiar affinity to Homola by the eye-stalks, which are very long, thin, apically inflated, as good as free,? by the first antennze not retractile into fossettes, by the first and third mazxillipeds, which so agree in the two genera that they can scarcely be distinguished. With the Maiacea, therefore, Latreillia cannot be confounded, although the form of the trunk is triangular, the legs are very slender, the epistome is qua- drate, and of the branchie there are ten pairs, of which three are connected with the maxillipeds, two with the chelipeds, and three with the following legs, but the last united with the penultimate legs.’ Latreillopsis, Henderson, 1888, with a type species, Latreillopsis bispinosa, from the Philippine Islands, ‘ occu- pies an intermediate position between the genera Homola and Latreillia. From Homola it is distinguished by the arrangement of the rostrum and supraorbital spines, the greater length of the ocular peduncles, and more especially by the elongated cylindrical legs. In Latreillia, on the other hand, the frontal region is narrow and produced so as to give the carapace a triangular outline, the supra- orbital spines are more strongly developed, and the eye- stalks and legs are of greater length.’ It may perhaps be regarded as something more than a mere coincidence that this link between Homola and Latreillia was obtained by the Challenger in one of the two localities in which the same vessel took specimens of those two genera. Homologénus, A. Milne-Edwards, 1888, bears a name altered from the pre-oceupied Homolopsis, 1880. It differs ' The expression ‘posterior turkish saddle,’ is applied by Milne- Edwards to the small arch formed by the sternal apodemes which spring from the hind margin of the last segment of the trunk. ? The Latin is tutis quantis liberis. THE RANININEA 139 from Homola in having a more ovoid carapace, a more de- veloped rostrum, feebler Jegs, and especially in the form the eyes which are very small and not narrowed at the ase. Here also should perhaps be placed some Australian species of the genus Paratymolus, Miers, 1879, in which the carapace is deflexed in front, flat behind, with the sides nearly straight, the ‘front’ being prominent and narrow. For a new family Paratymolide Mr. Haswell gives the characters, ‘carapace in general form similar to the Maioidea. External maxillipedes partly over the epi- stome.’ He thinks that it would perhaps be better placed among the Corystoidea. Mr. Miers, however, does not agree with this view, but thinks that it ought to stand near the Dromide. It is an argument the more for in- cluding the present tribe in the Brachyura, that two experts should be unable to agree whether a genus belongs to it or another tribe which is brachyuran beyond question. Legion 2.—Ranininea. The carapace is ovate-oblong, with the regions not defined, and the ‘front’ of varying width. The orbits are well marked. The first antennee are without special fossettes, and are placed to some extent behind the second pair. The third maxillipeds are moderately elongate. The sternal plastron or breastplate is wide anteriorly. The walking-legs have the terminal joint broad and com- pressed ; the last pair of legs are small and subdorsal in position. The vasa deferentia of the male are protruded. The pleon is short, partially extended, not folded under the trunk, with four pairs of appendages in the female. Dr. Henderson includes the epithet ‘smooth’ in the description of the carapace, but this is obviously unsuited to Ranina scabra. Dr. Boas has ingeniously suggested that the position - of the vulvz in the bases of the legs instead of in the sternal plastron has been brought about by the extreme narrowing of the plastron, and this may well have been 140 A HISTORY OF RECENT CRUSTACEA so, though such a species as Petalomera pulchra in the pre- ceding legion does not seem to suit the theory. One may, however, suppose that in some instances a re-widening of the plastron may have been developed without any re- arrangement as to the position of the vulve. This legion contains the single family Raninide, for which, therefore, no separate character is needed. It includes some nine genera, limited to the warm seas, and inhabiting chiefly the tropics, with a range of depth apparently not exceeding 300 fathoms. Ranina scabra (Fabricius), originally called Cancer raninus, Linn., and afterwards Ranina serrata, Lamarck, and Ranina dentata, Latreille, from Amboina and the Sand- wich Islands, was known to fame long before a separate genus was established for it. The carapace has been com- pared to an inverted triangle. Itis very broad anteriorly, but the sides slope very gradually to the rounded hinder margin. The eye-stalks are three-jointed, strongly geniculate, and have a very deep orbit. The pterygostomian regions of the carapace unite with the sternal plastron so as completely to separate the third maxillipeds from the chelipeds. The plastron itself is anteriorly almost trefoil-shaped, but to the rear becomes linear. The branchiz, Milne-Edwards says, are arranged as in the Brachyura, but in the confor- mation of the respiratory cavity there is a peculiarity of which he knew no other example. As in the Leucosiidz, the carapace is joined to the sternum and the cavity of the sides, without leaving above the base of the feet or maxil- lipeds any space for the entrance of the water necessary for breathing, but the afferent channel instead of being pierced beside the efferent channel, on the sides of the mouth, is situated behind and has a special opening below the base of the pleon. This view, however, is criticised by de Haan in a passage that is not free from perplexity. ‘In Portunus and Grapsus,’ he says, ‘the water is brought to the branchiz by a double path and removed by a double path ; it reaches the branchial cavity by the mouth and the apertures near the base of the chelipeds; but it passes out both by the space between the inferior lateral margin A DISCUSSION ON BREATHING 141 of the trunk and the epimera and by two ducts under the insertion of the pleon. In Hihusa the case is the same. Fig. 11—Ranina scabra (Fabricius), a male specimen, with separate figure of the pleon [de Haan]. In Calappa and Matuta the hinder ducts are not below but close to the pleon over the first joints of the fifth pair of 142 A HISTORY OF RECENT CRUSTACEA legs. In Dorippe, Leucosia, and Ranina, the lower border of the trunk closely coheres with the epimera (compare Milne-Edwards, vol. 2, p. 193). In the first the anterior apertures, in which the first joints of the third maxillipeds work, are remote from the base of the chelipeds; but in the following they are altogether wanting; so that these have only one path on each side by which the water reaches the branchiz, aud one by which it is withdrawn. The hinder ducts in Ranina are broader than in other families and amplified by lateral apophyses, but otherwise in Portu- nus and Grapsus they are in the same place. The water appears to enter the branchial cavity by the anterior aper- tures, and to issue by the hinder ones, and not to have a diverse or in Ranina and Leucosia a contrary motion (compare Milne-Edwards, vol. 1, p. 88, vol. 2, p. 194). In the anterior part there is a force, namely the movement of the maxillipeds, by which the water is brought in ; that being expelled behind, follows the movements of the body ; the apertures beside the base of the chelipeds and the branchial appendages of the maxillipeds are ciliated on the margin, and by these cilia alien bodies are kept away from the branchiz, when water is brought to them from in front, whereas [they would be] of no use but a hindrance to breathing, were the water brought from behind.’ Fritz Miller refers to the statement made by Milne- Edwards about the breathing arrangements of Ranina, but does not mention de Haan’s contrary opinion. Fritz Miller himself unfortunately had not had an opportunity of per- sonally investigating the question Judging from Milne- Edwards’ figure of Ranina dentata, it would appear to have an arrangement of the pterygostomian regions not unlike that already described in the genus Sesarma, by which the crab when on dry land is enabled for a long time to go on breathing the same small stock of sea-water. Such an arrangement would undoubtedly be convenient for the Ranina, if the story be true that it has a decided propensity for climbing on to the roofs of houses. Milne- Edwards attributes this story to Rumphius, but nothing of the kind appears to be included in that author’s account DOG-CRAB AND FROG-CRAB 143 of his Cancer raniformis, though in the next preceding description he tells of a swift-running ‘ dog-crab,’ Cancer caninus, which is said to burrow under houses and enter them. When the limbs of Ranina are drawn together it is said to look not unlike a frog, a resemblance to which the generic name points, as well as the trivial name of frog- crab, and the specific name raniformis given it by Rumphius. Eaninoides, Milne-Edwards, 1837, is nearly allied to Ranina, but has the last pair of legs very short and thread- like instead of equal in size and similar in shape to the preceding flattened pair. In Raninoides personatus, Hen- derson, the pterygostomian areas are described as being strongly granulated as well as slightly pubescent, and the same is said of the type species of a new genus, Notopoides latus, Henderson, 1888. In the female of this species there is an ovoid median opening in the sternum, between the third and fourth pairs of legs. Raninoides personatus has a similar opening but of very small size. The function of these apertures does not appear to have been ex- plained. Notépus, de Haan, 1841, includes several species, in which the last pair of legs are of moderate size, not fili- form. As the name of the genus implies, their position _ is dorsal, and this, though a character common to the family, is again emphasised in the specific name of Notopus dorsipes (Fabricius). Of a crustacean allied to this, Darwin, in his ‘ Naturalist’s Voyage,’ gives the following account :—‘ During our different passages,’ he says, ‘south of the Plata, I often towed astern a net made of bunting, and thus caught many curious animals. Of Crustacea there were many strange and undescribed genera. One, which in some respects is allied to the Notopods (or those crabs which have their posterior legs placed almost on their backs, for the purpose of adhering to the under side of rocks), is very remarkable from the structure of its hind pair of legs. The penultimate joint, instead of ter- minating in a simple claw, ends in three bristle-like appendages of dissimilar lengths—the longer equalling 144 A ILISTORY OF RECENT CRUSTACEA that of the entire leg. These claws are very thin, and are serrated with the finest teeth, directed backwards: their curved extremities are flattened, and on this part five most minute cups are placed which seem to act in the same manner as the suckers on the arms of the cuttle-fish. As the animal lives in the open sea, and probably wants a place of rest, I suppose this beautiful and most anomalous structure is adapted to take hold of floating marine animals.’ Iyreidus, de Haan, 1841, has the eye-stalks short and the orbits are ill-defined, which is contrary to the family character. The genus was originally instituted for Lyrei- dus tridentatus, the lyre-shaped crab of Japan. That species has been traced southwards to Australia; another species, Lyreidus Bairdi, 8S. I. Smith, has been found off the east coast of the United States. Zanclifer, Henderson, 1888, has the eyes rudimentary, with corneee of small size though pigmented, on short peduncles, in ill-defined orbits. The first antenne are small, completely concealed by the massive pedun- cles of the second pair, which meet together in the middle line. The name means sickle-bearing, in allusion to the uncinate character of the terminal joint in the walk- ing-legs. There is at present only one species, Zanclifer caribencis (de Freminville), and of this only . ; two specimens are known. One ee anvils Hicwiee of these, the figure of which is here reproduced, was obtained. by the Challenger off the coast of Brazil, the other was taken more than forty years earlier by M. de Freminville in the Caribbean Sea. The French captain described it under the name of Eryon caribensis, thus referring it to a fossil genus with which it has nothing to do, and making im- portant mistakes in the description which were pointed A RARE SPECIES 145 out by Milne-Edwards a few years afterwards. Dr. Hen- derson was only able to identify the Challenger specimen with de Freminville’s by help of a pencil-drawing pointed out to him by Professor Alphonse Milne-Edwards in the library of the Natural History Museum at Paris. The elder Milne-Edwards, though assigning the species to the vicinity of the Raninide, did not alter the generic name. Judging by the rudimentary nature of the eyes and the structure of the limbs, Dr. Henderson conjectures that this crustacean may be fossorial in habit. If it be so, the rarity of its capture would be the less to be wondered at. To one of the genera of this family may probably be assigned the West-Indian crab, which for some inscru- table reason has been called the Mamma Shrimp. It is figured and described by Patrick Browne in his ‘ History of Jamaica.’ Herbst (Bd. I., p. 196), in 1790, supposed it to be a near relation of Corystes cassivelaunus, but this notion is based only on a very slight superficial resem- blance between the two species. Since Ivreidus and Zanclifer agree in having the orbits ill-defined, the statement that in this legion ‘the orbits are well marked’ is too absolute. In the defini- tions of natural history, where living things are con- cerned, almost every assertion sooner or later requires to be qualified by the adverb ‘ usually.’ 12 146 A HISTORY OF RECENT CRUSTACEA CHAPTER XI SUB-ORDER II.—MACRURA TE carapace in general is shorter than the pleon and has the ‘front’ produced into a more or less decided rostrum. The stalked eyes are not enclosed in orbits, but usually rest in a hollow on the upper surface of the basal joint of the first antenne. Both pairs of antennz are generally elongate, the first not planted in fossettes, the second usually carrying a scale or acicle attached to the second joint. The third maxillipeds are elongated and pediform. The five pairs of peraeopods or limbs of the trunk vary greatly, as any of them may be chelate and any of them simple. ‘The sternal plastron or breastplate is linear in general. The vulvee of the female open in the basal joints of the third pair of legs, and the vasa deferentia of the male pass through those of the fifth pair. The pleon is seldom completely reflexed against the breastplate. Of the six pairs of pleopods the first varies from the succeed- ing, and all may be absent; but except in the Lithodide that belonging to the sixth segment is always present, this pair with the telson forming the Rhipidura or tail-fan. Otoliths of some kind are very commonly present in the basal joint of the first antennee. In the above definition the Pterygurous division of Milne-Edwards’ Anomura is included. After explaining the grounds upon which Milne-Edwards had introduced his tripartite arrangement, de Haan makes the following comment upon it:—‘The division of the Decapoda into Brachyura and Macroura is for various reasons to be pre- REVIVAL OF AN EARLIER VIEW 147 ferred. The Anomoura are not distinguished from the Brachyura and Macroura by any common character; from the former they differ by the disposition of the vulve, from the latter by not having a fan-shaped termination to the pleon. But all the organs vary extremely in the Anomoura, and no bond of connexion between the Apte- rura and Pterygura is found either in the shape of the antenne, mouth, maxillipeds, trunk, plastron, branchia, or in that of the pleon. The Anomoura contain forms which differ more from one another, than the Brachyura do from the Macroura. By the Anomoura the closest re- lationships are torn asunder, as the Dromiacea from the Maiacea, the Raninoidea from the Leucosiw, the Porcel- lanidea from the Galathes, the Megalopidea from the Astacoidea.’ This criticism, published in 1841, appears now to be winning deserved acceptance. The recent researches of M. F. Mocquard into the armature of the stomach also show the Anomura to be an artificial division. With the transfer of the Pterygura to the Macruran sub-order, in which all the families are pterygurous, the name becomes inappropriate and may give place to the older name Anomala, used by Latreille, though in a narrower applica- tion. Any slight inconvenience that may result from the similarity of name between the Brachyura anomala and Macrura anomala will be compensated by the reminder thus supplied that these two tribes correspond with the collective Anomura of Milne-Edwards. The Macrura contain the following tribes :—Anomala, Thalassinidea, Scyllaridea, Astacidea, Stenopidea, Penzi- dea, Caridea, among which will be found along with others those popularly well known as Hermit Crabs, Lobsters, Crayfishes, Prawns, and Shrimps. The following Table shows the subdivision of the tribes into legions and families :— 148 Tribes. Anomala . Thalassinidea Scyllaridea Astacidea . Stenopidea Pensidea . Caridea . MAcRura Legions. Hippinea . Lithodinea Pagurinea . Porcellaninea Galathciaca Crangoninea Polycarpinea Monocarpinea Haplopodinea A IIISTORY OF RECENT CRUSTACEA Families. « s Hippide. 1 Aipimetdes: . Lithodide. Coenobitidee, . | Paguride. Parapaguridz., Porcellanide. . Galatheide. Thalassinide. Callianassidee. *) Axiide. Thaumastochelide. {Seyland. * | Palinuride. Eryontide. Nephropsidz. Potamobiide. Parastacide. . Stenopide. { Penzide. ’ ( Sergestidee. » Crangonidz. Nikide. J Alpheidz. Hippolytide. Pandalide. Thalassocaridze Atyide. Pontoniide. Caricyphidez. Acanthephyride. az Palemonide. Nematocarcinide. Tropiocaride. (?) Stylodactylide. Pasiphzeidee. Oodeopidze. - Hectarthropida, MACRURA ANOMALA 149 TRIBE I.—ANOMALA. The pterygostomian regions are free from the epistome and marked off from the back by a suture or continuous furrow. The fifth pair of legs are generally weak, not fit either for walking, swimming, or grasping food and prey. The tribe embraces five legions, Hippinea, Lithodinea, Pagurinea, Porcellaninea, Galatheinea. Legion 1.—Hippinea. The carapace is ovate or subquadrate, comparatively smooth, the regions ill defined, the ‘ front’ broad. The corneze of the eyes are small. The first antennae are in general strongly developed, with one flagellum elongate, the other of moderate size or absent. The second antenne have usually a short flagellum and a massive peduncle of four or five joints, with or without a movable acicle on the second. The third maxillipeds are moderately broad, sub-operculiform. The walking-legs have a flattened terminal joint. The fifth pair are slender and filiform and folded under the preceding pair. The sterna of the trunk are linear. The pleon is partially extended, with the tel- son large, longer than broad, and the preceding segment carrying a pair of biramous lamellar appendages, not so arranged as to form a rhipidura. The males have no appendages to the pleon but those of the penultimate segment. The members of this legion inhabit the shallow waters of tropical and subtropical seas. They are divided between the two families of the Hippide and Albuneide. Family 1.—Hippide. The third maxillipeds are sub-operculiform, with a brcad fourth joint; the exopod is wanting. The first pair of legs are sub-cylindrical and not chelate. The telson is elongate, lanceolate. This family includes three genera. Hippa, Fabricius, 1793, has been much restricted since it was first instituted. It is now especially distinguished 150 A HISTORY OF RECENT CRUSTACEA from its companions by the large and long flagellum of the second antennee. J/ippa emeritus: (Linn.) is regarded by Mr. J. E. Ives as a very variable species widely distri- buted on the east and west coasts of North and South America. Itis used, he says, by the fishermen for bait, and large numbers are dug from the sand. It is not un- likely, as suggested by Milne-Edwards, that Hippa tal- poida, Say, the ‘ mole-like’ Hippa, is the same species. It was upon this that Professor 8. I. Smith made his obser- vations at the United States’ Biological Station at Wood’s Hole, Massachusetts, in the summer of 1875. He was there able to obtain a nearly complete series of the post- embryonal stages, and has since elaborately described the second, third, and last zoéa forms, and the succeeding me- galopa condition. Some of his figures are reproduced on Plate IV. He observed that the adults preferred a very narrow zone of the shore, at or very near low-water mark, where they lived gregariously, burrowing in the loose and changing sands. ‘The smooth, oval form of the animal,’ he says, ‘ with the peculiar structure of the short and stout second, third, and fourth pairs of thoracic legs, enables them to burrow with far greater rapidity than any other crustacean I have observed. Like many other sand-dwelling crustaceans, they burrow only backwards; and the wedge-shaped pos- terior extremity of the animal, formed by the abrupt bend in the abdomen, adapts them admirably for movement in this direction. When thrown upon the wet beach, they push themselves backward with the burrowing thoracic legs, and by digging with the appendages of the sixth segment of the abdomen slightly into the surface, direct ce aa extremity of the body downward into the sand.’ The second antennz are generally held between the second and third maxillipeds, with the peduncles crossed in front, and the flagella curved down and entirely round the mouth so that the setee with which they are densely armed all project inward. Their function is not un- reasonably supposed to be that of removing objectionable WEAK JAWS 151 particles from the other appendages within their reach. For this brushing service they must be well adapted, since in ordinary adult specimens there are from a hun- dred to a hundred and fifty joints in the flagellum, and from eight to twelve setae to each joint. Most of these setee are only slightly bent, but armed on the outside of the curve with a great number of variously shaped teeth. On either side of each bundle, however, there is a very long seta, convolutely curved inward at the extremity, and along nearly its whole length densely furnished with long, slender, secondary sete, arranged in a double series on the inner side of the curve. Already in the megalopa stage, Professor Smith found that the mandibles had become thin and foliaceous and completely consolidated with the walls of the oral opening. This extremely unusual condition of those organs persists in the adult, and seems to have per- plexed the few naturalists who have earlier examined them. It must be a subject of surprise that a crustacean of such a family as this should be able to dispense with the biting power usually so strongly developed in the mandibles. But_ we are told that in all specimens examined the alimentary canal was filled with fine sand, and as the material from the stomach showed under the microscope a small quantity of vegetable matter, the inference is not improbable that, much after the fashion of the earthworm, the creature ob- tains nutriment from the sand which it passes through its body. Milne-Edwards was evidently under the impression that the true second segment of the pleon in this genus was its first segment, but Professor Smith has shown very clearly that the first pleon-segment is in the adult coalesced with the trunk, a thing very unusual but none the less in this case quite to be depended on. Remipes, Latreille, 1806, has the peduncle of the second antenne large, but the flagellum quite small. The first segment of the pleon is free, the telson lanceolate, of great length. As in Hippa, the female carries appendages on the second, third, fourth, and sixth segments of the pleon. The founder of the genus and several writers since have supposed the first pleon-segment to be the last segment of 152 A HISTORY OF RECENT CRUSTACEA the trunk, a mistake which Professor Smith has now cor- rected. Remipes testudinarius, Latreille, has been recorded by this and various other names from many parts of the Indo-Pacific region. Its true name would seem to be Remipes adactylus (Fabricius). Remipes scutellatus (Fabri- cius) is found in the Atlantic. Mastigochirus, Miers, 1877, meaning ‘ with a whip-like hand,’ was previously called Mastigépus by Stimpson in 1858, but the name being pre-occupied had to be changed. Its chief distinction from Hemipes rests on the form of the long and slender first pair of legs, which have the terminal joint subdivided. The type specimen of Mastigochirus quadrilobatus, Miers, came from the Philippine Islands. A comparison of this with others subsequently obtained by the Alert in the Prince of Wales’ Channel showed Mr. Miers that ‘the number of joints in the terminal flagelli- form portion of the anterior limbs (which are imperfectly seen on account of the hairs with which they are thickly clothed) was understated in the original description ; in- stead of being ten or twelve, they are usually twice as numerous.’ Family 2.—Albuneide. The third maxillipeds are subpediform, with the fourth joint not greatly dilated; there is a small exopod. The first pair of legs are flattened and chelate. The telson is ovoid. Albunea, Fabricius, 1798, has for its type species the little Albunea symnista (Linn.), from eastern waters. The carapace is strongly grooved behind for the reception of the small first segment of the pleon. In Milne-Edwards’ ‘ Histoire Naturelle des Crustacés,’ vol. 2, p. 202, the dis- tinguishing characters of Remipes and Albunea are trans- posed, but the error is subsequently corrected. Legion 2.—Inthodinea. The carapace is broadly ovate, uneven, with the regions well defined and a prominent rostrum. The first antennz have cylindrical peduncles of moderate size and short uBeH op ‘XI4ys!y S@pourtT GLOBE-TROTIERS 153 flagella, The secoud antennz have an acicle on the second joint. The third maxillipeds are subpediform, with the third and fourth joints elongate. The first: legs of the trunk are chelipeds ; the three following pairs are well de- veloped, more or less cylindrical, and the last pair are slender, chelate, folded in the branchial chambers. The sternal plastron is wide. The pleon is bent under the trunk, having the first segment small and dorsally fused with the second; it has appendages only in the female, these being a rudimentary pair on the first segment, and, as a rule, a single one-branched appendage on the left side of each of the four following segments. The single family Lithodide has the characters of the legion. The members of it are found in the cold and tem- perate shallow waters of both hemispheres, but deep-sea dredgings, especially those of the Talisman, have shown that at great depths, even below a thousand fathoms, species occur in the tropics. Thus, it has been pointed out, the Arctic and Antarctic zones are connected by a submarine tunnel of cold water. The genera are not very numerous. One is found in the waters of Great Britain. Inthodes, Latreille, 1806, is now represented by several fine species from distant parts of the world. Lithodes maia (Linn.) has long been known. It is the devil-crab of the Norwegian fishermen, according to Herbst. Bell calls it the Northern Stone Crab, and is surprised that what he calls its slight resemblance to Maia squinado should have caused it to be at times confused with that species. The superficial resemblance, however, is not in- considerable, when the dorsal view alone is regarded. The ventral view permits of no confusion or mistake, for in Inthodes the pleon has in the third, fourth, and fifth segments paired calcified plates, the median portion being membranous with scattered calcareous particles. In the female the plates are greatly developed on the left side to the disparagement of those on the right, producing a want of symmetry akin to that which is found in the Paguride. The rostrum in Lithodes is spinulose, like almost all the other external parts of the animal. Lithedes histriw, de 154 A HISTORY OF RECENT CRUSTACEA Haan, portrayed in the adjoining Plate, is called by the Japanese Aka-oni-gani, which according to de Haan means the red crab of the devil. Lnthodes Agassizit, Smith, has been taken in the Atlantic from depths of a thousand and twelve hundred and fifty fathoms. Lithodes Murray:, Hen- derson, was obtained in the Southern Ocean from three hundred and ten fathoms depth. Cryptolithodes, Brandt, 1849, with its species Crypto- lithodes typicus, Brandt, from California, is especially dis- tinguished by the great development of the carapace, which completely hides the legs, antenne, and pleon, and these when viewed from below appear to be placed in the bottom of a cup-like cavity. According to Stimpson, this development of the carapace is unequalled in any even of the higher decapods, not excepting Cryptopodia and Chthra, and this is the only instance in which the carapace con- ceals all the feet. Echidnocérus, White, 1848, contains one or two mas- sive species from the West Coast of America, the carapace in Echidnocerus setimdnus (Gibbons) sometimes measuring ten inches in length and as many in width, and by a weight of over seven pounds exceeding that of the cara- pace even of the giant Macrocheira of Japan. Lomis, Milne-Edwards, 1837, has a very small rostrum, consisting of a single tooth. The little Lomis dentata is described by de Haan from Japan. Its carapace about half an inch in diameter forms a strong con- trast to the preceding species. Fic. 13.