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S. Fish Commission Steamer "Albatross"”, during 1891, Liett~w- Commander Z. L. Tanner, U.S.N., Commanding. Bull. Mus. Comp. Zool., Vol. XXV, No. 8, 1894, pp. 99- a, pl. Catalogue of the Crabs of the family Majidae in the U. S. National Museum. A review. Zoolog. Centralbl. I Jahrg. No. 6, 1/5, 1894, 1 page. A New Species of the Isopod-Genus Bathynomus. Proc. Acad. Nat. Sci. Phila., 1894, pp. 191-193. A Study of the Systematic and Geographical Distribution of the Decapod Family Atyidae Kingsley. . Proc. Acad. Nat. Sci. Phila., 1894, pp. 397-416. A Study of she Systematic and Geographic Distribution of the Decapod Family Crangonidae Bate. Prod. Acad. Nat. Sci. Phila., 1895, pp. 173-197. Art. XXXI.--The systematic position of Crangopsis vermi- formis (Meek), from the Subcarboniferous rocks of Ken- tucky. Amer. Journ. Sci., Vol. IV, 1897, pp. 285-289. Art. XXXII.--On a New Species of the Palinurid-Gems Linuparus found in the Upper Cretaceous of Dakota. Amer. Journ. Sci., Vol. IV, 1897, pp. 290-296, figs.4 Os Camarões Da Agua Doce Da: America Do Sul. Revista Museu Paulista, No. II, 1897, pp. 173-216, B.l Ueber Keimvariation. Biol. RR bia, XVIII, No. 4, 1898, pp. 139-157. G. Pfeffer und die "Bipolarität". Zool. Anz. XXII, No. 597, ER pp» 214-216. On New Facts Lately Presented in Pre to the Hypothesis of Bipolarity of Marine Faunas. | Amer. Nat. Vol. XXXIII, No. 391, July 1899, pp. 583- 591. The Geographical Distribution of Freshwater aa a and its bearing upon Ancient Geography. Proc. Amer. Phil. Soc., Vol. .XLI, No. 171, pp. 267-400, ‘. Sania 1302, i CONTENTS conte: 1901. Crustacea & pycnogonida collected during the Princetwon Expedition to North Greenland, Proc, Acad, Nat, Sci. Phil, : 144-168, 1906. Schizopod crustaceans in the United States National Museum, - The families Lophogastridae | & Eucopüdae, Prec. U.S, Nat. Mus., vol, Sys no, 1480: 23-54, 1908, Schizopod crustaceans in the U.S. National Museum: Schizopods from Alaska, Proc, U.S. Nat, Musa, vol, 54, no, 159 1913, The Alleghenian Divide, and its influence upon the freshwater fauna, Proc, Amer, Phil, SOC. vol, 52, no, \2i00477287=390. » a a | | : Mus lanıo us. ; Ren 1 Bulletin of the Museum of Comparative Zoölogy AT HARVARD COLLEGE. Wor, XXV. No. 8. REPORTS ON THE DREDGING OPERATIONS OFF THE WEST COAST OF CENTRAL AMERICA TO THE GALAPAGOS, TO THE WEST COAST OF MEXICO, AND IN THE GULF OF CALIFORNIA, IN CHARGE OF ALEXANDER AGASSIZ, CARRIED ON BY THE U.S. FISH COMMIS- SION STEAMER “ALBATROSS,” DURING 1891, LIEUT. COMMANDER Z. L. TANNER, U.S. N, COMMANDING. XIV. THE PELAGIC SCHIZOPODA, By ARNOLD ORTMANN. [Published by Permission of MARSHALL McDONALD, U. 8. Fish Commissioner. ] WitH ONE PLATE. CAMBRIDGE, MASS., U.S. A. : PRINTED FOR THE MUSEUM. SEPTEMBER, 1894. INVERTEERAT: x ZOOLOGY Grustacea No. 8.— Reports on the Dredging Operations off the West Coast of Central America to the Galapagos, to the West Coast of Mexico, and in the Gulf of California, in charge of ALEXANDER AGASSIZ, carried on by the U. S. Fish Commission Steamer “ Albatross,” during 1891, LIEUT. COMMANDER Z. L. Tanner, U. S. N., Commanding. [Published by Permission of MarsHaLL McDona_p, U. S. Fish Commissioner.] XIV. The Pelagic Schizopoda. By ARNOLD ORTMANN. EUPHAUSIACEA. Thysanopoda agassizi, nov. spec. Form of body rather stout. Antero-lateral angles of the carapace rectan- gular, rounded, and without a deuticle. The lateral margins without denticles. Rostral projection triangular, sharply pointed, longer than the eyes. Anterior part of the carapace slightly keeled above. Third, fourth, and fifth segments of the abdomen projecting posteriorly as acute dorsal spines. Sixth segment somewhat longer than the preceding. Preanal spine small, simple. Eyes moderate. The first joint of the antennular peduncle furnished at the distal end with a dorsal cushion-like, densely hispid elevation. This elevation pro- jects forward as an acute, somewhat outwardly directed, spine-like lappet, nearly as long as the second joint. The outer anterior corner of the first joint bears a smaller spine. The second joint projects forward as a spine-like lappet similar to the first joint. The outer corner of the antennal scale bears a denticle. Telson with 10 to 12 pairs of dorsal denticles, inner plate of the uropoda shorter than the outer, the latter as long as the telson. Length, 19 mm. This species is related by the long spine-like lappets of the antennule to Th. monacantha Ortmann, and by the hispid cushion of the first joint of the antennule to Th. obtusifrons Sars. But it may be recognized by the acute rostrum, the absence of lateral denticles on the carapace, and the presence of three dorsal abdominal spines. VOL. XXV.— NO. 8. 100 BULLETIN OF THE Stations of the “ Albatross”1: — 3382. 200 fathoms. (Gulf of Panama, 60 miles from the 100 fathom line.) One specimen. 3414. Surface to 200 fathoms.* (Between Galapagos and Acapulco, 350 miles from land.) One specimen. Nyctiphanes australis G. O. Sars. Challenger Schizopoda, 1885, p. 115, Pl. XX., Pl. XXI. figs. 1-7. Stations of the ‘‘ Albatross ” : — March 7, 1891. 8.30 p. m. Surface. (Gulf of Panama.) Hyd. 2619. Surface to 1,000 fathoms, open part of net. (Off Galera Point.) 3388. Surface to 400 fathoms, open part of net; nothing in the closed part towed at 400 fathoms. (Gulf of Panama, 25 miles from land.) 3409. Surface. (Bindloe I., Galapagos.) 3435. Surface. (Gulf of California). Stations of the “Survey” (between San Francisco and the Sandwich Islands?) : — 52. Surface. 54. Surface. Long. 129° 5’ W.; Lat. 35” 3’ 30” N. 74. Surface. Long. 133° 56’ 30” W.; Lat. 30° 4’ 30” N. 542. Surface, Long. 124° 57’ 30” W.; Lat. 35° 31’ N. Geographical Distribution. The “Challenger” obtained this species in the Australian seas, on the surface, at night (off East Moncceur Isl., Bass Strait ; off Cape Howe; off Port Jackson). The above named stations show that it is not restricted to the Australian seas. 1 For a list of stations and chart of the route of the “ Albatross,” see A. Agassiz, Bull. M. C. Z., XXIII. No. 1, p. 4 and Pl. III., 1892. + Indicates that the specimen came from the depth noted in the closed part of the Tanner tow-net. * Surface to 200 fathoms, or surface to xxx fathoms, hereafter indicates that the specimen was brought up in the open part of the Tanner deep-sea tow-net, and that, except as in the Gulf of California at no great distance from the coast in a closed area, nothing was found in the closed part of the Tanner net when towed at sea at 200 fathoms or any greater depth, so that specimens brought up in the open part of the net probably came from a depth of less than 300 fathoms. — A. Agassiz. See Bull. M. C. Z., XXIII No. 1, 1892. 2 A number of pelagic Schizopods collected by the “ Albatross” during the survey of the route for a submarine cable between San Francisco and the Sand- wich Islands have been examined by Dr. Ortmann, and are included in this report. A. Agassiz. a o PR 3 . s x A £ 5 ge a É à ” a pd ta x = 1“ Nr MUSEUM OF COMPARATIVE ZOOLOGY. 101 Euphausia splendens Dana. G. O. Sars, Challenger Schizopoda, 1885, p. 80, Pl. XIII. figs. 7-17. The rostral margin is somewhat less produced than in Sars's Figure 15. The. structure of the antennule is very characteristic ; the joints of the peduncle are not provided with lobes, and from the dorsal face of the first joint springs a fascicle of strong curved set. Survey stations (between San Francisco and the Sandwich Islands) : — 540. Surface to 300 fathoms. Lat. 35° 19’ 30” N.; Long. 125° 21’ 30” W. 541. Surface to 300 fathoms. Lat. 35° 25’ 30” N.; Long. 125° 9’ 30” W. 542. Surface. Lat. 35° 31’ N.; Long. 124° 57’ 30” W. 543. Surface. Lat. 35° 36’ 30” N.; Long. 124° 45’ 30” W. Geographical Distribution. Tropical and Southern Pacific; Southern Atlantic. Huphausia mucronata G. O. Sars. Challenger Schizopoda, 1885, p. 87, Pl. XV. figs. 9-11. Stations of the “ Albatross” : — March 7, 1891. 8.30 p.m. Surface. (Gulf of Panama.) Hyd. 2619. Surface to 300 fathoms, and surface to 1,000 fathoms. (Off Galera Point). 3382. 200 fathoms.f (Gulf of Panama.) 3388. Surface to 400 fathoms. (Gulfof Panama, 25 miles from land.) 3412. Surface. (Wenman I., Galapagos.) 3414. Surface to 200 fathoms, and surface to 300 fathoms. (Between Galapagos and Acapulco, 350 miles from land.) 13° 33° 30” N.; 97° 57’ 30” W. 8 p. m. Surface. (Between Galapagos and Acapulco, 250 miles S. E. of Acapulco.) 3416. Surface to 300 fathoms. (Near Acapulco.) 120 miles N. W. Acapulco. Surface to 175 fathoms. Off Guaymas. Surface to 500 fathoms. (Gulf of California.) Geographical Distribution. This species has been previously captured ouly by the “ Challenger ”: South Pacific, off the coast of Chili, surface. Euphausia pellucida Dana. G. O. Sars, Challenger Schizopoda, 1885, p. 75, Pl. XL, XII. Ortmann, Decap. u. Schizop. Plankton Exp. 1893, p. 11. Stations of the “ Albatross” : — March 7, 1891. 8.30 p.m. Surface. (Gulf of Panama.) 3388. Surface to 400 fathoms. (Gulf of Panama, 28 miles from land.) 102 BULLETIN OF THE Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and Galapagos). 3409. Surface. (Bindloe I., Galapagos.) 3412. Surface. (Wenman I., Galapagos.) 3414. Surface to 100 fathoms. Surface to 200 fathoms. | Between Galapagos and Acapulco, Surface to 300 to 350 miles from land. At 200 fathoms. 13° 33’ 30” N.; 97° 57’ 30” W. 8p.m. Surface. (Between Galapagos and Acapulco, 250 miles from land.) 3416. Surface to 300 fathoms. (Near Acapulco). 3434. Surface. (Gulf of California.) 50 miles south Guaymas. Surface to 700 fathoms. Off Guaymas. Surface to 500 fathoms. “Survey ’’ stations (between San Francisco and the Sandwich Islands) : —. 165. Surface: Lat; 30° 23" Nº: one 140726 30 a. 542. Surface. Lat. 35° 31’ N.; Long. 124° 57’ 30” W. 543. Surface. Lat. 35° 36’ 30” N.; Long. 124° 45’ 30” W. Geographical Distribution. Cosmopolitan: Arctic, North, Central, and South Atlantic, Antarctic, South and Central Pacific, and Indian Oceans. Euphausia diomedes, nov. spec. Frontal part of the carapace produced as a broad triangular-pointed plate, arched over the eyes, and covering their peduncles. Anterior part of carapace with a sharp keel, the lateral margins with two denticles on each side. Seg- ments of the abdomen smooth, without spines. Sixth segment longer than the preceding. Preanal spine tridentate. Eyes of moderate size. Basal joint of antennule with a projecting leaflet above, divided into two lappets at the top. Outer corner of the antennal scale unarmed. Subapical spines of the telson finely denticulated at inner edge. Inner plate of uropoda a little longer than outer, both shorter than the telson. This species agrees with E. pellucida in most respects, but the sos plate is very different, being in E. pellucida acutely produced and not broadly arched over the peduncles of the eyes. Perhaps E. diomedee might be better re- garded as a variety of E. pellucida. Station of the “ Albatross” :— 3409. Surface. (Bindloe I., Galapagos.) Two specimens, associated with E. pellucida. MUSEUM OF COMPARATIVE ZOÖLOGY. 103 Euphausia gibboides Ortmann. Decap. u. Schizop. Plankton Exp. 1893, p. 12, Pl. I. fig. 5. Stations of the “ Albatross” : — Hyd. 2627. Surface to 1,770 fathoms. (Between Cape San Francisco and Galapagos.) Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and Galapagos, about 250 miles from the Galapagos.) “ Survey ” station (between San Francisco and the Sandwich Islands): — 540. Surface to 300 fathoms. Lat. 35° 19’ 30” N.; Long. 125° 21’ 30” W. Geographical Distribution. This species was obtained by the “Plankton Expedition ” in the tropical part of the Atlantic, between 0 and 500 meters. Euphausia gracilis Dana. G. O. Sars, Challenger Schizopoda, 1885, p. 89, Pl. XV. figs. 12-23. Ortmann, Decap. u. Schiz. Plankton Exp. 1893, p. 13. . Stations of the “ Albatross” : — Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and Galapagos, about 250 miles from the Galapagos.) 3409. Surface. (Bindloe I., Galapagos.) 3412. Surface. (Wenman I., Galapagos ) Geographical Distribution. Central Atlantic; Tropical Pacific; Austra- lian seas; Celebes Sea. Surface to about 1,000 meters. Nematoscelis megalops G. O. Sars. G. O. Sars, Chall. Schiz. 1885, p. 127, Pl. XXIII. figs. 5-10. Ortmann, Plankton Exp., 1893, p. 15. “Survey” stations (between San Franeisco and the Sandwich Islands) : — 540. Surface to 300 fathoms. Lat. 35° 19’ 30” N.; Long. 125º 21’ 30” W. 541. Surface to 300 fathoms. Lat. 35º 25’ 30” N.; Long. 125° 9’ 30” W. Geographical Distribution. North Atlantic; Greenland, Nova Scotia, British coasts ; Southern subtropical Atlantic. Nematoscelis microps G. O. Sars. G. O. Sars, Chall. Schiz. 1885, p. 131, Pl. XXV. figs. 1-4. Ortmann, Plankton Exp. 1898, p. 16. The identification of this species is somewhat doubtful, since in none of the specimens are the elongated legs preserved. 104 BULLETIN OF THE Stations of the “ Albatross”: — 3382. 200 fathoms. (Gulf of Panama, about 60 miles from the 100 fathom line.) Hyd. 2619. Surface to 1,000 fathoms. (Off Galera Point.) Hyd. 2627. Surface to 1,770 fathoms. (Between Cape San Francisco and Galapagos.) Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and Galapagos.) 3414. Surface to 200 fathoms, and surface to 300 fathoms. (Be- tween Galapagos and Acapulco, about 250 miles from land. 3416. Surface to 300 fathoms. (Near Acapulco.) 50 miles South Guaymas. Surface to 700 fathoms. Off Guaymas. Surface to 500 fathoms. Geographical Distribution. North Atlantic; Mediterranean ; Central Atlantic. Surface and 600-800 meters. ¢ Nematoscelis tenella G. O. Sars. G. O. Sars, Chall. Schiz. 1885, p. 133, Pl. XXV. figs. 5-7. Ortmann, Plankton Exp. 1898, p. 16. 12° 34’ N.; 97° 21’ W. (Between Galapagos and Acapulco.) Geographical Distribution. Central Atlantic; Cape of Good Hope; Philippine Islands. Surface to 650 m. Stylocheiron abbreviatum G. O. Sars. G. O. Sars, Chall. Schiz. 1885, p. 147, Pl. XX VII. figs. 11-13. Ortmann, Plankton Exp., 1898, p. 17. Hyd. 2619. Surface to 300 fathoms. (Off Galera Point.) _ Geographical Distribution. Mediterranean; Tropical Atlantic; Sub- tropical Pacific (north of the Sandwich Islands). Surface to considerable depths : 1,300-1,500 meters (Plankton Exp)., 600-1,200 meters (Chun). Stylocheiron suhmi G. O. Sars. G. O. Sars, Chall. Schiz., 1885, p. 142, Pl. XX VII. fig. 1-4. Ortmann, Plankton Exp. 1898, p. 17. In none of the specimens are the elongated legs preserved, but this species is recognizable by the form of the eyes. Stations of the “ Albatross ”: — 3388. Surface to 400 fathoms (open part of net, nothing in closed part at 400 fms.). (Gulf of Panama, 25 miles from land.) MUSEUM OF COMPARATIVE ZOOLOGY. 105 Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and Galapagos, about 250 miles from the Galapagos.) 3414. Surface to 300 fathoms. (Between Galapagos and Acapulco, 350 miles from land.) 12° 34 N. 97° 21’ W. (Between Galapagos and Acapulco, about 300 miles S. E. of Acapulco). Geographical Distribution. Central Atlantic, Pacific; New Guinea and Philippine Islands. Surface and 1,300-1,500 meters. Stylocheiron flexipes Ortmann. Plankton Exp. 1893, p. 18, Pl. I. fig. 7. Stations of the “ Albatross’: — 3382. 200 fathoms. (Gulf of Panama, about 60 miles from the 100 fm. line.) Hyd. 2627. Surface to 1,770 fathoms (open part of net). (Between Cape San Francisco and Galapagos.) Geographical Distribution. Central Atlantic, between surface and 500 m. | MYSIDACEA. BOREOMYSIS G. O. Sars. Synopsis of the known Species. a, Eyes of the usual structure, with visual elements. b, Eye-peduncles conical or fusiform, cornea moderately or not at all expanded, not projecting laterally beyond the carapace. cy Frontal margin produced to a sharp rostrum or pointed in the middle. d, No lateral frontal spines over the eyes. e, Eye-peduncle conical, cornea somewhat expanded. Rostrum well developed. f, Eye-peduncle not prolonged as a tubercle over the cornea. g, Rostrum bent upwards. | 1. B. arctica (Kröyer). Greenland, Norway, 200-400 fathoms. (Cf. G. O. Sars, Monogr. Norg. Mys. 3, 1879, p. 10, Pl. XI.-XIII. ga Rostrum perfectly horizontal. 2. B. nobilis G. O. Sars. Spitzbergen Sea, 459 fathoms. (Den Norske Nordhavs Exp. Zool. Crust. 1885, p. 54, Pl. V. figs. 22-28.) f, Eye-peduncle prolonged to a sharp tubercle over the cornea. 3. B. californica n. sp. Gulf of California. 106 BULLETIN OF THE e, Eye-peduncle fusiform, cornea very small, not expanded. Rostrum represented by a small pointed projection. 4. B. mierops G.O. Sars. South of Nova Scotia, 1,250 fathoms. (Chall. Schizop. 1885, p. 184, Pl. XXXIII. figs. 7-10.) d, A lateral frontal spine over each eye, therefore the frontal margin three-spined. Eye-peduncle conical, cornea expanded. 5. B. tridens G. O. Sars. Norway, 300-400 fathoms. (Monogr. Norg. Mysid. 3, 1879, p. 16, Pl. XIV.) ca Frontal margin obtusely rounded, without a rostral spine. Eye- peduncles conical, cornea expanded. 6. B. obtusata G. O. Sars. North Pacific, 345 and 2,740 fathoms. (Chall. Schizop. 1885, p. 182, Pl. XXIII. figs. 1-6.) b, Eye-peduncles constricted, very thin and cylindrical at the base. Cornea greatly expanded, projecting laterally considerably beyond the carapace. - Frontal margin obtusely pointed, without a rostrum. 7. B. megalops G. O. Sars. Norway, 80-200 fathoms. (Monogr. Norg. Mysid. 3, 1879, p. 18, Pl. XV., XVI.) a, Eyes imperfectly developed, calyciform, without pigment or visual elements. 8. B. scyphops G. O. Sars. Arctic and Antarctic, deep-sea. (Nordhavs Exp. 1885, p. 56, Pl. VI. Chall. Schiz. 1885, p. 178, Pl. XXXII. figs. 10-20.) Boreomysis californica, nov. spec. A S.4~ ru This new species agrees so closely in almost every regard with B. arctica, that it is useless to give a detailed description. The only difference I observe is the peculiar character of the eye, whose cornea is somewhat less expanded, and whose peduncle is prolonged over the cornea as a sharp conical tubercle. The color of the cornea is pale brown, as in B. arctica (pigmento fulvescente). It is somewhat doubtful whether this species belongs to the genus Boreo- mysis or to a new genus. The rudimentary condition of the pleopods and the want of male appendages to the antennule show that the specimens are females, but the incubatory lamell® are not developed. In the largest specimen I observe at the base of the legs seven pairs of very little leaflets, which may be the seven pairs of incubatory lamelle characteristic of the genus Boreomysis, and there- fore I believe that this specimen, and also the two smaller ones, which do not show these leaflets, are not fully developed females. On the other hand, in case they are males, this species must be the representative of a new genus agree- ing with the genera Mysidella and Heteromysis in the rudimentary condition of the male pleopods, but differing in the structure of the other appendages which are normally developed here. 50 miles south of Guaymas (Gulf of California). Surface to 700 fathoms. (From the open part of net.) Three specimens. MUSEUM OF COMPARATIVE ZOÖLOGY. 107 Siriella thompsoni (MiLxe-EDwarDS). G. O. Sars, Chall. Schiz. 1885, p. 205, Pl. XXVI. figs. 1-24. Ortmann, Plankton Exp. 1893, p. 23. “ Survey stations ” (between San Francisco and the Sandwich Islands): — 74. Surface. Lat. 30º 4’ 30” N.; Long. 133° 56’ 30’ W. 133. Surface (females only). Lat. 32° 35’ N.; Long. 135° 3’ W. 165. Surface (males only). Lat. 30º 23 N.; Long. 180° 26’ 30” W. Geographical Distribution. Tropical and subtropical seas, surface ; Atlantic, Pacific, and Indian Oceans. Siriella gracilis Dana. Cf. G. O. Sars, Chall. Schizop. 1885, p. 209, Pl. XXXVI. fig. 25-28. Galapagos: Charles Island, surface. 13° 33’ 30” N.; 97° 57’ 30” W. 8 p.m. Surface. (Between Galapagos and Acapulco, about 250 miles S. E. of Acapulco. Geographical Distribution. Restricted up to the present to the Tropical Pacific. All the specimens were taken at the surface of the sea. Euchaetomera typica G. O. Sars. G. O. Sars, Chall. Schiz., 1885, p. 211, Pl. XXXVII. figs. 1-20. Ortmann, Plankton Exp. 1893, p. 28. Hyd. 2619. Surface to 300 fathoms. (Off Galera Point. Nothing in closed part of net at 300 fathoms.) Geographical Distribution. Tropical Atlantic and Northern subtropical Pacific, surface. 108 BULLETIN OR THE OBSERVATIONS ON THE VERTICAL DISTRIBUTION OF SCHIZOPODA. The following species were taken at the surface : — Station. March 7. Gulf of Panama. 3409. Time. 8.30 p. m. 7.24 p. m, Off Brinloe Isl., Galapagos. 3412. Off Wenman Isl. 132332302. Nex 97° 57’ 30” W. Ep: Nu , Galapagos. Sp. Ta: About 250 miles S. E. of Acapulco. 3434. 10.14 a. m. Gulf of California, off Altata. 3435. 8.56 a. m. Gulf of California, off Carmen Isl. Nyctiphanes australis. Euphausia mucronata. Euphausia pellucida. Nyctiphanes australis. Euphausia pellucida. Euphausia diomedeze. Euphausia gracilis. Euphausia mucronata. Euphausia pellucida. Euphausia gracilis. Euphausia mucronata. Euphausia pellucida. Siriella gracilis. Euphausia pellucida. Nyctiphanes australis. Number of Specimens. 