—Lomis den. Paralomis, Stimpson, 1858, has a ros- ‘aa (de Naan}. trum which is usually trispinose, and in this genus the third, fourth, and fifth segments of the pleon in the female have the lateral plates subequal, and the median portion occupied by a series of large calcareous plates instead of particles. Hapalogaster, Brandt, 1851, has the appendages of the second pleon-segment in the female biramous instead of one-branched as in the other Lithodidw. Its second antenne are much longer than the carapace, as in Porcel- RANGE OF THE HERMIT-CRABS 155 lana. The pleon is soft as in a hermit-crab, but re~- flexed. That the fifth pair of legs in the crustaceans of this family should be folded in the branchial chambers must seem a very strange arrangement, unless consideration is directed to the advantage which may thus be attained in keeping the branchiee clear from parasites. Legion 2.—Pagurinea. The carapace is elongate, becoming weak or membra- naceous behind the cervical groove, which divides the gastric and hepatic regions from the cardiac and branchial. The second antennz have an acicle. The third maxilli- peds are subpediform, with the third and fourth joints elongate. The chelipeds and two following pairs of legs are well developed, the last two pairs are small, one or both being usually chelate. The sternal plastron is linear. The pleon is spirally twisted or extended; the tergal ele- ments are as a rule rudimentary. There is generally a single biramous appendage to the second, third, fourth, and fifth segments of the pleon on the left side, the first three of these being well-developed and ovigerous in the female. The sixth segment in both sexes has a pair of appendages. Common as the Hermit-Crabs are between tide-marks, they are also found in depths of over two thousand fathoms. The legion contains three families, the Cenobitide, Pagu- ride, and Parapaguride. The first two of these families are phyllobranchiate, that is, have the branchial plumes formed by a series of foliaceous plates, whereas the third family is trichobranchiate, having the branchial plumes made up of long cylindrical filaments. Fumily 1.—Cenobitide. The first antenne have a very elongate peduncle, its first joint deflexed and as long as or longer than the eye- stalks, the second and third joints narrow and cylindrical ; one of the flagella enlarged. In the second antenne the 156 A HISTORY OF RECENT CRUSTACEA peduncle is compressed, the terminal joint long. The branchial plumes are laminar. The species are partially terrestrial. The family in- cludes two well-known genera. Birgus, Leach, 1815, is a genus of eminent distinction. The broadly ovate carapace covers large branchial cham- bers, of which, however, the fourteen pairs of small branchiz only occupy a small fraction, but on the other hand, in evident adaptation to an aerial life, the lining membrane of the chambers is covered with vascular pul- monary outgrowths. The pleon is not twisted. It is very broad. Dorsally its first segment is represented by a corneous band, as the four following are by four corneo- calcareous overlapping plates, flanked by small corneous pieces which seem to represent the side-plates. The second, third, and fourth segments have a large biramous appendage on the left side, but only in the female. All the underside of the pleon is membranous, until a quadri- lateral plate is reached which represents the sixth segment and which gives attachment to a rudimentary appendage on each side and to the terminally rounded telson. The account given by Darwin of that which is probably the type and perhaps the only species of this genus is too interesting to be omitted. When treating of the Coral Islands of the Pacific, he says:—‘I have before alluded to a crab which lives on the cocoa-nuts: it is very common on all parts of the dry land, and grows to a monstrous size ; it is closely allied or identical with the Birgos latro. The front pair of legs terminate in very strong and heavy pincers, and the last pair are fitted with others weaker and much narrower. It would at first be thought quite impossible for a crab to open a strong cocoa-nut covered with the husk; but Mr. Iiesk assures me that he has re- peatedly seen this effected. The crab begins by tearing the husk, fibre by fibre, and always from that end under which the three eye-holes are situated; when this is com- pleted, the crab commences hammering with its heavy claws on one of the eye-holes till an opening is made. Then turning round its body, by the aid of its posterior THE COCOANUT-CRAB 157 and narrow pair of pincers, it extracts the white albumin- ous substance. I think this is as curious a case of instinct as ever I heard of, and likewise of adaptation in structure between two objects apparently so remote from each other in the scheme of nature, as a crab and a cocoa-nut tree. The Birgos is diurnal in its habits; but every night it is said to pay a visit to the sea, no doubt for the purpose of moistening its branchiz. The young are likewise hatched, and live for some time, on the coast. ‘I'hese crabs inhabit deep burrows, which they hollow out beneath the roots of trees ; and where they accumulate surprising quantities of the picked fibres of the cocoa-nut husk, on which they rest as on a bed. The Malays sometimes take advantage of this, and collect the fibrous mass to use as junk. These crabs are very good to eat ; moreover, under the tail of the larger ones there is a great mass of fat, which, when melted, sometimes yields as much as a quart bottle full of limpid oil. It has been stated by some authors that the Birgos crawls up the cocoa-nut trees for the purpose of stealing the nuts: I very much doubt the possibility of this; but with the Pandanus! the task would be very much easier. I was told that on these islands the Birgos lives only on the nuts which have fallen to the ground. Captain Moresby informs me that this crab inhabits the Chagos and Seychelle groups, but not the neighbouring Maldiva archipelago. It formerly abounded at Mauritius, but only a few small ones are now found there. In the Pacific, this species, or one with closely allied habits, is said? to inhabit a single coral island, north of the Society group. T'o show the wonderful strength of the front pair of pincers, I may mention, that Captain Moresby confined one in a strong tin-box, which had held biscuits, the lid being secured with wire ; but the crab turned down the edges and escaped. In turning down the edges, it actually punched many small holes quite through the tin!’ Mr. Boddam-Whetham, in his ‘ Pearls of the Pacific’ (1876), declares that the crab first ascends the tree to push 1 See Proceedings of Zovlogical Society, 1832, p. 17. 2 Tyerman and Bennett, Voyage, Sc., vol. ii. p. 33. 158 A HISTORY OF RECENT CRUSTACEA down a nut, descends to strip it of its husk, and then ‘re- ascends the tree, if the situation is favourable, and holding the nut by a bit of the fibre, which it leaves on for the purpose, it lets it fall upon a rock, or stone, and thus breaks it.’ I could wish that he had spoken of having seen this wonderful manceuvring with his own eyes. Dr. T. H. Streets declares that ‘the wonderful stories about these crabs climbing the trees after cocoa-nuts are purely fictitious.’ Rumphius is the original authority for the statement that these crustaceans in their night ramblings ascend the cocoa-nut palms and appropriate the nuts. It is to their love of that food that they owe the title of the robber-crab. It is said that they can be lured out of their holes by pre- senting to them a cocoa-nut attached to the end of a stick. Rumphius says that this crab in the language of Amboina is named Catattut and Atattut, but that it is familiarly ‘¢ called by his own countrymen ‘ Don Diego in ’t volle har- nasch,’ its Latin name being Cancer crumenatus, of which the Belgic equivalent is Beurs-Krabbe. This title of purse- crab alludes to the packet of fat under the tail, which is accounted a delicious marrow-like morsel by those who like it. The oil from it is, or once was, regarded as a panacea for sprains and contusions. Herbst declares that the claws of the Birgus are so strong that they easily crack a cocoa-nut which a human being could not break open with a stone. He says, moreover, that if they have once seized hold of an object, it is easier to break the claws than to make them let go. Yet what cannot be done by force may be achieved by cunning, forif, he says, you just tickle the creature under the tail, it becomes so irritated that it gives itself a nip on the tail, and dies by its own claw! Herbst wrongly figures the fourth pair of legs as simple, whereas they are, in fact, chelate. The naturalists of the Challenger were informed by an intelligent native at Sam- boangan that the female crab carries about large masses of the eggs with it in the month of May, and retains them so attached until the young are developed just like the parent. At Samboangan it is called ‘Tatos,’ and appreciated es THE PAGURIDE 159 a delicacy. The naturalists visited Santa Cruz-Major in search of it for the curious reason that there are no pigsin that island. ‘ Wild pigs,’ they say, ‘destroy not only these crabs, but dig up Shore Crabs (Ocypoda) and Land Crabs from their holes. In Ceylon, near Trincomali, the wild swine come down every night to the beach to dig up crabs, and large tracts of sandy beach are ploughed up by them in the search.’ Cenobita, Latreille, 1826, while agreeing with the pre- ceding genus in the character of the antennz, approaches the next family in the formation of the pleon. This is soft and membranous and twisted on itself; the dorsal plates are narrow, with appendages to the segments as in Birgus, but those of the sixth segment are well developed and unsymmetrical, the appendage on the left being the larger. The species protect themselves in a variety of shells, and are widely distributed over the Indo-Pacific region, Cenolite rugosa, Milne-Edwards, being within those limits almost ubiquitous. Family 2.—Paguride. The first antennz have a peduncle of moderate size, the first joint short and stout, the second and third slender and cylindrical ; both the flagella are small. In the second antennee the peduncle is sub-cylindrical. The branchial plumes are laminar. The species are marine. The genera in Dr. Henderson's reckoning are nineteen, two or three of which are included in the British Fauna. In fourteen of the genera the pleon is spirally twisted or bent abruptly, soft and membranous, with imperfect segmentation, while in the remaining five it is not spirally twisted, and it has distinct movable segments which are usually cal- cified. Pagtrus, Fabricius, 1798, originally included the whole family of crustaceans that walk about with borrowed shells, though beginning with the above-described latro, which has no such domicile. It is now greatly restricted, and it may be useful to point out some of the characters by 13 160 A HISTORY OF RECENT CRUSTACEA which this genus and some of its immediate neighbours are distinguished from one another. Pagirus (in restricted sense). The ‘front’ without distinct rostral projection. LHye-stalks stout, with basal scales usually wide apart. Acicle of second antenne short and robust, the flagellum long and naked. The third maxillipeds approximate at the base. The left cheliped usually the larger. The fourth pair of legs chelate. Hupagirus, Brandt, 1851. The ‘front’ with a dis- tinct rostral projection. LEye-stalks stout, with basal scales wide apart. Acicle of second antennze long and slender, the flagellum long and naked. The third maxil- lipeds distant at the base. ‘The right cheliped usually the larger. The fourth pair of legs subchelate. Clibanarius, Dana, 1852. The ‘front’ with a distinct rostral projection. The eye-stalks usually slender, with the basal scales close together. Acicle of second antennz short, the flagellum naked. The chelipeds subequal and similar. The fourth pair of legs chelate. Aniculus, Dana, 1852, and Calcinus, Dana, 1852, agree with Clibanarius as above defined, except that Aniculus has the fourth pair of legs subchelate, and Calcinus has the chelipeds very unequal. Diogénes, Dana, 1852. There is a movable rostriform process between the eye-stalks, distinct from the rostrum. The acicle of the second antenne has a broad base; the flagellum is ciliated. The left cheliped is the larger. The fourth pair of legs chelate. When characters are set out in this way, it would seem that there should be little difficulty in determining to what genus a species belongs, but nature does not always lend itself very obligingly to the necessities of classification. Thus, in regard to Pagurus similimdnus, Henderson, its author is obliged to say : ‘The chelipedes are of equal size, and in every respect similar to one another, belonging essentially to the form which is charac- teristic of the genus Clibanarius,’ and presently afterwards, under the species Clibanarius strigimdnus (White), Dr. Henderson observes: ‘As in the case of Pagurus simili- SPECIES RE-ASSORTED 161 manus, this species shares the characters of Pagurus and Chibanarius, though its affinities are more with the latter genus; the chelipedes are subequal, a distinct ros- tral projection is present, and the ocular peduncles are tolerably long and slender; at the same time the ophthal- mic scales are arranged as in Pagurus. He adds that ‘the special features of Clibanarius strigimanus are the curious striated (stridulating ?) areas on the inner surface of the hand of each chelipede, and the narrow and acute terminal portions of the ophthalmic scales.’ In Bell’s ‘History of British Stalk-eyed Crustacea,’ ten species are named and described as belonging to the genus Pagurus, but the majority of them are now differ- ently classified. Thus Pagurus Bernhardus (Linn.) and Pagurus ulidianus, Thompson, both become Eupagurus Bernhardus (Linn.) ; Pagurus Prideaux (needlessly altered to Prideauait), Leach, and Pagurus cuanensis, Thompson, are likewise transferred to Hupagurus, though retaining their original specific names; Pagurus Thompsoni, Bell, is a synonym of Hupagurus pubescens (Kroyer), Pagurus For- hesii, Bell, a synonym of Hupagurus sculptimanus (Lucas),' and a British species not mentioned by Bell, Pagurus tricarinatus, Norman, is now identified with Hupagurus excavatus (Herbst). Payurus Hyndmanni, Thompson, Pa- gurus levis, Thompson, and another British species not mentioned by Bell, Pagurus ferrugineus, Norman, are now transferred to the genus Anapagurus, the last-mentioned being a synonym of Anapagurus chiroacanthus (Lilljeborg). All the nine species are at a glance distinguished from Pagurus by having the right cheliped larger than the left. In Bell’s two remaining species the left cheliped is the larger. Of these Pagurus Dilwynii, Sp. Bate, is a synonym of Diogenes varians, Costa, thus leaving to the original genus no British species except Pagurus fasciatus, Bell, a species which may be the same as Pagurus striatus, La- treille, and which, at any rate as far as Bell was con- cerned, was not described from nature at all, but from a 1G. 0.Sars refers the Pagurus Forbesii, Bell, to the genus Spiro- pagurus, 162 A HISTORY OF RECENT CRUSTACEA coloured drawing supplied him by a friend! Natural his- tory would probably soon be enlivened by many miraculous illustrations if it became lawful to construct a fauna upon the sketches of friends, however trustworthy. It may here be noticed that one of the most attractive figures in Herbst’s work is that of his Cancer megistos, afterwards called Pagurus megistus, but of this Milne-Edwards observes that it appears to be an imaginary species, the bulk of which belongs to a Pagurus, while the fan-tail termination has been taken from some lobster-like animal. Many of the Pagurids are very beautifully coloured, but they are deci- dedly weak about the tail. Just as the quarrymen in old days used to make Ammonites ‘ perfect’ by carving the front of the shell into a serpent’s head, so no doubt some Eastern artist made the really handsome Pagurus into a perfect specimen by giving it what he thought a satisfactory tail, regardless of the fact that such an ornament would have made life impossible to the creature itself. He had not before his eyes the fear of J. C. Fabricius, who winds up his acknowledgments to his predecessors by the awe- inspiring denunciation, ‘damnande vero memorize John Hill et Louis Renard, qui insecta ficta proposuere.’ In regard to Pagurus striatus, Latreille, or, as it ought perhaps rather to be called, Pagurus arrosor (Herbst), the facts of distribution are noteworthy, since the specimens taken in the Mediterranean, among the Philippine Islands, and at Japan, show no points of distinction. When Eupagurus ewcavatus was dredged among the Shetland Isles, Canon Norman, though not then knowing it by its right name, shrewdly suspected that it would prove to be a deep-water Mediterranean form, and as Portunus tuber- culatus, Roux, and the echinoderm Spatangus meridionalis, Risso, had been dredged in the same locality, he takes occasion to remark that ‘all deep-water dredging seems to establish this fact more clearly, that deep-water species have a much more extended geographical range than shallow-water and littoral forms. These Mediterranean species must have made their way northwards in the abyss of the sea round the western coast of Ireland, in which HERMITS ON THE WAR-PATH 163 locality they will doubtless at some future day be found’ Pagurus granulatus, Olivier, one of the largest Pagurids, being seven inches and a half in length, has a range from the West Indies to the Cape. The names Hermit-crab and Soldier-crab, as applied to the Pagurids, are of ancient date, the ensconced crus- tacean being supposed to resemble a hermit in his cell ora warrior in his castle. It is a disputed point whether the Pagurids kill and eat the molluscs before taking possession of their shells. Some writers, as Bell, are persuaded that they do. Others, as Stalio, deny this, maintaining that they are always, as without dispute they are often, content with dead shells. A hermit has from time to time to change its abode to suit its own increase in size, and itis said that when on search for new lodgings, if it meets one of its own kind occupying a desirable shell, it will engage in combat, and if possible take the coveted fortress for itself. As the occu- pant of the envied shell is likely by the nature of the case to be equal in size to its antagonist, and has besides the point of vantage which its occupancy gives, the attack can seldom be successful, and it must be a lucky chance that has enabled any one to witness such a conflict, at least under natural conditions. In their account of tho invertebrate animals of Vineyard Sound and the adjacent waters, Verrill and Smith say:—‘ Active and interesting little ‘“ Hermit-crabs,” Hupagqurus longicarpus [Say], are generally abundant in the pools near low-water, and con- cealed in wet places beneath rocks. In the pools they may be seen actively running about, carrying upon their backs the dead shell of some small gastropod, most com- monly Anachis avara or Ilyanassa obsoleta, though all the small spiral shells are used in this way. They are very pugnacious and nearly always ready for a fight when two happen to meet, but they are also great cowards, and very likely each, after the first onset, will instantly retreat into his shell, closing the aperture closely with the large claws. They use their long slender antenna very efficiently as organs of feeling, and show great wariness in all their actions.’ The natural pugnacity and greediness of these 164 A HISTORY OF RECENT CRUSTACEA creatures may be restrained under the influence of tho tender passion, for at the Hamburg Aquarium the late Mr. W. A. Lloyd observed the male EHupagurus Bernhardus, in the spring of the year, ‘take hold of the shell in which a female was contained, and carry her about for weeks together, grasping the thin edges of the shell, and when the female was fed, the male did not take away the food as he would if a male one fed in his vicinity.’ Aristotle supposed that the Pagurids were generated out of earth and mud, and Gesner argues from this that he can never have taken a gravid female out of her shell, or he would have been disabused of his opinion by seeing the bunches of eggs on the appendages of the pleon. Stalio says that the mother takes care to discharge the young ones in some place where they will have a good chance of finding shells appropriate to their size. According to Mr. Spence Bate it is not necessary for the mother to leave her shell in order to release the young, for when they issue from the egg they are ejected by the current of water that passes outward during the process of respiration. He reports that he had himself seen them thus ejected through the branchial passage under the wing of the carapace. The same writer quotes an interesting experience on the part of Mr. Gurney, who found in a capsule of Buscinum eggs a little whelk-shell, not larger than No. 5 shot, occupied by a young Hermit-crab about an eighth of an inch long, and in another capsule a second Hermit-crab of similar size, but not ensconced in a shell. Hence it appears that the instinct of seeking an extraneous covering is developed at a very earlyage. In the earliest stages of life the Pagurids are symmetrical and therefore unsuited to the occupation of a spiral shell. It may not be possible absolutely to prove that in their later phases they have gradually acquired the formation that suits them to so peculiar a lodging, but it may at least be said that no other explana- tion looks equally probable. The genus Anapagurus has been already referred to as containing some British species. This genus and two others form a group by themselves, distinguished from Ewpagurus A JAPANESE HERMIT 165 and its immediate neighbours by the possession of a con- spicuous appendage in the male at the fifth pair of legs, and distinguished from one another by the shape and S. N. ns mel Fig. 14.—Spiropagurus spiriger (de Haan), with separate figure of the fifth pair of feet carrying the spiral appendage. position of that appendage. They are alike in having the fourth pair of legs subchelate. Spiropagurus, Stimpson, 1858. The fifth leg of the male on the left side has at the base a more or less spirally twisted appendage (the protruded vas deferens). Catapagurus, A. Milne-Edwards, 1880. The fifth leg of the male on the right side has at the base an appendage curved in one plane round the right side of the pleon. Anapagurus, Henderson, 1886. The fifth leg of the male on the left side has at the base an appendage which is short and curved, instead of long and coiled. That the distinguishing feature of Spiropagurus did not escape the notice of de Haan is clear from the description, the figures, and the specific name of his Pagurus spiriger. This, which is the type species of Spiropagurus, is now found to be widely distributed in Eastern waters. 166 A HISTORY OF RECENT CRUSTACEA The genus Ostracondtus, A. Milne-Edwards, 1880, and Tylaspis, Henderson, 1885, require notice, because, unlike all other Paguride, they have the hinder part of the carapace broad and firm, a character to which their names ‘shelly-back’ and ‘ callous shield’ make reference, whilst they also have the pleon poorly developed. The species Tylaspis anomala, Henderson (see Plate VII.), was dredged by the Challenger in the mid-South Pacific, from a depth of 2,375 fathoms, the greatest depth, as already mentioned, at which any of the Anomala were found. This strange- looking animal has the pleon not spirally twisted, and the appendages of its sixth segment are almost symmetrical. It is inferred therefore that it occupies some other dwell- ing-place than a Gastropod shell. This species has in the male a pair of genital appendages on each of the first two segments of the pleon, agreeing in that particular with Paguristes, Dana, 1852, and Sympagurus, 8. I. Smith, 1883. The last-named genus, though belonging to the phyllo- branchiate Pagurids, nevertheless shows a slight tendency in the formation of the branchiz to agree with the next family. Family 3.—Parapaguride. The definition is the same as that of the Paguride, ex- cept that the branchial plumes are filamentous. The species are marine and confined to deep water. There are six genera. Dr. Henderson says :—‘ In all, the gills are moditied trichobranchiz, each consisting of a cen- tral stem which gives rise to two collateral rows of rounded filaments, gradually decreasing in size towards the apex, whereas in the Paguridee the stem gives rise to two rows of flattened leaflets.’ Parapagurus, 8. I. Smith, 1879, is typical of the ad- vances made in recent years in submarine science, since a genus so lately known now includes six species, together covering in their range the whole breadth of ocean between 40° north latitude and-45° south. The genus agrees with Lupagurus in having the third maxillipeds widely separated A MUTUAL BENEFIT SOCIETY 167 at the bases, the chelipeds very unequal, and the eleven pairs of branchize distributed in couples to the third max- illipeds and three following appendages, while the fourth pair of legs have the three remaining pairs of branchie. But it differs from Hupagurus as well in the structure ot the branchize as in having well-developed pairs of male appendages on the first and second segments of the pleon. The type species, Parapagurus pilosimdnus, Smith, has a great range in depth, since American dredging expeditions have taken it at thirty or forty stations in the Atlantic between deeps of 250 to 2,221 fathoms. Low down in the ocean a species may be prolific, for at 319 fathoms nearly four hundred specimens were taken at once. Notice has often been taken of the curious habit which Eupagurus Prideaux has of associating itself with the sea- anemone, Adamsia palliata. Surmises are sometimes made as to the advantages which the companions may hope to obtain from the alliance. Theanemone may obviously obtain a greatly increased range for supplies of food, by the superior locomotive powers of the hermit, and though the weight of both anemone and shell may seem an unneces- sary encumbrance to the crustacean, that objection is gradually diminished by the circumstance that the anemone in course of time almost entirely absorbs the shell. On the other hand the presence of the anemone may be a very valuable protection to the hermit, since numerous fishes are in the habit of swallowing these recluses, shell and all, merely spitting out the shell after they have digested its inmate. But it is most probable that to many fishes an Adamsia palliata would be by no means an agreeable morsel, even when flavoured with crab-sauce. It is also not unlikely that the anemone may contribute to the com- missariat by throwing out its darts as some swift gliding shrimp passes by, and thus reducing it to a condition in which it can be captured by the pagurid. This alliance, however, which is so familiar, is very far from being the only one in this legion of the Crustacea. Rather it may be regarded as a well-known example of a very prevalent habit. Thus upon shells containing Hupagurus pubescens 168 A HISTORY OF RECENT CRUSTACEA the Epizoanthus americanus fixes itself. First a single polyp finds lodgment, and as its basal membrane spreads over the shell, buds arise from it forming fresh polyps, and gradually this same membrane absorbs the shell though retaining its spiral shape. In this absorption there is a great advantage to the hermit, because as it grows its in- crease of bulk still finds room in the yielding polyp-mass, without any necessity arising for a change of domicile. In the case of Catupagurus Sharreri, A. Milne-Edwards (see Plate IV.), there is sometimes a triple alliance, for over a colony of Epizoanthus americanus there settles itself the single polyp Adamsia sociabilis. The numerous specimens of Parapagurus pilosmanus that were taken in depths reaching to six or seven hundred fathoms were found only in colonies of Kipizoanthus paguriphilus, but those that were taken at much greater depths ‘ were either ina very different species of Hyizoanthus, in naked gastropod shells, or in an actinian closely resembling, if not identical with, Urticina consors, Verrill. Dr. Carl Aurivillius has recently pub- lished very interesting observations on the ‘ Symbiosis’ or living together of Hydroids, Sponges, and Pagurids. Hy- dractinia echinata is frequently found coating the outside and inside of various shells that are occupied by Hermit- crabs. The mode of growth is such that the hydroid not only repairs in effect the damaged mouth of a shell, but also frequently extends its boundaries. This is especially the case in districts where shells are few, and where the growing Pagurid might be put to much inconvenience to find a larger lodging. By the extension of the hydroid colony, which sometimes gives a quite monstrous appear- ance to the shell, the hermit is saved the trouble of making any change of abode. The hydroids are saved from the danger and damage they would be exposed to from the rolling about of an empty shell. On the inside of it they do not develop any of the nutritive polyps which might incommode the hermit and also suffer injury from its movements, but they line the interior with a network, to the satisfactory smoothness of which the hermit itself con- tributes. It might be supposed that this was effected by Pil. vit. Pylocheles spinosus Ni Porcellana Uroptychus — Jonvicornis insignis eae ry by or ae 'Maailleped ete ie Uroptychus gracilimanus — DUBIOUS DOMICILES 169 the friction of its body, but Aurivillius shows that there is a. secretion from glands in the sides of the carapace adapted for the purpose, and that the joints in the fourth and fifth pairs of legs of Hupagurus are nicely arranged to assist in distributing the secretion. Paguropsis, Henderson, 1888, is regarded as holding a unique position among Hermit-crabs, inasmuch as the last two pairs of legs of the trunk are subdorsally placed, and the unpaired appendages of the pleon are on the right side instead of the left. Dr. Henderson observes that ‘among the Pagurids generally, the soft abdomen, as a result of its being thrust into a Gastropod shell, the ‘spiral of which is normally right-handed, has assumed a similar curve, and the original right side thus closely applied to the columel la loses its appendages.’ The two specimens taken at a depth of about a hundred fathoms off Tables Island, were free, but the character of the pleon makes it probable that it was protected in some way. The position of the appendages on the right side might be explained as adapted to some species of Gastropod with a left-handed spiral, but the fact that the pleon is simply bent on itself points to some other kind of dwelling. Pylochéles, A. Milne-Edwards, 1880, has the carapace completely calcified, the chelipeds equal, the pleon sym- metrical and well developed with broad semi-calcareous terga and paired appendages of one kind or another on the first six segments, those of the sixth segment forming with the telson a powerful swimming fin. This remarkable genus is said to form a connecting link between the Pagu- ride and Thalassinide. The type species, Pylocheles Agassizit, A. Milne-Edwards, was dredged by the Flake from a depth of 200 fathoms off Barbados, and found in the hollow of a piece of sandstone, the mouth of which was closed by its claws, as the mouth of a shell is by those of of an ordinary hermit. Pylocheles spinosus, Henderson, which is depicted on Plate VIJ., is Australian. Nothing is known about its mode of lodging itself. For this genus Mr. Spence Bate in 1888 established the family Pyloche- lide, which he placed between the Galatheidz and Thalas- 170 A HISTORY OF RECENT CRUSTACEA sinidee. In the family he only places, besides Pylocheles, Pomatochéles, Miers, 1879, and a new genus Cheiroplatéa, and, as he states that it includes all those paguriform Anomura that are trichobranchiate, he was evidently un- aware that the family Parapaguride had been already established by Smith for this very purpose. His Cheiro- platea cenobita (see Plate X.) from the Pacific is no doubt a remarkable animal, having among other singular charac- ters a chelate extremity to the third maxillipeds. The single specimen is a female with very large but not very numerous ova. Mr. Bate compares it with Glaucothoé, Milne-Edwards, which Miers and Bate agree in regarding as only an adolescent form. Considering Cheiroplatea in its adult condition as representing a link between Cenolita and the trichobranchiate Macrura, Mr. Bate remarks that ‘it has an appearance strongly suggestive of its being allied to a Pagurus that had failed to obtain a molluscous shell for itself, and had consequently retained some of the ma- crurous characters of its youthful condition.’ Both Pylo- cheles and Cheiroplatea recall the earliest post-larval forms observed in the Paguridze. Legion 4.—Porcellaninea. The carapace is well developed, broadly ovate, smooth, with the regions faintly defined. The eye-stalks are short and stout, the eyes always pigmented and partially con- cealed in orbits. The first antennee are concealed. Inthe second antennz the peduncle is directed backwards, its second and third segments are coalesced, the flagellum is long and slender. The third maxillipeds have the third joint broad, the fourth provided with a prominent internal lobe. The chelipeds are broad and often flattened, the first three pairs of walking-legs well developed, the last pair slender and inflexed. The pleon is symmetrical, bent under the trunk, having on the sixth segment a pair of lamellar appendages which with the telson form a swimming fan; also in the male it hag a pair of genital appendages on the second segment, and in the female a pair of uniramous THE PORCELAIN CRABS 171 appendages to the fourth, to the fifth, and sometimes to the third segment. Notwithstanding the brachyuran characteristics this legion is found to be in close affinity with the next, the Galatheinea. Here it is supposed that the pleon has become reduced in size and has lost its importance as an organ of locomotion, owing to the special habits which the animals have adopted. They are found under stones between tide-marks and in shallow water among stones, sponges, and corals. One species has been taken at a depth of 390 fathoms. There is but one family. Family Porcellanide. The characters of the single family are those of the legion. Eleven genera are assigned to it, most of which were instituted by Stimpson in 1858, and some on very slender distinctions. Ouly one belongs to British waters. Porcellana, Lamarck, 1801, has the ‘front’ dentate, the first joint of the second antennz much produced, fully reaching the margin of the carapace. The chelipeds have a projecting lobe near the base of the inner margin of the fifth joint, the terminal joint often contorted. The walking-legs have the terminal joint short and robust, ending in a single claw. To this genus belong the only British species of the family, Porcellana platychéles (Pen- nant) and Porcellana longicornis (Linn.), both of which are common under stones, along which they slidder with some rapidity. They will sometimes flatten themselves against the upturned stone, remaining quiet and evidently trying to look as if they were not there. Quite after the fashion of their kindred, the Galatheidee, they will lift up their claws to resist attack, but their flattened habit of body makes this posture of defence in their case ridicu- lously ineffective. If one of the threatening claws be seized, they pretty readily relinquish it and skurry away. To understand the likeness between these crustaceans and the Galatheide it is necessary to flatten out the pleon of 170 A HISTORY OF RECENT CRUSTACEA sinide. In the family he only places, besides Pylocheles, Pomatochéles, Miers, 1879, and a new genus Cheiroplatéa, and, as he states that it includes all those paguriform Anomura that are trichobranchiate, he was evidently un- aware that the family Parapaguride had been already established by Smith for this very purpose. His Cheiro- platen cenobita (see Plate X.) from the Pacific is no doubt a remarkable animal, having among other singular charac- ters a chelate extremity to the third maxillipeds. The single specimen is a female with very large but not very numerous ova. Mr. Bate compares it with Glaucothoé, Milne-Edwards, which Miers and Bate agree in regarding as only an adolescent form. Considering Cheiroplatea in its adult condition as representing a link between Cenobita and the trichobranchiate Macrura, Mr. Bate remarks that ‘it has an appearance strongly suggestive of its being allied to a Pagurus that had failed to obtain a molluscous shell for itself, and had consequently retained some of the ma- crurous characters of its youthful condition.’ Both Pylo- cheles and Cheiroplatea recall the earliest post-larval forms observed in the Paguridee. Legion 4.—Porcellaninea. The carapace is well developed, broadly ovate, smooth, with the regions faintly defined. The eye-stalks are short and stout, the eyes always pigmented and partially con- cealed in orbits. The first antennz are concealed. Inthe second antenne the peduncle is directed backwards, its second and third segments are coalesced, the flagellum is long and slender. The third maxillipeds have the third joint broad, the fourth provided with a prominent internal lobe. The chelipeds are broad and often flattened, the first three pairs of walking-legs well developed, the last pair slender and inflexed. The pleon is symmetrical, bent under the trunk, having on the sixth segment a pair of lamellar appendages which with the telson form a swimming fan ; also in the male it has a pair of genital appendages on the second segment, and in the female a pair of uniramous THE PORCELAIN CRABS 171 appendages to the fourth, to the fifth, and sometimes to the third segment. Notwithstanding the brachyuran characteristics this legion is found to be in close affinity with the next, the Galatheinea. Here it is supposed that the pleon has become reduced in size and has lost its importance as an organ of locomotion, owing to the special habits which the animals have adopted. They are found under stones between tide-marks and in shallow water among stones, sponges, and corals. One species has been taken at a depth of 390 fathoms. There is but one family. Lamily Porcellanide. The characters of the single family are those of the legion. Eleven genera are assigned to it, most of which were instituted by Stimpson in 1858, and some on very slender distinctions. Ouly one belongs to British waters. Porcellana, Lamarck, 1801, has the ‘front’ dentate, the first joint of the second antenneze much produced, fully reaching the margin of the carapace. ‘The chelipeds have a projecting lobe near the base of the inner margin of the fifth joint, the terminal joint often contorted. The walking-legs have the terminal joint short and robust, ending in a single claw. To this genus belong the only British species of the family, Porcellana platychéles (Pen- nant) and Porcellana longicornis (Linn.), both of which are common under stones, along which they slidder with some rapidity. They will sometimes flatten themselves against the upturned stone, remaining quiet and evidently trying to look as if they were not there. Quite after the fashion of their kindred, the Galatheidee, they will lift up their claws to resist attack, but their flattened habit of body makes this posture of defence in their case ridicu- lously ineffective. If one of the threatening claws be seized, they pretty readily relinquish it and skurry away. To understand the likeness between these crustaceans and the Galatheide it is necessary to flatten out the pleon of 172 A HISTORY OF RECENT CRUSTACEA the Porcellana and so institute a comparison. The zoea of Porcellana longicornis (see Plate VII.) has not unfrequently been studied, and the reality of its connection with the adult Fia. 15.—Porcellana longicornis (Linn.), an early post-larval form [Stebbing]. form need not be doubted, but the extraordinary difference between the one and the other can scarcely fail to surprise any one who for the first time compares them. It is strange that the smooth circular carapace of the grown-up Porcellana should result from a larval form in which the TROPHIES FROM EGYPT 173 dorsal shield has two long horns behind and one of porten- tous length in front. ven after the general appearance of the adult has been assumed, the young crustacean shows several interesting differences from its elders. ‘The accompanying figure of a little one, an eighth of an inch long, taken off the back of its mother, exhibits a carapace with numerous little spines not found in the parent, and the telson simply ovate, instead of being subdivided by sutures into seven portions. Porcellana Lobertsoni, Hen- derson, is remarkable as having been taken not in shallow water, but at a depth of 390 fathoms in the West Indies. Dr. de Man states that ‘the genus Porcellana is represented in the Bay of Bengal by no fewer than fifteen species.’ Several of them, however, as he explains, belong to the other genera of this family, which Dr. de Man retains as subgenera. Petrolisthes, Stimpson, 1858, has the ‘front’ undulated, the first joint of the second antenne remarkably short, not reaching the margin of the carapace, the fifth joint of the chelipeds often dentate on the inner margin, and the walking-legs as in Porcellana. Among the Crustacea collected on Napoleon’s celebrated Egyptian expedition, a species, beautifully and elaborately figured by Savigny, was named Porcellana Boscit by Audouin, to whom the French Government entrusted the task of describing the species in Savigny’s splendid work, in consequence of the latter author’s long-continued illness. This species was trans- ferred by Stimpson to his genus Petrolisthes, and it well exhibits the unusual prominence which in this family is often assumed by the third maxillipeds, projecting as if they were a powerful pair of feathered antenna. The name of the genus meaning ‘ rock-slider’ points to one of the characteristic habits of the family. Porcellanella (White), Stimpson, 1858, differs from Porcellana chiefly in having the last joint in the walking- legs not simple but multiunguiculate. Between these two, and agreeing with Porcellanella and Polydényx, Stimpson, in the multiunguiculate joint, the Russian writer Czerni- avsky has insinuated his genus Porcellanides, 1884, in his 14 174 A HISTORY OF RECENT CRUSTACEA work on the Decapod Crustacea of the Black Sea. The book, which is more in Latin than in Russian, contains a wealth of bibliographical information. Legion 5.—Galatheinea, The carapace is elongate, the regions well defined and usually rugose, with a prominent and acute rostrum. The eyes are placed in very incomplete orbits, the eye-stalks short and stout. The first antennz are exposed. The peduncle of the second antennz is directed forward and generally has the second and third joints coalesced; the flagellum is long and slender. The third maxillipeds are subpediform, with the third and fourth joints narrow and often spinous within. The chelipeds and walking-legs are often elongate and slender ; the last pair of legs are feeble and inflexed. The sterna of the trunk are broad. The pleon is broad and well developed, simply bent, or folded on itself, never adpressed to the trunk. In the female the second to the fifth segments have each a pair of simple and slender ovigerous appendages, those of the second and fourth sometimes rudimentary. In the male the pair of accessory genital appendages of the first segment are well developed, rudimentary, or absent; those on the second segment are well developed; the short, usually flattened pair of appendages on each of the next three segments, are well developed or rudimentary. In one genus the male is destitute of appendages on the first five segments. In both sexes the appendages of the sixth segment and the telson form a swimming fan that is usually powerful. The number of branchiz, so far as is known, is generally four- teen pairs in this and the preceding legion. There is only one family. The proximity which is now accorded to the three legions, the Pagurinea, Porcellaninea, and Galatheinea, in spite of external unlikeness, is confirmed, as M. Jules Bonnier observes, in a very interesting indirect manner by the circumstance that Bopyrids of the same genus Pleuro- erypta occur in all three. A WELL-CONSTRUCTED KEY 175 Family Galatheide. The characters are those of the legion. About ten genera are included, two of which—Galathea and Munida— belong to the British Fauna, and, according to Dr. Hender- son, have many species inhabiting shallow water. With the exception of one doubtful genus, the remainder are as yet known only from deep water, and it must be said that according to Dr. Henderson’s own report, only a few out of the species of Munida come from small depths, some going down to more than 2,000 fathoms, and the majority being taken most abundantly at depths varying from 100 to 300 fathoms. Galathéa, Fabricius, 1793, has the carapace usually free from spines, except on the anterior gastric area, but furnished with furry transverse strie. The rostrum is flattened, rather broad, generally having teeth on the margins. The seyments of the pleon are unarmed. There are numerous species occurring at very varied depths. They swim backwards with activity, and Mr. Couch states that it is very remarkable to witness the accuracy with which they will dart backward for several feet into a hole very little larger than themselves, an acrobatic performance which he had often seen carried out, and always with pre- cision. There are five British species, all of which occur also on the coasts of France, where they have been studiea and described very carefully by M. Jules Bonnier. He supplies a very useful key to discriminate them, depending partly on the shape of the third maxillipeds, and partly on the presence or absence of an epipod in the limbs of the trunk. The epipod, it will be remembered, is the branch which issues from the basal joint of an appendage. In Galathea squamifera, Leach, Galuthea nexa, Kmbleton, and Galathea dispersa, Spence Bate, there are epipods to the chelipeds and the two following pairs of limbs ; in Galathea intermedia, Lilljeborg, there are epipods to the chelipeds, but not to the following pairs of limbs; in Galuthea stri- gosa, Fabricius, there are no epipods to any of the three 176 A HISTORY OF RECENT CRUSTACEA pairs. The third maxillipeds in squamifera have the third joint shorter than the fourth, in nexa equal to it, in dis- ersa longer than it. By this simple combination all the five species are neatly distinguished. The sexes of Gala- thea often show a considerable difference in the chelipeds, those of the male being the longer. In Galathea squami- fera, the two last joints of the chelipeds in the female touch all along the inner margins of the chelee, whereas in the male they stand apart, and have a peculiar curvature, meeting only at the apices. This is so pronounced a feature that it misled Spence Bate into establishing a separate species, which he called digiti-distans, meaning ‘with the fingers wide apart.’ Galathea magnifica, Has- well, an Australian species, only half an inch long, ap- pears to make up for diminutive size by its striking appearance. The description of it says, ‘Colour bright red, with a brilliant purple stripe down the centre of the carapace ; legs ornamented with transverse bands of darker red and purple; fingers dark reddish brown, yellow at the tips.’ Munida, Leach, 1820, nearly resembles Galathea, but is distinguished by having a slender stiliform rostrum, and the supraorbital spine on each side of its base not small, . but well developed. Moreover, in general, the carapace has a spinulose surface, and its cardiac region distinct, and the pleon has one or more segments with a series of spinules on the anterior dorsal margin. The chelipeds and walking-legs are elongate and slender. The type species Munida rugosa (Fabricius, 1775) is distributed over all the seas of Europe. The very long chelipeds make it conspicuous. The third maxillipeds have the third joint longer than the fourth. The chelipeds and ambulatory legs are without epipods. It is not to be met with in shallow waters. Bell, on insufficient grounds, altered the name to Munida Rondeletit. Though the old naturalist Rondelet well deserved honour, this was not the right way to pay it. It may be noticed, however, that G. O. Sars, writing in 1889, speaks of Munida Rondeletii, Bell, and Munida reqoss (Fabricius) as two distinct though THE OBJECT OF LARGE OVA 177 closely allied species. In 1882 he had explained that Bell’s Munida Rondeletit was distinguished from the other species by its very small eyes, not furnished with a circlet of hairs, and by the complete want of the two dorsal spines on the third pleon-segment. But Bell gives an- other specific character, ‘ second and third segments of the abdomen, the former with six, the latter with four small spines on the anterior margin ; the other segments with- out spines.’ In two specimens from the Clyde, both having circlets of hairs to the eyes, the pleon has on successive segments, in one case, six, four, and two spines, but in the other six and four and none. Grimothea, Leach, 1820, established to receive the Galathea gregaria of Fabricius, is still in an uncertain position, it being supposed by some that the species is a young form of Munida subrugosa, Dana. Munidopsis, Whiteaves, 1874, has eyes devoid of pig- ment, and the stalk of the eye frequently prolonged beyond the cornea in the form of a spine or spines. The species are found in depths varying from 100 to more than 2,000 fathoms. ‘It is probable, Dr. Henderson remarks, ‘ that the loss of sight is compensated by a greater development of the tactile sense, and in some species this is evidenced by the great length of the antennal flagella, which in all probability enable the animal to grope its way about on the bottom.’ The eggs are few and large, as is often the case with the ova of deep-water species, which are supposed to find their advantage in passing through several of their metamorphoses within the egg, so that the young one is hatched in a form nearly like that of the parent. Eumunida, 8. 1. Smith, 1883, occupies an, exceptional position, for the peduncle of the second antennz has five distinct joints, the third maxillipeds are without the usual two pairs of rudimentary arthrobranchie, and the pleon of the male is without appendages on the first five seg- ments. The type species, Eumunida picta, Smith, was taken in the North Atlantic. Uroptychus, Henderson, 1888, is the equivalent of 178 A HISTORY OF RECENT CRUSTACEA Diptichus, A. Milne-Edwards, 1880, the name Diptychus being pre-occupied. Of the species Uroptychus insigmas, Henderson, and Uroptychus gracilimdnus, Henderson, figures are given on Plate VII. In this genus the second antennze have on the second (the first free) joint of the peduncle an acicle, thus differing from all the rest of the family, except Eumunida, in which one is also present, though of very small size. Dr. Henderson says :—‘ In those species which T have examined, the fifth arthrobranchia, counting from before backwards, is not of larger size than the others, whereas in most of the Galathodea it is distinctly en- larged.’ According to M. Jnles Bonnier, in the species Uroptychus rubrovittatus (A. Milne-Edwards) there are no arthrobranchie, their places being taken by a correspond- ing number of pleuro-branchize—that is, by branchize in- serted on the pleura or sides of the segments, instead of being placed on the articulating membranes that unite the appendages tothe segments. In this genus, and in Ptycho- gaster, A. Milne-Edwards, 1880, and in Humunida, there is a comparative weakness of the swimming-fan, which probably for that reason is twice folded on itself. The members of these genera being sometimes found in the branches of Gorgoniz, it is conjectured that they lead a sedentary life, that the swimming-fan is in consequence losing its importance, and an advance is thus being made towards the brachyuran type. Ptychogaster Milne- Edwardsi, Henderson (see Plate VIT.), from Patagonia, has the pleon, except the telson and uropods, covered with rows of short stout spines. The larval development in species of the genera Lithodes, Eupagurus, Anapagurus, Munidopsis, Galathea, Munida, and Porcellana, has been carefully studied by G. O. Sars, and his results confirm from this point of view the close union of the legions to which these genera re- spectively belong, as well as the propriety of including the whole group among the Macrura. From Sars’ work on this subject have been borrowed the figures grouped together on Plate VIII., representing the end of the pleon in the last larval stage respectively of Lithodes maia Pi. viii. End of Pleon in the last larval stage a. Lithodes maia (Linn.). b. Eupagurus Bernhardus (Linn.). ¢. Porcellana Jongicornis (Linn.). d. Galathea intermedia, Lilljeborg e. Munida rugosa (Fabricius) PERILS OF BABY-FARMING 179 (Linn.), Eupagurus Bernhardus (Linn.), Porcellana longi- cornis (Linn.), Galathea intermedia, Lilljeborg, and Munida rugosa (Fabricius). It will be remembered that the larval forms of Crus- tacea often show not the smallest resemblance to the adults, and also that it is extremely difficult to breed in confinement those which pass through many transforma- tions from the egg to the perfect condition. In this in- terval at every moult, the shedding of the skin is attended with danger. The movement, the saltness, the temperature, of the water in which they are kept should correspond with the conditions they would have experienced in their proper marine home. When all this has been suitably cared for, the supply of appropriate food must be considered, and this will probably not be the same for all the stages. When several specimens occupy a common nursery the more ad- vanced are very apt to destroy the less forward, and the creatures being as a rule very small there are risks of confusions, the larvae of distinct species being perhaps mistaken for the stages of one and the same species. In calm weather, and, at least, in the latitude of Great Britain, especially, though not exclusively, after dark in the months of August and September, it is easy in many parts of the sea by means of asurface-net to obtain an abundance of larval forms, but there is a great difficulty in determining the species and genera to which they severally belong. Being minded to connect together the several stages of a erustacean’s life with some approach to certainty, Professor Sars made a practice of carefully drawing and dissecting the forms he met with, and then by comparison of a long series he was able in numerous instances to assign them in proper sequence to species of which the adults were already known. Considering the vast numbers of the Crustacea, it is evident that there is valuable work to be done on these lines, enough to occupy a crowd of zoologists for many years to come, and the plan is available for many who have no access to the constantly improving resources of the modern scientific aquarium or marine biological station. 180 A HISTORY OF RECENT CRUSTACEA CHAPTER XII TRIBE II.—THALASSINIDEA THE carapace is short and compressed, with litile or no rostrum. The last segment of the trunk is articulated with the preceding. The eye-stalks are small. Both pairs of antenne have long peduncles. Of the trunk-legs the first pair are perfectly or imperfectly chelate, the last pair are short, more or less abnormal, directed backwards. The pleon has the segments not overlapping, with the side-plates feebly developed and having their hinder angles generally rounded. The pleopods are long, biramous, variable ; the swimming fan is strong, The branchie vary in number and form. In this tribe are included four families, the Thalassi- nide, Callianassidee, Axiide, and Thaumastochelide. The division of the Macrura adopted by the late Mr. Spence Bate, into Trichobranchiata, in which the branchial plumes are made up of long cylindrical filaments, Phyllobranchiata, in which the plumes are formed by a series of foliaceous plates, and Dendrobranchiata, in which the branches of the various plumes divide and subdivide in an arborescent manner, does not seem practically very convenient. It has been already seen that two families so intimately allied as the Paguride and Parapaguride would have to be placed, the former in the Phyllobranchiate, the latter in the Trichobranchiate, division. But also in the present tribe Spence Bate himself points out a weakness in the arrangement, for of the genus Callianassa he says :—‘ The structure of the branchiz of Callianussa is so intermediate in character that it may be claimed by anatomists as be- EYE-LASHES AND EAR-SLITS 181 longing to either the Phyllobranchiata or to the Tricho- branchiata, as the plumes consist of two rows of long slender filaments so closely impacted together that they are flattened into plates,’ and elsewhere he remarks that ‘in some genera, as in Thalassina, the branchie are both foliaceous and filamentous.’ Family 1.—Thalassinide. The carapace is dorsally flattened, with rostrum. The eyes are small, the eye-stalks cylindrical. The first pair of antennee have the flagella long ; the second have no scale on the second joint. The first pair of trunk-limbs are un- equal, imperfectly chelate, the last joint or finger being longer than the thumb; the four following pairs are simple, with the terminal joint long. In the pleon the uropods, that is, the appendages of the sixth segment, are slender and acute, the outer branch not transversely sutured ; the telson is also without suture, obtusely pointed. The branchiee are complex. The family includes but one genus. Thalassina, Latreille, 1806, has the characters of the family. It contains but few species, perhaps only the type Thalassina anomalus (Herbst, vol. 3, part 4, p. 45, 1804), which Latreille in 1806 called Thalussina scorpionoides. This is widely distributed in the Pacific. A specimen nine inches long was procured by the Challenger at Kandavu, one of the Fiji Islands. Some points of Mr. Spence Bate’s minute description will teach the student what to look for in various other species of the Macrura. For the small sub-conical eyes imperfect orbits are formed by help of the rostrum and depressions in the upper surface of the first antenne. Projecting forwards from the rostrum and upper part of the orbit and backwards from the antenne are numerous hairs which form for the eyes a protecting fringe, which is in Greek the blephdris in English the eye-lashes. The basal joint of the first antenne has a long triangular slit, the opening of the ear, which is thus described :—‘ The auditory apparatus consists of a large 182 A IIISTORY OF RECENT CRUSTACE& calcareo-membranous chamber, attached to the upper wall of the antenne. Around the orifice that opens into it, within the chamber, there is a curved row of closely planted delicately ciliated hairs, each of which is attached to the base by a flexible membranous articulation, from which it proceeds flattened and tolerably broad for more than half its length, when it narrows rapidly and becomes ciliated, the cilia being short and fine; the hairs extend nearly if not quite across the auditory chamber, the floor of which is covered with small points, while the cavity contains much angular calcareous sand. This I found mostly gathered into a compact mass, but most probably when the animal was in a living condition it was not so, being then kept in a state of motion by the aid of the long slender ciliated hairs that have just been described.’ In discussing the peculiar combination of slender filaments and flattened plates in the branchiee of this crustacean, Mr. Spence Bate observes :—‘ In a respiratory chamber, such as in the genus now before us, the water flows in by the posterior extremity, for which purpose the carapace can be raised or depressed at will within certain limits; and as we may assume that in a large chamber such as the present, the water flows along the lower margin, pass- ing out at the anterior end only, it is probable that the largest amount of current will correspond with that por- tion of the chamber where the trichobranchiate filaments are best developed and most abundant, whereas the phyl- lobranchial plates are present in the centre and deeper recesses of the chamber, where the circulation will be more quiescent, and the power of oxvgenation less effi- cient.’ As there is reason to suppose that the animal may inhabit hollow passages in the mud, where the circulation of water through the branchial chamber would not be very vigorous, and least so in the part most distant from the direct current, Mr. Spence Bate infers that in the central portion of the chamber the branchiz have been developed into thin foliaceous plates of considerable dimensions, so that through the tenuity of their structure the blood may be brought over a large surface into contact with the aerating medium within the chambers. MONTAGU’S CALLIANASS.A 183 Family 2.—Callianasside. The carapace is laterally compressed, with rostrum minute or absent. The eyes and antenne are as in the preceding family. The first pair of trunk-limbs are un- equal, perfectly or imperfectly chelate, the third and fourth pairs simple, the others variable. The uropods and telson are usually broad, without sutures. The branchie are filamentous, with the filaments sometimes compressed. Six or seven genera are assigned to this family, of which two are British. Callianassa, Leach, 1814, was instituted to receive a species which Colonel Montagu described in 1805 (and published in 1808) under the name Cancer Astacus sub- terraneus. He found it at the depth of nearly two feet beneath the surface, while digging into a sandbank in the estuary of Kingsbridge or Salcombe in South Devon. Though it was by no means plentiful, he ascertained that the larger arm was not constant to one side, and that the extreme disproportion sometimes exhibited by it was not invariable. The crustaceous covering of the body he describes as ‘very thin and not far remote from mem- branaceous.’ The exceedingly narrow attachment between the first four joints of the larger cheliped and the follow- ing three which form its monstrous termination give to this species a very peculiar appearance. The second pair of feet are minutely chelate. The second pair of pleopods are slender and filamentous, while the following three pairs are broad and foliaceous. A. Milne-Edwards in 1870 dis- tinguishes seventeen recent species. Czerniavsky in 1884 points out that the Mediterranean Callianassa laticauda, Otto, should be added to the list. Callianassa Stinvypsom, Smith, is a species found on the east coast of the United States. This and other deep- burrowing crustaceans are more often obtained from the stomachs of fishes than by intentional methods of capture. Cherimus, Spence Bate, 1888, was instituted chiefly 184 A IUISTORY OF RECENT CRUSTACEA on account of the contradictions in different writers in regard to the third maxillipeds of Callianassa, some call- ing them pediform, others operculiform. In Cheramus they are distinguished as pediform, but it seems rash to establish a new genus on the very character which some authors ascribe to the old one, especially as Callianassa is not unrepresented in England, France, and the Mediterra- nean, and specimens might have been examined to clear up the disputed point. In the British Museum Leach’s type-specimens of Callianassa subterranea, from Kings- bridge in South Devon (Salcombe at the mouth of the Kingsbridge estuary being probably intended), have third maxillipeds that might well be described as pediform. But other specimens at the same museum, which have been labelled as belonging to the same species, were shown me by Mr. Pocock, and in these, which came from Jersey, the third and fourth joints of the maxillipeds in question are greatly expanded, quite deserving the name operculiform. But these specimens also have a more quadrate telson than those from Devonshire, and are doubtless quite distinct. Since, however, in the type of Callianassa the maxillipeds are pediform, the chief reason for the institution of Cheramus is cut away. Its name signifies ‘a gap,’ but it has net succeeded in filling one. Calltanidea, Milne-Edwards, 1837, closely resembles Cullianassa, but with some differences in the branchial arrangements, and, besides having the second pleopods like the following three pairs, in all these pleopods ‘ the margins, instead of being fringed with small hairs or cilia, have these modified into soft and flexible articulated mem- branous filaments.’ Milne-Edwards supposed that these were true branchial appendages, and that a link was thus established between this family and the Squillide in the sub-order Stomatopoda. With his own genus he coupled Guérin’s Isea. But Mr. Spence Bate regards it as pro- bable that Guérin’s genus was founded on a damaged specimen of Callianidea, and with some reason thinks that the fringed pleopods of that genus cannot be regarded as branchial for purposes of classification. UPOGEBIA BROUGHT TO LIGHT 185 Upogebia, Leach, 1814, was founded to receive another species discovered by the industrious Montagu, and de- scribed by him in 1805 (1808) as Oancer Astacus stellatus. The colour, he says, is ‘yellowish-white, covered with minute stellated orange spots, as it appears under a lens, which give a predominance to the last.’ In this genus the first pair of legs are subequal and subchelate, the other pairs being simple; the second pair of pleopods is like the three following pairs, with the margins strongly ciliated ; the components of the swimming fan are broad- ended. It seems to have escaped the notice of writers sub- sequent to Leach that the earliest name of this genus was Upogelia, which must therefore be retained in preference to Leach’s own alteration of it into Gebia, or Risso’s Gebios. Bell refers to the ‘ Edin. Encycl., xi. p. 400,’ as an authority for Gebia stellata, printing xi. by mistake for vii., and probably guessing at Gebia by mistake for the actual Upogebia. The type species was taken along with the type of Callianassa. On the nearly allied American species de- scribed by Say, Verrill and Smith make the following observations :—‘ The Gebia affinis is a crustacean somewhat resembling a young lobster three or four inches in length. It lives on muddy shores and digs deep burrows near low- water mark, in the tenacious mud or clay, especially where there are decaying sea-weeds buried beneath the surface. The burrows are roundish, half an inch to an inch in diameter, very smooth within, and go down obliquely for the distance of one or two feet, and then run off laterally or downward, in almost every direction, to the depth of two or three feet, and are usually quite crooked and wind- ing. We have found them most abundant on the shore of Great Egg Harbour, New Jersey, near Beesley’s Point, but they also occur at New Haven and Wood’s Hole, &c. This species is quite active; it swims rapidly and jumps back energetically. It is eagerly devoured by such fishes as are able to capture it. When living the colors are quite elegant. Along the back there is a broad band of mottled, reddish brown, which is contracted on the next to 186 A HISTORY OF RECENT CRUSTACEA the last segment ; each side of this band the mottlings are fewer, and the surface somewhat hairy. The last segment and the appendages of the preceding one are thickly specked with reddish brown; their edges are fringed with grey hairs.’ lLeach’s statement that Upogebia stellata makes winding horizontal passages in the mud, ‘ often of a hundred feet or more in length,’ appears still to await confirmation. A second British species was named Gebia deltdéura by Leach, on the ground that the interior lamella of the tail- fan is ‘truncate and formed like the Greek Delta.’ No doubt he was alluding to the inner branch of the uropods. This is an obscure feature on which to base the specific name, and Bell has been not unnaturally misled into sup- posing that Leach was referring to the telson, which, how- ever, is not at all deltoid in form, and which Leach himself expressly describes as ‘quadrate’ and ‘nearly quadrate.’ According to Leach ‘ this species lives with G. stellata,’ and Bell suggests that it is probably identical with it. The Mediterranean ‘ Gebios littoralis,’ Risso, is a nearly allied species, which ranges to the coast of Norway, and may therefore be expected to occur in intermediate waters. The name Gebia no doubt signifies ‘life in the ground,’ and Upogebia ‘ subterranean life,’ in allusion to the burrowing habits which make specimens of the genus rare. The young ones, however, may be taken pretty plentifully at the sur- face, and Sars has in consequence been able to describe the first larval stage or Zoea-form, the second or transition from Zoea to Mysis stage, the third or Mysis-form, the last larval stage, and the first post-larval stage of adolescence (see Plate IX.) From these descriptions it will be seen, he observes, that Gelia in some respects is very distinct from Nephrops and Calocaris, two of the genuine Macrura which he had previously been examining, as well as from all the Carides, while in several points of development it ap- proaches the Anomura. In the Carides as in Calocaris the rule appears to be that the first larval stage or Zoea form is characterised by the presence of three pairs of well- developed swimming appendages, representing the exopods Peteinura gubernata = . A “ a iv at Upogebia fiecoralis Palinurus vulgaris. Larva, [% stage. bi fon % norvegicus Larva, 2% stage 15 = LARVAL LINKS 187 on the three pairs of maxillipeds, while the endopod of the last pair of maxillipeds is fully developed, distinctly articu- lated and setiferous. On the other hand in Gebia, or, to give it its right name, in Upogebia, as in the Brachyura and Anomura, this last pair of maxillipeds is entirely unde- veloped in the first larval stage, the exopod or swimming branch being developed later on, but the endopod remaining undeveloped during the whole larval life. But again from both Brachyura and Anomura the larva of Upogelia is distinguished, because, just as in the Carides, a real Mysis- stage is passed through, in which not merely the three pairs of maxillipeds, but also the first three pairs of trunk- limbs are furnished with swimming-branches. As to the intimate structure of the maxillipeds and mouth-organs generally, Sars remarks that the larva of Upogebia shows a very striking likeness to the larvee of certain Anomura, for example, Galathea. The Jaxea nocturna, Nardo, 1847, which Heller in 1856 called Calliawis adriatica, may belong to this family, but the rostrum is well marked. Family 3.—Aaiide. The carapace is produced to a horizontally flattened point or rostrum. ‘The first pair of trunk-legs are chelate and subequal; the second pair are small, chelate, equal ; the last three pairs are simple. The first segment of the pleon is very short. The outer branch of the uropods is not longer than the inner. The branchie are filamentous, cylindrical, and compressed. The family contains three genera, one of them British. Awius, Leach, 1815, has for type species Awius stiryn- chus, Leach, first found at Sidmouth. Norman says that this species has ‘ the telson quadrangular, the hands smooth, the fingers channelled, the particular articulation of cepha- lothorax and abdomen described by Mr. Couch, and the transverso-lateral tufts of hair on the abdominal segments.’ He supposes that Leach and Bell, in attributing an elongate-triangular form to the telson, were misled by 188 A HISTORY OF RECENT CRUSTACEA the appearance of a dried specimen. Spence Bate declares that ‘Axius has been taken only on the southern coast of England, but Bell and Marion have reported it from the Mediterranean and Milne-Edwards from the coasts of France. The name of the species may be guessed to signify ‘ with a stiff rostrum.’ The same feature belongs to a second species, Awius glyptoctrus, von Martens, found in Australian waters. ‘The second antennz in this genus have a movable spine or scale representing the exopod on the second joint. Paraxius, Spence Bate, 1888, was founded for a species taken off Celebes Island, in which the second antenne have no ‘scaphocerite,’ that is, no scale, spine, or other representative of the exopod on the second joint, and no ‘ stylocerite.’ Hiconawius, Spence Bate, 1888, has three species, all taken from depths of some hundreds of fathoms in the Pacific. Here the second antennz have ‘the peduncle furnished with a scaphocerite and stylocerite.’ ‘This genus,’ the author says, ‘differs from Parawius in having both scaphocerite and stylocerite, which are absent in that genus; this character also separates it from Awius, which has a small scaphocerite only. The stylocerite, which is present in this genus, is wanting in Azius, as it is in all the Macrura, except Eiconaxius and Cheiroplatea. Its presence is a feature most prevalent in the Anomurous Crustacea.’ In the description of the type species, Liconaxius acutifrons, Spence Bate says of the second pair of antenna, ‘its third joint is externally produced to a long sharp tooth or stylocerite.’ Yet in his glossary ‘stylocerite’ is defined as ‘style or large spine on outer wargin of the first joint of the first pair of antenne,’ and in the Intro- duction to his Report on the Challenger Macrura, be attributes a stylocerite to the first antenne in species of Peneus, &c., but states that it does not exist in the Trichobranchiata. Under all the circumstances it seems as if it would be just as well to call a spine a spine instead ofa stylocerite. The single specimen of Viconazius parvus, half an inch long, taken from a depth of 520 fathoms, had A STRANGE CLAW 189 seven eggs, which, as so commonly in deep-water species, were extremely large. From one of these Mr. Spence Bate extracted a young animal, and this proved to be not unlike the young of the lobster at the same stage, but more advanced, thus so far confirming the view that the great size of the deep-water ova is in relation to the more than usual advancement of the embryo before it is hatched. Family 4,—Thaumastochelide. The carapace is produced to a flattened point or ros- trum. The first pair of antenne have on each peduncle two long subequal flagella; the second have a scale or exopod. The first pair of trunk-limbs are chelate, un- equal, somewhat unsymmetrical; the small second pair are chelate, subequal, symmetrical; the outer branch of the uropods is larger than the inner. The branchize are filamentous, cylindrical. To this family Spence Bate assigns only two genera, one of which is British. Thawmustochéles, Wood-Mason, 1874, is appropriately named ‘the creature of wonderful claws.’ The type spe- cies, Thaumastecheles zalewcus (von Willemoes Suhm) (see Plate X.), was taken by the Challenger from a depth of 450 fathoms in the West Indies, along with a great number of other curious marine animals frequenting the globigerina ooze in that locality. It is blind, and not only without eyes but without eye-stalks, unless perchance the latter are re- presented by a pair of tubercles projecting from the ‘front,’ The ‘ front’ is sub-membranous and translucent, and Spence Bate supposes that the optic nerve may terminate so closely behind it as to receive impressions of light. But though there are no eye-stalks, there are excavations in the anterior margin of the carapace corresponding to orbits, and also depressions in the first pair of antennze such as eye-stalks often rest in. The inference then is clear that eye-stalks once existent have been lost, and this probably from their being detrimental instead of useful to a burrowing creature. The burrowing character is in- 190 A HISTORY OF RECENT CRUSTACEA ferred from the general agreement of the species with others that are known to be fossorial. This agreement is exhibited more especially in the tail-fan, but other features favour the notion of such a habit. The flagella of the first antenne, fringed with long fine hairs, may assist in keeping open abreathing hole. The anterior outlet of the branchial chamber is protected against intrusive particles by a joint of the first maxillipeds so disposed as to serve for an operculum. Of the very unequal first legs the limb on the right side has the thumb and finger monstrously developed into a pair of combs carrying about sixty unequal teeth apiece, and, as Spence Bate observes, ‘it appears probable that when partially closed it has the power of raking the neighbourhood to a considerable distance, and so entrapping small animals and other material from which the blind creature has the power of selecting its food.’ As this extremely elongate hand could not convey the food to the mouth, the short second and third pairs of legs are also conveniently chelate. The fifth pair are the same, at least in the female, but in these the minute chela buried in a thick brush of fur probably has some function other than that of assisting its mistress to feed. Calocaris. Bell, 1853, has but a single species, Calocaris Macandrec, Bell, found in the waters of Ireland, Scotland, and Norway. It is still comparatively rare, as might be expected of an animal which burrows at depths of 80 and 150 fathoms. Its habits would seem to be tolerably sluggish, since specimens are sometimes overgrown with a small zoophyte, the polyzoon Triticella flava, Dalyell, which can scarcely serve any purpose of concealment. The eyes are present but have lost their pigment, so that vision is probably dim. The first pair of legs are unequal, but not strikingly so. These and the next pair are chelate, while the remaining three pairs are simple. Spence Bate makes it a character of the family that tbe tail-fan has the outer plates much larger than the inner, but, though this is true of Thawmastocheles, it scarcely applies to Calocaris. Cheiroplatea aad} C.cenobita Telson and Uropods Icatipes 7 ce Va Nematocarcinus re ger \. ee undulatipes or _ a x —\.sulcatipes. 1° Leg “SMS Ef Zz WBA. sulcatipes Lf f Telson and Uropods = A” A NEW TRIBAL NAME 191 CHAPTER XIII TRIBE ITJ.—SCYLLARIDEA Tue first antenne carry two flagella; the second have no scale. The trunk-legs are six-jointed through coalescence. The first pair are not much larger than the second, and simple or scarcely subchelate; the three following pairs are simple, and the fifth pair is simple in the male, more or less winutely chelate in the female. The branchize are wel] developed ; epipodal plates on the first joint in the first four pairs of trunk-legs have podobranchiz attached to them as distinct plumes. All these same limbs have arthrobranchiz, and the last four segments of the trunk have pleurobranchiz. The first segment of the pleon is without appendages. In this tribe Spence Bate says that the ova are very small, and that the young are hatched in a Phijllosomu- form. With the Astacidea and Stenopidea it forms what he calls the normal group of the Trichobranchiate Macrura. It contains two families, the Scyllaride and Palinuride, and the tribal name given it by Spence Bate was Synaxidea (see p. 46), derived from a new genus Synazes, which he considered to combine some of the features of both families. As Synazes is itself a synonym, it was not possible to retain the tribal name derived from it, while Heller’s term loricata adopted by Paulson, Boas, and others, is not in conformity with the names of the neighbouring tribes. Family 1.—Scylluride. The carapace is depressed, with orbits for the eyes excavated in the dorsal surface. The second antenne are 192 A HISTORY OF RECENT CRUSTACEA short, squamiform. The mandibles have a one-jointed ‘palp.” The trunk-legs are simple, except the fifth pair in the female, which are minutely chelate. To this family there are assigned six or seven genera, one of which is occasionally met with in the waters of Great Britain. In this and other families in which the fifth pair of legs are chelate in the females only, they are supposed to be so constructed to assist in rupturing the ovisac, and liberating the embryo from the ovum. Bell explains the unusual structure of the second antennas by suggesting that they have been developed into bread flat organs of natation, and probably also constitute a pair of shovels for the purpose of burrowing. Scylldrus, Fabricius, 1793, has been much subdivided since its first institution. As re-defined by Dana, it has the rostrum very salient, the sides of the carapace not incised, the second antennze almost contiguous, the exopod of the third maxillipeds ending in a lash; the pairs of branchiz twenty-one. Tn various writers the expression will be found in such definitions as the above, that the palp of the third maxil- lipeds is or is not furnished with a flagellum. Now Pro- fessor Huxley in ‘The Crayfish’ says that, in the terms usually applied to the maxillipeds by writers on descriptive zoology, ‘the exopodite is the palp, and the metamor- phosed podobranchia, the real nature of which is not recognised, is termed the flagellum.’ It must therefore be borne in mind that the flagellum mentioned by Huxley as an equivalent to the podobranchia or epipod on the first joint is quite distinct from the flagellum of the exopod, the term being used in the latter instance merely to signify a whip-like termination, a many-jointed, more or less flexi- ble lash. Scyllarus latus (Rondelet), Latreille, is found in the Mediterranean and Atlantic. It is said sometimes to attain a length of a foot and a half, and to be delicious food, superior to the lobster itself. Patrick Browne in his ‘History of Jamaica,’ calls it ‘The Mother Lobster,’ and Petiver designates it, ‘the great broad warty crab.’ In THE MOTHER LOBSTER 193 Savigny’s fine folio plate its characteristics are beautifully delineated. The enormously broad ultimate and antepen- ultimate joints of the second antennz will astonish and perplex any one who for the first time becomes acquainted with a crustacean of this family. In the present species the quadrangular rostrum, the little eyes very wide apart, and implanted at a little distance from the sharp anterior angles of the great oblong tuberculate carapace, the com- parative smallness of the legs entirely unchelate, and the breadth of the tail-fan, are characters which will attract and deserve attention. Thenus, Leach, 1819, has still only the type species, Thenus orientalis (Fabricius), in which the carapace is broader than long, with a bilobed rostrum, and the eyes placed on visible stalks at its anterior angles. There are twenty-one pairs of branchie. Ibaéceus, Leach, 1815, has the carapace much broader than long, deeply incised on the sides, with a bilobed rostrum, and the small eyes planted far from the front angles; the broad second antennze not very remote on their inner margins, the pairs of branchize twenty-one or twenty-two. Species of this remarkable genus are dis- tributed all over the Eastern seas, but Ilacus verdi, from ‘St. Vincent, Cape Verde Islands, and also from Sambo- angan in the Philippines, is said to afford the only speci- mens of the genus taken elsewhere than along the Pacific coasts of Asia and the Australasian Islands. ‘Hence,’ Spence Bate who instituted the species observes, ‘the similarity that it bears to Ibaccus incisus (Péron) is the more remarkable, and, judging by the several figures and descriptions published, the differences are slight, except in the character and number of the dentations that arm the margins of the carapace and antenne.’ He also calls attention to the thinning out of the sharp lateral margins to an extent equalling that of some of the Brachyura. Moreover, while the cervical groove, often so conspicuous in the Macrura, is here wanting, the lateral notches are greatly deepened, and widely separate the suborbital and hepatic regions from the branchial. As in 192 A HISTORY OF RECENT CRUSTACEA short, squamiform. The mandibles have a one-jointed ‘palp. The trunk-legs are simple, except the fifth pair in the female, which are minutely chelate. To this family there are assigned six or seven genera, one of which is occasionally met with in the waters of Great Britain. In this and other families in which the fifth pair of legs are chelate in the females only, they are supposed to be so constructed to assist in rupturing the ovisac, and liberating the embryo from the ovum. Bell explains the unusual structure of the second antenne by suggesting that they have been developed into bread flat organs of natation, and probably also constitute a pair of shovels for the purpose of burrowing. Scylldrus, Fabricius, 1798, has been much subdivided since its first institution. As re-defined by Dana, it has the rostrum very salient, the sides of the carapace not incised, the second antennee almost contiguous, the exopod of the third maxillipeds ending in a lash; the pairs of branchize twenty-one. In various writers the expression will be found in such definitions as the above, that the palp of the third maxil- lipeds is or is not furnished with a flagellum. Now Pro- fessor Huxley in ‘The Crayfish’ says that, in the terms usually applied to the maxillipeds by writers on descriptive zoology, ‘the exopodite is the palp, and the metamor- phosed podobranchia, the real nature of which is not recognised, is termed the flagellum.’ It must therefore be borne in mind that the flagellum mentioned by Huxley as an equivalent to the podobranchia or epipod on the first joint is quite distinct from the flagellum of the exopod, the term being used in the latter instance merely to signify a whip-like termination, a many-jointed, more or less flexi- ble lash. Scyllarus latus (Rondelet), Latreille, is found in the Mediterranean and Atlantic. It is said sometimes to attain a length of a foot anda half, and to be delicious food, superior to the lobster itself. Patrick Browne in his ‘History of Jamaica,’ calls it ‘The Mother Lobster,’ and Petiver designates it, ‘the great broad warty crab.’ In THE MOTHER LOBSTER 193 Savigny’s fine folio plate its characteristics are beautifully delineated. The enormously broad ultimate and antepen- ultimate joints of the second antennz will astonish and perplex any one who for the first time becomes acquainted with a crustacean of this family. In the present species the quadrangular rostrum, the little eyes very wide apart, and implanted at a little distance from the sharp anterior angles of the great oblong tuberculate carapace, the com- parative smallness of the legs entirely unchelate, and the breadth of the tail-fan, are characters which will attract and deserve attention. Thenus, Leach, 1819, has still only the type species, Thenus orientulis (Fabricius), in which the carapace is broader than long, with a bilobed rostrum, and the eyes placed on visible stalks at its anterior angles. There are twenty-one pairs of branchie. Ibicus, Leach, 1815, has the carapace much broader than long, deeply incised on the sides, with a bilobed rostrum, and the small eyes planted far from the front angles; the broad second antennz not very remote on their inner margins, the pairs of branchize twenty-one or twenty-two. Species of this remarkable genus are dis- tributed all over the Eastern seas, but Ibacus verdi, from ‘St. Vincent, Cape Verde Islands, and also from Sambo- angan in the Philippines, is said to afford the only speci- mens of the genus taken elsewhere than along the Pacific coasts of Asia and the Australasian Islands. ‘ Hence,’ Spence Bate who instituted the species observes, ‘the similarity that it bears to Ibaccus incisus (Péron) is the more remarkable, and, judging by the several figures and descriptions published, the differences are slight, except in the character and number of the dentations that arm the margins of the carapace and antenne.’ He also calls attention to the thinning out of the sharp lateral margins to an extent equalling that of some of the Brachyura. Moreover, while the cervical groove, often so conspicuous in the Macrura, is here wanting, the lateral notches are greatly deepened, and widely separate the suborbital and hepatic regions from the branchial. As in 194 A HISTORY OF RECENT CRUSTACEA others of this family, the basal joint of the second antenne is not free, but closely fused with the ventral portion of EE Fig. 16.—/bacus incisus (Péron) [Desmarest]. the head. Spence Bate enumerates twenty-two pairs of branchiz in this species. Why he cnanges Jbacus into Ibaccus he has not bequeathed us any explanation. Pseudibacus Veranyi, Guérin, may receive a passing mention, as a Mediterranean species. Arctus, Dana, 1852, has the rostrum very short and truncate, the second antennze remote from one another, the exopod of the third maxillipeds without a lash, and the pairs of branchize nineteen in number. In the definition of this genus Dana is practically fol- lowing de Haan in stating that the palp of the third maxillipeds is without a flagellum. Mr. Spence Bate translates this into his own terminology, and speaks of the genus ‘ having no ecphysis attached to the second pair of gnathopoda,’ which would mean that there was no exopod to the third maxillipeds at all. But that is not the case. THE CRAWFISH 195 The exopod, or ‘ecphysis,’ or ‘palp,’ is present, but as de Haan’s figure shows, and as his statement declares, the lash-like termination is absent. It rather looks as if Dana had stolen the type species of Scyllarus, on which to found his new genus. At any rate he changed Scyllarus arctus into Arctus ursus, both in the generic and specific name making allusion to a bear, not because of any resemblance in shape between Bruin and this crustacean, but evidently because of the thick and short pilose substance which protects the tuberculate sur- face of the latter, and which is said to give it in its perfect condition a smooth velvety appearance, like the shining coat of the bear. Aretus ursus occasionally makes its appearance in Eng- lish waters. It is recorded from many parts of the Medi- terranean, and also from Australia and Japan. There are several other species of the genus. They do not seem to attain any remarkable size. Family 2.—Palinuride. The carapace is longitudinally subcylindrical, with orbits for the eyes partially excavated. The second an- tenn are subcylindrical, with a long rigid multiarticulate flagellum. Spence Bate assigns to this family five genera, one of which is found in British waters. Palinarus, Fabricius, 1797, is restricted by Spence Bate to those species which have asmall central rostriform tooth or tubercle that overhangs but does not cover or enclose the ocular segment, which have short flagella to the first antenne, and in which the segment that carries those antenne is anteriorly produced and laterally compressed in front. Such species appear to be confined to the northern hemisphere. The type, Palinurus vulgaris, Latreille, of which the true specific name is involved in some perplexi‘y, is found in many parts of Europe, including the shores of Great Britain. Bell considers that it is without doubt the Carabos of Aristotle. It is a very handsome species, some- 196 A HISTORY OF RECENT CRUSTACEA times attaining a length of eighteen inches, and is valued for food, though it has a less delicate flavour than the lob- ster. Though its front legs make a very feeble show in comparison with the powerful chelz of the lobster, when the mandibles are compared the advantage is greatly in favour of the Palinurus, or Crawfish as it is often called. Spence Bate has pointed out that in this genus and its immediate kindred there are button-shaped tubercles on either side of the trunk, which fit into cavities on the under surface of the carapace, and have a very great power of re- tention, this buttoning of the carapace being probably an important protection to the branchize that are placed beneath it. Its long stiff antennze are said frequently to prevent it from entering the pots set for catching crabs and lobsters, and thus, while disappointing it in its search for food, indirectly help to save its life. As in Palinurus the ear-stones are introduced, and yet the animal has no claws with which to pick up grains of sand and place them in the auditory cavity at the base of the first antenne, it might well be wondered how the otoliths reach their de- stination; but Hensen explains that the crustacean has only to burrow with its head in the sand, and the required particles will easily find their way into the ear-chamber. [ Palinosytus], Spence Bate, 1888, has the rostrum an- teriorly produced so as to reach beyond the ocular segment, and by its connection with the segment belonging to the second antenne forms a channel for the protection of the ocular segment. ‘The first antennz have two short flagella, and their segment is not produced beyond the extremity of the rostrum. This genus belongs at present only to the southern hemisphere. A specimen of Palinosytus Lalandit (Lamarck), ten inches long, was taken by the Challenger near Tristan daCunha. Also a small specimen, about an inch long, was taken near the Cape of Good Hope, and this in all but sexual character already appeared to have the perfect adult form. Palinosytus Hiigeli (Heller) is the common Crawfish of Sydney, in Australia, and if, as Haswell supposes, it be the same as the New Zealand Pulinurus tumidus, Kirk, it must be credited with attaining ADAM WHITE 497 the great size of two feet in length, with a carapace more than twenty-one inches in circumference. Already in 1883, Mr. T. Jeffrey Parker, F.R.S., had proposed a new sub- genus Jasus for those species of Palinurus which have the rostral character assigned to Palinosytus and which have no stridulating organ. He therefore claims that the name Jasus should supersede Palinosytus. Innuparis, White, 1847, has the rostrum dilated, bi- partite, with the processes flat, and the anterior margin spinulose. To this genus belongs Linuparis trigdnus (de Haan). Panulirus, White, 1847, contains the numerous Eastern and one or two Western species, in which there is no central rostriform tooth, which have the ocular segment exposed and membranous, the flagella of the first antennz long and slender, and their segment produced considerably in ad- vance of the frontal margin, that being generally armed with strong teeth. Panulirus penicillatus (Olivier) has already been mentioned as having exhibited the singular monstrosity of an eye-stalk developing a flagellum or lash- like termination. In this species Spence Bate enumerates twenty-six pairs of branchiz, this number including six pairs of ‘mastigobranchie,’ which are in fact epipods, whether accompanied or not by podobranchiz, which also arise from the first joint. With the help of Mr. R. I. Pocock, I have come to the conclusion that Linuparis and Panulirus were not named as generally supposed by Dr. J. E. Gray, but by Mr. Adam White, in 1847, the characters of the new genera being left to be interred from those of the known species which were transferred to them, a slovenly method of definition which is much to be deprecated. Palinurellus, von Martens, 1878, is distinguished from Palinurus, by the feeble antennz, the nearly smooth cara- pace, and its rostriform front covering the base of the antenneg and eye-stalks. The type Palinurellus gundlachi is from Cuba. The genus Synawes, which Spence Bate established in 1881, and retained in 1888, is described as having the rostrum produced beyond the segment of the first antennee and united with that of the second antenna 198 A HISTORY OF RECENT CRUSTACEA so as to make a perfect orbit and to cover the ocular seg- ment. Itis said to have the antenne of Palinurus, the trunk-limbs like those of Seyllarus, the carapace like that of Astacus, and the pleopods like those of Scyllarus, so as to form a truly inosculant genus. The type species is Synawes hybridica, Spence Bate, from the West Indies. Spence Bate himself observes that ‘ Palinurellus, von Martens, ac- cording to that author differs from Synaxes in having the posterior pair of pereiopoda chelate in the female,’ but does not explain how that can be any distinction, if, in Synazes, ‘the pereiopoda are like those of Scyllarus,’ as he declares them to be, for in Scyllarus also the last pair are chelate in the female. The student must be prepared sometimes to find it as difficult to reconcile authors with themselves as with one another. Under the circumstances one may accept the decision of Dr. Boas, quoted with evident ap- proval by von Martens, in 1882, that Synazes is a synonym of Palinurellus. The strange form known as Phyllosoma was at one time regarded as belonging to a distinct genus, but is now known to be larval, by such marks as the median eye, and the rudimentary character or unjointed condition of the various parts. A considerable number of specimens of Phyllosoma were obtained by the Challenger, of sizes varying from the seventeenth of an inch up to an inch and two-fifths, the latter being larger than some specimens of Palinurus that have attained the permanent form. In a general way the Phyllosoma forms may be assigned to different stages in the development of the Scyllaride and Palinuride, bat to assign the successive stages to par- ticular species does not seem always possible at present, and in especial there appears to be an awkward gap between the most advanced Phyllosoma and the earliest post-larval form. No such perplexity, however, affects the first larval form, or brephalos, when actually extracted from the ovum. A specimen of this kind is shown on Plate IX., in Spence Bate’s figure of a juvenile Palinurus vulgaris. A FOSSIL’S KITIT AND KIN 199 CHAPTER XIV TRIBE IV.—ASTACIDEA THE first antennz: carry two multiarticulate flagella; the second are furnished with a scale. The trunk-legs have seven distinct joints. The first three pairs of trunk-legs, and sometimes the other two pairs also, are chelate. The first pair are the largest. The branchiz are well developed. The first segment of the pleon has appendages, except in the Parastacidee. In this tribe the young are said to be hatched in the Megalopa form. It contains four families—the Eryontide, Nephropsidee, Potamobiide, and Parastacidee. Family 1.—Lryontide. The carapace is dorsally depressed, with little or no rostrum. The eyes are wanting or abnormal. The second antenne have a long multiarticulate flagellum. The third maxillipeds are pediform. The pleopods, exce,t the first pair, have a process attached to the inner branch (the stylamblys of Spence Bate’s terminology). The uropods have no transverse suture. The telson is tapering. To this family are assigned seven genera, but one of these, Hryon, Desmarest, 1820, which gives its name to the family, is a fossil genus from the Lias of England and the lithographic limestone of Bavaria. It is only in re- cent years that, the depths of the ocean have yielded forms which appear to be properly classified in close proximity to the ancient fossil species. Polychéles, Heller, 1863, has the arterior angles of the 16 200 A HISTORY OF RECENT CRUSTACEA carapace projecting ;_ the eye-stalks obscure, ‘immovably lodged in an orbit excavated in the dorso-frontal margin of the carapace, more or less covered by the antero-lateral margin of the carapace ;’ the second antennee terminating in a long and slender flagellum; the first four pairs of trunk-legs chelate ; the fifth pair simple in the male, some- times chelate in the female ; the pleon not longer than the carapace. The type-species, Polycheles typhlops, Heller, was first taken in the Mediterranean. Since then various species have been recorded from both the Atlantic and the Pacific, and from depths varying from 220 to 1,070 fathoms. Since in the female all the legs are usually chelate, the generic name, meaning ‘ with many chele,’ is not inappropriate. Pentachéles, Spence Bate, 1878, meaning ‘the creature with five cheles,’ seems to differ from Polycheles only in the particular alluded to in the generic name, the male in this instance, as well as the female, having the fifth pair of legs chelate. The genus has a wide range in both the great oceans, and the species descend to great depths. Spence Bate observes that Pentacheles euthrix (v. Wil- lemoes Suhm) has a close general resemblance to his own Polycheles baccata. Stereomastis, Spence Bate, 1888, is said to differ in nothing externally from Pentacheles, but to be established ‘to receive those species in which the mastigobranchial lash does not exist.’ It was probably foreseen that some apology would be expected for such a definition, and the remark is accordingly appended, that ‘ difference of in- ternal structure as a specific character is of more value than any external distinction, which, though more con- venient for classification, is of little importance if it does not represent structural variation.’ Yet the example of the present genus gives but feeble support to this senten- tious aphorism, especially as in the two preceding genera the mastigobranchial lashes are for the most part of great tenuity, and in Stereomastis Sumi, Spence Bate, the third maxillipeds have ‘a rudimentary mastigobranchial plate,’ though the trunk-limbs are without any. The meaning of the generic name would naturally imply the presence WHERE THE FOOD THERE THE FEEDERS 201 a ae lash, but it is explained to mean ‘the absence of a lash.’ Willemoesia, Grote, 1873, was at first named Deodamia by Dr. vy. Willemoes Suhm, but that name was pre- occupied. Here the eye-stalks are rudimentary, not lodged in a notch in the dorsal surface of the carapace, but in the frontal space. The first antenne have the first joint pro- duced to a scale-like process, which is forced up into a crest-like ridge; the two flagella are very unequal. The trunk-limbs are all chelate in both sexes. The telson tapers to a joint. The type species, Willemoesia lepto- dactyla (v. Willemoes Suhm), occurs in the Mediterranean, Atlantic, and Pacific between the depths of 1,300 and 2,225 fathoms. This and the species of the kindred genera are almost always taken on an oceanic floor of globigerina ooze, and Mr. Spence Bate infers from this that the cha- racter of the food may have been one of the most perma- nent influences in their geographical distribution. The remark is capable of a very extended application. Family 2.—Nephropside. The carapace is sub-cylindrical, with a pronounced rostrum. The second antenne have a long multiarticulate flagellum. The segments of the pleon are dorsally imbri- cated. The outer branch of the uropods has a transverse suture. The ‘mastigobranchie’ or epipodal plates are large, havinga well-developed podobranchial plume attached to all the trunk-legs except the last: pair. Six genera are assigned to this family. Spence Bate calls it the Homaride, from Homarus, the name which Milne-Edwards gave to the genus containing the common lobster, but since that genus was already named Astacus by Leach, Homarus must be discarded as a synonym. Since a freshwater genus in a different family has been misnamed Astacus, by which the application of Astacide as a family name has been confused, it seems better to give a new family name to the lobsters, and for this pur- pose Nephropside readily suggests itself. 202 A HISTORY OF RECENT CRUSTACEA Nephrops, Leach, 1819, has the eyes wider than their foot-stalks and reniform or kidney-shaped in accordance with the meaning of the generic name. ‘The scale of the second antenne is large, reaching the end of the peduncle. The first pair of trunk-legs are long, slender, and pris- matic in shape, not very unequal. The type-species, Nephrops norweyicus (Linn.), is distributed generally through the seas of Europe, belonging not only to Nor- way, but also to Great Britain and the Mediterranean. It is a beautiful species both inform and colouring. Accord- ing to Spence Bate, the branchial arrangement is identical with that of the common lobster, but Huxley draws a slight distinction, saying that ‘the branchial plume of the podobranchie of the second maxillipeds is small or absent, so that the total number of functional branchiee is reduced to nineteen on each side’ in Nephrops, as compared with twenty in the lobster. Sars has figured and described the ‘second larval stage’ (see Plate IX.),! the ‘last larval stage,’ and the ‘ first post- larval stage’ of this species. The larval pleon is highly remarkable, not so much on account of the great dorsal spines that arise from the fourth, fifth, and sixth segments, as of the telson, which spreads itself out into two ciliated and spinulose spine-like branches, which together make its arch equal in breadth to the length of the animal. A second species, Nephrops Thomsoni, Spence Bate, has been taken between Australia and New Zealand, and in the Philippines. Eunephrops, S. I. Smith, 1885, is very near to Nephrops, except that, like the American lobster, it has a well-developed podobranchia to the second maxillipeds, and the scale of the second antenne is very small. The type species, Eunephrops Bairdit, was taken in the Caribbean Sea. Astieus, Leach, 1814, has the eyes not wider than the foot-stalks and subglobose. The scale of the second an tennee is spine-like, not reaching the end of the peduncle. 1 The form norvegicus, accidentally used on the Plate, is not the original spelling, but a later refinement. FROM ARISTOTLE UNTO THIS DAY 208 The first pair of trunk-legs are large, robust, markedly un- equal. ‘The type-species is Astacus gammarus (Linn.), which Milne-Edwards and Bell speak of as Homarus vulgaris. Occasionally this is corrected by authors into Homarus gammarus. Spence Bate admits that Leach has un- doubted priority, but regrets that to acknowledge his claim would only have the result of creating great con- fusion, which Leach himself would have deprecated, and that it would introduce terms not likely to be generally accepted. The sentimental consideration that Dr. Leach would deprecate a particular result may be dismissed, since in natural history the author of a name once pub- lished has no more control over it than any other person. In the due recognition of priority there is probably a better chance than any other principle affords of eventually clearing away confusion. No doubt, to our eyes, the age of Leach, as far as Crustacea are concerned, seems a kind of primitive antiquity, but in the perspective of another century or two the writers of to-day will seem to stand close by his side or very little in front, and if our, nomen- clature is carried out without principle, we must expect to be treated like the pre-Linnean zoologists, and have our nomenclature put altogether out of court. It may be mentioned that Adam White, a considerable authority in his time, uses the name Astacus gammarus for the lobster, in his ‘Popular History of British Crustacea,’ published in 1857, thus showing that he was not to be daunted or led astray by the authority either of Milne-Edwards or of Bell. Leach remarks that ‘ Aristotle has very distinctly described this species under the name agtaxos.’ He is referring no doubt to the very interesting but rather per- plexing second chapter of the fourth book of Aristotle’s ‘ History of Animals.’ Astacus americanus (Milne-Edwards) closely resembles the European species, but has two spines on the under surface of the rostrum, which are wanting in its congener. It is, like the other, a large and extremely prolific species, much sought after for food. It is reckoned that a million a year are consumed in Boston alone. Professor S. I. 204 A HISTORY OF RECENT CRUSTACEA Smith has studied its development, and carefully described the embryo as it appears some time before hatching, also the first, second, and third larval stages, and the first post- larval stage. In this genus it appears that the Zoea stage Fie.18.— AstacusAmericanus (Milne-Edwarde), early larval form, lateral view [S. 1. Smith]. Fic. 17.—Astacus Americanus (Milne- Edwards), early laival form, dorsal view (S. I. Smith]. is omitted, as far as the free existence of the animal is con- cerned, and that the young one is hatched in the Mysis Fic. 19.— Astacus Americanus (Milne-Edwards), third stage [S. I. Smith]. form. Professor Smith did not accurately ascertain the age of the youngest larvee he described, but supposed them to be at most a few days old and not to have moulted more LARVAL LOBSTERS 205 than once. In this stage they are free-swimming Schizo- pods about a third of an inch long, without appendages to the pleon, but with six pairs of pediform appendages under the carapace, each with an exopod developed into a power- ful swimming organ. ‘The eyes are bright blue; the anterior portion and the lower margin of the carapace and the bases of the legs are speckled with orange; the lower margin, the whole of the penultimate, and the basal por- tion of the ultimate segment of the abdomen [pleon], are brilliant reddish orange.’ In the second stage appendages to the pleon have appeared on the segments from the second to the fifth, these same segments carrying dorsal spines as in the preceding and following stages, but with successive reductions in their size. In the third stage the appendages of the sixth segment of the pleon are well developed, although quite ditferent from those in the adult. Considering that the Norway Lobster and the Common Lobster when adult are so nearly allied that they might almost be included in a single genus, the difference be- tween the larval forms of the two is at first sight rather startling, but when more narrowly examined it will be seen that the structure in both is essentially the same, only that the telson of the larval Nephrops has been trans- versely outdrawn to a portentous extent. The larval Porcellana has been already mentioned as developing a monstrous spine in the longitudinal direction; the larve of the Cirripede, Lepas fascicularis, bristle with spines, and it is likely that many of the infant Crustacea may find in these processes an efficient protection to their minute and delicate frames against foes not much bigger than themselves. That they have such enemies it is easy to guess, and Professor Smith says of his young lobsters of the first stage, ‘They appeared, while thus in confine- ment, to feed principally upon very minute animals of different kinds, but were several times seen to devour small zoée, and occasionally when much crowded, so that some of them became exhausted, they fed upon each other, the stronger ones eating the weaker.’ We cannot afford to find fault with their juvenile morals, since similar prac- 206 A HISTORY OF RECENT CRUSTACEA tices have been followed, in some stages of society, by human beings themselves. Phobérus, A. Milne-Edwards, 1881, has the eyes close together, small, and implanted on short rudimentary eye- stalks. he scale of the second antenne is large. The first pair of trunk-legs are long, slender, and cylindrical ; the second and third more slender and not quite so long; the fifth slightly subchelate. In Phoberus tenuimdnus, Spence Bate, from New Guinea, the entire surface of the animal is spinous. Nephropsis, Wood-Mason, 1873, has the eye-stalks small, the second antennz without a scale, the first pair of trunk-legs large, the second slender, the third slender and with the chele minute, the last two pairs slender and simple. All the recorded specimens have been taken at great depths, from two or three hundred down to eight hundred fathoms. The type-species, Nephropsis Stewarti, Wood-Mason, from the Andamans, was supposed to be blind, but, according to Spence Bate, ‘it appears both from Wood-Mason’s own figures and from an examination of the Challenger specimens, that this genus cannot be described as being without organs of vision.” Nephropsis atlantica, Norman, from the Faré Channel, has small and immature eyes. Eutrichochéles, Wood-Mason, 1876, was instituted to receive the Cancer modestus of Herbst from India, which, according to Wood-Mason, is ‘especially interesting as being the nearest known blood-relation of the remarkable blind crayfish,’ Nephropsis Stewurti. Family 3.