5 9 Many. 8 jun. In the first place one observes that all surface catches which contain a con- siderable number of specimens were made at night, that is to say after sunset. The catches at Stations 3434 and 3435, made in the forenoon, contain but few specimens. In all the other catches made in the daytime the Schizopoda are wanting. This fact shows again that the pelagie Schizopoda live at the surface of the sea chiefly in the night, especially the species Nyctiphanes australis, Euphausia mucronata, pellucida, and gracilis. Other hauls made between surface and various depths contain the following species taken in the open part of the Tanner net : — Depth. 0-100 fathoms. 0-175 fathoms. 0-200 fathoms. Station. 3414. Euphausia pellucida. 350 miles S. E. of Acapulco. 120 miles N. W. Acapulco. Hyd. 2628. Euphausia mucronata. Thysanopoda agassizi. 250 miles from the Galapagos. 3414. 350 miles S. E. of Acapulco. Euphausia mucronata. Euphausia pellucida. Euphausia gibboidos. Euphausia gracilis. Nematoscelis microps. Stylocheiron suhmi. MUSEUM OF COMPARATIVE ZOÖLOGY. 109 Depth. Station. 0-300 fathoms.! _ Hyd. 2619. Euphausia mucronata. Off Galera Point. 3414. Euphausia pellucida. 350 miles S. E. of Acapulco. 3416. Nematoscelis microps. 25 miles S. E. of Acapulco. Stylocheiron abbreviatum. Stylocheiron suhmi. Euchetomera typica. 0-100 fathoms.? 3388. Nyctiphanes australis. | Gulf of Panama, 25 miles from Euphausia mucronata. land. Euphausia pellucida. Stylocheiron suhmi. 0-500 fathoms. Off Guaymas, from open part Euphausia mucronata. of net. Euphausia pellucida. Nematoscelis microps. 0-700 fathoms. 50 miles S. of Guaymas, from Euphausia pellucida, open part of net. Nematoscelis microps. 0-1,000 fathoms. Hyd. 2619. Nyctiphanes australis. Off Galera Point, from open Euphausia mucronata. part of net. Nematoscelis microps. 0-1,770 fathoms. Hyd. 2627. Euphausia gibboidos, Between Cape San Francisco Nematoscelis microps. and the Galapagos (nothing Stylocheiron flexipes. in closed part of net). This series shows that the catches in the open part of the Tanner net to depths of more than 300 fathoms do not contain more species than those between O and 300 fathoms. It is also to be noted, that the hauls to 500 and more fathoms* contain a remarkably small number of species. All the species obtained by the hauls extending from the surface to greater depths than 300 fathoms certainly occur, as is shown by other catches, in depths less than 300 fathoms, and it is very probable, that they occurred also in the same lesser depth here; especially Euphausia mucronata, pellucida, and gracilis, Nematoscelis mi- crops, and others. From 200 fathoms were obtained in the closed part of the Tanner tow-net, in the Gulf of Panama, about 60 miles from the 100 fathom line (Station 3382), Thysanopoda agassizi, 1 specimen, Euphausia mucronata, 6 specimens, Nematoscelis microps, many specimens, Stylocheiron flexipes, 3 specimens. 1 It should be borne in mind that at no station at sea did the closed part of the Tanner net bring up anything from a depth of 300 fathoms. — A. Agassiz. 2 Nothing in the closed part of the Tanner net when towed at 400 fathoms. 8 Is also found at Station 3382, in 200 fathoms, in the Gulf of Panama. 4 All of which come from the open part of the Tanner net, the closed part of the net having at no station at sea brought up anything. — A. Agassiz. 110 BULLETIN CF THE Very interesting is the Station 3414,1 at 11.14 a. m., 350 miles S. E. of Aca- pulco, Here were obtained in the open part of the Tanner net : — Number of 3 specimens. 0-100 fathoms. Euphausia pellucida. 3 0-200 fathoms. Thysanopoda agassizi. 1 Euphausia mucronata. 2 Euphausia pellucida. 32 Nematoscelis microps. 1 0-300 fathoms (nothing in Euphausia mucronata. the closed part of the Tanner Euphausia pellucida. 17 net towed at that depth 15 Nematoscelis microps. , 5 minutes). Stylocheiron suhmi. 2 Euphausia pellucida is the only species which comes in the daytime, although in small numbers, near the surface of the sea, the other species swim- ming at a greater depth. And, indeed, most of the E. pellucida are found by day at a greater depth than 100 fathoms. On the other hand the catch from O to 300 fathoms contains no more specimens of this species than that from O to 200 fathoms. It is therefore very probable that most specimens of E. pellucida swim during the daytime in depths from 100 to 200 fathoms. Tt seems that the species E. mucronata and Nematoscelis microps are under analogous conditions; they are wanting in the daytime in the zone of water above 100 fathoms, but in the zone between 100 and 300 fathoms they are present. Since other species are but rarely contained in the several catches, it is impos- sible to get a good idea of their vertical distribution. But according to existing data one may conclude that the most important and most abundant. Schizopoda, especially the species of the genus Euphausia, live in the daytime in a depth ‚from about 100 to 200 or 300 fathoms, and ascend at night to the surface.? 1 This locality, 350 miles from the nearest land, was the one selected for testing the vertical distribution of the pelagic fauna by towing with the Tanner deep-sea tow-net at depths of 100, 200, and 300 fathoms during the morning hours when the surface species would naturally have sunk. See Bull. M. C. Z., Vol. XXIII. No. 1, p. 52.— A. Agassiz. 2 This agrees with the well known paucity of the surface fauna during the bright hours of the day. Nearly all pelagic material is collected more abundantly at night. — A. Agassiz. E Meisellitho ER ASSES > N SSS a is} = fe) D an is} D < q E Es: "ALBATROSS’ EX 1891 A Ortmanndel. 7 - i us \ { ite Ex, ui 5 —. x ho 1% 4 te ) 4 o N i = Ay . > eS KR; a (0.0) be = = = er a : ep) A O É Wa A, yyy 7 AD 7 < 22 Vg MP. /) = ZIG EG A.Ortmann.del. a nennen 1. 2 ço MUSEUM OF COMPARATIVE ZOOLOGY. RE) EXPLANATION OF PLATE. Thysanopoda agassizi, nov. spec., lateral view, 2. scale, $. Euphausia diomedee, nov. spec., frontal margin, eyes, antennule, and antennal scale, 1º, frontal margin, eyes, antennule, and antennal Boreomysis californica, nov. spec., a young female, lateral view, $. un antennula (b), 42. antenna (c), +2. mandibula (d), 22. first maxilla (e), 22. second maxilla (/), 2. maxilliped or first cormopod (g), epipodite omitted, 12. second cormopod (A), 12. third cormopod (7), 1). uropod (u), 42. telson (2), 2. DE sal wre ee ees Mn te, É Ee ER Rt e LOWING REPORTS ARE IN PREPARATION ON THE DREDGING CALIFORNIA, IN CHARGE OF ALEXANDER ÁGASSIZ, CARRIED ON BY “THE U.S. Fısu Commission STEAMER “ ALBATROSS,” DURING 1891, Liner. CoMMANDER Z. L. TANNER, U.S. N., COMMANDING. R. von LENDENFELD. The Phosphores- cent Organs of Fishes. 5; 4 February to May, 1891. H. LUDWIG. IV.5 The Holothurians. A “AGASSIZ. “The Pelagic Fauna. C. F. LUTKEN. The Ophiuride. A. AGASSIZ. The Deep-Sea Panamic Fauna. E I MARK: The Actinarians. na cn 12 On Calamocrinus, anew | gmo. Pp. MERRILL. V.º The Rocks of the Galapagos. G. W. MÜLLER. The Ostracods. eee tet the Annelids: JOHN MURRAY The Bottom Specimens. BERGH. The Nudibranchs. A. ORTMANN. XIV.” The Schizopods. . BRANDT. The Sagitte. ROBERT RIDGWAY. The Alcoholic Birds. = BRANDT. The Thalassicole. P. SCHIEMENZ. The Pteropods and Het- C. CHUN. The Siphonophores. eropods. 53 €. “CEUN. The Eyes of Deep-Sea Crustacea. W. SCHIMKEWITSCH. VIILS The Pyc- CLARKE. XI." The Hydroids. nogonidee. SE DALI, The Mollusks. “| S. H. SCUDDER. VII! The Orthoptera of avn the Galapagos. W. PERCY SLADEN. The Starfishes. IL. STEJNEGER. The Reptiles. TH. STUDER.: X.1° The Alcyonarians. Cc. H. TOWNSEND. The Birds of Cocos Island. M. P. A. TRAUTSTEDT. The Salpide and Doliolide. E. P VAN DUZEE. The Halobatide. H. B. WARD. The Sipunculoids. H. V. WILSON. The Sponges. W. McM. WOODWORTH. IX. The Pla- narians. : VIS The Crustacea. ARMAN. The Fishes. IESBRECHT. The Copepods. 1 Bull. M.C. Z., Vol. XXI., No. 4, June, 1891, 16 pp.; and Vol. XXTIT,, No.-1, February, 1892, É gem M. C. Z., Vol. XVII., No. 2, January, 1892, 95 pp., 32 Plates. 3 Bull. M. C. Z., Vol. XXIV., No. 7, August, 1893, 72 pp. + Bull. M. €. Z., Vol. XXIII., No. 5, December, 1892, 4 pp., 1 Plate. Be Bull. M. ©. Z., Vol. XXIV., No. 4, June, 1893, 10 pp. [Zool. Anzeig., No. 420, 1893.] 6 Bull. M. C.Z., Vol. XVI., No. 13, July, 1898, 3 pp. 7 Bull. M. 23 Z.. Vol. XXV., No. 1, September, 1893, 25 pp. Vol. XXV.,No. 2, December, 1893, 17 pp., 2 Plates. ., Vol. XXV., No. 4, January, 1894, 4 pp., 1 Plate. ., Vol. XXV., No. 5, February, 1894, 17 pp. .Z., Vol. XXV. No, 6, February, 1894, 7 pp., 5 Plates. . Z., Vol. XXV. No. 8, September, 1894, 13 pp., 1 Plate. PUBLICATIONS OF THE MUSEUM OF COMPARATIVE ZOÖLOGY AT HARVARD COLLEGE. There have been published of the BuLLETINS Vols. I. to XXIV.; of the Memoirs, Vols. I. to XVI. Vols. XVI. and XXV. of the BuLLETIN, and Vols. XI. and XVII. of the MEMOoIRS are now in course of publication. The BuLLETIN and Memoirs are devoted to the publication of original work by the Professors and Assistants of the Museum, of investigations carried on by students and others in the different Laboratories of Natural History, and of work by specialists based upon the Museum Collections. The following publications are in preparation: — Reports on the Results of Dredging Operations from 1877 to 1880, in charge of Alexander Agassiz, by the U. S. Coast Survey Steamer “ Blake,” Lieut. Commander C. D. Sigsbee, U.S. N., and Commander J. R. Bartlett, U.S.N., Commanding. : Reports on the Results of the Expedition of 1891 of the U. S. Fish Commission Steamer “ Albatross,” Lieut. Commander Z. L. Tanner, U. S. N., Com- manding, in charge of Alexander Agassiz. Contributions from the Zoölogical Laboratory, in charge of Professor E, L. Mark. Contributions from the Geological Laboratory, in charge of Professor N. S. Shaler. Contributions from the Petrographical Laboratory, in -charge of Professor J. Eliot Wolff. Subscriptions for the publications of the Museum will be received on the following terms : — For the BuLLETIN, $5.00 per volume, payable in advance. For the Memorrs, $8.00 = “é ce These publications are issued in numbers at irregular inter- vals; one volume of the Bulletin (8vo) and half a volume of the Memoirs (4to) usually appear annually. Each number of the Bulletin and of the Memoirs is also sold — separately, and a price list of the publications of the Museum will | be sent on application to the Director of the Museum of Compara- | tive Zoölogy, Cambridge, Mass. a ALEXANDER AGASSIZ, Director. > a a Abdruck aus: ' Zoologisches Centralblatt x ri unter Mitwirkung yon Ü Professor Dr. ©. Bütschli und Professor Dr. B. Hatschek N in Heidelberg in Prag ES herausgegeben von x) Dr. A. Schuberg Na Privatdocent a. d. FA Hochschule > Karlsruhe. FM Jahrgang, No&«. . vom Ae E ? + (Verlag von Wilhelm Engelmannin Leipzig.) Um dem Zwecke des „Zoolog. Centralblattes“, rasch uber die neu erscheinende Litteratur zu berichten, in möglichst vollkommener Weise dienen zu können, bitten wir die Herren Herausgeber und Verleger von - Zeitschriften, sowie die Herren Verfasser von einzeln oderin Zeitschriften erscheinenden einschlägigen Schriften, uns Exemplare ihrer Publikationen zusenden zu wollen. Besonders wertvolle Publikationen oder nicht zum Referate ge- langende Schriften werden auf Wunsch gerne zurückgesandt. Alle Sendungen für das „Zoolog. Centralblatt“ sind, als solche be- zeichnet, an die Redaktion, Dr. A. Schuberg, Karlsruhei.B.. Hirschstrasse4, zu adressieren. Druckschriften können auch auf dem Buchhändlerwege durch die Verlagsbuchhandlung Wilhelm Engelmann in Leipzig übermittelt werden. Rathbun, M.J., Catalogue of the Crabs of the ee Majidae Tr tire U.S. National Museum. )— In: Proceed." "US Nat: Mus. Vol. 16, 1893. p. 63—103 pl. 3—8. Die vorliegende Arbeit bildet eine Fortsetzung des im Jahre 1892 am derselben Zeitschrift erschienenen Kataloges der Periceridae; sie enthält die im U. S. National-Museum vorhandenen Brachyuren aus “der Familie Majidae (nach Miers’ Fassung). Die Zusammenstellung ‚der Unterfamilien, Gattungen und Arten (letztere nur soweit, als sie ‚dem Verfasser vorlagen) in Tabellenform ist für das praktische Be- diirínis recht wertvoll. Das System schliesst sich im wesentlichen, mit geringen Änderungen an Miers’ (Journ. Linn. Soc. London 1879, an, eine Kritik dieses recht künstlichen und in vielen Punkten an- Kechtbaren Systems wird nicht versucht. — Eine neue Gattung, Lep- proc, wird beschrieben, nebst einer Anzahl neuer Arten. | Als Anhang werden bisher unpublizierte Stimpson’sche Be- schreibungen einiger Formen gegeben, die von der North Pacifie Expedition stammen. \ A. Ortmann (Strassburg 1. E.) »* “ - 1 u e 14 2 4 % ix A ' I Xe E N N A - A TN ad W 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 191 A NEW SPECIES OF THE ISOPOD-GENUS BATHYNOMUS. BY DR. A. ORTMANN. In the year 1877, A. Agassiz dredged at 955 fathoms, in the Gulf of Mexico, a gigantic Isopod, described by A. Milne-Edwards (Compt. Rend. Acad. Sc., t. 88, 1879, p. 21, and Annal. Magaz. Nat. Hist. (5) III., 1879, p. 241) as Bathynomus giganteus. De- lineations of this form were subsequently published by Filhol (La- vie au fond des Mers, Paris, 1885, p. 147),* and by A. Agassiz (Three Cruises of the “Blake.” Bull. Mus. Compar. Zool., Vol. XV., 1888, fig. 252.) Wood-Mason and Alcock made mention of the same species (Annal. Magaz. Nat. Hist. (6) VII., 1891, p. 270) taken by the ““Investigator’’ in the Bay of Bengal at 740 fathoms. Lastly, Hansen (Det K. Dansk. Vidensk. Selsk. Skr. Nat. Math. Afd. (6), V. 3, 1890, pp. 252, 318, 378) pointed out the close resemblance to the family Cirolanid&, while Milne-Edwards proposed to place this genus in a new group or family, ‘‘Cymothoadiens branchifêres.” This latter opinion was adopted by Wood- Mason and Alcock in creating the family Bathynomid«. After a careful examination of both opinions I believe Hansen’s classification to be correct. Bathynomus giganteus, which is remarkable, not only for its enor- mous size, but also for other morphological characters, was hitherto the only species of the genus. I describe herein a second species collected by L. Döderlein, during his sojourn in Tokio, Japan (1880- 81), which, although smaller than the other, always attains dimen- sions unusual among the Isopoda. I propose to name the new species in honor of the discoverer, Bathynomus döderleini. Diagnosis. —Body more slender than in 5. giganteus, three times as long as broad (DB. giganteus is not two-and-a-half times as long as broad). The last segment of the body (telson) is but little broader than long, its posterior margin is provided with seven spines, the middle one of which is the greatest. In the median line of the upper surface is a distinct longitudinal ridge. Both branches of the uropoda are pointed at the ends. | 1 I have only seen the copy in Marshall, Die Tiefsee und ihr Leben, 1888, p. 261, fig. 86. 192 PROCEEDINGS OF THE ACADEMY OF ~ [1894. Deseription.—Total length of the greater specimen 125 mm., breadth 42 mm., of the smaller 103 mm. and 36 mm. The whole upper surface finely granulated and punctured. Frontal margin, in the middle, feebly sinuated, with a short pro- cess bent downwards. Eyes placed in the lower surface of the head, beneath the frontal margin, which is distinctly raised. Lamina frontalis equilaterally triangular, the angles rounded, the anterior meeting with the frontal process. Clypeus produced forward as a blunt, triangular projection, extending over the frontal margin so as to be visible from above, its longitudinal diameter greater than that of the labrum. The stalk of the antennule has three joints, the flagellum is about as long as the stalk, with nearly thirty joints. Stalk of the antennze five-jointed, the first joint short and concealed, Flagellum in both specimens mutilated, the longest fragment has twenty-five joints, and reaches to the posterior margin of the first segment of the trunk. | Segments of the body finely punctured, the first as long as the head, the others considerably shorter, decreasing a little from before to behind. The first and second epimera nearly alike, not produced posteriorly, the four following posteriorly acutely produced, especi- ally those of the fifth, sixth and seventh segments. The three an- terior pairs of feet stout, second joint (see Hansen) not thickened, third longer than broad, fourth with the inner margin thorny, the process of its outer margin reaching to the middle of the sixth joint (but in the first pair of feet very short), sixth joint elongated and curved. The four following pairs of legs similar to each other, in- creasing in length. Second joint not remarkably thickened or en- larged. Third joint distally enlarged, the anterior margin with prickles, similar prickles at the anterior margin of the fourth and fifth joints. Sixth joint but little longer than the fifth, narrow. Segments of the pleon evenly arched, the lateral angles of the second to fifth produced posteriorly and provided with a longitudinal ridge, those of the third segment longest. Pleopoda with roundish, almost equal branches, carrying at the hinder part of their bases the tufts of branchix characteristic of the genus, but since both are dried specimens the pleopoda and the branchiz have become crumpled, and therefore it is impossible to give the details. | Last segment (telson) punctured and finely granulated, at the base but little larger than long, the lateral margins somewhat con- 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 193 verging posteriorly. Posterior margin truncated and provided with seven spines. The median line of this segment is occupied by a longitudinal keel, produced to the end of the middle spine of the posterior margin. ‘This spine is somewhat longer than the others which are likewise somewhat unequal, on either side the second (from the middle outwards) being a little longer than the other laterals. Stem of the uropoda produced at tbe inner posterior angle, outer branch elongated, the margins nearly parallel, acuminated at the end. The inner branch almost triangular, acuminated posteriorly, longer than the outer, not looking over the telson. Both branches with several prickles at the margins. The legs were originally covered with hair, but now are nearly worn bare because of the dry conservation. The hairs on the mar- gins of the uropods and the telson are also preserved only here and there. This species occurs on the Japanese coast, near Enoshima, Sagami Bay. The depth is not recorded; probably it lives associated with the famous Japanese Hexactinellide and Lithistide. The types be- long to the Döderlein collections and are deposited in the museum of Strassburg, Germany. t F ae om. 1894.] NATURAL SCIENCES OF PHILADELPHIA. 397 ‘ ASTUDY OF THE SYSTEMATIC AND GEOGRAPHICAL DISTRIBUTION OF THE DECAPOD FAMILY ATYIDZ Kingsley. BY ARNOLD E. ORTMANN. In the following paper I propose to give a revision of the family Atyide with especial reference to its geographical distribution. For a true representation of the geographical range of a group of animals it is necessary to examine the details of the distribution of all the known species, as well as to define the systematic limits of each. Every error in determining a species may be followed by great confusion difficult to solve by subsequent investigation. In revising the known genera and species it is necessary to state the relations and affinities to each other in order to get an idea of the peculiarities of the geographical distribution and to find out their cause. The family Atyide, although a small one, comprises a consider- able number of ill-defined species and genera, since most authors in creating such did not investigate their relations to those already known. In the typical genus Atya there are farther difficulties due to the change of characters undergone by one species in the different stages of life, which were wholly neglected by the majority of authors. I have, notwithstanding, succeeded in revising the family, pointing out the identity of certain species and genera, defining some more correctly, and stating the affinities so as to leave but a few species doubtful. I have determined a peculiar geo- graphical distribution of the family agreeing well with its habits and morphological characters. The family Atyide is a very characteristic one among the Decapod group of Eucyphidea. It shows on the one hand a number of primitive characters, on the other a very peculiar shape of the fingers of the chele. As I have stated in a former paper,’ the Atyide are closely connected with the family Acanthephyride, which live at great depths in the sea and contain, without doubt, the most primitive Eucyphidea. "The morphological differences between the two families are the following: 1. The mandible in the Acanthephyride is furnished with a palpus (synaphipod), in the Atyide it is wanting. ! Decapoden u. Schizopoden der Plankton-Expedition, 1893, p. 42. 398 PROCEEDINGS OF THE ACADEMY OF [1894. 2. The fingers of the chele in the Acanthephyride are normal in shape, in the Atyide they are provided with a peculiar pencil of hairs. I may add that the habits of the two families are wholly different, the Acanthephyride being true marine animals, especially abyssal, the Atyide being true fresh-water forms. Among the Atyide Kingsley distinguished two subfamilies, Aty- ine and Ephyrine. Since, however, there are but a few genera in this family, a subdivision is needless. The genera form a continu- ous series, the transition being so gradval that it is difficult to define the limits of the two subfamilies. In the following synopsis of the genera the first three named, Xiphocaris, Troglocaris, and Atyaéphyra may be regarded as belonging to the subfamily Ephyrin® as created by Kingsley, the others as belonging to the Atyinw. Because the genus Ephyra, from which is derived the name Ephyrine, is a synonym, this subfamily must be renamed, and I propose to name it, if at all, Xiphocarine. | The presence of exopodites on the pereiopoda of the Xiphocarine, the shape of the carpal and propodal joints of the first two pairs of pereiopoda, and the shape of the rostrum constitute a very close re- semblance to the Acanthephyride. Atyaéphyra makes a transition to the Atyine, bearing exopodites only on the first two pairs of pereio- poda, and having the carpal joints of these legs excavated at the distal extremity. This excavation is very characteristic in the true Atyine, but in Caridina the carpal joint only of the first pair of legs shows this peculiarity, that of the second pair being normal. Atyoida is intermediate between Caridina and Atya in the shape of the propo- dal joints of these legs. Within the limits of Caridina occurs a reduction of the form of the rostrum (being in the Xiphocarine long and serrated), which in most species of Caridina is longer or shorter and serrated, in a few very short and not serrated. In Atyoida and Atya the rostrum is usually short, but now and then it bears a few teeth on the inferior margin. Thus the series formed by Xiphocaris, Atyaéphyra, Caridina, Atyoida, and Atya is a continuous one, whilst the genus Troglocaris is closely allied to Xiphocaris differing only by the rudimentary condition of the eyes, due to its subterranean habits in cave-waters. The genus Atya is the most extreme of the family. The adult males of the species of this genus attain a considerable size, and the third pereiopoda undergo with increase of age a change in shape 1894.] NATURAL SCIENCES OF PHILADELPHIA. 399 the surface of the body and legs bearing a peculiar sculpture. The most extreme species, Atya crassa, may be separated from the others according to the sculpture of the body and placed in a separate sub- genus, Evatya. Fossil Atyide are not known, although A. Milne-Edwards’ de- scribes a Caridina nitida from the ‘‘marnes d’ Aix-en-Provence’’ (upper eocene or lower oligocene). None of the arguments given by him prove that this fossil is a Caridina. The presence in a fresh- water deposit makes it probable that it belongs to Atyide, but for the same reason Homelys minor of Meyer,’ from the fresh-water de- posits of the upper miocene of (Eningen, would belong to the same family. ATYIDZ Kingsley, 1879. Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1879, p. 414. Bate, Challenger Macrur., 1888, p. 691. Ortmann, Zoolog. Jahrb., V, 1890, p. 455. Mandibles stout, crown broad, dilated, slightly divided, without a synaphipod. First four pairs of pereiopoda with epipodites. First two pairs of pereiopoda chelate, nearly equal, carpus of the second not annulated. Tips of fingers with pencils of hairs. Rostrum longer or shorter, serrated or not serrated. &. Pereiopoda with exopodites [Xiphocarince]. d,. All the pereiopoda with exopodites. Carpal joints of the first two pairs of pereiopoda not excavated or but indis- tinctly so. en nyes well developed. „an... 4. XIPHOCARIS. ea byes rudimentary. Bein... TROGLOCARIS. d,. Only the first two pairs of pereiopoda with exopodites. Car- pal joints of the first and second pair of pereiopoda distally - Bxeamated en nl, ATYAEPHYRA. a,. Pereiopoda without exopodites [Atyince]. d,. Carpal joint of the second pereiopoda normal, not excavated. Rostrum mostiy compressed and serrated. . . CARIDINA. 6,. Carpal joint of the second pereiopoda like that of the first distally excavated. c,. Movable finger shorter than the immovable part of hand, the latter distinctly divided in a palmar por- tion and an immovable finger... . . . . . ATYOIDA. C, Both fingers alike in size, no palma developed . ATYA. 2 Bull. Soc. Philomat., Paris (7), II, 1879, p. 77. 3 Paleontographica, X, 3, 1862, p. 172, pl. 19, figs. 3-8. 400 PROCEEDINGS OF THE ACADEMY OF [1894. XIPHOCARIS v. Martens, 1872. Ephyra de Haan, Faun. Japon., Crust., Dec. 6, 1849, p.185.* (Nomen preoccu- patum.) Xiphocaris v. Martens, Archiv f. Naturg., 38, 1, 1872, p. 139. Miersia Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1879, p. 416. Xiphocaris Kingsley, Bull. Essex Instit., vol. 14, 1882, p. 127. Paratya Miers, Annal. Mag. Nat. Hist. (5), IX, 1882, p. 194. Xiphocaris Pocock, Annal. Mag. Nat. Hist. (6), III, 1889, p. 17. Miersia Ortmann, Jenaische Denkschr., VIII, 1894, p. 8. a,. No supraocular spines. Rostrum longer or shorter, with an inter- rupted series of teeth on the upper margin, the basal series containing 9-18, the apical 3-6 teeth Lower margin of rostrum with numerous (16-40) teeth. . . . . X. elongata. SUBSPECIES (or varieties). b,. Rostrum longer than carapace. . . X. elongata typica (1) d,. Rostrum shorter than carapace. c,. Rostrum longer than the scaphocerite. . X. elongata intermedia (1). à hee eon eaten them the stalk of antennule. et .X. elongata gladiator. data Anonym than the stalk of antennule. SEC RON AR a; 7, RD . X. elongata brevirostris. a). Supraocular spines present. Rostrum about as long as the scaphocerites or somewhat longer. An uninterrupted series of 20-24 teeth on the upper, 2-4 teeth on the lower margin. TR a ROO et A .X. compressa (3). 1. Xiphocaris elongata (Gusin), 1857. Hippolyte elongata Guérin, Anim. Artic. in: Ramon de la Sagra, Hist. de Vile de Cuba, 1857, p. 54, pl. 2, fig. 16. Oplophorus americanus Saussure, Mem. Soc. Phys. Hist. Nat. Geneve, t. 14, 2, 1858, p. 472, pl. 4, fig. 31. Xiphocaris elongata (Guér.) v. Martens, Arch. f. Naturg., 38, 1, 1872, p. 140. Oplophorus elongata (Guér.) Kingsley, Bull. Essex Instit., X, 1878, p. 68. Xiphocaris elongata (Guér.) Pocock, Ann. Mag. Nat. Hist. (6), III, 1889, p. 17 ff, pl. 2, figs. 5-8. Xiphocaris gladiator, var. intermedia, brevirostris Pocock, ibid. -Oplophorus elongatus (Guér.) Sharp, Proceed. Acad. Nat. Sci., Phila- delphia, 1893, p, 121. Geographical distribution: Fresh-waters of the Antilles. —Cuba (Guérin, v. Martens); Hayti (Saussure); Dominica (Pocock); St. Domingo (Sharp). 2. Xiphocaris compressa (de Haan), 1849. Ephyra compressa de Haan, Faun. Japon. Crust., Dec. 6, 1849, p. 186, pl. 46, fig. 7. Atyephyra conpressa (d. H.) v. Martens, Arch. f. Naturg., 34, 1, 1868, p. 51 ff, pl. 1, fig. 4. Atyephyra more “essa ie EI. pis Ann. Mag. Nat. Hist. (5), IX, 1882, p. 193. 4 Non Zphyra Roux, Memoir. Salicoques, 1831, p. 24, ik is jaca with Acad A. Milne- Edwards, and belongs to the Acanthephyride. 5 I put in parentheses following each species, the number of specimens I “have examined myself, 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 401 Miersia compressa (d. H.) Ortmann, Zoolog. Jahrb., V, 1890, p. 463. Miersia compressa (d. H.) Ortmann, Jenaisch. Denkschr.. VIII, 1894, p. 8. Geographical distribution: Fresh-water of Australasia.—Japan (de Haan); Yokohama (v. Martens), Tokio (Miers, Ortmann); Island of Adenare, near Flores (v. Martens); Queensland: Burnett (Ort- mann). TROGLOCARIS Dormitzer, 1853. Dormitzer, Lotos, III, 1853, p. 85. Only one species known, distinguished from Aiphocarıs by the rudimentary condition of the eyes. Supraocular spines present. 1. Troglocaris schmidti Dormitzer, 1853.6 Dormitzer, ibid., p. 85 ff, pl. 3. Geographical distribution: In the waters of the caves of Car- niola. Caves of Kumpole and Gurk (Dormitzer). ATYAEPHYRA Brito-Capello, 1866. Atyaephyra Brito-Capello, Deser. Esp. nov. Crust. Arachn., Portugal, Lisboa, 1866, p. 5 Hemicaridina Ortmann, Zoolog. Jahrb., V, 1890, p. 464. Only one species known. 1. Atyaephyra desmarestii (Miilet) 1832 (16). Hippolyte desmarestii Millet, Annal. Sci. Nat., t. 25, 1832, p. 461, pl. 10B. Hippolyte desmarestii Millet, Milne-Edwards, Hist. Nat. Crust., II, 1837, p. 376. Caridina desmarestii (Mill.) Joly, Annal. Sci. Nat. (2), Zool., t. 19, 1843, p. 34 ff, pl. 3. Caridina desmarestii (Mill.) Heller, Crust. südl. Europ., 1863, p. 238, pl. 8, fig. 3. Atyaöphyra rosiana Brito-Capello, Descr. esp. nov. Crust. Arachn., Portugal, Lisboa, 1866, p. 6, pl. 1, fig. 1 Hemicaridina desmarestii Gui. ) Ortmann, Zoolog. Jahrb., V, 1890, p. 464. Geographical distribution: Fresh-water of southern Europe. — Portugal: Coimbra (Brito-Capello); southern and western France BRs Joly); Corsica, Sicily, Dalmatia (Heller). CARIDINA Milne-Edwards, 1837. Caridina Milne-Edwards, Hist. Nat. Crust., II, 1837, p, 362. Caradina Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1879, p. 415. a,. Rostrum longer or shorter, serrated. Anterior margin of carapace with an antennal-spine. d,. Upper margin of rostrum not serrated. Carpal joint of the first pereiopoda but slightly longer than broad.. . . C. typus (2). a CAE A . O americana.” 6 There is no doubt that the Palemon anophthalmus Kollar, Sitz. Ber. Akad. Wiss., Wien, I, 1848, p. 137, from the caves of Kompoljska and Portis- kavez in Carniola is the same species as Troglocaris schmidti. As there is no published description by Kollar, the name anophthalmus cannot be employed. + C americana is a somewhat doubtful species, but certainly it is closely allied to €. typus. 402 PROCEEDINGS OF THE ACADEMY OF [1894. d,. Upper margin of rostrum serrated. c,. Carpal joint of the second pereiopoda shorter than the hand, carpal joint of the first pereiopoda short. Rostrum about as long as the antennal scale... ....... C. brevicarpalis (1). c,. Carpal joint of the second pereiopoda longer than the hand. d,. Rostrum horizontally projecting or slightly deflexed, shorter than the antennal scale. e,. Carpal joint of the first pereiopoda short, not more than à as long as broad. j,. Lower margin of rostrum serrated. g,. Upper margin of rostrum with about 13-20 teeth, rostrum mostly longer than the first joint of the antennule, h,. Eggs small and numerous. Fingers of the second pereiopoda twice as long as the palm. i,. Carpal joint of the first pereiopoda distinctly longer than broad: > a eee Ree ei E O. weberi. i,. Carpal joint of the first pereiopoda nearly as broad “asd islong . RR cl ee Sa eee C. japonica. ho Eggs greater and not numerous. Fingers of the second pereiopoda but slightly longer than the palm. eee. EN Re C. pareparensis. upper margin of rostrum with 3-5 teeth; rostrum as = Ae or a little longer than the first joint of the anten- Mule pass coe. RR eee: O O. timorensis. g,. Upper margin of rostrum with 7-12 teeth; rostrum shorter than the first joint of the antennule. ED E eR ido E RO e RS o C. parvirostris. J.. Lower margin of rostrum not serrated... . O. richtersi. e,. Carpal joint of the first pereiopoda longer, at least twice as long as broad. fi. Spine at the base of the antennulx shorter than the first joint. g,. Dactylus of the fifth ea nearly half as long as the propodus:. Bin We ieee fine O. levis. 92. Dactylus of the fifth pereiopoda very short, 2-1 of the propodus. h,. Rostrum shorter than the stalk of the antennule, upper margin with 20-30 teeth, lower with 5-14. Pos RE. ee bear A C. multidentata. h,. Rostrum about as long as the stalk of the antennule. i,. Teeth of the upper margin of rostrum 10-15, not continued to the tip of rostrum, on the tip 1-2 teeth, on the lower margin 7-12, ae EROS, (RT nai REL C. africana (many). io. Teeth of the upper margin of rostrum 20-25, in a continuous series to the tip... . . . . ©. fossarum. 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 403 Jo. Spine at the base of the antennuls longer than the first ara. . . C. serratirostris. d,. Rostrum slightly Heat a Toner en the antennal scale. Upper margin partially destitute of teeth. e;. The proximal teeth on the upper margin of rostrum crowded, numerous. Jı. Carpal joint of the first pereiopoda a little shorter than the hand. g,. Carpal joint of the first pereiopoda 2-24 as long as nn. RN ie ee Oywycki (many): . Carpal joint a Re fire ee only 13 as long as nd. ET een Olmiloriean (> J,. Carpal rt a Ihe Ara sera very much shorter pine hand... . „ern. 2 nen. Cl grandirostris. . The proximal teeth on the As margin of rostrum re- rote, not numerous..... ..... .C. gracilirostris. . Rostrum very short, not serrated. Laie margin of the carapace without an ente spine. 6,. Fingers of the first pereiopoda about as long as the palm. . C. singhalensis (many). Dy: Pincers a the bast pereiopoda en ansehen than the palm. en... SE cre. RUN Fal .C. brevirostris. 1. Caridina typus Milne-Edwards, 1837.8 Caridina typus Milne-Edwards, Hist. Nat. Crust., II, 1837, p. 363, pl. 25 bis, gs. 4, 5. C. exilirostris Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 29. C. siamensis Giebel, Zeitschr. f. d. ges. Naturw., 21, 1863, p. 329. C. typus M. E., Miers, Philosoph. Trans. London. 168, 1879, p. 492. Richters, Beitr. Meeresfaun. Maurit. Seychell. Decap., 1880, p. 162, pl. 17, fig. 23. C. typus M. E., de Man, in Weber, Zoolog. Ergebn. Reis. Niederl. Ost- Indien, II, 1892, p. 367, pl. 21, fig. 22. C. typus M. E., de Man, Not. Leyd. Mus., 15, 1893, p. 300. C. typus M. E., Sharp, Proceed. Acad. Nat. Sci., Philadelphia, 1893, p. 111. C. typus M. E., Ortmann, Jenaische Denkschr., VIII, 1894, p. 8. Geographical distribution: Fresh-water of the Islands’ of the Indian Ocean and of Indo-Malaysia.— Mauritius (Richters, Sharp); Rodriguez (Miers); Seychelles (Richters); Siam (Giebel); Fiores, Timor, Saleyer, Celebes (de Man); Amboina (Ortmann); Loo-Choo (Stimpson). 2. Caridina americana Gu£rin, 1857. Guérin, Anim. Artic. in Ramon de la Sagra, Hist. de Vile de Cuba, 1857, p. De pl 2) fig. 13, Vv. Martens, "Arch. f. Naturg., 38, 1, 1872, p. 135. Pocock, Ann. Mag. Nat. Hist. (6), Anan 1889, p. 16, pl. 2, fig. 4. Geographical distribution: Cuba (Guérin, v. Martens); Dominica (Pocock). | 8 Caridina typus Bate, Challenger Macr. 1888, p. 704, pl. 119, fig. 3, from San Jago, Cape Verde Isl. is probably a different species. 404 PROCEEDINGS OF THE ACADEMY OF [1894. 3. Caridina brevicarpalis de Man, 189. De Man, in Weber, Zool. Erg., etc., II, 1892, p. 397, pl. 24, fig. 30. Ortmann, Jenaische Denkschr., VIII, 1894, p. 9. Geographical distribution: Celebes (de Man); Amboina (Ortmann). 4, Caridina weberi de Man, 1892. De Man, in: Weber, Zool. Erg., etc., II, 1892, p. 371, pl. 22, fig. 23. De Man, Not. Leyden Mus., 14, 1892, pl. 9, fig. 8. Geographical distribution: Sumatra; Java; Saleyer; Celebes; Flores (De Man). 5. Caridina japonica de Man, 1892. De Man, Not. Leyd. Mus., 14, 1892, p. 261, pl. 9, fig. 7. Geographical distribution: Japan: Kagar, Hayagana (De Man). 6. Caridina pareparensis de Man, 1892. De Man, in: Weber, Zool. Erg., etc., II, 1892, p. 379, pl. 22, fig. 25. Geographical distribution: Celebes (De Man). 7. Caridina timorensis de Man, 1898. De Man, Not. Leyd. Mus., 15, 1893, p. 300, pl. 8, fig. 6. Geographical distribution: Timor (De Man). 8. Caridina parvirostris de Man, 1892. De Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 375, pl. 22, fig. 24. Geographical distribution: Flores (De Man). 9. Caridina richtersi Thallwitz, 1891. C. serrata Richters, Beitr. Meeresf. Maur. Seych. Decap., 1880, p. 163, pl. 17, figs. 24-27 (nomen preoccupatum ). C. richterst Thallwitz, Abhandl. Mus. Dresden, 3, 1891, p. 27, foot-note. Geographical distribution: Mauritius (Richters). 10. Caridina levis Heller, 1862. Heller, Sitz. Ber. Acad. Wiss., Wien, 45, 1, 1862, p. 411. De Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 376, pl. 23, fig. 27. Geographical distribution: Java (Heller, De Man). 11, Caridina multidentata Stimpson, 1860. Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 29. De Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 380, pl. 22, fig. 26. Geographical distribution: Bonin Isl. (Stimpson); Celebes (De Man). 12. Caridina africana Kingsley, 1882.9 Kingsley, Bull. Essex Instit., vol. 14, 1882, p. 127, pl. 1, fig. 3. Geographical distribution: S. Africa: Zulu Land (Kingsley). 9 Having examined the types of this speciesin the Museum of the Academy of Nat. Sci., Philadelphia, I can give the following details :— Carpal joint of the first pereiopoda twice as long as broad on the distal ex- tremity, a little shorter than the hand. Fingers about equal to the palm. Car- pal joint of the second pereiopoda four times as long as broad on the distal ex- tremity, a little longer than the hand. Fingers about 1% as long as the palm. Dactylus of the fourth pereiopoda about 1-5 of the propodus, the fifth pereiopoda re in none of the type specimens preserved. 1894.] NATURAL SCIENCES OF PHILADELPHIA, 405 13. Caridina fossarum Heller, 1862. Heller. Sitzb. Acad. Wiss., Wien, 45, 1, 1862, p. 411. De Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 397. Geographical distribution: Persia: Schiraz (Heller). 14, Caridina serratirostris de Man, 1892. De Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 382, pl. 23, fig. 28. Geographical distribution: Flores; Saleyer; Celebes (De Man). 15. Caridina wycki (Hickson), 1888. Atya wycki Hickson, Annal. Mag. Nat. Hist. (6), II, 1888, p. 357, pl. 13, 14. Caridina wycki (Hicks.) Thallwitz, Abhandl. Mus. Dresden, 3, 1891, p. 27. Caridina wycki (Hicks.) de Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 386, pl. 24, fig. 29-29k. Caridina wycki ( Hicks.) de Man, Not. Leyden Mus., 15, 1893, p. 302, pl. 8, fig. 7. Caridina wycki (Hicks.) Ortmann, Jenaische Denkschr., VIII, 1894, p. 9. Geographical distribution: From East- Africa to eastern Australia. — East-Africa: Dar-es-Salaam (Ortmann); Ceylon (Ortmann); Celebes (Hickson, Thallwitz, de Man); Saleyer (de Man); Flores (de Man); Timor (de Man); Queensland: Burnett (Ortmann). 16. Caridina nilotica (Roux), 1833.10 Pelias niloticus Roux, Annal. Sci. Nat., t. 28, 1833, p. 73, pl. 7, fig. 1. Caridina longirostris Milne-Edwards, Hist. Nat. Crust., II, 1837, p. 363. Caridina longirostris Lucas, Explor. Alger. Anim. Artic., 1849, p. 40, pl. 4, Hg. A. Caridina longirostris Heller, Sitzb. Acad. Wiss., Wien, 45, 1, 1862, p. 412. Caridina longirostris de Man, in: Weber, Zool. Ergebn., etc., II, 1892, p. 396, pl. 24, fig. 291, 29m, 29mm. Caridina longirostris Sharp, Proceed. Acad. Nat. Sci., Philadelphia, 1893, p. Ih. Geographical distribution: Northern Africa. — Nile (Roux); Algiers (Lucas, Sharp); River Macta, near Oran (Milne-Edwards). 17. Caridina grandirostris Stimpson, 1860. Stimpson, Proceed. Acad. Nat. Sci., Philadeiphia, 1860, p. 28. Geographical distribution: Loo-Choo (Stimpson). 18. Caridina gracilirostris de Man, 1892. De Man, in Weber, Zoolog. Ergebn., etc., II, 1892, p. 399, pl. 25, fig. 31. Geographical distribution: Sumatra, Celebes, Saleyer, Flores (De Man). 19. Caridina singhalensis Ortmann, 189. Ortmann, Jenaische Denkschr., VIII, 1894, p. 9, pi. 1, fig. 2. Geographical distribution: Ceylon (Ortmann). 10 Tt is doubtful, whether the following quotations belong to this species or to Car. wycki: C. nilotica Hilgendorf, Mon. Ber. Akad. Wiss., Berlin, 1878, p. 828.—Mozam- bique, Tette. C. longtrostris Richters, Beitr. Meeresf. Maur. Seych. Decap., 1880, p. 162.— Seychelles. C. nilotica Pfeffer, Jahrb. Hamburg Wiss. Anstalt., VI, 1889, p. 35.—Zanzibar. 406 PROCEEDINGS OF THE ACADEMY OF [1894. 20. Caridina brevirostris Stimpson, 1860. Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, .1860, p. 29. Geographical distribution: Loo-Choo (Stimpson). DOUBTFUL SPECIES.” Caridina denticulata de Haan, Faun. Japon. Crust., Dec. 6, 1849, p. 186, pl. 45, fig. 8.— Japan. Caridina leucosticta Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 28.— Japan, Simoda. Caridina serrata Stimpson, ibid., p. 29.—Hongkong. Caridina acuminata Stimpson, ibid., p. 29.—Bonin Isl. Caridina spathulirostris Richters, Beitr. Meeresf. Maur. Seych., 1880, p. 163, pl. 17, fig. 28.— Mauritius. Caridina curvirostris Heller, 1862. Heller, Verhandl. Zool. Bot. Gesellsch., Wien, 12, 1862, p. 525. Heller, Crust. Novara, 1868, p. 105. Miers, Catal. Crust. New Zealand, 1876, p. 78. Geographical distribution: Auckland (Heller). This species is provided with an supraorbital and an antennal spine, the spine at the base of the antennule is longer than the first | joint. | It may belong to the genus Xiphocaris and may be identical with a species of Aiphocaris from the River Avon, near Christ Church, pre- sent in the Museum of Strassburg. Unfortunately I cannot give a description of these specimens and a comparison with Heller’s species. ATYOIDA Randall, 1839. Randall, Journ. Acad. Nat. Sei., Philadelphia, VIII, 1839, p. 140. This genus? has, up to the present time, been very doubtful. Examining specimens of Atyoida bisulcata from Oahu, Sandwich, in the Museum of the Academy of Natural Sciences of Philadelphia (No. 162), I find that the hands of the two anterior pairs of legs are wholly different from the typical Atya, in the same manner as figured by F. Müller in Atyoida potimirim (1. ¢., figs. 3 and 4). In 11 The following three species described by Bate do not belong to Caridina; but to the family Aippolytide:— Caridina truncifrons Bate, Proceed. Zool. Soc. London, 1863, p. 499, pl. 40, fig. 2, belonging to Latreutes. Caridina cincinnuli Bate, ibid.. p. 500, pl. 40, fig. 3, and Caridina tenutros- tris Bate, ibid., p. 501, pl. 40, fig. 4, both belonging to Firdius. (All three from Australia, St. Vincents Gulf. 12 Atya serrata Bate, Challenger Macrur, 1888, p. 699, pl. 119, fig. 2, from San Jago, Cape Verd Isl., and some other species described from the West Indies (see below), may belong to this genus. In 4. serrata the rostrum is shorter and dentate below. Ea 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 407 Atyoida the hands are formed like those of Caridina: the dactylus (movable finger) is inserted on the upper margin of the propodus, being shorter than the latter and forming a chela, as usual in the Decapoda, consisting of a palmar portion and two fingers. In Atya, on the contrary, the dactylus articulates with the propodus on the posterior end of the latter, both joints being exactly alike and form- ing a hand of a very peculiar shape among the Decapoda, the palmar portion being wholiy reduced, and the hand consisting only of two fingers about alike in size, and connected with each other at the posterior ends. The carpal joint of the chelipeds in Atyoida is longer than in Atya, especially on the second pair of legs. dy. Rostrum dentate below. Carpal joint of tbe first pair of pereio- poda longer than broad... . . . . A. potimirim. a,. Rostrum not dentate below. Gaara 2: of the first pair of pereiopoda not longer than broad.. . . . A. bisulcata (many). 