—Potamobiide. The carapace is sub-cylindrical, with a pronounced rostrum. The fourth and fifth pairs of trunk-legs are not chelate. The outer branch of the uropods has a transverse suture. The first maxillipeds have an epipod devoid of branchial filaments; the second maxillipeds and the first three pairs of trunk-legs have the podobranchiz always provided with a plaited Jamina, None of the branchial fila+ CRAYFISHES 207 ments and attendant sete: terminate in hooks. The first segment of the pleon has appendages in the male and usually also in the female, those of the four following segments being relatively small; in the male those of the first segment are stiliform, and those of the second segment are always peculiarly modified. The telson is frequently divided by a transverse incomplete hinge. To this family three genera are assigned, which belong to the fresh waters of the northern hemisphere only. Potamobia, Leach, 1819, meaning ‘the creature that lives in a river,’ is the genus that has so commonly of late years been called Astacus. The name. is often also quite needlessly altered into Potamolius, and that by writers who use the name Geli unchanged, properly ignoring Risso’s pseudo-correction of it into Gebios. In Potamobia the last segment of the trunk carries a pleurobranchia and the two or the three preceding segments have rudiments of the pleurobranchie. According to Mr. Walter Faxon, whose authority on this subject is not likely to be disputed, the English species should be called pallipes (Lereboullet), | the Potamobia torrentium (Schrank), and the Potamobia fluviatilis ( (Auctorum) being distinct. It will be remem- bered that it was on this genus that the celebrated Ré- aumur conducted his investigations into what was at the time something of a mystery, namely the exuviation or shedding of the coat of the crustacean. Here too Rathke found materials for studying the development of the em- bryo, unfortunately for the commencement of such a study lighting upon an exceptional group, in which the young enters into liberty in a form not very remote from that of its parents. Cambérus, Erichson, 1846, has the pleurobranchize entirely suppressed, so far as is known, and the podo- branchia of the fourth pair of trunk-legs has no lamina. The third pair of trunk-legs, and sometimes also the second or the fourth pair, have in the male the third joint provided with a conical, recurved, hook-like process, and in the female the hinder edge of the penultimate sternum of the trunk is elevated into a transverse prominence, on the 208 A HISTORY OF RECENT CRUSTACEA posterior face of which there is a pit or depression, an arrangement designated by Dr. Hagen as the annulus ventralis. Mr. Faxon enumerates no less than fifty-five species, twenty-one of them being described by him as new in 1884. Cambarus Diogenes, Girard, which is widely distributed in the United States, constructs curious ‘chimneys’ at the mouth of its burrows, and Cambarus dubius, Faxon, it is said, ‘makes mud chimneys like C. Diogenes, which it seems to represent in the mountain regions, C. Diogenes belonging to the low lands.’ Cam- barus argillicéla, Faxon, is closely related to the two pre- ceding species. ‘he types of it were dug out of burrows in solid blue clay in Detroit, Michigan. ‘The burrows were three to five feet deep. At the bottom of each burrow was a pocket in a layer of loose gravel and clay, holding water. Just above the water-line an enlargement in the burrow formed a shelf on which the animal rested.’ It is a pleasing picture of retirement, safety, and comfort, if one can accommodate one’s mind to the feelings and re- quirements of a crayfish. Cambarus pellucidus (Tellkampf) is the blind species of Mammoth Cave, Kentucky, in which it is noticed as a singular circumstance that Cambarus Bartonit (Fabricius) occurs with well-developed eyes. Cambaroides, Faxon, 1884, is only introduced by its author as a sub-genus of Potamobia, but it may as well follow its destiny at once and become a genus. “Huxley in ‘The Crayfish’ mentions Astucus dauricus, Pallas, and Astacus Schrenkit, Kessler, as restricted to the basin of the Amur, which sheds its water into the Pacific over_against Japan. He points out that the branchial system of the Amurland Astaci is apparently the same as that of the rest of the genus, but that the second and third trunk-legs in the male have a hook-like process on the third joint, and that the females have the transverse prominence already noticed in Cambarus. It is on this combination of charac- ters from Cambarus and Potamobia that Faxon has founded his Cambaroides, to include the two species just mentioned and the Astacus japonicus of de Haan. In this species he suspects the existence of two forms of the male, a pecu- THE GLOBE PARTITIONED BY CRAYFISHES 209 larity that has long been known in the genus Cambarus. It was at one time supposed that one of the forms, not much differentiated from the female, might be sterile, and that the more highly developed and specialised form was the fertile male. But Mr. Faxon, having kept some specimens of the latter form under observation, found that after pairing at the next exuviation they assumed the less differentiated form, and his inference has been generally accepted that the two forms alternate in the same individual during a certain part of its life. As it is not probable that the Potamobiide have a monopoly of this curious -changefulness, the chance of its occurrence is one more pitfall to be guarded against in the institution of new species. Family 4.—Parastacide, These agree very closely with the preceding family except in regard to the branchiz, appendages of the pleon, and the telson. Here the first maxillipeds have the epipod almost always provided with a certain number of well-developed branchial filaments; the podobranchie of the following appendages are devoid of more than a rudiment of a lamina, while some of their filaments and attendant sete terminate in hooks. The first segment of the pleon has no appendages in either sex, and the appendages of the four following segments are large. The telson is never divided by a transverse hinge. To this family there are allotted six genera, all be- longing to the Southern hemisphere, and living, like those of the preceding family, only in fresh or brackish waters. The facts of distribution in regard to the two families are remarkable. Several species of Potamobia are found in rivers of Europe and Asia, and five species of that genus exist in rivers of North America, west of the Rocky Mountains, whereas fifty-two species of Cambarus inhabit the rivers and lakes of North America east of that range. Of the Parastacide, Astacoides, Guérin, 1839, with its solitary species madagascariensis, is found only in Mada- gascar; Parastacus, Huxley, 1878, was established for 210 A HISTORY OF RECENT CRUSTACEA species that belong to Southern Brazil; Paranephrops, White, 1831, is found only in New Zealand and (possibly) Fiji, while even within the limits of New Zealand its two species, planifrons and zealandicus, are found by Mr. Chilton to have distinct and separate ranges; Astacopsis, Huxley, 1878, and Engwus, Erichson, 1846, belong to Australia and ‘Tasmania, while Charaps, Erichson, 1846, belongs to Australia alone. Cheraps was instituted only as a sub- genus by Erichson, and by Mr. Haswell it is united with Astacopsis. Spence Bate, in remarking upon the peculi- arities of distribution here set forth, speaks of ‘ the several genera being adapted each to its own locality, no two genera being known to exist in one habitat,’ but to support this statement he assigns Astacopsis to Australia, Engeus to Tasmania, and Cheraps to Van Diemen’s Land, intend- ing perhaps a just reproach to those who altered the name of Van Diemen’s Land into Tasmania. In fact the small burrowing Lngeeus may be peculiar to that island, and, if not, it is separated by rather subtle distinctions from Astacopsis, so that the three genera in question form a very united group, and it is singular that, while they agree together in their branchial arrangement, they differ in that respect from all the other genera in the two families under discussion. The unnamed ‘ Australian Crayfish’ of Huxley, which sometimes reaches a length of twenty inches, is pro- nounced by Mr. Haswell to be Astacopsis serratus (Shaw). In Paranephrops zealandicus, Mr. Wood-Mason has ob- served that the young are specially fitted for attachment under the pleon of the mother. The specimens examined were under a third of an inch in length. The two hind- most pairs of legs have the sixth joint ‘provided at its extremity with a strongly hooked, exceedingly acute, movable claw, and on the lower edge at the end with six or seven sharp spines, against which the claw folds, and thus forms a very efficient prehensile arrangement.’ PI. xi. : i Base of Third Mazulliped : fear ca laiee lave mi ee ene a: 4 Plan of Branchial arrangement + \ Nt \ First Maxilia = Second First Second Mazilla Maxulliped Maxilliped _ Stenopus hispidus (Olivier) A SMALL TRIBE 211 CHAPTER XV TRIBE V.—STENOPIDEA THE carapace is produced to a laterally compressed ros- trum. The first antennz have two flagella, the second have a scale. The mandibles have a three-jointed palp. The exopod of the third maxillipeds is small, slender, and almost rudimentary. The first three pairs of trunk-legs are chelate, the third pair being the longest and largest. The branchize are filamentous; only the second maxillipeds have a podobranchial plume ; the hindmost pleurobranchial plume is the largest. The first pair of pleopods is one- branched and foliaceous; the uropods and telson have no transverse suture. Family Stenopide. This being the only family has the characters of the tribe. It contains two genera long included among the Penzide, with which they agree in having the third pair of trunk-legs larger than the two preceding pairs, but sepa- rated from that group by the structure of the branchiz. Of the third genus now transferred to this family, the branchiz have not been described. Stendpus, Latreille (in Desmarest), 1825, has a long, flat, obtusely pointed scale on the second antenne, the third trunk-legs long and slender, the fourth and fifth pairs with the antepenultimate joint subdivided, the telson taper- ing. The genus ranges from the eastern to the western hemisphere and from the Arctic regions to the tropics. Stenopus hispidus (Olivier) is recorded from the Pacific, from Bermudas, and perhaps from Greenland. Spence Bate’s figures of this species are reproduced on a re- 212 A HISTORY OF RECENT CRUSTACEA duced scale in the adjoining Plate. Stenopus spinosus, Risso, is from the Mediterranean. Spongicola, de Haan, 1849, has but one species, Spongi- cola venusta, with an extensive range in the Pacific. The scale on the second antennz is broad, not ending in a point, and fringed with long plumose hairs. The third pair of trunk-legs have the hand large and thick and the preceding joint short. In the two following pairs the antepenultimate joint is not subdivided, and the terminal joint is tridentate. The telson is ovate. The species is said to live in the beautiful Huplectella and other similar sponges Aphdreus, Paulson, 1875, has the third trunk-legs long and slender; the fourth and fifth pairs with ante- penultimate joint undivided and finger unidentate. The telson is acute. The third maxillipeds resemble antenna, each of the two slender terminal joints being subdivided into four jointlets. The type species is Aphareus inermis from the Red Sea. BRANCHING BRANCHIA 213 CHAPTER XVI TRIBE VI.—PENEIDEA THE branchial structure typically consists of a series of plumes, that are attached by, or very near, their basal extremity to the animal, and from a long central stalk send off on each side a single row of branches that divide and subdivide in a variety of ways according to the genus or even the species. The appendages of the trunk are supplied with nerves from separate ganglionic centres, except the last pair, which is supplied not from its own segment but the preceding. The third pair of trunk-legs are chelate, the two following pairs never are. The ex- traded ova do not appear to be definitely attached to the appendages of the mother prior to hatching as in most other Macrura. The first larval form is supposed to be a Nauplius. This tribe corresponds with what Spence Bate calls the Dendrobranchiata normalia, in allusion to the rami- fied, or tree-like structure of the branchize. He allots to it two families, the Penzeide and Sergestidee. Family 1.—Pencide. The carapace at the sides is deeply produced and carried further back than in the median dorsal line; its rostrum is laterally compressed, this part at least being carinated. Of the segments of the pleon the first three are usually not longitudinally carinate, but the three that follow are almost always much so. The sides of the first are produced so as to overlap the hind lateral margin of the carapace and the front lateral margin of the second 17 214 A HISTORY OF RECENT CRUSTACEA segment of the pleon. The telson is generally dorsally flattened or grooved. The eye-stalks are usually two- jointed. The first antennz have two multiarticulate flagella, and the first joint of the peduncle flattened to receive the eye-stalk and laterally strengthened on the outer side by a spine-like process, on the inner by an un- jointed appendage often fringed with hairs. The second antenne have a broad, thin, foliaceous scale, and a long flagellum. The mandibular ‘ palp’ is never more than two- jointed. The third maxillipeds are long and pediform. Both the second and third maxillipeds and the three or four following pairs of appendages carry ‘ mastigobranchiz’ or epipodal plates. The first three pairs of trunk-legs are chelate and similar, the second longer than the first, and the third than the second. The trunk-legs with occasional exception of the third pair have the antepenultimate joint unusually long in relation to the penultimate (in this respect agreeing with the Stenopidea and Nemato- curcinus). This family includes nearly a score of genera, only one of which frequents the shores of Great Britain. In his very detailed discussion of the family Mr. Spence Bate says that in the Peneeide the anterior three segments of the pleon ‘ are never carinated, but those that are posterior to them are always extremely so. Yet he subsequently mentions that Penceus velutinus, Dana, has the ‘ pleon cari- nated from the second somite to the posterior extremity of the sixth,’ and he gives a similar account of three of his own species, besides mentioning two others in which the carina begins on the third segment. On the other hand in the description of Penwus gracilis, Dana, he says nothing of any carina on the pleon, but states that all the six seg- ments are dorsally smooth. Similar remarks will apply to other genera. In Sicyonia, for example, he describes species which have the carina of the pleon extending from the first to the sixth segment, and in Gennadas species that have no carina on any segment of the pleon except the sixth. Pencus, Fabricius, 1798, has a dorsally serrate rostrum, APPENDAGES OF THE PENAIDEA 215 two- or three-jointed eye-stalks, flagella of the first antennze not longer than the carapace, a two-jointed man- dibular ‘ palp,’ the third maxillipeds long and pediform, the first three pairs of trunk-legs carrying exopods, the fourth and fifth pairs not longer than the preceding, the pleo- pods with two foliace- ous branches in every pair except the first, which in the male has a large membranous appendage attached to the base. This ap- pendage, called by Spence Bate the pe- tasma or curtain, is rudimentary in the female. In this genus there are no podo- branchie. The first species assigned to it by Fabricius was the large Penceus monddon, which occurs in the ae ag Cae Allanticus (Milne-Edwards), first u pleopods of the male, with petasmata united in neighbourhood of Cey: - fhe median line (Sp. Bate.]. lon, Western Australia, and the Philippines, and is perhaps identical with the Japanese Penceus semisulcatus of de Haan. Penwus cara- mote (Risso) is found in the Mediterranean and Atlantic, and is sometimes taken in English waters. Penceus canaliculatus, Olivier, appears to extend with little variation from Japan to Australia, and to differ only in small particulars from Penceus caramote. Thus, it has nine teeth instead of twelve on the dorsal crest, straight instead of wavy ridges on either side of the carina of the carapace, the spine on the outer margin of the first joint of the first antenne not nearly instead of quite reaching the extremity of the eye, no tooth on the second joint of 216 A HISTORY OF RECENT CRUSTACEA the third trunk-legs ; and the two teeth on each side of the telson in caramote are wanting in canuliculutus. Penceus esculentus, Haswell, is said to be the common edible prawn of Sydney, Newcastle, and other places in Australia, and but few must be required to make a dish, if they often reach, as they do sometimes, the length of nine inches. It is perhaps not distinct from the type species of Fabricius. In Peneus and some at least of the other genera in the family, there is on the ventral surface of the trunk a struc- ture peculiar to the females, to which Spence Bate has given the name of Thélicwm (see Plate XII.), ‘ which,’ he says, ‘so far as I am aware, has never been previously figured or described by any naturalist.’ Yet he presently after refers to one description of it by de Haan, and might have men-- tioned that it is described by that author in no less than four species. Of the female of Penceus canaliculatus, de Haan says that ‘the sternum is channelled between the three anterior legs, between the fourth having a narrow rounded horny Jobe, and between the fifth a broader membranaceous orbiculate lobe, which in advance of the middle is cleft and embraces the median spine.’ Referring to the same species and sex, Spence Bate says :—‘ On the ventral surface in both our specimens, between the poste- rior pair of pereiopoda, is a large thelycum, consisting of a dichotomous, calcareous capsule, which extends forwards as far as the base of the antepenultimate pair of pereiopoda, whence project two large, leaf-like, membranous appen- dages (Plate XXXII. fig. 49). They appear to be con- nected with the internal organs by means of foramina in the floor of the capsule, and have no connection with the fifth pair of pereiopoda.’ Paulson also, in 1875, figures and describes these appendages in various species of Pencus. The organ appears to vary considerably in different species, but the question is complicated by the probability that it may undergo important changes of form at different stages of the animal's existence. Spence Bate’s figures and de- scriptions will no doubt lead the way to the clearing up of this question. QUESTIONS OF DEVELOPMENT 217 Another intricate matter is the development of Pencus. Fritz Miiller in 1864 believed himself to have discovered the earliest stage. Of the brood of some prawns belong- ing to Penceus or some immediately kindred genus, he says, ‘they quit the egg with unsegmented oval body, an unpaired frontal eye, and three pairs of swimming-feet, of which the first are simple, the other two two-branched, belonging, therefore, to the larval form so frequent among the lower Crustacea, to which O. F. Miiller gave the name of Nauplius. No indication of a carapace, of the paired eyes, of mouth-organs near the mouth which is over-arched by a helmet-shaped hood!’ Between this and the adult there are various Zoea and Mysis or Schizopod stages, not to mention the Protozoea of Glaus interposed between the ege and the Nuuwplius form. Spence Bate alludes to the claim made by Professor Brooks in 1882 that, having captured and kept in confinement a specimen, he had witnessed every moult between the youngest Protozoea and the young Pencevs, but against this is set the comment of Mr. Walter Faxon in 1883 that Professor Brooks’ ‘youngest Protozoea is an older stage than the youngest stage secured by Fritz Miiller, to which he adds that ‘no observer has rediscovered Miiller’s Nauplius.’ Hence Spence Bate himself says that ‘two links of importance are yet wanting: the one is. that which connects the earliest Protozoea form with Fritz Miiller’s Nauplius, and the other that which connects the Nauplius with Penceus ; either of these being demonstrated will prove the con- nection, and establish the splendid hypothesis of Fritz Miiller.’ Solenocéra, Lucas, 1850, with its Mediterranean species Solenocera Philippi, Lucas, is by Victor Carus made a synonym of Lenceus siphonoctras, Philippi, but it differs from Pencus in having the flagella of the first antennze longer than the carapace, and should therefore be called Solenocera siphonoceras (Philippi), the earlier name Penceus membranaceus, Milne-Edwards, having been already used by Risso for a different species. The flagella in question are rather remarkable, since the primary is very slender, 218 A HISTORY OF RECENT CRUSTACEA whereas the secondary is dilated and longitudinally hollowed so that its companion can be sheltered within it when not in use, but at other times the two pairs of flagella together form the efferent branchial tube, which is continued back- wards by the peduncles of the first and the scales of the second antenne, these making a broad channel between the bases of the peduncles of the second antennz, where it is closed in below by the mandibular ‘ palp,’ and diverges on each side of the upper lip into the passages from the branchial chambers. The generic and specific names alike signify ‘a creature with channel- or pipe-forming antenne.’ Pleoticus, Spence Bate, 1888, also has the flagella of the first antennz longer than the carapace, but without the grooved arrangement. + Its second antenne claim notice as having the flagellum ‘three times the length of the animal, or more.’ Sieyonia, Milne-Edwards, 1830, has its species, two of which occur in the Mediterranean, distinguished for the rigidity of the integument. ‘The flagella of the first antennee are very short; there are no exopods to the trunk-legs as there are in Penceus, and the pleopods are all single-branched. From Penceus it differs in the struc- ture and arrangement of the branchie, though agreeing with it apparently in the absence of podobranchie. In defining the genus Spence Bate says that the second maxillipeds carry ‘a mastigobranchial plate without a podobranchia,’ ‘ one arthrobranchial and one pleurobran- chial plume.’ On the next page, after giving a scheme of the branchiz of Sicyonia which includes six pleurobranchiz and no podobranchiz, he states that it differs from Penceus ‘in the absence of any traces of pleurobranchie, in the reduction of the arthrobranchial plumes, and in the pre- sence of one podobranchial plume attached to the first pair of gnathopoda’ [i.e. second maxillipeds]. Presently after, in the description of Sicyonia carinata (Olivier), he says of these same second maxillipeds that the first joint ‘carries a long and slender mastigobranchia shaped like that in Penceus, and, as in that genus, there is no bran- chial plume attached to it.’ Thus there both is and is not Pl. xii. First j Maxilliped . #f showing the Thelycum Lower Lip =e Branchial Plume, in Section Epistome Hepomadus glacialis, Sp. Bate THOUSANDS OF FATHOMS 219 a podobranchia to the second maxillipeds, and there are no traces of pleurobranchiee although pleurobranchiz are developed on six pairs of appendages. These are riddles which those who have specimens to compare with the de- scriptions may be able to solve. Aristeus, Duvernoy, 1841, is distinguished from Pence us chiefly by the circumstance that on the second and third maxillipeds and the first three trunk-legs it has the podo- branchize which the other is without. 7 z Caridina, 224 Caridion, 233; Gordoni, 235 Carpus, alias carpopodite, fifth joint, wrist, 43; its occasional subdivision, 44; in the Poly- carpinea, 228 Cassidina, emarginata, latistylis, maculata, neo-zealanica, typa, 365 Catapagurus, 165; Sharreri, 168 Catattut, Amboinese name of cocoanut crab, 158 Catometopa, the tribe defined, 78 Catta, Professor, on distribution, 99 Cenobita rugosa, 159 Cenobitide detined, 155 Cephalon, 32 Cephalothoraz, 32 Cerapus dentalii, an Indian amphi- pod, 335 Cerataspis monstrosus, one of the Penxidx, 220 A HISTORY OF RECENT CRUSTACEA CHL Ceratocarcinus, 120 Ceratocephalus, 364 ; Grayanus, 365 Ceratolepis hamata, 258 Ceratothoa, misapplication of the name, 354 ; species properly be- longing to, auritus, crassa, lati- cauda, linearis, 353, 354 Cercocytonus, a cancelled generic name, 434 Cervical groove, 33, 52; absent from ‘ Ibacus verdi,’ 193 Ceylon, crab-hunting pigs in, 159 Cheraps, distribution of, 210 Cheetilia ovata, 372 Cheetiliide, the family, rejected by Miers, 373 Chalaraspis alata, 260 Chalarostylis elegans, 309 ‘Challenger, H.M.S., abyssal &e. species found by, 18 Chameleon species, a, 235 Charybdis cruciatus, vivid colour- ing of, 69, its names upheld, 70 Chavesia costulata, 429 Cheiroplatea, telson in, 47; ceno- bita, 170 Chelate, 45 Chelifera, the Isopod tribe, de- fined, 318 Chelipeds, 44 Chelura terebrans, a wood-boring Amphipod, 17 Cheramus, 183; its position ques- tioned, 184 Cheraphilus, bispinosus, nanus, trispinosus, 226; echinule:.tus, neglectus, 227 Chevreux, M. Ed., many Amphi- pods on Maia squinado, found by, 22; on Helleria brevicornis, 425 Chilton, Mr. C, on the Phreatoi- cide, 388, 390 Chioncecetes opilio, size of, 117 Chiromysis, synonym of Heteromy- sis, 273 Chitin, 62 3a Chlorida preoccupied, 287 Chioridella,substitute for Chlorida, 281, 287 INDEX CHL Chlorotocus, 237, 238 Chorinus algatectus, 113; aculea- tus, 115, 116; longispina, 116 Chorismus, 234 Ciliczea, 364 Circeis, bidentata, tridentata, 365 Circulation, 182 Cirolana, 342; borealis, concharum, Cranchii, spinipes, 243 Cirolanidz defined, 341 ‘Cirripedia, alias Thyrostraca, posi- tion and sub-division of, 11; their range, 17; large species of, 31 Cladocera, a sub-order of Branchio- poda, 9 Cladocopa, «» sub-order of Ostra- coda, 10 Classification, of animals, 1; of Arthropoda, 3; of Crustacea, 6; of the Anomura, 8, 133, 146; of the Schizopoda, 223, 256; of the Tanaidw, 328; of the Phreatoicids, 391 flaus, Dr. C., on foot-jaws of Copepoda, 42; development of Stomatopoda, 288 Cleantis, filiformis, tubicola, 375 Clibanarius, 160 Cocoanut Crab, Birgus latro, man- ners and nature of, 156 Codonophilus argus, 356 Ceecidotea stygia, a blind cave- dwelling species, 377 Ceelenterata, 1 Collecting, chapter on, 12; the eatable crab, 65 Colouring, of common shrimp, 16 ; American Lady Crab, 68 ; Chary- bdis cruciatus, 69 ; Ocypode, 86 ; Grapsus pictus, 94; Lazy Crab, 121; Galathea magnifica, 176; Upogebia stellata, 185; larvee of American lobster, 205; Al- pheus comatularum, 231; Al- pheus affinis, 231; Hippolyte varians, 235; Gnathophausia, 260; Euphausia superba, 262; Squilla empusa, 283 ; Gnathiide, 338; Nasa and Dynamene, 361; Trichoniscus roseus, 422 445 CRA Columbus, his argument from a crab, 95 Concheecetes, 135; conchifera, 136 Concholestes dentalii, an Indian amphipod, 335 Conilera, 342; cylindracea, vora- city of, 343 ; Copepoda, an order of Entomos- traca, 9; where found, 17; bathymetrical range of, 20; first antenne of, 35; foot-jaws of, 42 Corallana, hirticauda,tricornis,315 Corallanid detined, 341 Cordiner, Rev. Charles, work by, 371 Corilana erythraa, 346 Coronida, 281; Bradyi, trachurus, 287 Coronis 287 Corophium, position of heart in the Amphipod, 328 Corystide, 72 Corystinea defined, 72 Corystes, 74; cassivelaunus, fea- tures of, 72, 73 ; supposed rela- tion of, 145 Corystoidea, 139 Couch, J., on second antenne of Corystes, 73; on Autonomea Olivii, 253 Corwich, the, 11] Coxa, alias coxopodite or first joint, 43 Crab’s eyes, 83 Crab-fish, 5 Crab Island, Drake at, 26; land- crabs at, 80 Crabe enragé, 65 Crabyzos longicaudatus, 373 Crangon, 224, 225; vulgaris, dis- tribution of, 225; Allmann, bispinosus, fasciatus, nanus, sculptus, trispinosus, 226; cata- phractus, lar, salebrosus, 228 ; munitus, parasite of, 395 Crangonide defined, 224 Crangoninea defined, 224 Crawfish, 5, 196 Crayfish, 5; Australian, 210 preoccupied, 231, 284, 446 CRA ‘Crayfish, The,’ by Huxley, on the second maxilla, 41; on struc- ture of Crustacea, 48; on‘ palp’ and ‘ flagellum,’ 192; on Amur- land Astaci, 208 Crossophorus imperator, a giant among Ostracoda, 31 Cruregens, 332; fontanus, 333 Cruripeds, 44 Crustacea, alias Crustata, defini- tions of, 3; meaning of name, 5; subdivision of class, 6 Cryptocheles pygmza, 237 Cryptocope, 325 Cryptodromia lateralis, 136 Cryptolithodes typicus, 154 Cryptoniscian forms, 394, 397, 398, 401, 405 Cryptoniscide discussed, 401 Cryptoniscus, planarioides, 402; larveformis, paguri, 403 Cryptopodia, 154 Cryptopus, synonym of Cerataspis, 220 Cryptosoma cristatum, its priority questioned, 125 Cryptothir, balani, minutum, 404 Cryptothiria, synonym of Crypto- thir, 401, 404 Cubaris, albomarginatus, javanen- sis, melanurus, officinalis, tri- folium, 433 Cuma, 8, 301; arenosa, Audouinii, Edwardsii, scorpioides, 302; pulchella, 303 Cumacea, origin of name, 8; dis- cussion of, 291; suborder de- fined, 301 Cumella, limicola, pygmea, 306 Cumide defined, 301 Cumopsis, 302; Edwardsii, levis, longipes, 303 Cuvier, on the pinna and crab, 100 Cyathura, 331; carinata, 333 Cyclaspis, 302; cornigera, levis, pusilla, 303 Cyclide, 54 Cyclinea, 71 Cyclodorippe, doubtful position of, 130 Cycloés granulosa, 125 A HISTORY OF RECENT CRUSTACEA DEE Cyclograpsus, respiration of, 97 Cycloidura venosa, 364 Cyclometopa, the tribe defined, 55 Cyclorhynchus preoccupied, 234 Cyclura preoccupied, 364 Cylisticus convexus, 428 Cylloma, 433; oculatum, 434 Cymodoce, emarginata, Lamarckii, truncata, 362; abyssorur, 363 Cymonomus granulatus, 132 Cymopolia Caronii, 132 Cymothoa, sexes of, 350; eremita, on tongues of fish, 353 ; cestrum, 354 Cymothoide, as a group, defined, 339; Hansen’s tabular view of, 340 Cymothoidz, in restricted sense, defined, 341; discussed, 350, B51 Cynthia preoccupied, 276 Cynthilia, synonym of Siriella, 276 Cyproniscide, 397 Cyproniscus cypridinz, descrip- tion of, 397 Cyrtomaia, Murrayi, Suhmi, 110 Cyrtopia, larval stage of Euphau- siide, 266 Cystisoma, genus of Amphipoda Hyperidea, 30 Czerniavsky, V., bibliographical writings of, 174; remarks on Callianassa by, 183 Dacryuvs, alias Dactylopodite, finger, nail, or seventh joint, 43 Dajide defined, 398 Dajus described, 398; mysidis, sirielle, 399 Danalia, curvata, Dohrni, Lobian- coi, 403 Darwin, Charles, on inosculant forms, 93; on Grapsus at St. Paul’s Rocks, 94; on a crab allied to Notopus, 143; on the cocoanut crab, 156 Darwin, Erasmus, on the nature of flesh, 6 Decapoda, objection to the word,7 Deep-water species, 18, 19, 20, mixtus, INDEX DEF 201, 219, 237, 243, 250, 262, 259, 261, 269, 291, 326, 383, 387 Definition, difficulties of, 5; need for caution in, 145 De Freminville, inaccurate de scription by, 144 De Haan, on respiratory arrange- ments, 41, 140; on ‘spurious females, 109; on the clothing of Chorinus, 116; on the food of various crabs, 124; on the impropriety of establishing the suborder Anomura, 146 Delage, M. Yves, on breathing of Apseudide, 320; on circulatory apparatus of Tanaide, 378 De Man, Dr. J. G., on Thelphusa, 77; on Porcellanide, 173 Demon-faced Crab, the, 132 Dendrobranchiata, 180, 213 Dendrotion, 382 ; Dennisia sagittifera, marking of, 249 Deodamia preoccupied, 201 De Paw, description of death of Drake by, 25 Desmarest, A.G., edition of Bosc’s Crustacea by, 25; history of Crustacea by, 437 7 Desmosoma, aculeatum, armatum, lineare, tenuimanum, 386 Deto, acin sa, echinata, 431 Development of Cancridz. 