1. Atyoida potimirim F. Müller, 1881. F. Müller, Kosmos (Krause), IX, 1881, p. 117 ff, figs. 1-20. Geographical distribution: Brazil: Itajahy (F. Müller). 2. Atyoida bisulcata Randall, 1839. . Atyoida bisulcata Randall, Journ. Acad. Nat. Sci., Philadelphia, VIII, 1839, p. 140, pl. 5, fig. 5. Atyoida bisulcata Dana, U.S. Expl. Exp. Crust., 1852, p. 540, pl. 34, fig. 1. Atyoida bisulcata Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 28. Atyoida tahitensis Stimpson, ibid. Atyoida bisulcata and tahitensis A. Milne-Edwards, Annal. Soc. Entomol., France (4), IV, 1864, pp. 151 and 152. Atya disulcata (Rand.), Bate, Challenger Macrur., 1888, p. 700, pl. 120. Atya bisulcata (Rand.), Sharp, Proceed. Acad. Nat. Sci, Philadelphia, 1893, p. 111. Geographical distribution: Hawaiian Isl. (Randall, Stimpson): Oahu (Dana, Sharp); Tahiti (Stimpson). ATYA Leach, 1817. Atys Leach, Trans. Linn. Soc. London, XI, 1815, p. 345 (nomen przoccupa- tum ). Atya Leach, Zoolog. Miscell., III, 1817, p. 29. a,. Rostrum shorter than the antennular peduncle, without teeth on the mpper mara. .. FO ........[Bubgenus Abya). d,. Rostrum without lateral keels and without lateral teeth near the base. €). Rostrum longer than the first joint of the antennule, ee quae: or sometimes bent upward. Eee ie . A. moluccensis (6). ee as es as or shorter than the first joint of the antennule, bent downward. A. spinipes"” (12). 13 4. spinipes might be regarded as a variety of A. moluccensis. > > 408 PROCEEDINGS OF THE ACADEMY OF [1894. d,. Rostrum with lateral keels ending by angles or short spines on each side of the base of rostrum. c,. Carapace not sculptured with keels, but often punctate. Third pair of legs (in the adult) without a spine on the inferior margin. d,. Rostrum very short. Lateral keels ending in front in angles, not in spines. EB ., .) Saw . A. brevirostris (3). d,. Rostrum longer. Lateral keels ending in front F “in spiniform angles. e; Merus of the first two pairs of pereiopoda hairy. f,. Rostrum straight. ER .. 2A. margaritacea (8). fo». Rostrum bent downward. RES NI Ras 2A. robusta. e,. Merus of the first two pairs of pereiopoda not ‘hairy (9)... . 2 UA seabra (8 CG. Carapace strongly sculptured in front with keels. Third pair of legs on the inferior margin with a spine in adult specimens.» . . . A. gabonensis (1). a). Rostrum as long as the antennal scale, upper margin with six to eight spines. Anterior part of carapace with numerous spines and spiny carinations ..... . . [Subgenus: Avatya Smith] TOMER 20. RR . A. (Bvatya) crassa. 1. Atya moluccensis de Haan, 1849. . moluccensis de Haan, Faun. Japon. Crust., Dec. 6, 1849, p. 186. .armata A. Milne-Edwards, Annal. Soc. Entomol., France (4), IV, 1864, p. 149, pl. 3, fig. 3. . armata v. Martens, Arch. f. Naturg., 34, 1, 1868, p. 47, pl. 1, fig. 6. . moluccensis d. H., Miers, Annal. Magaz. Nat. Hist. (5), V, 1880, p. 382, pl. / a an Zoolog. Jahrb., V, 1890, p. 467, pl. 36, fig. 9. . dentirostris Thallwitz, Abhandl. Mus., Dresden, 3, 1891, p. 26. fig. 7. . moluccensis d. H., de Man, in Weber, Zoolog. Ergebn. Reis. Niederl. Ost- Indien, II, 1892, p. 357, pl. 21, fig. 20. . moluccensis d. H., Ortmann, Jenaische Denkschr., VIII, 1894, p. 10. Geographical distribution: Fresh- water of the Indian Archipelago. — Sumatra (de Man, Ortmann); Java (A. Milne- Edwards,'® Miers, de Man); Batjan (Miers); Bali (Miers); Celebes (Miers, de Man, Doado AA AA 14 The differences between the New Caledonian species A. margaritacea and rodusia and the West Indian A. scabra are very doubtful, since the anterior pereiopoda of the latter have the merus furnished with a few hairs. I suppose that the locality given by Milne-Edwards for margaritacea and robusta is not correct, and that there is no difference from A. scabra. (See below.) 15 I think the differences of A. gabonensis and perhaps also of A. crassa are not of specific value, but that they are differences of age: A. gabonensis would be a very old state of A. scadra, but it may be that A. crassa is a distinct species. 16 A. Milne-Edwards records his specimens, 1. c., erroneously from the Philip- pine Islands (see de Man, l. c., p. 357, foot-note). sd 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 409 Thallwitz); Saleyer (de Man); Ceram (v. Martens); Timor (de Man); Flores (de Man); Amboina (Ortmann); Philippine Islands: Samar (v. Martens). 2. Atya spinipes Newport, 1847. A, spinipes Newport, Annal. Magaz. Nat. Hist., XIX, 1847, p. 159. A. pilipes Newport, ibid., p. 160. A. spinipes and pilipes Newp., A. Milne-Edwards, Annal. Soc. Entomol., France (4), IV, 1864, pp. 149, 150. A. pilipes Newp., Miers, Catal. Crust., New Zealand, 1876, p. 79. A. spinipes and pilipes Newp., Miers, Annal. Magaz. Nat. Hist. (5), V, 1880, p. 282, pl. 15, figs. 5, 6. A. pilipes Newp., Ortmann, Zoolog. Jahrb., V, 1890, p. 466, pl. 36, fig. 8. Geographical distribution: This species represents the A. molue- censis in the fresh-water of the Pacific Islands. —Philippine Islands (Newport); Caroline Isl. (Ortmann); Fiji Isl. (Ortmann) ; Samoa Islands (Newport, Miers, Ortmann).” Atya brevirostris de Man, 1892. De Man, in: Weber, Zoolog. Ergebn., etc., II, 1892, p. 360, pl. 21, fig. 21. Ortmann, Jenaische Denkschr., VIII, 1894, p. 10. Geographical distribution: Flores (De Man); Timor (De Man); Amboina (Ortmann). ?4, Atya margaritacea A. Milne-Edwards, 1864. A. Milne-Edwards, Annal. Soc. Entomol., France (4), IV, 1864, p. 148, pl. 3, 1222. Ortmann, Zoolog. Jahrb., V, 1890, p. 465, pl. 36, fig. 7. Geographical distribution: New Caledonia (A. Milne- Edwards). 15. Atya robusta A. Milne-Edwards, 1864. A. Milne-Edwards, ibid., 1864, p. 148, pl. 3, fig. 1. Geographical distribution: New Caledonia (A. Milne-Edwards). 6. Atya scabra Leach, 1815. Atys scaber Leach, Trans. Linn. Soc. London, XI, 1815, p. 345. Atya scabra Leach, Zoolog. Miscell., III, 1817, p. 29, pl. 131. Atya scabra Desmarest, Consider. Génér. Crust., 1825, p. 217. A. mexicana Wiegmann, Arch. f. Naturg., II, 1, 1836, p. 145. A. scabra Lch., Milne-Edwards, Hist. Natur. Crust., II, 1837, p. 942, pl. 24, figs. 15-19, and Atlas, Cuvier’s Regn. anim., pl. 51, fig. 4. A. sulcatipes Newport, Annal. Magaz. Nat. Hist., XIX, 1847, p. 159, pl. 8, fig. 1. A. occidentalis Newport, ibid. A. scabra Lch., Stimpson, Boston Journ. Nat. Hist., VI, 1857, p. 498. A. scabra, sulcatipes, and occidentalis A. Milne-Edwards, Annal. Soc., En- tomol., France (4), IV, 1864, pp. 146, 147. A. vivalis and tenella Smith, 2 and 3 Rep. Peabody Acad. Sci., 1871. p. 94. A.scabra and occidentalis v. Martens, Arch. f. Naturg., 38, 1, 1872, p. 135. A. punctata Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1878, p. 91. A. occidentalis Newp., Kingsley, ibid., p. 92. A. sulcatipes Newp., Bate, Challenger Macrur., 1888, ‘p. 694, pl. 118, 119, fig. 1. A. occidentalis Newp., Pocock, Annal. Mag. N. H. (6), IIÍ, 1889, p. 11, pl. 2, fig. 3. A, scabra Lch., Sharp, Proceed. Acad. Nat. Sci., Philadelphia, 1893, p. 111. 7 The locality, “ New Zealand,” given by Newport is an error. 410 PROCEEDINGS OF THE ACADEMY OF [ 1894. Geographical distribution: Fresh-water of the West Indies and the Cape Verde Islands. — Mexico (Wiegmann, Milne-Edwards, v. Martens, Stimpson, Sharp); Nicaragua (Smith); Cuba (v. Martens); Hayti (Kingsley); Jamaica (Newport); Dominica (Pocock); Mar- tinique (Sharp); Tobago (Mus. Strassburg™).—Cape Verde Islands: San Nicolao (Newport); San Jago ( Bate). 7. Atya gabonensis Giebel, 1875. Atya gabonensis Giebel, Zeitschr. f. d. gesammt. Naturwiss. (2), XI, 1875, p. 52. Euatya sculptilis Kölbel, Sitz. Ber. Acad. Wiss. Wien, vol. 90, 1, 1884, p. 317, ee, pos Ayta sculptata Ortmann, Zoolog. Jahrb., V, 1890, p. 465. Geographical distribution: Gaboon (Giebel); Orinoco (Kölbel). 8. Atya (Evatya) crassa Smith, 1871. Smith, 2 and 3 Rep. Peabody Acad. Sci., 1871, p. 95. Kölbel, Sitzb. Acad. Wiss., Wien, vol. 90,1, 1884, p. 318, foot-note. Geographical distribution: Nicaragua (Smith); Mexico: Presidio (Kolbel). DOUBTFUL SPECIES. Atya poeyi Guérin, Crust. in Ramon de la Sagra, Hist. de l’ile de Cuba, 1857, p. 46, pl. 2, fig. 7.—Cuba. Caridina mexicana Saussure, Mem. Soc. Phys. Hist. Nat. Genéve, 14, 2, 1858, p. 463, pl. 4, fig. 26.—Mexico. Atyoida glabra Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1878, p. 93.— Nicaragua. Atya serrata Bate, Challenger Macrur., 1888, p. 699, pl. 119, fig. 2.—Cape Verde Isl.: San Jago. These species may be the young of A. scabra or may belong to Atyoida. Considerations concerning the geographical distribution of the Atyide. Some species of Atyide were formerly considered to be marine animals; there is now no doubt that this family contains only fresh- water forms. This family is probably one of the most primitive groups of Decapoda living in fresh-water, having immigrated at an early geological period. Only two species, Caridina wycki and gracilirostris, are recorded by Weber” as found ‘in a few cases in brackish waters of Sumatra 18 This locality is not yet published : there is one adult male fromTobago in the museum at Strassburg. 19 Die Stisswassercrustaceen der Indischen Archipels. — Zoolog. Ergebn. Reise Niederl. Ost.-Indien., II, 1892, p. 542. e 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 411 and Celebes.” I believe, that this occurrence may be considered as a re-adaptation of these two species, as they are found also in fresh- water. Since the genus Caridina is not a primitive one, while the genera of the Xiphocarine are so, and live exclusively in fresh- water, it is very probable, that the fresh-water habit of the family must be regarded as the original manner of living. I believe, there- fore, that the Atyide, even of the Indian Archipelago, are not im- migrants from the sea, as stated by Weber (1. c., p. 543), but “true localized fresh-water animals, forming an old element of the fresh- water fauna.”” The main differences of the Atyide and their supposed ancestors, the Acanthephyride, are morphological as well as biological, the Acanthephyride being true marine, and essentially abyssal animals. To all appearance the morphological differences are causally connected with the change of habits. The peculiar pencil of hairs at the distal extremities of the fingers is adapted for securing the special food required, as described by F. Müller in Atyoida potimirim.” No doubt the other species of Atyide feed in the same manner. I cannot say whether the absence of the synaphipod of the mandible is due to the same cause, since the function of the synaphipod is unknown, but it may be in connection with it. On the other hand the habits of the Acanthephyride are wholly unknown, so that we cannot compare this family with the Atyide, but it is very probable that the mor- phological differences of the Acanthephyride correspond to differences in the habits, especially in securing food. We can state, briefly, that the Atyide are closely allied to the most primitive Eucyphidea, forming a peculiar branch of develop- ment very early separated from the main stem, now represented hy the Acanthephyride. Their several characters are connected with a change of habit, and with the immigration to fresh-waters. The geographical range of the Atyide embraces the whole of the circumtropical parts of the world, members of the family being re- corded from all the localities explored within these limits. Only in two localities does the range exceed the true tropics: in Japan, where it extends as far north as Tokio, and in the Mediterranean province, 20 See de Man, ibid., pp. 387, 399, 400. 21 Weber, 1. c., p. 533: “echte regionale und locale Süsswassertiere, die einen alten Bestand der Süsswasser Fauna bilden.” 22 Kosmos, IX, 1881, p. 117 ff. 412 PROCEEDINGS OF THE ACADEMY OF [1894. where it extends northward to southern France and southern Austria. This nearly exclusive distribution within the tropics, at least in the warmer climates, shows that the family was probably also in former times an inhabitant of the warmer parts of the world, and the possi- bility is granted that the immigration into fresh-water took place at a time when climatic zones were not at all differentiated, a tropical climate prevailing everywhere. If this immigration took place in a later time, the poles having undergone a cooling, one could not understand the presence of the family in all parts of the tropies, as well as the occurrence of some genera (Xiphocaris, Caridina, Atya) on both of the present great continents, the eastern and western. After the cooling of the northern and southern circumpolar regions” the range of the family was divided into two parts: an eastern com- prising the tropical Africa, Asia, Australia, and the Pacific islands, and a western comprising tropical America.* The most primitive genera of the family were restricted in range by the concurrence of the more extremely developed ones, and the latter preserved a more circumtropical distribution. It is very interesting to examine the geographical range of the genera and species from the point of view here given. The most primitive genus, Xiphocaris, shows a distribution the peculiarity of which can only be understood by supposing that the range of this genus was formerly a more extended one, but that in most parts of the world the representatives were exterminated. Only three species survived, one of which lives now in the fresh-waters ot the West Indies, the other in Indo-Malaysia, from Japan to Australia, and the third in New Zealand. From the intermediate countries species of this genus are not recorded. The Indo-Malaysian species, Xiphocaris compressa, repeats, as we know at present, this peculiarity in a reduced manner, being only recorded from Japan, the island of 23 See Ortmann Jenaische Denkschr., VIII, 1894, p. 74, and Pfeffer, Versuch uber die erdgeschichtliche Entwickelung der jetzigen Verbreitungsverhiltnisse unseres Thierwelt. Hamburg, 1891. 24 In case the Alyide immigrated from the sea into the fresh-water after this separation, it is very probable that the geographical distribution would not be a circumtropical one, but that different groups immigrated into the western and eastern continents. We know another group of Decapoda, in which the latter is the case: the family Te/lphuside, one subfamily of which the Telphus- inc, being restricted to the tropical and subtropical parts of the eastern continents (Mediterranean, African, Indian, Indo-Malaysian, etc.), two other subfamilies, Trichodactyline and Pseudotelphusine, being restricted to the tropical parts of America. 1894. ] NATURAL SCIENCES OF PHILADELPHIA, 413 Adenare, and from Queensland.” The closely allied genus Troglo- caris, the only species of which might be regarded as a fourth form of Xiphocaris, lives in the subterranean waters of Carniola, a per- fectly isolated locality in no way connected with the others named. The third primitive genus, Atyaéphyra, is found near the locality of Troglocaris on the northern borders of the Mediterranean Sea. It is somewhat less primitive. The scattered localities at which are found the species of these three genera forming the subfamily Aipho- carine are no doubt the remains of a more universal distribution in former times: the species now living show the character of true survivals. In the subfamily Atyine, the genus Atyoida shows a survival character similar to that of the Xiphocarine; being recorded from the Sandwich Islands, Tahiti, and southern Brazil. But this genus must be the subject of farther study. | The genus Caridina appears to be nearly a circumtropical one. Its range is divided into two very unequal parts: the one comprising the West Indies and containing only one species, the other compris- ing a continuous area of the old world and containing at least nine- teen other species. This area extends from South Africa along the east coast to the southern borders of the Mediterranean Sea and to Persia, crossing the islands of the Indian Ocean and Indo-Ma- laysia to Japan and Australia.” Species of this genus have not yet been found in West Africa, in southern Asia (except Ceylon and Siam), and in the Pacific islands, but it may be that some species will be discovered later in these countries. This distribution of the genus can only be understood by suppos- ing that it was present before a separation of the eastern and western parts of the tropics took place, and that the extended range of former times is now restricted to the tropical parts of the continents border- ing the Indian Ocean and to its islands, and to the islands of eastern Asia from Japan to Australia. The occurrence of one species in the Nile and in the rivers of Algiers is due, I believe, to a more recent immigration from the central and eastern parts of Africa, not unlike the occurrence of Palemon nitolieus.” 25 It may be that this species will be found on other islands between Asia and Australia, but it is very remarkable that the large collections of fresh-. water Crustacea made by M. Weber in the Indian Archipelago, and described by de Man, do not contain this species. 26 A poorly described species is recorded from the Cape Verde Islands. 27 See Ortmann, Zoolog. Jahrb., V, 1891, p. 745. ar PROCEEDINGS OF THE ACADEMY OF [1894. It is very probable that farther investigations will prove that the range of Caridina is a somewhat different one, since fresh-water crustacea of smaller size are mostly neglected by collectors, and the fauna of the fresh-waters of most tropical countries are very little known. Accordingly, the view given above on the geographical distribution of Caridina may, perhaps, have to be changed later. The distribution of the most extreme genus of the family, Atya, is somewhat similar to that of Caridina. It is found, like the latter, in the West Indies and Indo-Malaysia, but there are some modifica- tions. One species is known from West Africa, which is identical with another described from the Orinoco, and there is recorded one species from the Cape Verde Island, identical with the common West Indian form. The presence of identical fresh-water species, both in the West Indies and in West Africa, is a very remarkable fact, but not an isolated one among the Decapoda. We know another group of fresh-water Crustacea which shows the same peculiarity. Of the genus Palemon there are three species described from West Africa, two of which, Pal. jamaicensis (=vollenhoveni) and Pal. olfersi, are likewise present in the West Indies, and one, Pal. macro- brachion, is closely allied to a West Indian species, Pal. acanthurus.”® In Atya the identity of species of both continents bordering the Atlantic is due, no doubt, to other reasons than in Palemon, the latter being a very recent genus, having immigrated to the fresh- waters quite recently, while some species are now immigrating from the sea to brackish and fresh-water. On the contrary, the immigra- tion to fresh- water of the ancestors of Atya took place a long time ago, and, I think, this fact indicates a former connection of Africa and America. The other range of the genus Atya extends over the islands of the Pacific from Sumatra to the Samoan islands. None is recorded from southern Asia, from the islands of the Indian Ocean, or from East Africa.” The two species described by A. Milne- Edwards from New Cale- donia, A. margaritacea and robusta, are very doubtful, as I have stated above. I do not know another example of a fresh-water 28 See Ortmann, ibid., p. 747.— Palemon vollenhoveni is certainly the same as Pal. jamaicensis, in the paper quoted I supposed them to be nearly allied, but distinct species. 29 Only Hilgendorf (v. d. Decken's Reisen, III, 1, 1869, p. 101) records a very _ doubtful species from the Seychelles, belonging, perhaps, to Atyoida. 1894. ] NATURAL SCIENCES OF PHILADELPHIA. 