59, 60; of the Anomala, 172, 178; of Norway lobster, 202; of Ameri- can isobster, 204; of Craytish, 207; of Euphausiide, 265; of Squillide, 288; of Gnathiide, 335, 337; of Epicaridea, 396, 397, 402, 404 Diaphoropus, slight foundation for the genus, 239 Diastylidz defined, 310 Diastylis, 310; discussion of the name, 311; stygia, 20; Good- siri, 29, 310; biplicata, cornuta, echinatus, insignis, levis, lamel- lata, Rathkii, rugosa, spinosa, tumida, 3]1 Diastylopsis, Dawsoni, resima, 311 Dicera preoccupied, 75, 76 44:7 EBN Dicerobates eroogoodoo, the huge fish, 222 Dicranodromia, an genus, 137 Diogenes, 160; varians, 161 Diops, parvulus, spinosus, 306 Diptychus preoccupied, 178 Distribution, questions of, 22, 23; by unconscious human agency, 99; in the deep sea, 153; of Asta- cidea, 209; by wading birds, 241; of Eucopia, 261; of Sto- matopoda, 280; of Serolide, 358; of Oniscoidea, 422, 428, 433 Dodecas elongata, one of the Am- phipoda Caprellidea, 30 Dohrn, Dr. A., on the structure of the Guathiids, 336, 337 Dollfus, M. Adrien, on distribu- tion of Porcellio, 428; on Lu- casius, 429; on the parts of tie head in Oniscoidea, 435 Don Diego in ‘t volle harnasch, 158 Dorippe, facchino, 130, 132; ja- ponica, 131, 132; dorsipes, 132 Dorippide defined, 130 Dorodotes, 237, 238 Doryphorus preoccupied, 233 Dotilla, brevitarsis, fenestrata, 102 Doto preoccupied, 102 Drake, Sir Francis, 25 Dressing, crabs practise, 112, 113, 115 Dromia, 134; origin of the name, 135; Rumphii, vulgaris, 135 Dromide defined, 134 Drominea defined, 133 Dynamene, Montagui, rubra, ver- sicolor, viridis, 361, 362 Dynomene, 136 inosculant EARSTONES, alias otoliths, 36, 37, 182, 196 Ebalia, Bryérii, Cranchii, nux, Pennantii, tuberosa, tumefacta, 129; undecimspinosa, 130 Ebner, Dr. V. von, on respiratory apparatus of Tylos, 423; on Helleria, 425 448 ECH Echidnocerus setimanus, size of, 154 Echinoplax Moseleyi, 110 Ecphysis, alias exopod, 194 Edible crab, the, good contrivance for extirpating, 57 Edotia, bicuspida, triloba, 374; tuberculata, 375 Eriophthalma, 7, 8, 43; defined, 291 Egeon, fasciatus, sculptus, 226 Eggs, of Gecarcinus, 83; often large in deep-water species, 177, 189; of Squilidz, 288; of Cu- macea, 298 Eiconaxius, acutifrons, parvus, 188 Hisig, Dr.,on behaviour of Inachus, 113 Eisothistos, 331; mimicry by, 335 Elamene Mathzi, 102 Elaphocaris, a larval Sergestes, 221 Eluma, 433; purpurascens, 434 Endopod, alias endopodite, 36 Endostome, 62 Engeus, distribution of, 210 Entione achezi, 406 Entomostraca, 6, 7; subdivision of, 9; where met with, 14,17; numbers and sizes of, 31; seg- ments of, 32; mandibular palp in, 32 Entoniscidz defined, 405 Ent ‘niscus, brasiliensis, Creplinii, Miilleri, porcellanz, 406 Ephyra (?) compressa, 241 Ephyrina Benedicti, 244 Epicaridea, discussion of, 392; phylogenetic table of, 393 ; mar- supial plates of, 297, 393 Epichthys giganteus, 352 Epipod, 41, 42; of first maxillipeds in Eucopia, 260 Epistome, the, 52, 435 Epizoanthus, americanus, paguri- philus, colonial polyps asso- ciated with Hermit-crabs, 168 Eretmocaris, 254; longicaulis, eye of, 35, 255 Ergasticus, Clouei, Naresii, 110 Ergyne cervicornis, 413 great vermiformis, A HISTORY OF RECENT CRUSTACEA EUP Erichsonia filiformis, 375 Erichthalima, 290 Erichthide, larval Squillidz, 281 Erichthus, 289 Eriocheir japonicus, 95 Eriphia, ridges on endostome of, 62 Eryon, a fossil genus, 199; cari- bensis, 144 Eryontidz defined, 199 Erythrops, 267, 275; elegans, ery- throphthalmus, Goésii, pyg- meus, serratus, 275 Estheria californica, a large Phyl- lopod, 31 Ethusa, 18, 132; mascarone, 53, 132; granulata, 132 Ethusina, challengeri, 18 ; abyssi- cola, 132 Eubelum lubricum, 433 Eucheta glacialis, mandibular ‘palp ’ in, 39 Euchetomera, tenuis, typica, 267, 276 ; Eucolomban, ornatus, picta, 345 Eucolumba, ornatus, picta, 345 Eucopia australis, 260; distri- bution of, 261 Eucopiide defined, 260 Eudora preoccupied, 305 Eudorella, emarginata, truncatula, 305 Eudorellopsis, deformis, resima, 305 Eugerda globiceps, 382 Eukyphota, meaning of, 224; iso- pods parasitic on, 410 Eumetor liriopides, 404 Eumiersia, synonym of Nemato- carcinus, 249 Eumunida picta, 177 Euneognathia, new genus, gigas, 338 Eunephrops Bairdii, 202 Eupagurus, 110; Bernhardus, cu- anensis, excavatus, Prideaux, pubescens, sculptimanus, 161; isopods parasitic on, 409, 410, 411 Euphausia, luminosity of, 262; pellucida, superba, 262 INDEX EUP Euphausiide: defined, 261 Euphylax, 71 Euplectellaaspergillum, Crustacea living in, 212, 349 Euprognatha rastellifera, abund- ance of, 111 Eurycope, 384; gigantea, mutica, sizes of, 29; cornuta, gigantea, mutica, phalangium, robusta, 385; cornuta, parasite on, 401 Eurydice, 842; achatus, pulchra, truncata, 344 Eurynome, 120; aspera, boleti- fera, scutellata, tenuicornis, 121 Euryozius, a sub-genus, 63 Eurypanopeus, 56 Eurythenes gryllus, size and dis- tribution of the Amphipod, 30 Eurytium, 56 Eutrichocheles modestus, 206 Evatya, 241 Evolution, the theory of, tested, 97; links in the chain of, 103; exemplified in hermit-crabs, 164; bearing of parasites upon, 403 Eyes, 34, 35; of Ommatocarcinus, 92; of eatable shrimp, 225; of Acanthephyra microphthalma, 213; of Eretmocaris, 255; of Schizopoda, 265, 266, 268, 269, 273, 275; of the Squillida, 279, 282; of the Edriophthalma, 291; of the Cumacea, 292; of the Apseudidz, 320; of the Sero- lide, 359 Eye-lash, 181 Eye-stalk, in the Podophthalma, 35; in Panulirus penicillatus, 197; in Polycheles, immovable, 200; in Willemoesia, rudimen- tary, 201 Exopod, alias exopodite, exo- gnathite, scale, acicle, outer branch, 36, 39; sometimes called the palp, 192 Exuviation, 84, 207 Fasricius, J. C., condemnation of Hill and Renard by, 162 449 GAM Faro Isles, the, 118, 206 Faxon, Mr. W., on the English craytish, 207 ; on Cambarus and Cambharoides, 208, 209 Fiction, 25, 107, 162 Fiddler crabs, English, 66; Ameri- can, 89, 91 Fish-lice, Copepoda known as, 17 Flabellifera, the tribe, defined, 330 Flabellum, or fan, of the second maxille, 41; of the pleon, 46, 116, 330 Flagellum, or lash, of antenne, 35, 36, 37, 38; of an exopod, 192; alternative name for po- dobranchia, 192 Food, Crustaceans used for, 12, 14, 26, 57, 65, 81, 95, 124, 158, 225, 229, 247, 282 Food of Crustaceans, 21, 25, 86, 94, 124, 151, 201, 248, 285, 315, 336, 342, 357 Fossettes, 51 Fraisse, Dr., on parasitic Crusta- cea, 109, 402, 404 Fraudulent specimens, 107, 162 Freshwater Crustaceans, 13, 14, 17, 23, 28, 76, 207, 209, 246, 217, 257, 333, 355, 373, 376, 379, 389 .Frog-crab, the, 143 ‘ Front,’ the, 52 Fulton, Dr.,on Dajus mysidis, 399 Furcilia, larval stage of Euphau- siide, 266 GALATHEA, courage of, 15; swim- ming powers of, 175; dispersa, intermedia, nexa, squamifera, strigosa, 175; digiti-distans. magnifica, 176; gregaria, 177; development of, 179 Galatheide, bathymetrical range of, 175 Galatheinea defined, 174 Galene, 93 Gammaridea, size of, 30; pecu- liarities in limbs of, 390; the tribe, 436 Gammarus, pulex, 13, 23; littoral species of, 16 450 GAS Gastric region, 52 Gastroliths, 83 Gastrosaccus, 267, 277; sanctus, spinifer, 277; Normani, 278 Gebia, synonym of Upogebia, 185 Gebios, synonym of Upogebia, 185 Gecarcinide defined, 78 Gecarcinucus, 79 Gecarcinus, 79; curious particulars of, 80; ruricola, 80; lagostoma, 84 Gecarcoidea, 79, 80 Gelasimus, 88; arcuatus, 88, 89, 91; pugilator, vocans, 89; minax, 91 Genders of generic names, discus- sion of, 75, 120 Genera, protest against multiply- ing, 227; minute distinctions of, 323; attempts at reduction of, 360 Gennadas, bathymetrical range of, 19; eyestalk of, 220 Geograpsus, 94 Geothelphusa, 76 Gerstaecker, Dr., work on Crus- tacea by, 360 Geryon, quinquedens, eggs of, 62 ; doubtful systematic place of, 93; tridens, luminous eyes of, 103 Gesner, on the habits of Pinno- theres, 100; criticism of Aris- totle by, 164 Giard, Professor, explanation of ‘spurious females’ by, 109, 396 Giard and Bonnier, on Epicaridea, 392, 393, 396, 399, &c. Gigantione Moebii, 414 Gigantostraca, the sub-class, 6; rarity of, 10 Glaucothoé, 170! Globigerina ooze, species taken on, 201 Glossobius, synonym of Cerato- thoa, 353, 354 Glyphocrangon, distribution of, A HISTORY OF RECENT CRUSTACEA GRA 229; large eyes and powerful telson of, 230; aculea tus, granu- losis, rimapes, 230 Glyptonotus, antarcticus, entomon, 372 Gnathia, marsupial arrangement in, 300; cerina, formica, Hali- daii, maxil'aris, 337 ; asciaferus, bathybius, Danielii, gigas, 338 Gnathiidez defined, 335 Gnachophausia, ingens, size of, 28; gigas, Goliath, 29; cha- racters of the genus, 258; cal- carata, gracilis, gigas, ingens, 260 Guathopods, 42 Gnathostoma,a sub-order of Cope- poda, 10 Gomeza, 76 Gonatonotus, 246 Gonerichthus, larva of Gono- dactylus, 290 Goniograpsus marmoratus, 94 Goniopsis, manners of, 98 Goniosoma cruciferum, synonym of Charybdis cruciatus, 70 Gonodactylus, faleatus, chiragra, 286 Gonoplax, alias Goneplat, Gone- plax, 91; angulata, rhomb» ides, sinuatifrons, 92; rhomboides, lung-stalked eyes of, 35 Goodsir, Harry, eyes of Cumacea described by, 292; on develop- ment of Cumacea, 293 Gosse, P. H., on action of fiddler- crabs, 66 Graeffe, Dr., on the toilette of the Oxyrrhyncha, 112, 113 Grapsicepon, 412; Edwardsi, Fritzii, messoris, 413 Grapside defined, 93 Grapsion, 405, 406; Cavolinii, 407 Grapsus, respiration of, 87, 97; habits of, 94; maculatus, 93; marmoratus, pictus, 94 Grass Crab, the, 75 *MM. Chevreux and Bouvier have recently confirmed the opinion that the genus Glaucothoé represents only larval forms, and they argue that these belong rather to the family Paguride than to the Parapaguride. INDEX GRE Greek, enigmas 253 Gribble, the, 367 Grimothea gregaria, position of, 177 Gumey, Mr., observation of young hermit-crabs by, 164 Gyge, branchialis, galathes, 412 in, 234, 250, doubtful HaBits, of littoral crustaceans, 15: cirripedes, 17; Cancridz, 57: of larval forms, 61; of Car- cinus meenas, 65; Corystes cas- sivelaunus, 73 ; Cancer ruricola, 80; the calling crab, 8€; Pin- notheres, 100; the Oxyrrhyncha, 112; Ranina, 142; Birgus latro, 156; Hermit-crabs, 163; Squil- lide, 280, 285; Cumacea, 294, 299; Isopoda, 315; Cymothoa, 354 Hagen, Dr., on Cambarus, 208 Halicarcinus, 101; Mathei, 102; planatus, antarctic distribution of, 102 Haliophasma maculata, 332 Hansen, Dr. H. J., on flabellum and joints of second maxillez, 41, 295; on Schizopoda, 268 ; on the Cymothoide, 339, &c. Hansenomysis, new generic name, Fylle, 268 Hapalogaster, 154 Haplocope, 325 Haplophthalmus, danicus, Mengii, 422 Haplopodinea defined, 253 Haplostylus, erythraus, Normani, 278 Harger, Oscar, on Astacilla, 371; on marine Isopoda of New Eng- land, 375 Harponyx pranizoides, 355 Haswell, Mr. W. A., on Elamene Mathzi, 102; on Paratymolidez, 139 ; on Eisothistos vermiformis, 335 Haswellia carnea, 366 Haynes, F. H., Mr., specimens of Pontonia received from, 241 451 HES Head, difficulty of defining a, 33 Heart, position of, 48; of Mala- costraca, 50 ; in Euphausiide, 262; in Stomatopoda, 279; in Cumacea, 300; in Isopods gene- ie 317; in [sopoda chelifera, 19 Hectarthropide, 254 Hectarthropus, meaning of, 254 Hedriophthalma, refinement upon Edriophthalma, 8 Helice, ‘musical crest’ in, 92 Heller, Dr. Camil, on the genus Thelphusa, 77 ; proposes the term loricata, 191; genera named after, 425 ~ Helleria brevicornis, 425 Helleriidz defined, 424 Helms, Mr. R., Phreatoicus austra- lis found by, 389 Hemiarthrus, Cranchii, philonika, typtonis, virbii, 417 ; abdomina- lis, 418 Hemilamprops, assimilis, cristata, rosea, uniplicata, 309 Hemilepistus ruderalis, 428 Hersioniscus balani, 404 Hemiplax, 93 Henderson, Dr. J. R, on bathy- metrical range of Anomura, 19; report on Challenger Anomura by, 134; on the habits of Zan- clifer, 145; on Pagurids and their dwellings, 169; on Uro- ptychus, 178 Hensen, Dr.,V., on the auditory arrangements of Palinurus, 196 ; of Palemonetes varians, 248 Hepatic lobes, 48 ; of Cyclome- topa, 55; of Catometopa, 78; of Oxyrrhyncha, 104; of Cumu- cea, 300; of Isopoda, 317 Hepatus princeps, 127 Heracleoticus of Aristotle, identi- fied with Thelphusa, 77 Herbst, J. F. W., 67, 72, 80, 135, 136, 145 Hermit Crabs, 147, 163 Herring food, 263, 292 Hesse, Hugéne, on habits of Cu- macea, 299; on the sexes of i 452 HET Gnathia, 337; on the Sphzro- mide, 362 Hetairus, 234; difficulties in the way of accepting, 235 Heterocarpus, ensifer, 238; cari- natus, 239 Heterocrypta, Maltzani, Marionis, 122 Heterocuma, Sarsii, var. granulata, 304 lleteromysis, 267 ; formosa, 273 Heterophryxus appendiculatus, 400 . Heterotanais, 323; limicola, Or- stedi, tenuis, 327 Hexapoda, alias Insecta, 3 Hexapus, explanation of the name, 102; relations of, 103 Hieroglyphics, pinna and crab in, 100 Hippa, 149; emeritus, talpoida, 150 Hippidee defined, 149 Hippinea defined, 149 Hippolyte, 234; Gaimardii, var- ians, 235; Cranchii, fascigera, Liljeborgi, Mitchelli, pandali- formis, Prideauxiana, producta, pusiola, securifrons, spinus, viridis, Whitei, 236; Thomp- soni, 237 Hippolytids defined, 233 Hoek, Dr. P. P. C., on Dajus my- sidis, 399 Holothuriaphilus, 101 Homaride, reason for discarding the name, 201 Homarus, a synonym of Astacus, 2 Homola, barbata, Cuvieri, orienta- lis, 137 Homolide defined, 137 Homologenus, 138 Homolopsis preoccupied, 138 Horse-shoe Crab, 17 Hoyle, Mr, W. E., on larval stages of Enphausiide, 265 Huenia, curious derivation of, 107; elongata, heraldica, proteus, discussion of, 107, 109 Huxley, Professor, terms used by, A HISTORY OF RECENT CRUSTACEA ION 86; on the maxillary fan, 41; on ‘palp’ and ‘flagellum,’ 192; on branchie of Nephrops, 202 ; on Amurland Cray-fishes, 208 Hyas, 113; araneus, coarctatus, small specimen of, 114 ; curious habits of, 114 Hyatt, Mr. Alpheus, Guides by, 40 Hyleocarcinus, 79, 80; Humei, 84 Hymenodora, 245 Hymenosoma orbiculare, 101 Hyperidea, tribe of Amphipoda, 436; specimens on jelly-tishes, 22; large species of, 30 Hypoconcha, 135; sabulosa, ex- amined by Herbst, 136 Hyssura, 331; producta, 333 Science Iats Hargeri, 378 Ianthe, speciosa, Bovallii, 378 Janthopsis Bovatlii, 378 Jathrippa longicauda, 378 Ibaccus, mis-spelling of Ibacus, 193 Ibacus, incisus, verdi, 193 Ichthyophilus, synonym of Nero- cila, 351 Ichthyoxenus, Jellinghausii, mon- tanus, 355 Tcotopus, meaning of name, 254 Idotea, emarginata, lacustris, linearis, marina, metallica, pelagica, sexlineata, tricuspi- data, 373 ; acuminata, appendi- culata, longicaudatus, parallela, prismatica, 374 Tdoteide defined, 372 Tlyarachna, longicornis, quadri- spinosa, 386 Tlyoplax, 93 Inachidee defined, 104 Inachus, dorsettensis, dorynchus, leptochirus, 106 Insecta, extent of class, at present, 3; formerly, 57 Insect, crab spoken of as an, 95 Tolanthe, 378 Tone, cornutus, gebiz, thoracicus, vicina, 414 INDEX IPH Iplinoe, 302; tenella, trispinosa, 803 Isa Montagui, amphipod found on Maia squinado, 22, 111 Ischium, alias ischiopodite, or third joint, sometimes called the genu or knee, 43 Ischnosoma, bacillus, bacilloides, bispinosum, quadrispinosum, spinosum, Thomsoni, 383 Isea, a doubtful genus, 184 Isocladus, armatus, spiniger, 364 Isopoda, sub-order of Edrioph- thalma, 8; size attained by, 29 ; sub-divisions of, 314; defined, 317 Ives, Mr. J. E., term cruriped proposed by, 44; on Hippa emeritus, 150 JRA, albifrons, Guernei, longi- cornis, Nordmanni, 379 Jetropsis, brevicornis, marionis, neo-zelanica, 379 Jamaica, Grass Crab of, 75; land crabs, 80; Oyster Crab, 101; Mamma Shrimp, 145; Mother Lobster, 192; isopod, 432 Jamna longicornis, 379 danira, alta, maculosa, 377; abys- sicola, laciniata, longicauda, spinosa, tricornis, 378 Japan, Crustacea of, 27 ; de Haan’s work on, 44, 88, 95, 101, 102, 107, 125, 128, 144, 154, 421 Jasus, priority over Palinosytus of, 197 Jaxea nocturna, 187 Jobert, M.,on breathing apparatus of land crabs, 85 Johnson, Dr. Samuel, on the lan- guage of natural history, 5 Johnston, G., species of Mga named by, 349 Jonah’s whale, fish fit to be, 222 KeEpon typus, 412 KergueJen Island, Crustacea from, 243, 338, 358, 378, 380, 381, 386 33 453 LEP King Crab, the, 27 Kirk, Mr. T. W., on Palinurus tumidus, 27 Kolga, a fossil genus, 220 Krauss, Dr. F., on South-African Crustacea, 69, 77, 86, 91, 98, 117 Kroyer, H., Chioncecetes opilio figured by, 117; on the Cumacea, 292, 293 Kosciusko, Mount, isopod found high up on, 389 LABIUM, alias lower lip, 40 Labrum, alias upper lip, 40 Lady Crab, the British, 66; the American, 67 Lady in the chair, the, picture of, 48 Lambrus, intermedius, macroche- los, 121 Lampropide defined, 308 Lamprops. 308 ; fa ciata, fuscata, quadriplicata, 309 Land Crahs, 14, 80 Lanocira Kroéyeri, 346 Larval forms, 59, 60, 172, 178, 204, 221, 222, 265, 288, 335, 337, 402 Latin, specimen of scientific, 418 Latreille, nomenclature of Crus- taceans by, 8, 9, 315 Latreillia, deceptive outward form of, 137; elegans, valida, 137 Latreillopsis bispinosa, 138 Latreutes, 234 Lazy Crab, the, 121 Leach, Dr. W. E., on the way to take Cancer pagurus, 57; his name for the Gulf-weed crab, 95; his name for the common lobster, 203 Leachia preoccupied, 370 Leacia, synonym of Astacilla, 370 Leander, 246; serratus, telson of, 46; Fabricii, Leachii, serratus, squilla, 247 Leidya distorta, 412 Leiolophus clavimanus, 98 Leiopus leptodactylus, unusual maxilla of, 321 Lepas, compared with Leucifer, 454 LEP 223; anatifera, size attained by, 31; fascicularis, larvae of, 206 Leponiscus pollicipedis, 405 Leptaspidia brevipes, curious habi- tat of, 381 Leptochela, gracilis, robusta, ser- ratorbita, 252 Leptochelia, 323; algicola, dubia, Edwardsii, Savignyi, 326 ; limi- cola, 327 Leptocuma Kinbergii, 304 Leptognathia, 324; laticaudata, Lilljeborgi, rigida, 327 Leptomysis, 267; gracilis, ling- vura, 274 Leptopodia sagittaria, 106; frau- dulent use of, 107 Leptosoma preoccupied, 374 Leptosquilla, 281 ; Schmeltzii, 288 Leptostylis, 311; manca, last less deficient in, 298; producta, 311 Leptotrichus, pulchellus, tauricus, Lerneza abyssicola, a parasitic copepod, 20 Leucifer, Reynaudii, eyes of, 35 ; typus, 222; comparison of, with Lepas, 223 Leucon nasica, 304 Leuconids defined, 304 Leucosia, australiensis, pulcher- rima, scabriuscula, splendida, 127; de Haan on respiratory system of, 41, 142 Leucosiidz defined, 127 Leucosiidea, alias Oxystomata, 53 Leydig, Dr. Fr., on olfactory or- gans, 37 Libinia emarginata, numbers cf, 120 Ligia, cursor, dilatata, exotica, oceanica, 421 Ligiide defined, 420 Ligidium, hypnorum, cephala, paludicola, 421 Life, expenditure of, 395 Limbs, 33 Limnoria, lignorum, 367; segnis, 368 Limnoriidx defined 367 melano- A HISTORY OF RECENT CRUSTACEA LYS Limulus, polyphemus, 17; moluc- canus, 27; use of legs as man- dibles by, 40 Links in the evolution of species, 55, 103, 137 Linnzus, the genus Cancer of, 57 ; view of Pinnotheres held by, 100; the genus Oniscus of, 318; Systema Nature of, 437 Linschotten, on man-eating crabs, 26 Liriope preoccupied, 403 Liri-psis, monophthalma,pygmea, 403 Lisp gnathus Thomsoni, distri- bution of, 110 Lissa chiragra, appearance and habits of, 116 Lithodes, camschatica, 28 ; histrix, Maia, 153; Agassizii, Murrayi, 154 Lithodide, distribution of, 153 Lithodinea defined, 152 Liver, the, 48, 55, 78, 104, 300, 317 Livoneca, classification of, 352; ovalis, Redmanni, 352 Lloyd, W. A., on behaviour of Eu- pagurus, 164 Lobothorax, auritus, typus, 353 Lobster, the Norway, 202; the common, 203; the American, 204; little, 371 Lomis dentata, 154 Lophogaster, typicus, 257, 259 Lophogastride defined, 257 Lophoxanthus, 56 Loricata, alias Scyllaridea, 191 Lucasius, hirtus, myrmecophilus, pallidus, pauper, tardus, 429 Lucifer preoceupied, 221 Luminosity of Crustacea, 103, 244, 259, 262, 263, 265 Lyprobius, 431 Lyreidus, Bairdi, tridentatus, 144; ill-defined orbits of, 145 Lysioerichthus, larva of Lysioe squilla, 290 Lysiosquilla, armata, 19, 281; ex- cavatrix, maculata, scabricauda, scolopendra, spinosa, 284; bur- INDEX LYS ns procedure of excavatrix, Lysmata seticaudata, 229 MACROCHEIRA Kampferi, great size of, 27, 107 Macroceeloma, concava, trispinosa, 119 Macromysis, synonym of Praunus, 267, 271 Macrophthalmus, 92 Macropodia, 105, 113; longiros- tris, rostratus, 105 Macropsis, 267, 272; Slabberi, re- markable eyes of, 273 Macropus preoccupied, 105 Macrostylis, 382; latifrons, spini- gera, 383 M crura, the suborder, 8; defined, 146; tabular view of, 148 Mera, littoral specimens of the amphipod, 16 Maia, 107, 111; squinado, charac- ter and habits of, 22, 111; ver- rucora, 112 Maiide defined, 111 Maiinea defined, 104 Maioidea, alias Oxyrrhyncha, 53 Malacostraca, the sub-class, im- portance of, 6; the name of, 7; defined, 50 Mamma Shrimp, the West Indian, 145 Mancasellus, brachyurus, tenax, 377 Mandibles, 39; in Hippa talpoida, 151; in Paratanais, 323; in the Gnathiidz, 336, 337 Marsupium, 45; inthe Schizopoda, 256, 257, 260, 261, 267; in the Cumacea, 298, 300; in the Iso- poda, 319, 337, 339, 357, 370, 376, 393, 398, 405 Masked Crab, the, 53, 73 Mastigobranchie, 197, 201 Mastigochirus quadrilobatus, 152 Mastigopus preoccupied, 152 Matuta, swimming and digging powers of, 126; lunaris, victor, 126 455 MIL Matutide defined, 126 Maxillew, 41; of Lophogastride, 259 ;-of Cumacea, 295; of Iso- poda chelifera, 318 Maxillipeds, 42; of Schizopoda, 256; of Squilla mantis, 282; of Cumacea, 296; of Isopoda, 316 Mayer, Dr. Paul, on development and auditory apparatus of Pale- monetes varians, 248; on sexes of the Cymothoide, 350 Measurements, abuse of, 232; use of, 289 Megalopa, larval stage of various crabs, 61; of Hippa, 151 Meinert, Dr. F., on the Cymo- thoidx, 351 Meinertia, new genus, imbricatus, 354 Meleagrina margaritifera, Pinno- theres encysted in, 101 Melita, littoral species of the Am- phipod, 16 Meningodora, 245 Mergui Archipelago, Crustacea of, 77 Merhippolyte, 234, 237 Merostomata, an order of extinct Gigantostraca, 10 Metus, alias meropodite, thigh, or fourth joint, 43 Mesarmadillo, Alluaudi, margina- tus, tuberculatus, 435 Mesorhcea, 121 Mesostenus preoccupied, 386 Metanauplius, larval stage of Eu- phausiidz, 266 Metaplax, 92 Metoponorthus, cingendus, meri- dionalis, 428; Barroisi, pruino- sus, 429 Microniscidz, 396 Microniscus, 396; calani, fuscus, 397 Miers, Mr. E. J., on Ethusina chal- lengeri, 18; report on the Chail- lenger Brachyura by, 55; on \ genera near to Xantho, 56; on ' Professor A. Milne-Edwards, 63 Miersia, 243 Miersiide, why discarded, 243 456 MIL Milne-Edwards, Professor Al- phonse, definition of Crustacea by, 4; on aspecies of Ozius, 63 ; revision of Callianasside by, 183 Milne-Edwards, Profe sor Henri, on development of Crustacea, 60; on the respiratory cavity of Ranina scabra, 140; history of Crustacea by, 437 Mimicry, by common shrimp and isopoda, 16; by species of Ebalia, 21; Antilibinia, 117; Parthe- nope, 121; Alpheus, 231; Eis»- thistos, 335, 363; Phreatoicus, 389 Minute species, 29, 232, 255, 275, 308, 328, 355, 379, 380, 382, 383 Mithrax, 120 Mocquard, M. F., on structure of the Crustacean stomach, 147 Monaco, the Prince of, adventure with the nipper crab, 68 Monocarpinea defined, 239 Montagu, Colonel, discovery of Callianassa by, 183; of Upo- gebia, 185; of a Cumacean, 292 Moresby, Captain, on the cocoanut crab, 157 Mother Lobster, the, 192 Mouldering, 83 Mound of crabs, 112 Mountaineering Crustacea, in As- cension Island, 14; in the Great Andes, 14, 429; in Jap-n, 14, 77; in Tasmania, 257; in Aus- tralia, 389; in the Philippines, 416 Mouth-organs, 39 Miiller, Fritz, on olfactory organs, 37; on respiration in Ocypode, 86; on differences in land-crabs, 96; respiration of Aratus, 97; development of Penzus, 217 Munida, Rondeletii, rugosa, 176 Munidopsis, 177 Munna, 379; Boeckii, Fabricii, Kréyeri, limicola, maculata, neo-zclanica, pallida, palmata, Whiteana, 380 Munnopside defined, 383 Munnopsis, australis, typica, 384 A HISTORY OF RECENT CRUSTACEA NEO Musical or stridulating apparatus, 39, 64, 85, 92 Myodocopa, a suborder of Ostra- coda, 10 Myra, 128; fugax, 127, 128 Mysidz defined, 266 Mysideis, 267 ; insignis, 274 Mysidella, 267; typhlops, typica, 273 Mysidopsis, 267, 273; angusta, didelphys, gibbosa, hibernica, 274 Mysis, 267, 269; arenosa, chamz- Jeon, flexuosus, Helleri, inermis, Kervillei, Lamornz, neglecta, oruata, Parkeri, spiritus, 270,271 Mysis-stage, of Penaeus, 217 Myto Gaimardii, larval form of Sabinea, 228 Nzsa bidentata, 361 Neesicopea, new genus, abyssorum, 363 : Nannastacide defined, 305 Nannastacus, Suhmii, unguicula- tus, 305; longirostris, Sarsii, 306 Nannoniscus, bicuspis, oblongus, 382 Napoleon in Egypt, 173 Nauplius, 213, 217, 222, 265, 279 Nauticaris, 234, 237 Nautilocorystes, 74, 76 Nautilograpsus,synonym