415 Decapod restricted to New Caledonia. Our present knowledge of the fresh-water fauna of the Pacific islands leaves it very improbable that New Caledonia has an isolated fauna, differing from that of the other islands. It is probable, on the contrary, that species found in New Caledonia will be found also in other islands, but since A. Milne- Edwards, in 1864, described these two species, they have never been recorded from any place in the Pacific. It may be added that the differences of these species from the West Indian, A. scabra, given by A. Milne-Edwards, are scarcely at all present. Iam, therefore, induced to suppose that both are erroneously recorded from New Caledonia, the true locality being the West Indies, and that they are identical with A. scabra. | If these considerations are correct, the genus Atya can be divided Into two groups: the one containing the species bearing on each side of the rostrum at the base a spiniform angle, the other containing the species without a spiniform angle. To the first belong the species A. scabra, gabonensis, and crassa, their range extending over tropical America and West Africa; to the second belong A. moluccensis, spinipes, and brevirostris, the range of which comprises the Indo- Malaysian and Pacific islands. The last named species, brevirostris, forms a transition from the second group to the first. Then the range of the genus Atya would be divided into two parts, each con- taining a separate group of the genus, and this peculiarity could be explained by supposing that these two groups may be developed separately from each other after the separation of the former con- necting range of the genus. This conjecture agrees with the fact, that Atya is the most extreme genus of Atyide, and with its supposed recent age. We know that some fresh-water animals are rapidly distributed over great distances, either in the adult or in the larval state, but in the Atyide we know nothing of the means of distribution. Comparing the other Crustacean Decapoda we may say, that the Atyide have not been transported to great distances. Nor is it probable that the eggs can endure a long time without water, or that the larva or the adult animals can leave the water for any length of time. Transportation of the species of Atyide, in either the active or passive state, from one fresh-water system to another over the land or through the air, cannot be supposed, at least over great distances. Neither can the Atyide live in the sea, so that the 416 PROCEEDINGS OF THE ACADEMY OF [1894. most important topographical barriers to distribution would be widely extending oceans and large tracts of land without fresh- water. The Pacific Ocean forms a barrier of the first kind, while the second may be partly connected with the climatic conditions of the warmer parts of the world. Smaller areas of sea and land, however, may be crossed by some forms, as is shown especially in the distribution of some species of Caridina and Atya”. The means of distribution are certainly very limited, and therefore a great number of species are confined to very narrow districts. Lastly, the ancient character of the family induces me to suppose that there are also bionomic barriers, the Atyide not being able to immigrate to localities occupied by other fresh-water animals better equipped for the struggle for existance. | I regret very much that exact observations on the habits of the species of Atyide, on the biology and bionomy, are wholly absent. It is very probable that the different genera and species on farther examination will show some differences, especially that the best de- _ veloped are more resistant to external influences. The conditions of geographical distribution of the Atyide are as follows :— 1. The Atyide cannot endure cooler climates. ( Climatic barriers. ) 2. They are true fresh-water animals. (Oceans and tracts of land without water form topographic barriers. ) 3. Being animals of an ancient type, they are probably restricted by the occurrence of other fresh-water animals. (Bionomie barriers. ) 4. The faculties of distribution are very limited. The Atyide are, therefore, confined to the fresh-waters of the tropics and subtropics; the distribution of the genera and species, especially of the more primitive ones, shows a remarkable character of survival. Only Caridina and Atya are of a more recent charac- ter, extending over continuous areas within the tropics. Because of the antiquity of the family it has no relations among the recent forms of the litoral regions of the tropical seas.” | 30 Caridina typus, wycki, nilotica; Atya scabra, moluccensis, spinipes. 31 Such relations to the Aflantic, Indo-Pacific, and Western-American regions (see Ortmann, Jenaische Denkschr., VIII, 1894, p. 76) are not at all evident, none of the well-known genera or species being limited by the borders of one of these regions. i A E [Reprinted from the Academy of Natural Sciences, March 13, 1895.] aw A STUDY OF THE SYSTEMATIC AND GEOGRAPHIC DISTRIBUTION OF THE DECAPOD FAMILY CRANGONIDA BATE. BY ARNOLD E. ORTMANN. eee In a former paper’ I gave in general terms the limits of the Indo- Pacific litoral region, to which I added a study of the origin of the recent litoral regions of the world. As these considerations, founded upon the geographical distribution of the Decapoda, contain but a few detailed investigations, it is necessary to go more into detail when a separate group of Decapoda is examined and to state the relations to the principles given in the paper quoted. In 1891 I revised the genera Palemon and Bithynis and gave an account of their geographical distribution. In 1894 I published an account of the family Atyide.* These groups of fresh water crustacea are wholly unlike each other in respect to their geographical range and agree only in that they are true tropical animals. Whilst the Palemon and Bithynis group of the Paleemonide is a very recent one, related in its distribution, without doubt, to the limits of the recent marine litoral regions, the family Atyida is comparatively an ancient one, showing in no way relations to the former. In the present paper I will treat of a true marine group, the family of Crangonids, which is characterized by the adaptation of most of its members to the cold waters of the Arctic and deep sea — regions, Fossil remains of Crangonida are unknown. In all species referred with more or less doubt to this family, the typical characters are not evident. The absence of Crangonide from the Tertiary deposits agrees with their morphological characters and their supposed recent - development. They form the most extreme end of one of the two ee 0 “main branches of the Eucyphidea.* The principal character is the more or less reduced condition of the second pas of pep opods The ! Jenaische Denkschrift. VIII, 1894, p. 68 P. are in Semon, Zoclos. _F Bschun gsreisen in Australien und dem malayischen Archipel. 2 Zoologische Jahrbücher, V, 1891, p. 693-750. 3 Proceed. Acad. Nat. Sci. Philadelphia, 1894, p. 397-416. * Ortmann, Zoolog. Jahrb., V, 1890, pp. 462, 463. f Une: PROCEEDINGS OF THE ACADEMY OF [1895. Crangonida are connected with the Nikide by the genus Glypho- crangon, but this connection is not a close one—there are some gaps. % Among the Crangonid:, the genus Pontocaris is no doubt the most | primitive in regard to the sculpture of the carapace; the number of gills and the shape of the second pair of pereiopoda. From Ponto- caris arise two divergent branches: the one through the subgenus Seleroerangon to Crangon, ending in Nectocrangon, characterized by no shortening of the second pair of pereiopoda, by the reduction o: the number of gills, and by the surface of the body becoming grad- ually smoother. The other branch is represented by the genera Pontophilus, Sabinea, Paracrangon, characterized by the reduction of the second pair of pereiopoda in length, by retaining the primitive number of gills and the sculpture of the body. In Pontophilus some species have the body more or less smooth. The genus Prionocrangon is an aberrant one, without eyes, but related probably to the genera Pontophilus and Sabinea of the second branch. | CRANGONIDA Bate, 1888. Crangonine Kingsley, Proceed. Acad. Nat. Sci. Philadelphia, 1879, p. 411. Crangonide Bate, Challenger Macrur., 1888, p. 481, Ortmann, Zoolog. Jahrb., V, 1890, p. 462. Mandibles simple, slender, incurved, not dilate or bifid, without a synaphipod. First pair of legs stouter than the second, hand sub- chelate, the dactylus closing on the margin of the palm, the pollex being spiniform. Second pair of legs very feeble, chelate, often shortened, not chelate, or wholly reduced. External maxillipeds pediform. Maxillz with more or less reduced innermost parts. Rostrum mostly short. à. Second pair of legs present. b,. Eyes present. G. Second legs not remarkably shortened (carpal joint and hand together longer than the merus). Gills seven on each side. Carapace with dentate longitudinal keels. . . . PONTOCARIS. c,. Second legs not shortened. . Gills five on each side. d,. Eyes free. Dactyli of the two posterior pairs of legs not Glaved.. Ur ah rn. 5 RR ee COCO a ate, CRANGON. d,. Eyes has adden Kr the frontal part of the carapace. Dactyli of the two posterior pairs of legs dilated, natatorial. RR at RE N oe 1985. ] NATURAL SCIENCES OFs PHILADELPHIA. 175 c,. Second legs rerharkably shortened (carpal joint and hand to- gether not longer than the merus). Gills seven.’ @. second less chelate... .°. » +... .. . . PONTOPHILUS. d,. Second legs not chelate. .... BS 2S ABE BA db, Eyes wanting. Second legs not re rather robust, with fringes of long, plumose setee A spiny am crest on the cara- page sr. . .... . PRIONOCRANGON. . Several pairs of legs 5 wholly ae Rostrum elongated. . PARACRANGON. PONTOCARIS Bate, 1888. Bate, Challenger Macrur. 1888, p. 495. Very nearly allied to Crangon, especially to Selerocrangon. Second periopoda not remarkably shortened, carpus and palma together longer than the merus. Six pleurobranchiz (i-o) and one podobranchia (h) present (see Bate, 1. c., p. 496). Carapace with seven keels, the five uppermost dentate. Abdomen sculptured. Anterior lateral angles of carapace projecting forward. Rostrum cnminate a: nn... Dropensalata. . Anterior lateral angles ao a ra directed outward and ar. Bieosirumsbidentate. : 1. 2 ea... Popennata. 1. Pontocaris propensalata Bate, 1888. : Bate, Challenger Macrur. 1888. p. 496, pl. 90, figs. 2, 3, pl. 85, fig. 5 Geographical distribution: Ki Island, near New Guinea, 140 fath. (Bate). 2. Pontocaris pennata Bate, 1888. Bate, ibid., p. 499, pl. 91. Geographical distribution: Arafura Sea, 49 fath. (Bate). CRANGON Fabricius 1798 (restrict). Fabricius, Suppl. Entomol. Syst., 1798, p. 409 (pr. part). Kingsley, Proceed. Acad. Nat. Sci. Philadelphia, 1879, p. 412. Second perciopoda not remarkably shortened, with chele. Eyes present, free. Five gills present: four pleurobranchiz (1. m. n. 0.), one arthrobranchia (ku) 5 The number of eills has not been examined i in n all species. CF found five gills in: Crangon boreas, salebrosus, intermedius, typicus, affinis, francis- corum, Nectocrangon lar, and seven in Pontophilus norvegicus, Sabinea seplemcarinata. By other authors (Bate, Smith) are recorded five in Crangon agassizi, and seven in Pontocaris propensalata, pennata, Pontophilus bre- virostris, abyssi, challengeri, Sabinea hystrix. 6 Smith records in Cr. agassizi a pleurobranchia on k, but no arthro- branchia. The branchial formula given by Bate (1. c., p. 482) is certainly wrong. 176 PROCEEDINGS @F THE ACADEMY OF [1895. G. O. Sars creates for some species the genus Sclerocrangon. I can not adopt this genus, but I retain it as a subgenus. a', Carapace strongly sculptured, at least two spines in the median line. Abdomen mostly strongly sculptured, seldom nearly smooth. EN . . . Subgenus: SCLEROCRANGON. “Median cee. a mentos with three or four spines. Lateral keels of carapace partly granulate or rugose. Abdomen sculp- tured by longitudinal keels and transverse furrows. c,. Epimera of the abdominal segments provided with spines. Carapace with more than three keels. Spines not excessively developed. Sternum with a sharply serrated keel. d,. Keels of the carapace sharply granulated, keels of the ab- domen sharp, epimera of the abdominal segments with one to three spines. e,. The rostrum is simple. .... . 2... Cr. salebrosus (NG e,. A long acute tooth is given off from the lower side of ros- trum, which reaches as far forward as the tip of the ros- RU N ous SN Meee 2. 2 Cramer d,. Keels of the carapace somewhat sure eels of the abdo- men not sharp. epimera of the abdominal segments only with one spine each". er J «a. Ll. Cr borces sey: > Epimera of the abdominal mens net spines. Cara- ni with three keels, the median one with four very long spines. Sternum with a dentated keel. . . . . Cr. sharpi (2). d,. Median keel of carapace with two spines. Lateral keels of carapace smooth, ending in front in the usual spines. Abdomen smooth, or with smooth longitudinal keels. CG. Epimera of the first and second abdominal segments with small spinules. Abdomen with longitudinal keels. Often a rudimentary third median spine in the median line of carapace between the two well-developed ones. RUN 2.2 ee ORIMGGESS ter LO) | RE g apy ce RE . Cro proce » Epimera a «done without idos Edi spines of carapace small. d,. Abdomen with longitudinal median keels. e,. Sixth abdominal segment with two sharp keels. GENE Do a A NTE . Or. intermedius (2). aa of the eh apdemanl pera behind the middle ao PUTO Wed. ye ree seme . . . Cr. angusticauda (4). dk. sbdomen-not sculptured. ren apace: Cr. munitus. Go. Carapace not sculptured, only with one median, and mostly with one lateral spine on each side (the latter being absent in Cr. capen- sis). Abdomen nearly smooth. ... . . . Subgenus: CRANGON. the) put in parentheses, following each species, the number of specimens E: have examined myself. 1895. ] NATURAL SCIENCES OF PHILADELPHIA. ERT d,. Carapace with three spines: one in the median line, and two laterals. | G. Fifth segment of the abdomen on the posterior margin with- out spines. Hand more stout, about three times as long as Pesan A RR a SS o. o Cr Crangon: SUBSPECIES. d,. All segments of the abdomen rounded dorsally. . Cr. crangon (many). do. . Some = the posterior ee of the abdomen sculptured. ,; Fourth and fifth segments (seldom also the third) with a Ee longitudinal Keel, sixth and seventh feebly furrowed. . . . Cr. crangon affinis (many). Pap hird. to fifth secure Ww bade Keels, sixth with two dis- ae keels, seventh furrowed. . Cr. crangon allmanni (1). CG. Fifth segment of the abdomen on the posterior margin, near the median line, with a posteriorly projecting spine on each side. d,. Hand more slender, about four times as long as broad. Ab- dominal segments rounded above . Cr. franciscorum (many). d,. Hand more stout, about three times as long as broad. Sixth and seventh segment of abdomen furrowed. . Cr. antarcticus. Dj ee hay Ww ich a Kane in are men hie the lateral ones N N EIER Ss ORS capensis. Subgenus SCLEROCRANGON G. O. Sarr, 1885. G. O. Sars, Den Norsk. Nordhays Exped., Zool., Crust. I, 1885, p. 14. 1. Crangon (Sclerocrangon) salebrosus Owen, 1839. Crangon salebrosus Owen, Crust. Zool. Beechey’s Voy. Blossom, 1839. p. 88, Pe 20. lie.-t. Stimpson, Proc. Acad. Nat. Sei. Philadelphia, 1860, p. 25. Kingsley, Bull. Essex Instit., 14, 1882, p. 129. Stuxberg, Vega. Exped. V, 1887, p. 53. Cheraphilus ferox G. O. Sars, Arch. Mathem. Naturvid. II, 1877, p. 339. Sclerocrangon salebrosus (Ow.) G. O. Sars, Den Norsk. Nordh. Exped., Zool., Crust. I, 1885, p. 15, pl. 2 Geographical distribution: Northern cireumpolar. —Kamschatka (Owen): Avatska Bay, 10 fath. (Stimpson), Spitzbergen, Jan. Mayen; off Norway, 100-459 fath. (G. O. Sars), Kara Sea, 55-60 fath. (Stuxberg). 2. Crangon (Selerocrangon) atox Faxon, 1893. Faxon, Bull. Mus. Comp. Zool. 24, 1893, p. 199. Geographical distribution: Western coast of Mexico, 660-676 fath. (Faxon). 178 PROCEEDINGS OF THE ACADEMY OF [1895. 3. Crangon (Sclerocrangon) boreas (Phipps) 1774. Cancer boreas Phipps, Voy. North Pole, 1774, p. 190, pl. 12 fig. 1. Cancer homaroides Fabricius, Faun. Grönland, 1780, p. 241. Astacus boreas (Ph.) Fabrieius, Entomol. Syst, II, 1793. p. 483. Crangon boreas ( Ph.) Fabricius, Suppl. Ent. Syst. 1798, p. 409. Sabine, Suppl. Append. Parry's first Voy. 1824, 235. Milne-Edwards, Hist. Nat. Crust. II, 1837, p. 342. Kroyer, Naturh. Tidsskr., IV, 1842, p. 218, pl. 4, figs. 1-14. Milne-Edwards, Atlas. Cuvier, Regn. Anim. pl. 51, fig. 2, (no date). Brandt, Krebse, in Middendorff’s Siber. Reis., II, Zool. 1851, p. 114. Danielssen, Beretn. Zool. Reise, 1859. p. 4. Stimpson, Proceed. Acad. Nat. Sci. Philadelphia, 1860, p. 25. Buchholz, Zweite Deutsch. Nordpol. II, 1874, Crust. p. 271. Kingsley, Bull. Essex Inst. X, 1878, page 54. Smith Trans. Conn. Acad., V, 1879, p. 56. Stuxberg, Vega Exped., V, 1887, p. 58. Cheraphilus boreas (Ph.) Miers, Annal. Magaz. Nat. His. (4) XX, 1877, p. 57. Hoek, Niederl, Arch. Zool , Supp]. 1, 7, Crust. 1882, p. 10. Murdoch, Rep. Pol. Exped. Point Barrow, 1885, p. 139. Crangon (Cheraphilus) boreas ( Ph.) Miers, Jour. Linn. Soc., Zool. XV, 1881, p. 60. Sclerocrangon boreas (Ph.) G. O. Sars, Christiania Vid. Selsk. Forh. 1882, p, 7. G.O. Sars, Den Norsk. Nordh. Exp. Zool. Crust. II. 1886, p. 6. Koelbel, Die Oesterr. Polarst, Jan Mayen, III, 1886, Zool. E. p. 51. Ortmann, Zool. Jahrb. V, 1890, p. 532. Geographical distribution: Northern circumpolar. Norway (Danielssen, G. O. Sars) Barents Sea and Nowaja Semlja, 25-140 fath. (Hoek); Franz Joseph Land (Miers); Beeren Island (G. O. Sars); Spitzbergen, shallow water (Hoek, G. O. Sars) Jan Mayen (Kölbel); Iceland (Kroyer); east coast of Greenland, 4-27 fath. (Buchholz); west coast of Greenland, to 87° 44‘ lat. northward (Miers); Davis Strait and Melville Island (Sabine); N. E. coast of America, from Labrador to Massachusetts Bay, 5-38 fath. (Smith); northern coast of America to Berings Strait, 10-26 fath. (Stimpson) ; Alaska: Point Franklin, 13 fath. and Port Clarence (Murdoch); Siberia (Brandt, Stuxberg). 4. Crangon (Sclerocrangon) sharpi mov. spec.® Paracrangon echinatus Sharp {non Dana), Proceed. Acad. Nat. Sci., Phila- delphia, 1893, p. 126. 8 Description: Carapace with three keels, the median one with four long spines, the first longest and placed on the upper margin of rostrum, which extendsa little beyond the eyes; the second spine nearly as long as the first, placed immediately behind the base of the rostrum. The spines are directed obliquely forward and upward. Lateral keels formed by four spines, the fore- most, on the anterior margin of carapace near the base of antenne, is the longest, and directed obliquely forward and outward, more than half as long as the cara- pace; the three others are smaller, but sharp. Abdomen sculptured, first to sixth segment with a median keel, that of the third arched and produced somewhat posteriorly, that of the sixth finely furrowed and ending in two spines posteriorly. Two other spines are placed at the posterior margin of this segment, one on each side. Fifth segment, on the posterior margin, near the median line, with a sharp spine on each side. Lateral faces of the first to fifth segment sculptured by two irregular transverse furrows, sixth segment laterally with an indistinct longi- tudinal ridge. Epimera of the first to fourth segment triangular, inferior angles blunt, without spines. Keel of sternum dentate, but not spinoso-serrate. Two specimens are in the Museum of the Academy of Natural Science of Philadelphia. 1895.] NATURAL SCIENCES OF PHILADELPHIA, 179 Geographical distribution: Alaska, Kodiac Archip.: Marmot Isle, 45 fath. (Sharp). 5. Crangon (Sclerocrangon) agassizi (Smith), 1882. Cheraphilus agassizi Smith, Bull. Mus. Compar. Zool., Cambridge, X, 1882, p. 32, pl. 7, fig.4,5. Rep. U.S. Fish Comm. for 1882, 1884, p. 362. Geographical distribution: Atlantic, eastern coast of United States, 31-41° N. Lat., 65-78° W. Long., 263-959 fath. (Smith). 6. Crangon (Scleroerangon) procax Faxon, 1893. Faxon, Bull. Mus. Comp. Zool., Cambridge, XXIV, 1893, p. 199. Geographical distribution: Western coast of Central America: Gulf of California to Panama Bay, 660 to 905 fath. (Faxon. ) 7. Crangon (Sclerocrangon) intermedius Stimpson, 1860. Crangon intermedius Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 25. Crangón tenuifrons Kingsley, Bull. Essex Inst., 14, 1882, p. 128, pl. 1, fig. 10. Geographical distribution : Bering Sea, Cape Chepoonski, 40 fath. (Stimpson); Alaska: Marmot Isl. (Kingsley). 8. Crangon (Sclerocrangon) angusticauda de Haan, 1849. Crangon angusticauda de Haan, Faun. Japon. Crust. Dec., 6, 1849, p. 183, pl. 45, fig. 15. Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 25. Sclerocrangon angusticauda (d. H.) Ortmann, Zoolog. Jahrb., V, 1890, p. 533. Geographical distribution: Japan, (de Haan): Simoda and Hakodati, sublitoral (Stimpson), Kadsiyama (Ortmann). 9. Crangon (Sclerocrangon) munitus Dana, 1852. Crangon munitus Dana, U.S. Explor. Exped. Crust., 1852, p. 536, pl. 33, fig. 5 Stimpson, Boston Jour. Nat. Hist., VI, 1857, p. 497. Kingsley, Bull. ee Inst. X, 1878, p. 54. Lockington, ibid. p. 159. Geographical distribution: Puget Sound (Dana); Lower Cali- fornia: Magdalena Bay (Lockington). Subgenus CRANGON. 10a. Crangon crangon (Linnaeus), 1758. Cancer crangon Linnaeus, Syst. Nat., 10 ed., 1758, p. 632. Astacus crangon (L.) Fabricius, Entomol. Syst., II, 1793, p. 486. Cancer (Astacus) crangon L. Herbst, Krabb. u. Krebse, IE 1796, p. 75, pl. 29, fig. 3,4. Crangon vulgaris Fabricius, Suppl. Ent. Syst. #879, p. 410. Leach, Malac. Podophth. Brit. 1815, pl. 37 B. Milne- Edwards, Hist. Nat. Crust. II, 1837, p. 341 and Atlas in Cuvier. Regn. Anim. pl. 51, fig. 1, (no date). Kroyer, Naturh. Tidsskr., IV, 1842, p. 239, pl. 4, fig. 29-33. Bell, Brit. Crust. 1853, p. 256. Kinahan, Proceed. R. I. Acad. Dublin, 1862, p. 68, 71, pl. 4. Heller, Crust. südl. Europ. 1863, p. 226, pl. 7, fig. 89. Meinert. Naturh. Tidsskr. (3) XI, 1877, p. 198. Kingsley, Bull. Essex Inst., X, 1878, p. 53. Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1878, p. 89, ibid. 1879, p. 411. Smith, Trans. Connecticut Acad. V, 1879, p. 55. Kingsley, Bull. Essex 180 PROCEEDINGS OF THE ACADEMY OF [1895. inst. XIV, 1882, p. 129, pl..1, fig. 5. Carus, Prodrom. faun. mediterr. I. 1884, p. 482. Henderson, Decap. and Schizop. Crust. Firth of Clyde, 1886, p. 32. Bate, Challenger Macrur. 1888, p. 484. Ortmann, Zool. Jahrb. V, 1890, p. 530. Crangon rubropunclatus Risso, Hist. Nat. Crust. Nice, 1816, p. 83. Risso, Hist. Nat. Europ. merid. V, 1826, p. 65. Crangon septemspinosus Say, Jour. Acad. Nat. Sci., Philadelphia, I, 2, 1818, p. 246. Dekay, Zool. New York, Crust. 1844, p. 25, pl. 8, fig. 24. Crangon maculosus Rathke, Mem. Acad. St. Petersburg, Sav. étr., III. 1837, p. 366. Geographical distribution: Northern circumpolar (?), but more boreal than arctic, extending considerably southward. Northern Atlantic: European coasts, northward to Iceland, and northeastern coast of America, southward to Virginia and N. Carolina. Northern Pacific: Japan, Yokosuka (Bate) and Bay of Tokio (Ortmann). Litoral, very shallow water. i0b. Crangon crangon affinis de Haan, 1849. Crangon vulgaris Owen, Crust. Zool. Beechey's Voy. Blossom, 1839, p. 87. Dana, U.S. Explor. Exped. Crust. 1852, p. 536. lisa) ‚Rep. Pol. Exped. Point Barrow, 1885, p. 138. Crangon afınis de Haan, Faun. Japon. Crust. Dec. 6, 1849, p. 183. Bate, Challenger Macrur. 1888, p. 484, pl. 86, fig. 1-3. Ortmann, Zoolog. Jahrb. V, 1890, p. 531. Crangon nigricauda Stimpson, Proceed. Calif. Acad. Sci., I, 2, 1856, p. 89. Stimpson, Boston Jour. Nat. Hist. VI, 1857, p. 496, pl. 22, fig. 6., Stimpson Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 25. Kingsley, Bull. Essex Inst. X, 1878, p. 54. Lockington, ibid. p. 159. Crangon propinguus Stimpson, Proceed. Acad. Nat. Sci.. Philadelphia, 1860, p. 25. Crangon nigromaculata Lockington, Proceed. Calif. Acad. Sci., III,1876, p. 34. Crangon alaskensis Lockington, ibid. Geographical distribution: Northern Pacific, somewhat deeper water. Japan (de Haan): Kobe Bay and Inland Sea, 19-50 fath. (Bate), Maizuru (Ortmann), northern Japan, 4-20 fath. (Stimp- son); Alaska: Mutiny Bay (Lockington), Norton Sound, 5 fath. (Murdoch); Puget Sound (Dana); Mouth of Columbia river (Stimpson); California, in deeper water than Cr. franciscorum (Stimpson): Tomales Bay (Stimpson), San Francisco (Dana, Stimp- son), Monterey (Owen), San Diego (Lockington). 10c. Crangon crangon allmanni Kinahan, 1862. Crangon allmanni Kinahan, Proceed. R. I. Acad., Dublin, VIII, 1862, pp. 68, 71, pl. 4. Kinahan, Trans. R. I. Acad. Vol. 24, 1871, p. 64. Metzger, Jahresber. Commiss. Unters. deutsch. Meere. II, III, 1875, p. 290. Meinert, Naturh. Tidsskr. (3) XI, 1877, p. 198. G. O. Sars, Arch. Math. Naturv. II, 1877, p. 339. G. O. Sars, Christiania Vid. Selsk. Forh. 1882, p. 4. G. O. Sars, Den Norsk. Nordh. Exp., Zool., Crust II, 1886, p. 6. Henderson, Decap. Schiz. Crust. Firth of Clyde, 1886, Ras Ortmann, Zoolog. Jahrb. V.1890, p. 532. Scott, Annal. Mag. Nat. Hist. (6) XIII, 1894, Dp. 413. Geographical distribution: Northern Europe, somewhat deeper 1895. ] NATURAL SCIENCES OF PHILADELPHIA. 181 water. England and Ireland (Kinahan); Scotland, 24-69 fath. (Metzger); Shetland Isl. (Kinahan); North Sea, 9-20 fath. (Metzger, Scott); Skagerrak and Kattegat, 6-49 fath. (Metzger, Meinert); Norway (G. O. Sars); Iceland, 20-50 fath. (G. O. Sars). 11. Crangon franciscorum Stimpson, 1856. Stimpson, Proceed. Calif. Acad. Sci., I, 2, 1856, 89. Stimpson, Boston Journ. Nat. Hist. VI, 1857, p. 495, pl. 22, fig. 5. Stimpson, Proceed. Acad. Nat. Sei., Philadelphia, 1860, p. 25. Kingsley, Bull. Essex Inst. X, 1878, p. 54. -Geographical distribution: W. coast of N. America, shallow water. Puget Sound, Shoalwater Bay, Tomales Bay, San Fran cisco, Monterey (Stimpson). 12. Crangon antarcticus Pfeffer, 1887. Pfeffer, Naturh. Mus. Jahrb., Hamburg. wiss. Anstalt. IV. 1887, p. 45, pl. 1, fig. 1-21. Geographical distribution: South Georgia, (Pfeffer). 13. Crangon capensis Stimpson, 1860. Stimpson, Proceed. Acad. Nat. Sci., Philadelphia, 1860, p. 24. Geographical distribution : Cape of Good Hope, Simons Bay, 12 fath. (Stimpson). NECTOCRANGON Brandt, 1837. “Argis Kroyer, Naturh. Tidsskr, IV, 1842, p. 267 ne pr&occupatum ),"YL2 Nectocrangon Brandt, Krebse in: Middendorff’s Siber. Reis. II, Zool. I, 1851, p. 114. Kingsley, Proceed. Acad. Nat. Sci., Philadelphia, 1879, Dp. 412. “Second pereiopoda not shortened, with chela. Five branchie, like Crangon. Eyes partly concealed by the-frontal margin. Posterior pereiopoda with lanceolate dactyli with fringes of hair. a,. Behind the rostrum two spines in the median line of carapace. pads N, lar (A). Ba ae a ses um mes all Basellanes sun in the median line Ra carapace, between the rostrum and the first spine a rudimentary Ba ne Nasen. MV, olaskensis (E). 1. Nectocrangon lar (Owen) 1839. Crangon lar Owen, Zool. Beechey’s Voy. Blossom, 1839, p. 88, pl. 28, fig. 1. Argis lar (Ow.) Kroyer, Naturh. Tidsskr. IV, 1842, p. 255, pl. 5. fig. 45-62. Nectocrangon lar (Ow.) Stimpson, Proceed. Acad. Nat. Sci. Philadelphia, 1860, p. 25. Stimpson, Annal. Lyc. New York, X, 1874, p. 125. Kingsley, Bull. Essex Inst. X, 1878, p. 55. Smith, Trans. Connect. Acad. V, 1879, p. 61. Murdoch, Rep. Pol. Exped. Point Barrow, 1885, p. 139. Geographical distribution: Northern eircumpolar.— Arctic Ocean 182 PROCEEDINGS OF THE ACADEMY OF [1895. (Owen, Stimpson); Northern Alaska: Point Barrow (Murdoch); Bering Strait: Avatska Bay, 10-20 fath. (Stimpson); Greenland: Godthaab (Kröyer); Labrador, (Smith); Gulf of St. Lawrence (Smith); New Foundland: St. Johns (Stimpson); Nova Scotia, 59 fath. ; Halifax, 26-52 fath. (Smith). 2. Nectocrangon alaskensis Kingsley, 1882. Kingsley, Bull. Essex Inst. XIV, 1882, p. 128. Geographical distribution: Alaska, Kodiac Arch.: Marmot Island (Kingsley). | PONTOPHILUS Leach, 1815. Pontophilus Leach, Melacostr. Podophth. Brit. 1815, pl. 37 A. Egeon Risso (pr. part. ) Hist. Nat. Europe mérid., V. 1826, p. 58. Chez aphilus and Aegeon Kinahan, Proceed. R. E Acad., Dublin, VIII, 1862, p. 68, 69. Second periopoda shortened, carpal joint and hand together not longer than merus, chel® present. Eyes present, free. Gills seven on each side: six pleurobranchis (i. k. 1. m. n. 0.) and one (rudi- mentary) podobranchia (h. ). d,. Median keel of carapace with more than three spines. Seven keels on the carapace, with numerous teeth. Abdomen strongly sculptured. b,., Rostrum emarginate. . . dam 1. . a Pi cataphracius e 6,. Rostrum acute, with lateral en cep ara + PS bengalense P. andamanensis.° a,. Median keel of carapace with three spines. Abdomen smooth or only the posterior segments with longitudinal keels. b,. Carapace with more than two lateral spines. Abdominal seg- ments with distinct keels. c, Three denticulate lateral keels on each side. Fifth segment of abdomen with a keel. Rostrum acute, simple . P. echinulatus. c,. Two lateral keels on each side, the upper with three, the lower with two spines. Third and fourth segment of abdomen with a simple keel, fifth with four, sixth with two keels. Rostrum Bon lateral Bein. fn, eee woe) eon IP. SPINOSUSIE . Two lateral keels, the upper nn two, the lower with one a d,. Sixth segment of abdomen with a double keel. Rostrum without lateral teeth. . 7... . 7"... SP; norvegicus: d,. Fifth segment of abdomen with four, sixth with two keels. Rostrum with lateral teeth..7: Cc. . 2 . Pbrevinosizis 9 I am not sure whether these two species (bengalensis and andamanensis) really belong to Pontophilus. 1895.] NATURAL SCIENCES OF PHILADELPHIA. 185 d,. Carapace with two lateral spines and a third very small one be- hind the supraorbital fissure. Rostrum with two minute lateral teeth on each side. Abdomen smooth. Eyes colorless . P. abyssi. P. occidentalis. b,. Carapace with two indistinct lateral keels, each with a spine. Sixth and seventh segments of abdomen feebly furrowed. Ros- trum acute, with a lateral tooth on each side . P, challengeri (2). 6,. Carapace with one lateral spine and a series of small spinules. Fifth segment of abdomen sculptured, sixth and seventh fur- rowed. Rostrum obtuse... . Ba. ro MOLEETSONN: . Median keel of carapace with two ne A . Abdomen strongly longitudinally and transversely sculptured. Carapace with a two-spined median keel, and two many-spined lateral ones on each side. Rostrum emarginate. . . P. sculptus. d,. Abdomen smooth or only with a few longitudinal keels. c,. Carapace with distinct and denticulate lateral keels. d,. Three lateral keels, the upper with two, the lower with one, the middle without teeth. Rostrum truncate . P. bidentatus. d,. Two lateral keels, the upper with o the lower with three TES TS ento o o, Se APS auıstralis: »» Carapace with. = ken fiat Bas acute, slender. Abdomen without keels. &- Rostrum without lateral teeth. . ..:... !..P. junceus. d,. Rostrum with one lateral tooth on each side. Spines of the lateral faces of carapace in an oblique plane, . . P. gracilis. d,. Rostrum with two lateral teeth on each side. Spines of the lateral faces of carapace in the same level.. . P. profundus. c,. Carapace without lateral spines and without distinct keels. Rostrum short, obtuse, fifth and sixth segments of abdomen with two longitudinal keels... . . ...- . . P. bispinosus (1). a,. Median keel of carapace with one spine. Abdomen smooth. 6,. Carapace with three lateral spines and a longitudinal series of small spinules. . .. Aina To pee mA intermedius: b,. Carapace with one o on en see ads RE SELES PUNOSUS: (E). d,. Carapace without lateral spines. c,. Rostrum broadly truncate. Telson furrowed . P. fasciatus (5). c,. Rostrum short, obtuse. Telson rounded dorsally. RPM Es aha cat os ee atte! wins cn lan ty. ous . P. neglectus. a;. Median line of carapace without spines. Carapace with seven keels, keels smooth, the upper and lower lateral keel with a spine each. Abdomen sculptured by transverse furrows. .P. carinicauda. 1. Pontophilus cataphractus (Olivi) 1792.10 _ Cancer cataphractus Olivi, Zool. Adriat., 1792, P. 50; plo 3 fig; É. 10 Recently there has been described a species by Henderson (Trans. Linn. Soe. London, Zool. (2) V, part 10, 1893, p. 446, pl. 40, fig. 16, 17) from the Bur- . mese coast named Aegeon orientalis, which is said to be nearly reiated to the Mediterranean P. calaphractus, 184 PROCEEDINGS OF THE ACADEMY OF [1895. Egeon loricatus Risso, Hist. Nat. Europ. mérid., V, 1826, p. 58. Crangon calaphractus (Oliv.) Milne-Edwards, Hist. Nat. Crust., II, 1837, p 343, and Atlas in Cuvier, Regn, anim. pl. 51, fig. 3 (no date). Heller, Crust. südl. Europ., 1863, p. 230, pl. 7, fig. 12-15. Miers, Annal. Mag. Nat. Hist. (5) VIII, 1881, p. 365. Carus, Prodrom. faun. medit., I, 1884, p. 482. Aegeon cataphractus (Oliv.) Ortmann, Zoolog. Jahrb., V, 1890, p. 535. Geographical distribution: Mediterranean Sea (Risso, Milne- Ed- wards, Heller, Carus); Senegambia (Miers). 2. Pontophilus bengalensis (Wood-Mason and Alcock) 1891. Crangon bengalensis Wood-Mason and Alcock, Ann. Mag. Nat. Hist. (6) VIII, 1891, p. 360. Alcock and Anderson, Journ. Asiat. Soc. Bengal, vol. 63, 2, 1894, p. 152. Geographical distribution: Indian Seas, 107-276 fath. (Wood- Mason, Alcock, Anderson). 3. Pontophilus andamanensis (Wood-Mason and Alcock) 1891. Crangon andamanensis Wood-Mason and Alcock, ibid. Geographical distribution: Indian Seas, 188-220 fath. (Wood- Mason and Alcock). 4. Pontophilus echinulatus (M. Sars) 1861. Crangon echinulatus M. Sars, Forh. Vid. Selsk., Christiana, 1861, p. 29, pl. 3, fig. 48-64. G. O. Sars, Arch. Math. Naturv., II, 1877, p. 339. Henderson, Decap. Schiz. Firth of Clyde, 1886, p. 33. Crangon serratus Norman, Rep. Brit. Assoc., 31 meet., 1862, p. 151. Norman, ibid., 38 meet., 1869, p. 265. Cheraphilus echinulatus (M. Sars). G. O. Sars, Forh. Vid. Selsk., Christiana, 1887, No. 18, p. 44. G. O. Sars, Den Norsk. Nordh. Exped., Zool., Crust., II, 1886, p. 7. Geographical distribution: Norway, 80-150 fath. (M. Sars, G. O. Sars); Shetland Islands (Norman); Scotland: Loch Fyne, 105 fath. (Henderson). 5. Pontophilus spinosus Leach, 1815. Tontophilus spinosus Leach, Malacostr. Podophth. Brit., 1815, pl. 37, A. Ortmann, Zoolog. Jahrb., V, 1890, p. 534. Crangon catapractus ne Edwards, Hist. Nat. Crust., II, 1837, p. 343 (pro parte). Crangon spinosus (Leh.). Bell, Brit. Crust., 1853, p. 261. Heller, Crust. südl. Europ., 1863, p. 229, pl. 7, fig. 16. Carus, Prodrom. faun. medit., I, 1884, p. 482. Henderson, Decap. Schiz. Firth of Clyde, 1886, p. 32. Geographical distribution: European Seas. — From Norway and Sweden to the Mediterranean Sea, to about fifty fath. (see Ortmann, ne) 6. Pontophilus norvegicus (M. Sars) 1861. Crangon norvegicus M. Sars, Forh. Vid. Selsk., Christiania, 1861, p. 183. M. Sars, Nyt. Magaz. f. Naturvid. 1861, p. 248. Goes, Ofv. K. Vet. Akad. Forh., 1863, p. 173. 1895.] © NATURAL SCIENCES OF PHILADELPHIA. 185 Pontophilus norvegicus (M. S.) Meinert, Naturh. Tidsskr. (3) XI, 1877, p. 200. Smith, Trans Connectic. Acad., V, 1879, p. 60. G. O. Sars, Forh. Vid. Selsk., Christiana, 1882, No. 18, p. 7. Smith, Bull. Mus. Compar. Zool., Cambridge. X, 1882, p. 34. G. O. Sars, Den Norsk. Nordh. Exp. Zool. Crust., II, 1886, p. 7. Ortmann, Zoolog. Jahrb., V, 1890. p. 534. Geographical distribution: Northern Atlantic. — Sweden: Bohus- län (Goês); Skagerrak, 320 fath. (Meinert); Norway, 30-500 fath. (M. Sars, G. O. Sars); Spitzbergen Sea (G. O. Sars); N. E. coast of America: Nova Scotia, 101-110 fath., Gulf of Maine, 115 fath., off Cape Cod, 105-524 fath. (Smith). “7. Pontophilus brevirostris Smith, 1881. Smith, Proceed. U. S. Nation. Mus., III, 1881, p. 435. Smith, Bull. Mus. Com- par. Zool. X, 1882, p. 35, pl. 7, fig. 1. Smith, Rep. U.S. Fish Com. for 1882- 1884, p. 362. Geographical distribution: Atlantic, eastern coast of United States, 51-155 fath. (Smith). 8. Pontophilus abyssi Smith, 1884. Smith, Rep. U. S. Fish Com. for 1882-1884, p. 363. Wood-Mason and Alcock, Annal. Mag. Nat. Hist. (6) VIII, 1891, p. 361. Geographical distribution: Atlantic, off the coast of United States, 37º N. Lat., 70º W. Long., 1917-2221 fath. (Smith); Bay of Bengal, 1748-1997 fath. (Wood-Mason and Alcock). 9. Pontophilus occidentalis Faxon, 1893. Faxon, Bull. Mus. Compar. Zool., XXIV, 1893, p. 200. Geographical distribution: Off the western coast of Central America, 978-2232 fath. (Faxon). 10. Pontophilus challengeri Ortmann, 1893. Pontophilus gracilis Bate, Challenger Macrur., 1888, p. 487, pl. 87 (nomen preoccupatum ). Pontophilus batei Faxon, Bull. Mus. Compar. Zool., XXIV, August, 1893, p. 200, footnote (nomen pr&occupatum). Pontophilus challengeri Ortmann, Decapod. Schizop. Plankton Exped., 1893, (September) p. 49. Geographical distribution: Atlantic, near Tristan da Cunha, 1900 fath. (Bate); Cape Verde Islands, ca. 2700 fath. (Ortmann); Pacific: New Zealand, 1100 fath. (Bate); near Torres Strait, 1400 fath. (Bate); near Philippine Islands, 2150 fath. (Bate). LE; Pontiphilus pattersoni (Kinahan) 1862. Cheraphilus pattersoni Kinahan, Proceed, R. I. Acad., Dublin, VIII, 1862, p. 69, 73, pl: 7. Geographical distribution: Northern England and Ireland (Kinahan). 186 PROCEEDINGS OF THE ACADEMY OF (1895. 12, Pontophilus sculptus (Bell) 1853. Crangon sculptus Bell, Hist. Brit. Crust., 1853, p. 263 (fig.). Henderson, Decapod. Schizop., Firth of Clyde, 1886, p. 32. Geographical distribution England: Weymouth (Bell), Firth of Clyde, 20 fath. (Henderson). 13. Pontophilus bidentatus (de Haan) 1849. Cranzon bidentatus de Haan, Faun. Don. Crust., Dec. 6, 1849, p. 183, pl. 44, fig. 14. Geographical distribution: Japan (de Haan). 14. Pontophilus australis (Thomson) 1878. Crangon australis Thomson, Trans. Proceed. New Zealand Inst., XI, 1878, p. 231, pl. 10, fig. A. 1. Filhol, Passage Venus., Miss. Campbell, III, 2, 1885, p. 430. Geographical distribution: New Zealand: Cook Straits, Dunedin, Stewart Isl. (Thomson), from Napier to Stewart Isl. (Filhol). 15. Pontophilus junceus Bate, 1888. Bate, Challenger Macrur. 1888, p. 491, pl. 88, fig. 2-4. Geographical distribution: Between Philippine Islands “and Borneo, 250 fath. (Bate.) 16. Pontophilus gracilis Smith, 1882. Smith, Bull. Mus. Comparative Zool., X, 1882, p. 36, pl. 7, fig. 2-3. Wood- Mason andAlcock, Annals and Mag. Nat. Hist. (6) VIII, 1891, p. 361. Geographical distribution: Atlantic, eastern coast of United States, 225-458 fath. (Smith); Bay of en 561-683 fath. (Wood-Mason and Alcock). 17. Pontophilus profundus Bate, 1888. Bate, Challenger Macrur. 1888, p. 490, pl. 88, fig. 1. Geographical distribution: Off Sydney, 2600 fath. (Bate). 18. Pontophilus bispinosus Hailstone, 1835. Pontophilus bispinosus Hailstone (nec Westwood), Mag. Nat. Hist., VIII, 1835, p. 271, fig. 30. Crangon nanus Kroyer, Naturh. Tidsskr., IV, 1842, p. 231, pl. 4, fig. 15-28. Metzger, Jahresber. Comm. Unters. Deutsch. Meer., II, III, 1875, p. 291. Meinert, Naturh. Tidsskr. (3) XI, 1877, p. 199. Henderson, Decap. Schiz. Firth of Clyde, 1886, p. 33. Scott, Annal. Mag. Nat. Hist. (6) XIII, 1894, p. 413. Crangon bispinosus (Hailst.) Bell, Brit. Crust., 1853, p. 268. Cheraphilus bispinosus (Hailst.) Kinahan, Proceed. R. I. Acad.” Dublin; VITI, 1862, p. 68, 72, pl. 5. Geographical distribution: Northern Europe.—Sund (Meinert) ; . Kattegat (Kroyer); Skagerrak, 10-110 fath. (Meinert); Norway (G. 1895. ] NATURAL SCIENCES OF PHILADELPHIA. 187 O.Sars); North Sea (Metzger, Scott); England (Bell, Kinahan, Hen- derson ). | VA w In 19. Pontophilus intermedius (Bate) 1863. Crangon intermedius Bate, Proceed. Zool. Soc., London, 1863, p. 503, pl. 41, ( fig. 6. Haswell, Catal. Austral. Crust., 1882, p. 181. Crangon batei Kingsley, Bull. Essex Inst., 14, 1882, p. 129. E nn WE Qe Geographical distribution: Australia, Gulf St. Vincent (Bate). 20. Pontophilus trispinosus Hailstone, 1835. Pontophilus trispinosus Hailstone, Mag. Nat. Hist., VIII, 1835, p. 261, fig. 25. Ortmann, Zoolog. Jahrb., IV, 1890, p. 533. Crangon trispinosus (Hailst.) Bell, Brit. Crust., 1853, p. 265. Metzger, Jahresb. Comm. Unters. Deutsch. Meer., II, III; 1875, p. 291. Carus, Pro- drom. faun. Medit., I, 1884, p. 482. Cheraphilus trispinosus (Hailst.) Kinahan, Proceed. R. I. Acad., Dublin, VIII, 1862, p. 69, 72, pl. 6. Geographical distribution: North Sea, 10-22 fath. (Metzger); England and Ireland (Kinahan); Marseille (Gourret); Azores (Barrois). 21. Pontophilus fasciatus (Risso) 1816. Crangon fasciatus Risso, Hist. Nat. Crust., Nice, 1816, p. 82, pl. 3, fig. 5. Risso, Hist. Nat. Europ. mérid., V, 1826, p. 64. Milne-Edwards, Hist. Nat. Sash NE 1837, _p. 342. Bell. Brit. Crust., 1853, p- 259. Heller, Crust. südl. Europ., 1863, p. 228, pl. 7, fig. 10. Carus, Prodrom. faun. Medit., I, 1884, p. 483. Norman, Annal. Magaz. Nat. Hist. (5) XIX, 1887, *p. -90. Aegeon fasciatus (Riss.) Kinahan, Proceed. R. I. Acad., Dublin, VIII, 1862, p. 69, 74, pl. 9. Ortmann. Zoolog. Jahrb., IV, 1890, p. 535. Geographical distribution: European Seas (Northern Europe, Mediterranean Sea) and Azores. (See Ortmann, 1. c.). 22. Pontophilus neglectus (G. O. Sars) 1882. Cheraphilus neglectus G. O. Sars, Forh. Vid. Selsk., Christiania, 1882, No. 18, p. 45, Pl. 1, fig. 7. G.O. Sars, Den Norsk. Nordh. Exp., Zool., Crust., II, 1886, p. 6. | Geographical distribution: Norway, 2-6 fath. (G. O. Sars). 23. Pontophilus carinicauda (Stimpson) 1860. Crangon carinicauda Stimpson, Proceed. Acad. Nat. Sci. Philadelphia, 1860, p. 25. Geographical distribution: Hong Kong (Stimpson). SABINEA Owen, 1835. Owen, Append. Voy. Capt. Ross, 1835, p. 82. Kingsley, Proceed. Acad. Nat. Sci. Philadelphia, 1879, p. 412. e Second pereiopoda very short, without chela. Gills seven, like Pontophilus, or five pleurobranchiz and two arthrobranchiz (see Smith, Sabinea hystrix). Eyes present, free. 188 PROCEEDINGS OF THE ACADEMY OF [1895. a,. Rostrum short, scarcely longer than the eyes. b,. Rostrum and telson blunt. ..... . ..S. septemcarinata (6). Br Rostrum and telson more acute. . . . . = dS, SR . Rostrum long, about as long as the ale ik . + So haste: 1. Sabinea septemcarinata (Sabine), 1824. CO BRO septemcarinatus Sabine, Suppl. Append. Parry’s Voy. 1824, p. 236, pl.2 2, fig. 11-13. Milne-Edwards, Hist. Nat. Crust. II, 1837, p. 343. Sabinea septemcarinata (Sab.) Kroyer, Naturh. Tidsskr. IV. 1842, p. 244, pl. 4, fig. 34-40, pl. 5, fig. 41-44. Metzger, Jahresb. Comm. Unters. deutsch. Meer. II, (II, 1875, p. 291. Miers, Ann. Mag. Nat. Hist. (4) XX, 1877, p. 58. Kingsley, Bull. Essex Inst. X, 1878, p. 55. Smith, Trans. Connect. Acad., V, 1879, p. 57, pl. 11, fig. 5, 9-13. Hoek, Niederl. Arch. Zool., Suppl. 1, 7, Crust. 1882, p. 12. G. O. Sars, Den Norsk. Nordh. Exp. Zool. Crust. II, 1886, p. 7. Stuxberg, Vega Exped., V, 1887, p. 54. Bate, Challenger Macrur. 1888, p. 493, pl. 89, fig. 2, pl. 90, fig. 1. Ortmann, Zoolog. Jahrb., V, 1890, p. 536. Geographical distribution: Arctic seas extending southward into boreal seas.