of Planes, minutus, 95 Naxia, hystrix, 116 Neasellus kerguelenensis, 381 Nebalia, a genus of Phyllocarida, 31, 313 Nebaliopsis typica, size of, 31 Nectocrangon lar, synonym of Argis lar, 228 Nematocarcinide defined, 249 Nematocarcinus, ensifer, 249; al- tus, cursor, lanceopes, undula- tipes, 250 Nematopus (preoccupied), elegans, Goésii, obesus, 275 Nematoscelis, borealis, megalops, 265 Neomysis, 267 ; vulgaris, 271 INDEX NEP Neotanais, 324; serratispinosus, 327 ; levispinosus, 328 ei norwegicus, Thomsoni, Nephropsidz defined, 201 Nephropsis, atlantica, Stewarti, 206 Nerocila, depressa, 351; Lovéni, munda, serra, 352 Nervous system, 2, 48; in Cyclo- metopa, 65; in Oxyrrhyncha, 104; in Cumacea, 300 Neszea preoccupied, 361 Nika, Couchii, edulis, processa, 229 Nikide defined, 229 Nikoides Danze, 230 Norman, Canon, on distribution, 66; on Axius stirynchus, 187; on Myside, 271; on male Ta- naids, 327 Norman and Stebbing, on Isopoda of the Porcupine, &c., 326 Nothocaris, 238 Notophryxus,clypeatus, globularis, lateralis, ovoides, 400 Notopoides latus, 143 Notopus dorsipes, 143 Notostomus, 245; perlatus, 246 ‘Novara,’ the, Crustacea of, 77 Nyctiphanes, australis, Couchii, norvegica, 263 OccIPUT, in Oniscoidea, 435 Ocypode, 85; arenaria, ceratoph- thaimus, rhombea, 86; Fritz Miiller’s discu-sion of, 87 Ocypodide defined, 85 Ocy podiidea, alias Catometopa, 53 Oeidia, synonym of Gomeza, 76 thra, 154 Olaus Magnus, pictures from, 25 Old Man’s Face Crab, 75 Olencira pregustator, 353 Oligoniscus monocellatus, 422 Olivi, pile of crabs described by, 11l Ommatocarcinus Macgillivrayi, 92 Oniscidz defined, 425 Oniscoidea defined, 420 Oniscus, the original genus, 318; 457 oz paradoxus, 357 ; asellus, fossor, murarius, punctatus, Simonii, 430 Onychophura, a small class of Ar- tbropods, 3 Oodeopide defined, 252 Oodeopus, 252; origin of the name, 253 Opercula‘a, order or suborder of Cirripedes, 11 Ophthalmic segment, 34 Oplophorus typus, armature of, 244 Oppian, on Pinnotheres, 100; his ignorance of Squillide, 282 Orbits, 51 Orchestia, littoral species of, 16 Orchestidz, short first antennze of the Amphipod family, 36 Oreophotus, 130 Orithyia, bimaculatus, laris, 125 Orphania tenuimana, 262 Osachila, 127 Ostracoda, order of Entomostraca, 9; subdivision of, 10; a giant species of, 31 Ostraconotus, 166 Otoliths, 36, 37, 182, 196 Ouracherus caudatus, 432 Ourozeuktes, caudatus, canthi, Owenii, 355 Ova, of Corystes cassivelaunus, 74; of Eupagurus, 164 ; of Munidop- sis, 177; of Caridea, 224; of Schizopoda, 256; of Squillida, 288 Ovaries, of the Stomatopoda, 279; of the Cymothoide, 350; of the Entoniscidez, 405; of Ergyne cervicornis, 414 Oxyrrhyncha defined, 104; spell- ing of the name, 105; manners of, 112; lead among Crustacea taken by, 118 Oxystomata defined, 123 Oyster Crab, the, 101 Oysters, eaten by the Shore Crab, 66; story of Pinnotheresand, 100 Ozius, ridges on endostcme of, 62 ; Edwardsi, 63 mammil- mona- 458 PAC Pachygrapsus marmoratus, 94; parasite of, 407 Packard, Dr. A. S.,on size of Phyl- locarida, 31 Pactolus Boscii, a made-up species, 106, 107 Paguride defined, 159 Pagurinea defined, 155 Paguristes, 166 Paguropsis, simply bent pleon of, 169 Pagurus, 159, 160; similimanus, 160; Bernhardus, cuanensis, Dilwynii, fasciatus, ferrugineus, Forbesii, Hyndmanni, levis, Prideaux, striatus, tricarinatus, Thompsoni, ulidianus, 161; ar- rosor, megistus, 162; granu- latus, 163 Palegyge, 410; affinis, Bonnieri, Borrei, de Mani, fluviatilis, Hoyli, 411 Paleemon, 246; carcinus, 28; Fa- bricii, heterochirus, jamaicensis, lar, Leachii, minans, serratus, squilla, varians, 247 Palemonella, tenuipes, orientalis, 247 : Palzmonetes, vulgaris, 248 Palestine, isopods of, 376, 429 Palinosytus, synonym of Jasus, Hiigelii, Lalandii, 196 Palinurellus, gundlachi, 197; hy- bridica, 198 Palinuride defined, 195 Palinurus, vulgaris, 27, 195; tu- midus, 27, 196 ‘Palp’ (endopodal joints), of the mandibles, 39; of the first maxille, 295, 316, 318; of the first maxillipeds, 336, 340 Palp, alias exopod, of the third maxillipeds, 192, 194 Pandalidz defined, 237 Pandalopsis, 238 Pandalus, annulicornis, breviros- tris, Montagui, narwal, 238 Panopeus, Benedict and Rathbun on the genus, 56 exilipes, varians, A HISTORY OF RECENT CRUSTACEA PAU Pantopoda, alias sea-spiders, 3 Panulirus, author of, 197; penicil- Jatus, 35, 197 Paracrangon, second trunk-legs obsolete in, 225 Paracyclois,124 ; Milne-Edwardsii, 126 Paradoxides, genus of Trilobites, 27 Paralamprops, 295; serrato-cos- tata, 309 Paralomis, 154 Paramunna, bilobata, 380 Paranephrops, planifrons, zealan- dicus, 210 Paranthura, 332; Costana, nigro- punctata, 333 Parapaguride defined, 166 Parapagurus, 166; pilosimanus, bathymetrical range of, 167 ; as- sociates of, 168 Parapasiphaé, 252 Parapseudes latifrons, 320 Parasites, 12, 17, 109, 128, 351, 353, 392 Parastacide defined, 209 Parastacus, 209 Paratanais, 323 ; Batei, forcipatus, rigidus, 327; linearis, 328 Paratelphusa, 77 Parathanas, decorticus, immatu- rus, 233 Paratya compressa, 241 Paratymolidz defined by Haswell, 139 Paratymolus, 139 ’ Paraxius, 188 Parerythrops, 267; obesus, 275 Pariambus typicus, amphipod of tribe Caprellidea, 22 Parthenope horrida, 121 Parthenopide detined, 120 Parthenopinea defined, 120 Pasiphaé, synonym of Pasiphea, 245; princeps, 28 Pasiphea, Savigny’s account of, 251 ; cristata, sivado, 251; prin- ceps, tarda, 252 Pasiphewide defined, 251 Paulson, 0, description of thely- Pycnogonida, INDEX PED cum by, 216 ; term loricata used by, 191 Pediculus marinus, of Rondelet, 352; of Seba, 354 Pedunculata, order or suborder of Cirripedes, 11 Pelocarcinus, synonym of Gecar- coidea, 80 Peltogaster, 402, 409; purpureus, 402; paguri, Rodriguezii, 403 Penwidee defined, 213 Penzidea defined, 213 Peneus, 214; canaliculatus, cara- mote, monodon, semisulcatus, 215; esculentus, 216; mem- branaceus, siphonoceras, 217; the petasma, 215; the thely- cum, 216; the development, 217 Penguin, Kucopia australis ob- tained from a, 261 Pentacheles euthrix, 200 Peron, afias thorax or trunk, 44 Pereopods, limbs of the five seg- ments immediately preceding the pleon, 44 Pericera cornudo, 119 Periceridaz defined, 119 Peripatus, genus assigned to the Myriapoda, or to the Oxycho- phora, 3 Perrier, Prof. E., 103 Peryscyphis, trivialis, 433; mean- ing of name, 434 Petalidium, 221 Petalomera pulchra (family Dro- mide), 136, 140 Petalomera preoccupied, declivis (family Pseudocumide), 308 © Petalophthalmus, 267; armiger, 268 Petalopus preoccupied, 308 Petalosarsia, new generic name, declivis, 308 Petasma, in Penwide and Serges- tide, 215 Peteinura gubernata, huge tail of, 220 Petiver, name given to Scyllarus latus by, 192 Petrolisthes Boscii, 173 Philoscia, corsica, Couchii, elon- 459 PLA gata, longicornis, muscorum, pubescens, pulchella, 430 ; ano- mala, bucculeutus, celleria, 431 Philougria, synonym of Trichonis- cus, riparia, rosea, vivida, 422 Philyra, 127; pisum, parasites upon, 128 Phlyxia, connection of, with Eba- lia, 129; orbicularis, undecim- spinosa, 130 Phoberus tenuimanus, 206 Phreatoicidz, 388 Phreatoicidea, a new tribe, 388 Phreatoicus described, 388; aus- tralis, typicus, 389; affinities discussed, 390 Phryxiens, 393, 408 Phryxus (preoccupied, but hitherto retained), paguri, resupinatus, 409; loogibranchiatus, 410; fusticaudatus, 411 Phyllobranchiata, 155, 166, 180 Phylocarida, a suborder of the Branch‘opoda, 9; palseozoic, 31 Phyllodurus abdominalis, 418 Phyllopoda, a suborder of the Branchiopoda, 9; large species of, 31 Phyllosoma, larval form of Scyl- laride and Palinuridz, 191, 198 Phymacerite, the ‘tubercle at base of second antenna, con- taining external orifice of tho green gland,’ 255 Pigs hunting crabs, 159 Pilumnoplax, 93 Pilumnus, hirtellus, xanthoides, 64 Pinnixa, 103 Pinnophylax, 100 Pinnoteres, 99 ; meaning of name, 100 Pinnotheres, 99; stories about,100; ascidiicola, lithodomi, pholadis, pisum, vetcrum, 101 Pinnotheride defined, 99 Pinnotherion vermiforme, 408 Pirimela denticulata, 64 Pisa, 113; Gibbsii, tetraodon, tri- bulus, 116 Plagusia, habits of, 98; chabrus, 460 PLA depressa, squamosa, tomentosa, 99 Plakarthrium typicum, 36 Planes minutus, the gulfweed crab, 95, 99 Plastron, 52 Platyarthrus Hoffmannseggii, in ants’ nests, 429 Platyaspis typica, 309 Platybema, 233; explanation of the name, 234; planirostris, rn- gosum o7 rugosus, 235 Platycopa, a suborder of Ostra- coda, 10 Platygrapsus, 94 Platymaia Wyville-thomsoni, 110 Platymera, 125 Platyonichus, bipustulatus, iri- descens, ocellatus, 67 Platysacus, larval form of Ser- gestes, 221 Pleon, 45 Pleopods, 45 Pleoticus, 218 Plesionika uniproducta, ophthal- mic segment in, 34 Pleuracantha preoccupied, 380 Pleurobranchie, 134 Pleurocrypta, galatesw, Hender- sonii, porcellane, strigosa, 410 Pleurogonium, 380; inerme, rubi- cundum, spinosissimum, 381 Pliny’s opinion about Pinnotheres, 100 Pocock, Mr. R. I., 184, 197 Podascon Dellavallei, 401 Podobranchiz, 134 Podocopa, a suborder of Ostracoda, 10 : Podophthalma, the order, 7; de- fined, 51 Podophthalmide defined, 71 Podophthalmus vigil, battledore ‘front’ of, 71 Peecilostoma, a suborder of Cope- poda, 10 Polperro, the geographical position of, 326 Polybius Henslowii, a great abun- dance of, 68 Polycarpinea defined, 228 A HISTORY OF RECENT CRUSTACEA PRO Polycheles,199; baccata, typhlops, 200 Polyonyx, 171 Pomatocheles, 170 Pontocaris, 228 Pontonia, cuastos, grinz, 242 Pontoniidz defined, 241 Pontophilus spinosus, 226; larval forms of, 227 Pontostratiotes abyssicola, an abyssal copepod, 20 Porcellana, 47; longicornis, platy- cheles, 171, 172; Robertsoni, 173; Creplinii, 406 Porcellanella, 171 Porcellanidez, 47, 171 Porcellaninea detined, 171 Porcellanides, 171 Porcellio,cristatus, dilatatus, levis, lamellatus, Marioni, pictus, pro- vincialis, scaber, spinicornis, 427; levis, scaber, extensive distribution of, 428 Porcupine, the, Isopoda of, 321, 826 Portumnus, 66; latipes, variega- tus, 67 Portunide defined, 65 Portunion menadis, 407; Frais- sei, Kossmanni, Moniezii, Sal- vatoris, 408 Portunus, arcuatus, corrugatus, depurator, holsatus, marmoreus, puber, pusillus, tuberculatus, 66 Potamobia, fluviatilis, pallipes, torrentium, 207 Potamobiide defined, 206 Potamonautes, 76 Praniza, synonym of Gnathia, 337 Praunus, 267 ; integer, 270; flexuo- sus, inermis, neglectus, 271 Preguediou, 282 Priority, recognition of, advo- cated, 203 Probopyrus, ascendens, palzmoneticola, 416 Procletes, biangulatus, Ellioti, 254 Promysis, 267, 275 Propodus, alias propodite, hand, or sixth joint, 43 241; melea- Giardi, INDEX PRO Prosthéte cannelée, 416 Protopodite, 36 Protosquilla, elongata, Guerinii, 287; larval form of, 290 Protozoa, 1 Protozoea, 217 Prudden, Mr. T. M., on Gelasimus minax, 91 Psalistoma, the ‘cutting margin of the mandible,’ 255 Pseudarmadillo carinulatus, 433 Pseuderichthus, larval form of Pseudosquilla, 290 Pseudibacus Veranyi, 194 Pseudione, callianas-e, confusa, Dohrni, Fraissei, Hyndmanni, insignis, 411 Pseudocalanus elongatus, parasite on, 897 Pseudocarcinus gigas, 26 Pseudocorystes, 74; armatus, 75 Pseudocuma, cercaria, ciliata, lon- gicornis, 307 Pseudocumide defined, 307 Pseudo-mandibles of Gnathia, 336 Pseadomma, 267; Sarsii, trunca- tum, 269 Pseudomysis, 267; abyssi, 274 Pseudorhombila, 93 Pseudosiriella, 267 ; frontalis, 277 Pseudosquilla ciliata, 286 Pseudotanais, 323 Pseudozius, Mellissi, 62; Bouvieri, 63 Pterelas, 349 . Pterygotus, a genus of the Mero- stomata, 26, 27 Pterygostomian regions, 52 Pterygura, 146; reason for dis- carding the name, 147 Ptilanthura, 332 Ptychogaster Milne-Edwardsi, 178 Pycnogonida, some peculiarities of the, 3, 4 Pylocheles, Agassizii, spinosus, 169 Pylochelidz, 169; a synonym of ‘Parapaguridz, 170 Pyrgoniscus cinctutus, 434 QUADRELLA, 65 461 SAB RACHITIA spinalis, 253 Ranina, scabra, 139; dentata, sca- bra, serrata, 140, 141 Raninidz, 140 Ranininea defined, 139 Raninoides personatus, 143 Rathbun, Miss M, on Panopeus, 56; on the Periceride, 120 Rathke, H., on the cray-fish, 84, 207 Rathke, J., Cymothoa lignorum of, 367 Réaumur, on exuviation, 207 Red Crab of the devil, 154 Regions of the carapace, 52 Regulus preoccupied, 239 Remipes, 151; adactylus, scutel- latus, testudinarius, 152 Respiration, see Branchiz and Breathing apparatus Rhabdosoma armatum, a slender species of Amphipoda Hype- ridea, 30 Rhinoceros-whale, the, 25 Rhinoryctes mirabilis, 431 Rhipidura, or tail-fan, 46, 146 Rhizocephala, an order of Cirri- pedes, 11 Rhoda, inermis, Jardineana, Ras- chii, 263 Rhomaleocaris, 242 Rhynchocinetes typus, 228 Rhyscotus turgifrons, 429 River Crabs, 76 Robber Crab, 158 Robertson, Mr. David, observa- tions on Corystes cassivelaunus, 74; Cumacea found in the Clyde by, 292; Leptaspidia brevipes found by, 381 Rocinela, 348, 352; danmoniensis, signata, 349; foveolatns, 350 Rondelet on Squilla mantis, 282 Rumph, or Rumphius, story attri- buted to, 142; his Cancer cani- nus, 143; on the cocoanut crab, 158 SABINEA, 225; septemcarinata, 227; larval form of, 228 462 SAN Sandhopper, a littoral amphipod, 16 Saophra, 353 Saophridz, 351, 353 Sars, Professor G. O., on the maxillary fan, 41; description of Scyramathia Carpenteri, 118; development of Macrura ano- mala, 178; of Upogebia, 186; on the Schizopoda, 257, 272; Cumacea, 292, 313; Sphyrapus, 322; Leptochelia, 327; Cypro- niscus cypridinz, 397, &c. Savart, 38 Savigny, 173, 251 Scalpellum regium, an abyssal cirripede, 20 Scaphocerite, 38, 188 Scaphognathite, 41 Schiddte and Meinert, great work on the Cymothoide by, 351 Schistomysis, 267; arencsa, Hel- Jeri, Kervillei, ornata, Parkeri, spiritus, 271 Schizopoda, a sub-order of Podo- phthalma, 8; range in size of, 28; Bate’s classification of, 223, 245; defined, 256 Sciacaris, 221 Sclerocrangon, boreas, cataphrac- tus, salebrosus, 228 Scleropactes, 431 Scopimera, with a pane in the leg, 102; globosa, 102 Scutuloidea maculata, 366 Scylla, 68; serrata, habits of, 69 Scyllaride defined, 191 Scyllaridea defined, and choice of the name explained, 191 Scyllarus latus, 192 Scyphacella arenicola, 422 Scyphax, ornatus, setiger, 481 Scyra umbonata, 119 Scyramathia Carpenteri, descrip- tion of, 118; origin of generic name, 119 Seal, devoured by small crustacea, 21; stomach of, filled with shrimps, 227 Sea-spiders, 3 Segments, 2, 32 A HISTORY OF RECENT CRUSTACEA soL Sensory filaments, 37 Seraphim, 27 Sergestes, literature of, 221; at- lanticus, 221 Sergestide defined, 221 Serolis, paradoxa, 357 ; avtarctica, australiensis, Bromleyana, Bron- gniartiana, carinata, cornuta, elongata, latifrons, longicau- data, minuta, nezra, pallida, septemcarinata, trilobitoides, tuberculata, 358; gracilis, 359; eyes of, 359 Serolidz defined, 356 Sesarma, 96; Pisonii, 97 Sexes, distinction of, 45; of Corystes cassivelaunus, 72; of the Oxyrrhyncha, 115; of Ga- lathea, 175; of Gnathiidee, 335 ; of Cymothoidx, 350; of Sphx- romide, 362 ° Shore Crab, the Common, 65 Shore-hopper, the, a littoral amphi- pod, 16 Sicyonia, branchie of, 218; cari- nata, 218 Siho maneki, meaning of the name, 88 Siphonostoma, Copepoda, 10 Siriella, 267; Clausii, crassipes, jaltensis, norvegica, 276; ar- mata, Brooki, 277 Size, standards of, 24 Skeleton shrimps, 16, 22, 30 Slabber, Martin, on metamorphoses of Crustacea, 59; on Macropsis, 273; on Eurydice achatus, 344 Sluiter, Dr. C. Ph., on manners of Oxyrrhyncha, 113 Smith, Professor S. I., on young of Cancer irroratus, 61; Platyo- nichus ocellatus, 67; Ocypode arenaria, 86; Gelasimus pugila- tor, 89; Euprognatha rastelli- fera, 111; Hippa talpoida, 150; Upogebia affinis, 185; Squilla mantis, 283, &c. a sub-order of Solenocera, Philippii, siphono- ceras, 217; meaning of the name, 218 INDEX SOL folenolambrus, 121 Spatuliform, 65, 71 Specimens, on collecting, 12 Spelzophorus, meaning of the dame, 130 Spencebatea abyssicola, 306 Spermatozoa, in the Squillide, 279 Spheroma, serratum, 360; cur- tum, Hookeri, Prideauxianum, rugicauda, 361 Sphzromidz defined, 359 Spheeroniscus, 433 ; flavomaculatus, 434 Sphyrapus, 321; malleolus, 321; anomalus, serratus, tudes, 322 Spider Crabs, 105 Spirontocaris, 234, 235; Cranchii, Gaimardii, pusiola, spinus, 236 Spiropagurus spiriger, 165 Sponge-dwellers, 17, 212, 349 Spongicola venusta, 212 ‘Spurious females,’ 109, 126, 128, 396 Squame, alias scale, acicle, sca- phocerite, exopod of second antenne, 38, 146, 188, 279, 316, 319, 377, 379 Squilla, 281; mantis, 282; ar- mata, Desmarestii, empusa, 283; nepa, scabricauda, 284; larval forms of, 289 Squillacea, Dr. Boas on, 279 Squillide, range of, 19; sizes, 29; ophthalmic segment, 34; first antenne, 38; defined, 279, 281 Stalio, Professor, on Carcinus meenas, 65; Maia squinado, 112; Lissa chiragra, 117; Calappa granulata, 124 Stenetrium, armatum, Haswelli, inerme, 379 Stenoniscus pleonalis, 432 Stenopide, 211 Stenopidea defined, 211 Stenopus, hispidus, 211; spinosus, 212 fractum, Stenorynchus, spelling of, 105; Phalangium, tenuirostris, 105 {sStephanomma Goésii, unusual eye of, 302 463 sys Stereomastis, meaning of the name, 201; Suhmi, 200 Stiliform, origin of the word, 250, 311 Stilomysis, 267; grandis, 274 Stimpson, distinction of two species by, 59; Latin descrip- tion by, 418 Stochasmus, a conjecture rather than a genus, 250 Stomach, on structure of, Dr. E. Nauck, 47; M. F. Mooquard, 147 Stomatopoda, a sub-order of the Podophthalma, 8 ; defined, 279 St. Paul’s Rocks, land crabs at, 94 St. Peter's Sand, great crabs at, 26 Strauchia taurica, 308 Streets, Dr. T. H., on climbing crabs, 158 Stridulating apparatus, 39, 64, 8&, 92, 161 Strongylura, 325 ; cylindrata, 328 Studer, Professor, on habits of Serolidz, 357 Stylamblys, 199, 255 Stylocerite, 188 Stylocheiron, longicorne, masti- gophorum, 265 Stylodactylide defined, 240 Stylodactylus serratus, 250 Styloniscus, 421 Stymphalus dilatatus, 421 Subchelate, 45 Subgenera criticised, 107, 129, 208 Suicide by a crab, alleged, 158 Sweden, marine fauna of lakes in, 23, 272, 372 Swimming appendages, 45, 66, 180, 256, 279, 294, 383 Symbiosis, 168 Sympagurus, 166 Synarmadillo clausus, 435 Synaxes, 191,197; hybridica, 198 Synaxidea, 46, 191 Syscenus infelix, 348 Syspasti, 425 pepe Habs a synonym of Helleria, 42 arctophylax, 464, TAB TABULAR view, of the class Crus- tacea, 49; sub-order Brachyura, 54; sub-order Macrura, 148; larval Squillidz, 290; Cumacean families, 312; sub-order Iso- poda, 314; Cymothoid group, 340; families of Epicaridea, 393; genera of Entoniscide, 405; genera of the Oniscide, 426; genera of the Armadilli- didz, 433 Tacha, crassipes, incerta, 346 Tail, alias pleon or post-abdomen, 45 Talisman, the, tained by, 153 Talitrus, a genus of Amphipoda, 16 Crustacea ob- Talorchestia, or beach-fleas, a genus of littoral amphipoda, 86 Tanaella, 325 Tanaide defined, 322; classifica- tion of, 9, 328 Tanais, 323; Dulongii, Edwardsii, filum, tomentosus, vittatus, 326; balticus, curculio, dubius, rhyn- chites, 327 Tasmania, pitted against Van Diemen’s Land, 210 Tatos, name of the Birgus latro at Samboangan, 158 Telson, 46; in Cumacea, 300 Testacea, distinguished from Crus- tacea, 5 Tetradecapoda, alias Hdrioph- thalma, 7 Tetralia, Paulson on the genus, 65 Thalassina, anomalus, scorpion- oides, 181 Thalassinide defined, 181 Thalassinidea defined, 180 Thalassocaride defined, 239 Thalassocaris, 239 Thaumastocheles zaleucus, 189; claws of, 190 Thaumastochelide defined, 189 Thaumastoplax, 102; last legs de- ficient in, 103 Thelphusa, 14; chilensis, depressa, fluviatilis, perlata, 76; dehaanii, 7 A HISTORY OF RECENT CRUSTACEA TUR Thelphuside, 76 Thelphusinea defined, 76 Thelycum, the, 216 Themisto (preoccupied), spinosa, lonzispinosa, 271 Thenus orientalis, 193 Thia, polita, residuus, 75 Thompson, Vaughan, on develop- ment of Crustacea, 59 Thomson, Mr. G. M., describes a new genus of Schizopoda, 256 Thoracica, an order of Cirripedes, 11 Thoracipoda, 7 Thoracostraca, objection to the term, 8 Thorax, 7, 32 Turanites velox, 70 Thyrostraca, alias Cirripedia, 6 13,.31 Thysanoessa, borealis, gregaria, longipes, macrura, neglecta, 264 ; longicaudata, 265 Thysanopoda, Couchii, tricuspida, 263; neglecta, 264 Titanethes albus, 422, 425, 426 Toulouroux, 79 Trachex, 4, 423, 425, 426 Transmutation of species, 103 Trapezia, 65 Trapeziide defined, 64 Tracailleur, th:, Crustacea taken by, 118, 122 Trichobranchiata, 155, 165, 180, 191 Trichoniscus, 421; pusillus, roseus, vividus, 422 Trichopleon ramosum, 378 Trilobita, an order of Gigantos- traca, 10, 11, 27, 3457 Triticella flava, polyzoon parasitic on Calocaris, 190 Troglocaris, a cave-shrimp, 241 Tropiocaride, 239, 245 Tropiocaris, 245 Trunk, alias thorax, person, 31 Tubercle, of second antenna, 38; molar, of mandible, 39 Tubercles, in the Palinuride, 195 Turkish saddle, 138 brevi- body, or INDEX TUR Turtle Crab, 95 Tylaspis anomala, species, 19, 166 Tylide de'ined, 423 Tylos, 423 ; armadillo, granulatus, granuliferus, Latreillii, spinu- losus, 424 Tympana, 102 Typhlapseudes, 321 Typhlotanais, 324, 326 Typton spongicola, 242 an abyssal Uca, 79; una, 84 Upogebia, affinis, stellata, 185; deltiura, littoralis, 186 Uropods, 46 Uroptychus, 177; gracilimanus, insignis, rubrovittatus, 178 VALVIFERA, 369 Vana longiremis, 383 Varuna litterata, 96 Vaunthompsonia, 303; anomala, cristata, meridicnalis, 304+ Vaunthompsoniidz detined, 303 Verges, position of, 45, 55, 104, 123, 146 Verrill and Smith, 67, 89, 185 Vertex, in Oniscoidea, 435 Virbius, 235, 236; gracilis, viridis, 416, 417 Voracity of Crustacea, 21 Vulve, position of, 45, 139, 146 the tribe defined, WALKER, Mr. A.O, on Crustacea from Singapore, 136 Walking, crab's method of, de- scribed, 58 Warty Crab, the great broad, 192 — Warty Crab, the great, 121 Weber, Professor Max, on fiesh- water decapods of the Pacilic, 23 WelJ-shrimp, character of the am- phipod, 14 465 You Westwood, J. O., on Gecarcinus, 84 White, Adam, genera named by, 197; his authority cited, 203; species assigned to Hippol) te by, 235 Whymper, Mr. E., Isopods and Amphipods found by, 14, 429 Willemoesia leptodactyla, 201 Windows in legs and breast of a crab, 102 Wood-lice, name applied to isopod crustaceans, 13 Wood-Mason, Prof. J., on tle Gecarcinide, 80; on young of Paranephrops, 210 Wood's Hole, Massachusetts, 150, 185 Woodward, Dr. H., the term tho- racipoda proposed by, 7, on an encysted VPinnotheres, 101; his Ceratocephalus Grayanus, 364 XANTHO, 56; floridus, hydrophi- lus, incisus, rivulosa, tubercu- lata, 62; Bouvieri, 63 Xanthodes, affinity with Kantho of, 56 Xavier's adventure with a crab, Xiphocephalus, synonym of Rhab- dosoma, 30 Xiphopeneus, sub-divided joints of, 219 Xiphosura, an order of Gigantos- traca, 10 Xyphicéphale, 30 Youne, of Cancer irroratus, 61; of Corystes cassivelaunus, 74; of Gecarcinus, 84; of Hippa talpoida, 150; of Porcellana longicornis, 172; of Palinuride, 198; of Astacus americanus, 204; of Paranephrops zealandi- cus, 210; of Nquillide, 280, 288, of Gnathiide, 337 466 A HISTORY OF RECENT CRUSTACEA ZAN ZUZ Zanclifer caribensis, rediscovered, | Zia, melanocephala, paludicola, 421 144; orbits of, 145 Zoea, a larval form, 69, 60, 61, Zenobia preoccupied, 374 101, 150, 172, 204, 222 Zeuxo preoccupied, 403; alphei, | Zoology, domestic, 13 416 Zuzara, 361 D. APPLETON & CO,’8 PUBLICATIONS. SIR JOHN LUBBOCK’S (Bart.) WORKS. THE ORIGIN OF CIVILIZATION AND THE PRIMIc TIVE CONDITION OF MAN, MENTAL AND SOCIAL CONDITION OF SAVAGES. Fourth edition, with numerous Ad- ditions. With Illustrations. 8vo, Cloth, $5.00. “This interesting work—for it is intensely 8. in its aim, scope, and the abil- ity of its author—treats of what the sciepti-ts Genominate anthrogology, or the natural history of the human species ; the complete science of man. body, and soul, including sex, temperament, race, civilization, etc.”"—/rovidence Press. PREHISTORIC TIMES, AS ILLUSTRATED BY ANCIENT REMAINS AND THE MANNERS AND CUSTOMS OF MODERN SAVAGES. Illustrated. 8vo. Cloth, $5.00. “This ig, perhans, the best summary of evidence now in our possession con- cerning the general character of prehistoric times The Bronze Age, The Stone Age, The Tumuli, The Lake Inhabitants of Switzerland, The Shell Mounds, The Cave Man, and The Antiguily of Man, are the titles of the most important chap- ters."—Dr. C. K. Adams's Manual of Historical Literature. ANTS, BEES, AND WASPS. A Record of Observations on the Habits of the Social Hymenoptera. With Colored Plates. 12mo. Cloth, $2.00. ‘This volame contains the record of various experiments made with ante, bees, and wasps during the last ten years, with a view to test their menta) con- dition and powers of sense. The author has caretuliy watched and marked par- ticular insects, and has had their nests under observation for long periods—: ne of his ants’ nests having been under constart inspection ever since 1874. His observations are made principally upon ants, because thcy show more power and flexibility of mind; and the value of his etndies is that they belong to the de- partment of original research.” ON THE SENSES, INSTINCTS, AND INTELLIGENCE OF ANIMALS, WITH SPECIAL REFERENCE TO INSECTS. “Tnternational Scientific Scries.” With over One Hundred Ilustra- tions. 12mo. Cloth, $1.75. The author has here collected some of his recent observations on the senses and intelligence of animals, and especially of insects, and hae attempted to give, very briefly, some idea of the organs of sense, commencing in each case with tbose of man himself. THE PLEASURES OF LIFE. 12mo. Cloth, 50 cents; paper, 25 cents. CONTENTS.—TueE Duty or Happiness. Tue Happiness oF Dery. A Sone or Books. Tae Cucrct or Books. ‘THE BLEseine or FRIENDS. THE VALue or Tims. THE PLEASURES oF TRAVEL. THE PLEASURES or Home, Screnck. EpucaTIon. New York: D. APPLETON & CO., 1, 3, & 5 Bond Street. D, APPLETON & CO,’8 PUBLICATIONS. JHE GEOLOGICAL HISTORY OF PLANTS. By Sir J. Wituram Dawson, F.R.S. Vol. 61 of The International Scientific Series. With Illustrations. 12mo. Cloth, $1.75. “The object of this work is ere in a connected form, a summary of the development of the vegetable kingdom in geological time. ‘l'o the geologist and botanist the subject is one of importance witb reference to their special pursuits, and one on which it has not been eaey to find any convenient manual of informa- tion.”—From the Preface. THE GEOGRAPHICAL AND GEOLOGICAL DISTRIBU. TION OF ANIMALS. By Anceto Heixprin, Professor of In- vertebrate Paleontology at the Academy of Natural Sciences, Phila- delphia, etc. Vol. 57 of The International Scientific Scries. One vol., 12mo, 435 pages, $2.00. “Jn the preparation of the following pages the author has had two objects in view: that of presenting to his readers such of the more significant facts con- nected with the past and present distribution of animal life as might lead to a proper conception of the relations of exieting faunas ; and, secondly, that of turnighing to the student a work of general reference, wherein the more ralieut features of the geography and_ geology of unimal forms could be sought atter and readily found.”—From the Preface. , ANIMAL MAGNETISM. From the French of Atrrep Bryer an) Cuarces Férk. Vol. 59 of The International Scientific Scries. 1Qmo. Cloth, $1.50. “The authors, after giving a brief, clear, and instructive history of animal magnetism from its remotest. known origin down through Mesmer and the Aca- demic period to the present day, record their personal investigations among the hysterical, nervous, and generally supersensitive female patients in the great Paris hospital, La Salpétri¢re, of which M. Féré is the assistant physician.”— Journal of Commerce. WEATHER: A POPULAR EXPOSITION OF THE NATURE OF WEATHER CHANGES FROM DAY TO DAY. By the Hon. Ratru Anercromby, Fellow of the Royal Meteorological Society, London. Vol. 58 of The International Scientific Series. 12mo. Cloth, $1.75. ‘Mr. Abercromby has for some yeara made the weather of Great Britain a special stucy, and has recently extended his experience by making a meteorologi- cal tour around the world. As a fruit of this preparation, he gives us a book that is to be commended for its simole, deliberate style, freedom from technicality and unnecessary theorizing, rational description, classification, and explanetion of atmospheric phenomena, and rich store of illustration from the weather-maps cf many parts of the world.”— The Nation. New York: D. APPLETON & CO., 1, 8, & 5 Bond Street. nt beat esse <5 Coal See sae Cate teater we ie ro oS Px : ; . ; ad scot ro ee ape, . fete Nese h eas Me ee ot on ise ‘ ot ; else m ad om Ba ; a vee Sy) ros hr Sota Fats