—Norway, to 106 fath. (M. Sars, Metzger); Barents Sea ahd Nowaja Semlja, 37-160 fath. (Hoek); Spitzbergen (Kroyer, G. O. Sars); Iceland (Kroyer); Greenland (Reinhardt, Liitten); Davis Strait (Sabine); Grinnell Land (Miers); N. E. coast of America: from Gulf of St. Lawrence to Massachusetts Bay, 25-85 fath. (Smith, Bate); Arctic coast of Siberia (Stimpson, Stuxberg). 2. Sabinea sarsi Smith, 1879. Smith, Trans. Connect. Acad.,.V, 1879, p. 59, pl. 11, fig. 6, 7, 8. G. O. “Sars, Forh. Vidensk. Selsk. Christiania, 1882, No. 18, p. 46. Smith, Rep. U. S. Fish Comm. f. 1882, 1884, p. 364. Geographical distribution: Northeastern coast of America, 60-150 fath. (Smith); Norway: Lofoten (Smith), Christianssund and Stavanger (G. O. Sars). E 3. Sabinea hystrix (A. Milne-Edwards), 1881. Paracrangon hystrix A Milne-Edwards, Annal. Sci. Natur. (6) Zool. XT, 1881, p. 6. Sabinea princeps Smith, Bull. Mus. Comp. Zool. X, 1882, p. 38, pl. 8, fig. 1. Smith, Rep. U. S. Fish Comm. f. 1882, 1884, p. 364. Geographical distribution: Atlantic: eastern coast of United States, 464-888 fath. (Smith); Guadeloupe, 734 fath. (A. Milne- Edwards). PRIONOCRANGON Wood-Mason and Alcock, 1891. Wood-Mason and Alcock, Annal. Mag. Nat. Hist. (6) VIII, 1891, p. 361. Second pereiopoda present, without chela, rather robust with a fringe of long hairs. Eyes and eye-stalks wanting. Carapace with a spiny median keel.—Gills unknown. Only one species known. 1895. ] NATURAL SCIENCES OF PHILADELPHIA. 189 1. Prionocrangon ommatosteres Wood-Mason and Alcock, 1891. Wood-Mason*and Alcock 1. ec. p. 362. Alcock and Anderson, Jour. Asiat. Soc. Bengal, Vol. 63, 2, 1894, p. 152. Geographical distribution: Bay of Bengal, 200-405 fath. (W ood- Mason, Alcock, and Anderson). PARACRANGON Dana, 1852. Dana, U. S. Explor. Exped. Crust. 1852, p. 537. Kingsley, Proceed. Acad. Nat. Sei., Philadelphia, 1879, p. 412. Second pereiopoda wanting. Eyes present, free. Carapace with long spines.—Gills unknown. a,. Branchial regions not areolate, five—spinous. . . . P. echinatus. a,. Branchial regions traversed by anastomosing ridges, dividing “these regions into cells of different sizes; they are armed with three an ony ym ee N Rev Pirareolatus, 1. Paracrangon echinatus Dana, 1852. Dana, U. S. Explor. Exped. Crust. 1852, p. 538, pl. 33, fig. 6. Stimpson, Boston Jour. Nat. Hist. VI, 1857, p. 497. Kingsley, Bull. Essex Instit. X, 1878, p. do. Geographical distribution: W. coast of North America: Puget Sound, Oregon (Dana). 2. Paracrangon areolatus Faxon, 1893. Paracrangon areolata Faxon, Bull. Mus. Comp. Zool. X XIV, 1893, p. 200. Geographical distribution: Western coast of Mexico: Tres Marias Islands, 676-680 fath. (Faxon). Considerations concerning the geographical distribution of the Crangonide. The geographical distribution of the Crangonide shows that only one genus, Pontocaris, no doubt the most primitive, is a true inhab- itant of the lesser depths of the tropics, the two species known being found in 49 and 140 fathoms in the Indo- Malaysian seas. All the other genera are partly confined to the seas of temperate or cold climates, partly there is the main range, and only a few species are present in the litoral of warmer climates. Pontocaris, I believe, must be regarded as a survival in the tropics, and its occurrence in somewhat deeper water, but within the limits of the litoral, shows already the tendency to descend into greater depths developed in many species of the other Crangonide. None of the other species present in the tropical parts of the world can be regarded as sur- vivals; they immigrated thither from the more northern localities. 2 190 PROCEEDINGS OF THE ACADEMY OF [ 1895. The main range of the genus Crangon comprises the cooler seas of the northern hemisphere both in the Atlantic and Pacific. There are three species showing a true circumpolar distribution: Or. salebrosus, boreas and crangon. The two first named must be regarded as true arctic animals, extending southward, it is true, in more temperate climates, but preferring considerable depths, from about 100 to 400 fathoms. Crangon crangon lives in very shal- low water, extending not as far northward as Cr. salebrosus and boreas, and a connection between the Atlantic and Pacific (Japanese) localities is not known. Perhaps such a connection was only present in former times, and this species can not be counted among the circumpolar ones, but is a survival of a formerly more extended distribution. The two varieties of Crangon crangon described above prefer deeper water, 50 and 60 fathoms, and they are restricted to one of the northern parts of the two great oceans, afinis being found in the northern Pacific from Japan to California, al/manni in northern Europe. Of the other species of Crangon eight show a distribution similar to the two last varieties. Five are litoral and restricted to the northern part of the Pacific, especially Cr. sharpi and intermedius to the most northern parts (Berings Sea and Alaska), Cr. angusticauda to Japan, and Cr. munitus and franciscorum to the western coast of United States. The latter replaces the typical Cr. crangon on this coast. A sixth species, Cr. agassizi, is found in the Atlantic near the eastern coast of United States, and must be regarded as a true deep sea animal, being recorded from about 200 to 900 fathoms. It is replaced on the western side of America by a nearly allied abyssal species, Cr. procax, 660-900 fathoms. On the western coast of Central America is found a second abyssal species, Cr. atrox, between 600 and 700 fathoms, being closely related to the northern circum- polar Cr. salebrosus. The presence of these three abyssal species on both sides of the American continent indicate a relation to the northern circumpolar seas, according to their affinities with the north- ern circumpolar species of the subgenus Sclerocrangon, but I do not believe that this demonstrates the connection of the western and eastern American seas in the tertiary period within the litoral, as held to-day generally by authors. Finally there are two antarctic species: Cr. capensis from the Cape of Good Hope, and Cr. antarcticus from South Georgia. The latter 1895. ] NATURAL SCIENCES OF PHILADELPHIA. 191 is regarded by Pfeffer" as a proof of the bipolar distribution of Crangon. I have doubted the correctness of Pfeffer’s opinion in this view,” and have pointed out that the examples of bipolar distribution of crustacea enumerated by him do not correspond exactly to the facts known, except in the case of Cr. antarcticus. But neither in this species, is, I believe, a bipolarity of the genus probable. Cr. antarcticus is the nearest allied to Cr. franciscorum and this fact induces me to suppose that a connection between the northern and southern range of Crangon is present along the west coast of America from California to Chili,-and in the same manner, I believe, there is a connection from the European seas along the western coast of Africa to the Cape of Good Hope, the locality of Cr. capensis. Litoral species of Crangon have not yet been recorded from the western coasts of America and Africa, but I hope that further investigation will demonstrate the presence of this genus in both localities, and thus strengthen my theory. Supposing my theory to be correct, the range of Crangon would be a northern circumpolar one, partly containing circum- polar species, partly species confined to the northern. parts either of Pacific or of Atlantig. Some species descended into the deep sea to a depth of about 900 fathoms and covfld propagate more southward. Along the west coasts of Africa and America, owing to the cooler temperature of the seas on these coasts, the range of Crangon could extend to the southern hemisphere, crossing the tropics. The range of the genus Nectocrangon, the nearest allied of Crangon, agrees wholly with that of the northern species of Crangon: one species, Nectocrangon lar, is a true arctic-circumpolar one extending very little southward (the most southern locality recorded is Nova Scotia), the other, Nectoerangon alaskensis, is restricted, as we know, at present to Alaska. The genus Pontophilus, the first of the series, representing the second branch of development arising from Pontocaris, has a nearly cosmo- politan horizontal distribution, but the several species are wholly dif- ferent from each other. The greatest number of species, like Crangon, is found in the litoral of the cooler seas of the northern hemisphere, ll Pfeffer, Die niedere Thierwelt des antarctischen Ufergebietes.—internat. Polarf. Deutsch. Exped. II, 1890, p. 520-572. 12 Ortmann, Jenaische Denkschriften, VIII, 1894, p. 77. 192 PROCEEDINGS OF THE ACADEMY OF [1895. but their range does not extend very far northward. Accordingly, arctic circumpolar species are not known, the northern litoral species being restricted to comparatively narrow districts, each to one side of the great oceans. Only one species, P. norvegicus, in the northern Atlantie, is found on both the European and American shores. Eight species are found in the European seas: P. echinulatus, spinosus, pattersoni, sculptus, bispinosus, trispinosus, fasciatus, neglectus; one on the east coast of United States : P. brevirostris. As the cooler waters of the western African coast allow a more south- ward extension, a mediterranean species, P. cataphractus, ranges southward to the Senegambia. In the Pacific northern species are not known, but two having a more southward range: P. bidentatus in Japan, P. carinicauda in China. The presence of the latter in the tropics is due, I believe, to a more recent immigration.. Of the northern litoral species some show a very large bathymetri- cal range, descending to considerable depths, especially P. echinu- latus, brevirostris to 150 fathoms, P. norvegicus to 500 fathoms. The next to the latter species, as regards the depth inhabited, are P. bengalensis, andamanensis, Junceus, being found in the tropical seas of India and Indo-Malaysia in depths of about 100 to 300 fathoms, and, farther, five Species are true deep sea animals. One of these, P. profundus, is only found near Sydney in 2,600 fathoms, another, P. oceidentalis, off the west coast of Central America in 900-2, 200 fathoms. The three others show the characteristic wide range of the true abyssal animals, Pont. gracilis being found in the Atlantic and Indian oceans from 200 to 700 fathoms, P. abyssi in the North Atlantic and Indian oceans from 1700 to 2,200 fathoms, and P. challengeri in the Atlantic and Pacific oceans from 1,100 to 2,700 fathoms. Lastly, two litoral species are known from the cooler seas. of the southern hemisphere: P. australis from New Zealand, and P. intermedius from Southern Australia. The horizontal and vertical range of Pontophilus may be sum- marized as follows: The main distribution of the genus is in the litoral of the northern hemisphere, especially in the temperate seas, a circumpolar rangeof none of the species is proven; a few litoral species extend more southward. A great number of species have a tendency to descend into deeper water, and, accordingly, some species are found in the deeper water even of the tropies, and have occupied a large area of the deep sea. In the cooler parts of the 1895. ] NATURAL SCIENCES OF PHILADELPHIA. + VEJO southern hemisphere is given the possibility to re-ascend into the litoral, and two litoral species are, in fact, found in Australia and New Zealand. The genus Sabinea contains two northern -species, one of which, 8. septemcarinata, is a true arctic circumpolar one, the other, S. sarsi, is found on both sides of the northern Atlantic. Both descend into greater depths, to about 150 fathoms. The third species, S. hystria, is an abyssal one, found in 400 to nearly 900 fathoms, and its range extends more southward, from the eastern coast of United States to Guadeloupe in the West Indies. The two known species of the most extreme genus of the second branch of Crangonidze, Paracrangon, live on the western coasts of America, probably in greater depths; at least P. areolatus is recorded from over 600 fathoms. The last genus, Prionocrangon, is very peculiar and its affinities are not certainly known. It probably is allied to Pontophilus, and then its habitat, in the deep sea of the Indian ocean, 200-400 fathoms, would not be strange, since Pontophilus contains also tropical species living in deeper water. The distribution of Crangonide may be thus summarized: The “regions.of life” in which Crangonide are found, are the litoral and the abyssal. Regarding the “*facies,”'* the Crangonide are principally, as we know, benthonic” in sand and mud. These habits admit a universal distribution of the family, but the genera and species are more restricted. The litoral species especially are not cosmopolitan, but are con- fined by barriers. Except the tropical genus Pontocaris, which must be regarded as a survival, the litoral Crangonid® are almost exclusively limited to the northern hemisphere, and the seas of tropical temperature must be considered as the climatic barrier pre- venting the distribution of Crangonida southward. Only a few species are adapted to the warmer seas, especially Crangon cataphractus in Senegambia and Pontophilus carinicauda in China, Generally, the Crangonide, originating in the cooler northern hemisphere, were 13 ““ Lebensbezirke,’’ J. Walther, Bionomie des Meeres, 1893, p. 13-15, p. 87- 176.—Walther does not give a satisfactory and correct definition of this word, on account of which his detailed discussion concerning this term is wholly out of place. Notwithstanding, the idea of ‘ regions of life’’ is a very good one. 14 Walther, ibid. p. 25-34. 15 See Haeckel, Planktonstudien, 1890, p. 18ff. “ 194. PROCEEDINGS OF THE ACADEMY OF [1895. separated from the cooler parts of the southern by the broad belt of the warm circumtropical seas. This zone, however, is not a con- tinuous one, but isinterrupted within the litoral on two tracts, on the western coasts of Africa and America. At these two localities there are two causes producing a lower temperature of the litoral seas than is usual in the tropics. On the one hand, there are cold currents run- ning from the southern cold seas along both shores northward as far as the equator and even beyond; on the other hand, on these coasts arises cold water from the sea-bottom, the equatorial currents directed from the coast to the west carrying away the surface water. A cooling of the litoral waters of the west coasts of Africa and America is thus produced, and although the most superficial layers of water may be warmed by the sun, in greater depths within the litoral there may prevail a low temperature. Thus, on the west coasts of Africa and America, it may be possible that northern litoral forms penetrate into the tropics and beyond, and may reach the litoral of the cooler antartic hemisphere. The presence of Crangon capensis and C. antarcticus may be thus explained. By adaption to a cooler temperature a large number of Cran- gonidze are able to descend to greater depths,º and by this habit they may enter and cross the tropics in the deep sea. The species adapted to the greater depths show, as usually in deep sea animals, a very large horizontal range, and, therefore, they can reach the southern hemisphere, while a re-ascending into the litoral of the antarctic regions is possible. We know of the genus Pon- tophilus, which is the only one containing true deep sea species of wide distribution, two species in southern Australia and New Zealand, the presence of which is probably due to this cause. Other barriers against the distribution of the species of Cran- gonida are of a topographical character. At first, the great conti- nents of northern Eurasia and North America cause a complete separation of the northern temperate parts of the Atlantic and Pacific, and, therefore, these oceans contain distinct species. Farther, the Crangonide, living mostly benthonic, can not pass over deep seas, and in the arctics the deep sea and the litoral are closely connected. See Monaco, Zur Erforschung der Meere, ete., translated into German by Marenzeller, Wien, 1891, p. 135, and Pfeffer, Versuch über der erdgeschichtliche Entwickelung der jetzigen Verbreitungsverhältnisse unserer Tierwelt, Hamburg, 1891. 1895.1 NATURAL SCIENCES OF PHILADELPHIA. 195 of the Pacific and Atlantic are inhabited by different species. Only the true arctic species being able to live along the most northern shores of America and Asia show & circumpolar distribution, no topographic barriers of the kind mentioned there being present. The species not living in the arctic, but in the boreal” seas, are re- stricted by such topographic barriers. It is evident, therefore, that the means of dispersal of the Crangonid&, except Pontocaris and a few species of Pontophilus, do not act against the climatic barriers and mostly also not against the topographic. Only a few known species are present on both shores of the Atlantic: Pontophilus norvegicus (100-150 fath.) and Sabinea sarsi (60-150 fath.). Whether these species can pass over the barrier formed by the northern Atlantic as adult animals or as larvee, or whether this distribution is due to other causes, we can not say at present. On the shores of the Atlantic and Pacific very nearly allied species are sometimes found. ‘These must be derived from common ancestors living when the arctic ocean was not as cold as at present, and when a circumpolar connection was present for these species as in the case of the circumpolar forms now living. Later these species retreated more southward, and by the topographic separation of the range, the morphological characters could change, and distinct forms could develop. The geographical distribution of the Crangonide is a very char - acteristic one and important as limiting the northern zoo-geographical_ regions of the litoral. Apart from a few species living in the tropics, in the antarctic and in the deep sea, the family of Crangonidee char- acterizes the northern circumpolar region, as defined by me formerly.” This region is characterized by the genera Nectocrangon and Sabinea. Among the northern species we can distinguish true arctic species showing a circumpolar range, especially Crangon salebrosus, boreas, Nectocrangon lar, Sabinea septemcarinata, and boreal species. The latter are not circumpolar, but more restricted. Crangon crangon affinis is restricted to the Pacific, Pontophilus norvegicus and Sabinea sarsi to the Atlantic. The other species are more localized and char- acterize each a separate local fauna, and we-can distinguish a Japan- ese fauna, a fauna of the Berings Sea, a fauna of the western coast of lv Regarding the distribution of ‘‘arctic’’ and “boreal” seas see Pfeffer, Versuch, etc., 1891. 18 Jenaische Denkschriften, VIII, 1894, p. 78. 196 PROCEEDINGS OF THE ACADEMY OF [1895. America. Characteristic of the first is Crangon angusticanda ; Pon- tophilus bidentatus ; of the second, Crangon sharpi, ©. intermedius: Nectocrangon alaskensis ; of the third, Crangon munitus, C. franeis- corum, Paracrangon echinatus.” In the Atlantic, we have species peculiar to the European coasts: Crangon crangon allmanni, Ponto- philus echinatus, P. spinosus, P. pattersoni, P. sculptus, P. bispinosus, P. trispinosus, P. fasciatus, P. neglectus, and one peculiar to the east coast of America: Pontophilus breviorostris. Accordingly, within the limits of the arctic region we can dis- tinguish three sub-regions: 1. The arctic-circumpolar; 2. the Atlantic- boreal; 3. the Pacific-boreal. The two latter are divided into local faunas, the Atlantic into the northern European and the fauna of the east coast of United States; the Pacific into the local faunas of the Berings Sea, of Japan, and of the west coast of North America. The arctic litoral region is the centre of origin of the family of Crangonidee, and the centre of its development. The geographical distribution of the species not living within the arctic litoral may be characterized and classified as follows: 1. Survivors of a more cosmopolitan distribution in the tropics of Indo-Malaysia: Pontocaris propensalata, P. pennata. 2. Immigrants into the litoral of warmer seas from the northern litoral: Pontophilus cataphractus, P. carinicauda. 3. Immigrants into the deep sea. a. Localized species.” North Atlantic: Crangon agassizi, 200-900 fath., Sabinea hystrix, 400-900 fath.; Indo-Malaysia: Pontophilus bengalensis, 107-270 fath., P. andamanensis, 180-220 fath., P. junceus, 250 fath., Prionocrangon ommatosteres, 200-400 fath.; off Australia: Pontophilus profundus, 2600 fath.; off western coast of Central America: Crangon atrox, 600-700 fath., Cr. procax, 600- 900 fath., Pontophilus occidentalis, 900-2200 fath., Paracrangon areolatus, 670-680 fath. b. Widely distributed abyssal species: Pontophilus gracitis, 200- 700 fath., Pontophilus abyssi, 1700-2200 fath., Pontophilus chal- lengeri, 1100-2700 fath. 4. Immigrants into the litoral of the antarctic region. Crangon antarcticus, Cr. capensis, Pontophilus australis, P. inter- medius. 19 Paracrangon echinatus is perhaps an abyssal species, judging from the depth recorded for Paracrangon areolatus. 20 Some of these species may be more widely distributed. "a 1895.] NATURAL SCIENCES OF PHILADELPHIA. 197 The occurrence of the recently described Aegeon orientalis Henderson, from the litoral of the Burmese coast (Gulf of Marta- bem) is remarkable, because this species is said to be related to the Mediterranean Pontophilus cataphractus. It may, however, belong to the genus Pontocaris, and the description and figure given by Henderson do not refute this supposition. ankam meen ts RD: Rudd ‘Sri | Rb e OS Cesare roti a tl een y THE AMERICAN JOURNAL or SCIENCE, VOL. IV, 1897.] N MK A 2 (© N N Ortmann— Crangopsis vermiformis. 283 ART. XXXI.— The systematic position of Crangopsis vermi- ‚Formis (Meek), from the Subcarboniferous rocks of Ken- tucky ; by ARNOLD É. ORTMANN, Ph.D. In 1872 and 1875 F. B. Meek described* a peculiar Crus- tacean from the lowermost Subcarboniferous rocks (base of Waverly series) near Danville, Ky., under the name of Archwo- caris vermiformis, but owing to the imperfect condition of his specimens he did not express any opinion as to the sys- tematic position of this fossil. The Museum of Geology of Princeton University possesses quite a number of specimens of this form, which were collected by M. Fischer at or near the “same locality (Boyle Co., Ky.), and which are also for the most part poorly preserved. Yet a few specimens are better, and one of them shows clearly a peculiar feature which enables us to make out its approximate systematic position. Previously, Crustacean remains closely resembling Meek’s species have been reported by Saltert from the Subcarbon- iferous (Mountain Limestone) of Scotland under the name Paleocrangon socialis, the generic name being subsequently changed into Crangopsis Salter,f in order to prevent confusion with Palwocrangon Schauroth. Salter places his fossils among the Macrurous Decapods, considering the presence of a cara- pace, of seven distinct abdominal segments, and of caudal swimmerts as conclusive. ‘These three characters are all that is known of Crangopsis, and Archwocaris of Meek shows exactly the same; there is nothing that should induce us to separate generically the American from the Scotch fossil. Accordingly, we should consider Archwocaris as a synonym of Crangopsis, and the American species should be called Cran- gopsis vermiformis (Meek). The three characters which induced Salter to place his genus among the Decapods are not sufficient to warrant the correctness of this position. On the contrary, these three characters are present, among the Mala- costraca, in the same combination also in the living orders of the Stomatopoda, Euphausiacea, and Mysidacea,§ and we can- not make out the proper position of these fossils according to our present knowledge. From one specimen however in the Princeton collection (Mus. No. 1597°) we learn another very important character. * Proc. Acad. Philad., 1872, p. 335; Geol. Surv. Ohio, Palzont., ii, 1875, p. 321, pl. 18, fig. 1. + Trans. Roy. Soc. Edinburgh, xxii, p. 394; Quart. Journ. Geol. Soc. London, xvii, 1861, p. 533, fig. 8. t See Zittel, Handb. Palzont., ii, 1885, p. 682. S Compare Boas, in Morpholog. Jahrb., viii, 1883. . 284 Ortmann— Crangopsis vermiformis. Of this specimen the body is complete, showing the carapace and the whole abdomen preserved en situ. Fortu- nately, the hinder and upper part of the carapace is broken away, thus enabling us to see that in addition to the seven abdominal segments exposed in specimens with unbroken carapace, there are, in front of them, four other segments present, originally covered by the hinder expansion of the cara- pace, and these four (thoracic) segments are dorsally perfectly closed, smooth, and uninjured, thus proving that they were not connected and anchylosed with the carapace, but free dorsally. These free thoracie segments are exhibited in a few other specimens (Mus. No. 1597), but since in the latter the abdomen is not complete, their exact number cannot be determined. This character clearly shows that Crangopsis vermiformas cannot be a Decapod. In the Decapods all the thoracic seg- ments are firmly united dorsally with the carapace. Neither can Crangopsis belong to the Huphausiacea, because in this order only the last (fifth) thoracic segment is dorsally free, while all the others are united with the carapace. In the Stomatopoda the five thoracic segments are free, but they are not covered by the carapace; only in the Mysidacea we have the same condition as shown by Crangopsis. Thus, according to this character, this genus should be placed in the order of Mysidacea, and it is the first fossil form assigned to this group. I think, however, it would be a little rash to assume posi- tively that Crangopsis belongs to that group of recent animals designated as the order Mysidacea, since we know nothing of the other characters of this form. It is true, the character mentioned is present, among the living Malacostraca, only in the order of Mysidacea, but it is a mere secondary one, the principal characters being drawn from the differentiation of the appendages of the body. In the fossil Crangopsis only faint traces of limbs have been discovered, but their number, their shape and differentiation are entirely unknown, and accordingly we are at a loss to recognize the typical characters of any par- ticular order of the Malacostraca ; we may even imagine that Crangopsis possessed in the conformation of the thorax the characters of Mysidacea, while the limbs were developed according to the Decapod-type, a condition which is not alto- gether impossible. Since Crangopsis belongs to the earliest forms of Malacostraca, we are to expect that it belongs to a primitive group, perhaps to that group which forms the origi- nal stock from which all the now living Malacostraca originated. But the presence of a carapace covering entirely the thorax indicates that this genus belongs to the Zhoracostraca, and further, the fact that the four last thoracic segments are dor- Ortmann— Crangopsis vermiformis. 285 sally free, shows that closer relations exist to the Mysidacea than to any other order. There is no doubt that the Carboniferous and Permian fossils designated by Brocchi* as a new family (Vectotelsonide) of the order Amphipoda belong to that primitive gronp of Mala- eostraca which gave origin to the different now living orders. This family contains the genera Palwocaris Meek and Worthen, Uronectes Bronn (=Gampsonyx Jordan), and Nectotelson Brocchi, but its position among the Amphipods, as maintained by Brocchi, is certainly erroneous. The Nectotelsonid® show a number of characters common to all Malacostraca, but no typical characters of any of the orders of this subclass; they represent a mere collective type of different Malacostracous orders. The general characters of all Malacostraca are the following : Body with a limited number of segments; the number of the anterior segment is somewhat donbtful, but there are certainly eight segments of the “ cormus” bearing the cormopods, and seven of the abdomen or pleon, six of which bear pleopods, the last one forming with the telson a caudal fin. A differentiation between the appendages of the cormus and the pleon is present. This primitive type of Malacostraca is divided into two large sections: the Zhoracostraca, having a carapace developed and stalked eyes, and the Arthrostraca having no carapace and ses- sile eyes.t The first section is farther characterized by the prevailing presence of the caudal fin (which is reduced only in the Decapoda Brachyura); of the second section only a part of the Isopods retains the caudal fin. In the Thoracostraca the legs are either differentiated in the primitive manner into cor- mopods and pleopods, or the former are again divided (Deca- poda) into three maxillipeds and five pereiopods (thoracic legs). In the Arthrostraca, there is never a differentiation of maxilli- peds and pereiopods, but often (Amphipoda) the pleopods are divided into swimming (anterior) and jumping (posterior) feet. The Nectotelsonide of Brocchi show on the one hand the primitive characters of the Malacostraca; they have a limited number of body-segments, divided according to the appendages into a cormus and a pleon with a caudal fin.: On the other hand no carapace is developed and stalked eyes are present. The latter character, and the shape of the antenn&, and the gill-like appendages on the bases of the cormopods separate this group from the Arthrostraca, and Jordan and Meyer were perfectly right in so far as giving Uronectes a position inter- * Bull. Soc. Geol. France, iii, 8, 1880. . ¢ I disregard the Cumacea, which are intermediate between both in this respect. 1 The details of structure given here are best known in Uronectes (= Gampsony%). Compare Jordan and Meyer, Palzontographica, iv, 1, 1854, p. 1, ff. pl. 1. 286 Ortmann— Crangopsis vermiformis. mediate between the Arthrostraca and Thoracostraca: but in pointing to the resemblance to the Amphipods they were wrong, since there are no closer relations present to that order. The other genera referred by Brocchi to the Nectotelsonide are only incompletely known, but their general appearance strongly favors the opinion that they really belong to the relatives of Uronectes. The description of the genus Nectotelson of the Permian of Autun, France, is very poor and contradictory. Brocchi gives it seven thoracic segments (p. 6) and four abdom- inal segments, but his figures show nothing that might warrant this number, and fig. 1 (pl. 1), indeed, shows clearly that the number four for the abdominal segments is incorrect. Further, he says (p. 7) that probably the eyes were small and sessile: but the specimens did not show any traces of these organs! He did not discover in his specimens an appendage of the antennee: these characters and the much smaller size are the only differences of Nectotelson and Uronectes. The limbs of Nectotelson (pl. 1, fig. 2) are badly preserved, but they resemble apparently those of Uronectes.* As regards the genera Paleocaris and Acanthotelson of Meek and Worthen,t I refer only to the descriptions and resto- rations given by Packardt from which it is apparent that both are closely related to Uronectes. In order to get an approximate idea of the systematic posi- tion of Brocchi’s Nectotelsonide, we may rely upon a combi- nation of the characters of these three or four genera, and if we consider these characters as conclusive for this family, we may say that the Wectotelsonide show the typical characters of the subclassis Malacostraca; but further on they unite charac- ters of the Arthrostraca (the missing carapace) with taose of the Thoracostraca (stalked eyes), thus proving to be a primitive group from which the former as well as the latter might be derived. | I may add here that Packard creates the suborder Syncarida for these genera,S which thus consists of Brocchi’s family Nectotelsonide. * It is astonishing that Brocchi in comparing Nectotelson with Uronectes did not consult the paper of Jordan and Meyer quoted above, and that he describes a very bad figure that we possess of Gampsonyx (he gives a copy pl. 1, fig. 7), while Gampsonyx (Uronectes) is known as completely as we might expect to know a Palzeozoic Crustacean. + Paleocaris typus, Coal Measures of Illinois (Proc. Acad. Philad., 1865, p. 49, and Geol. Surv. Ill. ii, 1866, p. 405; iii, 1868, p. 552). Acanthocaris, three species from the Coal Measures of Illinois (ibid.). A second species of Palwocaris has been described by Woodward from the Coal Measures of England (Geol. Magaz., 1881, p. 533). 1 Mem. Nat. Acad. Sci., Washington, iii, 1886, and Proc. Boston Soc. N. H., - xxiv, 1889. - § Compare Calman, 1896, p. 801, footnote 1. Ortmann— Crangopsis vermiformis. 287 This fossil group of Orustaceans has become the more inter- esting, since very recently a peculiar living species has been discovered in fresh-water pools of the mountains of Tasmania, which was first described by G. M. Thomson* under the generic name of Anaspides, and of which W. T. Calmant gives a more detailed investigation, especially with reference to its relation to the fossil forms here under discussion. Anaspides, indeed, is the most important discovery among the recent higher Crustaceans, and it is no doubt a living form belonging to the group Syncarida. Calman has shown conclusively that the characters of Anaspides are a combination of the Podoph- thalmate type (Thoracostraca) with a completely segmented body and the lack of a carapace, i. e. with Edriophthalmate type (Arthrostraca). But, on the other hand, the details of structure in Anaspides point to a closer connection with the “Schizopoda” of the Euphausid-type as well as of the Mysid- type. ai ae however, it is best to regard the Syncarida of Packard, including the recent genus Anaspides, as a group of equal rank with the other chief divisions of the subclass Mala- costraca, namely as an order, and, indeed, as the most primitive order from which all the others are to be derived: there is no doubt about the genetic relation of the Euphausiacea, Mysi- dacea, and Decapoda to the Syncarida, but I am convinced that further study will show that also the other orders of Mala- costraca, Squillacea, Cumacea, Isopoda, and Amphipoda are to be connected directly or indirectly with this primitive order. The chief characteristics of the order Syncarida (Packard) derived from the morphological features displayed by the. recent Anaspides would be the following: Body with a limited number of distinct segments, differen- tiated into a “cormus” and a “pleon.” No carapace devel- oped. Stalked eyes present. Antenne with a scale. Cormo- pods on the coxal joints with “branchial lamelle,” and on the basal joints with an “ exopodite.” Penultimate segment of the pleon with two well developed appendages forming with the telson a caudal fin. É Comparing Crangopsis with the Syncarida we see at once that it is distinguished by the presence of a carapace, thus coming clearly under the subdivision Zhoracostraca. As we have seen above, we may assign it to a particular order, Mysi- dacea, but we must bear in mind that the typical characters of this order drawn from the appendages of the body are not * Trans. Linn. Soc. Zool. (2), vol. vi, 1894. + Trans. Roy. Soc. Edinburgh. vol. xxxviii, part 4, 1896. ti Compare Calman, 1. e. p. 795 and 801. 288 Ortmann— Crangopsis vermiformis. recognizable, and therefore its position among the Mysidacea is not beyond doubt. Indeed, I do not believe that Crangopsis really belongs to the order Mysidacea, but that it is related to the Syncarida. At present, however, we are at a loss to ascer- tain its true position, since the morphology of the appendages of the body is unknown: yet there is much probability that Crangopsis may be a transitional form from the true Syn- carida to one of the more specialized groups of Thoracostraca, namely the Mysidacea. Whether we shall connect it system- atically with the latter group or with the Syncarida, depends on the knowledge of the other details of structure. In the latter case, the synopsis of the Syncarida ought to be changed as to include this form provided with a carapace. I may be permitted here to direct attention to a few other Malacostracous Crustaceavs found in Palsozoic strata, the position of which with Crangopsis is likely more correct than with the Decapoda. The oldest form referred to the Decapoda, Palewopalemon newberryi,* from the Upper Devonian of Ohio, has been placed by J. Hall among the “Caridide ;” but certainly it does not belong to the typical forms of this group, as the name might suggest, which are now called Hucyphidea. Zittelt places this genus among the Penezde. Although there is no character known which contradicts this position, there is, on the other hand, none which seems to warrant it. On the con- trary, no characters are present at all which stamp this fossil as a Decapod: it may belong equally well among the Euphau- siacea or Mysidacea. Indeed, in the figure of the only known specimen the carapace appears posteriorly elevated over the . abdomen as if separated from the trunk, a feature which sug- gests a condition similar to that of the Mysidacea or Euphau- siacea. But, of course, we cannot judge from this character, as it might be due as well to fossilization. In the Coal Measures of England a peculiar Crustacean has been found, described by Huxley under the name Pygoceph- alus cooperi.t Huxley considers this form to come near to the recent Mysis, but to possess some relations to the Stomato- pods, while Zittel places it among the Decapod-group Penwide. I should like to endorse the opinion of Huxley in so far as the wanting chel&, the non-differentiation of maxillipeds and perei- opods, and the presence of exopodites are strongly against its * Whitfield, this Journal (3), vol. xix, 1880, p. 41, and Ann. N. Y. Acad. Sci., vol. v, 1891 prot), pt. 12, figs. 19-271. Han, Pal) N. N, vol’ vir 1888. pues pl. 30, figs. 20-23. + Handbuch d. Palxont., ii, 1885, p. 683. t Quart. Journ. Geol. Soc., London, xiii, 1857, p. 363, pl. 13 and 18, 1862, p. 420. Ortmann— Orangopsis vermiformis. 289 affinity with the Decapods. Pygocephalus may belong to the “Schizopods”* in the old sense, which comprise the Euphau- siacea and Mysidacea of recent systems, but we are at a loss to say to which of the two latter orders it may be referred. In conclusion I may add that no Paleozoic Crustacean is known in which Decapod-characters have been observed.t The only genus Anthrapalemont of the Coal Measures of Scotland and Illinois, which has been referred to the Decapods from the appearance of the external form of the body, has incompletely preserved legs, so that its true position remains doubtful. It may be well to remember that true Decapods, i. e. Crustaceans in which typical Decapod-characters are evi- dent, are not found until the Triassic period, and that it may be possible that they did not exist at all in Paleozoic times. On the other hand, it is sure that upwards from the Upper Devonian period, through the Subcarboniferous, Carboniferous and Permian, Malacostraca have been found, which represent either a mere collective type of this subclass or show even some tendency to become more specialized: at least a differen- tiation of Thoracostraca and Arthrostraca took place probably in the earliest Subcarboniferous or Upper Devonian period. Remains of this primitive group, which may be conveniently called Syncarida (Packard), have not yet been found in Meso- -zoic or Tertiary strata, but this group às still represented by the genus Anaspides, living in fresh water on the mountains of Tasmania. Princeton University, January, 1897. * Huxley unites the Schizopods with the Decapods, and, accordingly, he calls Pygocephalus a Decapod: but he expressly states its nearer relation to ‘‘ Mysis,” a Schizopod. + Even an alleged abdomen of a Brachyurous Decapod, Brachypyge carbonis, has been described from the Coal Measures of Belgium (Woodward, Geol. Magaz., 1878, p. 433, pl. 11, and de Koninck, Bull. Acad. Roy. Belg. (2), Ixv, 1878, p. 83, figs. 1, 2). It is extremely unintelligible why this fossil should belong to a Crus- tacean at all, and whoever has seen the abdomen of a living crab, cannot doubt that this fossil is no such thing. Probably Brachypyge belongs to the Arach- noidea (compare the Carboniferous Anthracomarti). 1 Salter, Quart. Journ. Geol. Soc, London, xvii, 1861, p. 529, figs. 1-7. Meek and Worthen, Geol. Surv. Ill., ii, 1866, p. 407, pl. 32, fig. 4, and iii, 1868, p. 554. Etheridge, Quart. Journ. Geol. Soc., London, xxxv, 1879, p. 404, pl. 23. AM. Jour. Sci —FouRTH SERIES, You. IV, No. 22.—Oot., 1897. 20 290 Ortmann— Linuparus atavus. ART. XXXII.—On a New Species of the Palinurid-Genus Linuparus found in the Upper Cretaceous of Dakota; by ARNOLD E. ORTMANN, Ph.D. THE Geological Museum of Princeton University has lately acquired two unique specimens of a hitherto unknown fossil species belonging to the family Palinurid&, which are not only the first remains of this group of Decapoda found on the American continent, but which—as regards the completeness of preservation—surpass anything that is known of this group from the European deposits. It is true, Palinuroid-Decapods have been found in Europe, especially in England and Ger- many, in great numbers, and the systematic relations of these forms—as belonging to the family of Palinuride—are beyond any doubt. But there is hardly a form the affinities of which to the living genera of this family have been ascertained : accordingly, for most of them new genera have been created, and although the old generic name of Palinurus has been used for some of these European forms, there is nothing that indi- cates a closer connection of this fossit Palinurus with the laving Palinurus “sensu strictiore.” The American fossil here to be described not only shows'all the chief characteristics of the family, but it is so well pre- served that the writer has been enabled to make out its generic position, and he was exceedingly surprised that this fossil from. the Upper Cretaceous is congeneric with a species living now- adays in the Japanese seas, namely with Palinurus trigonus of de Haan,* the name of which stands at present as Zenu- parus trigonus (d. H.). The genus Zinuparus created by Gray in 1848 for this Japanese form is—as far as we know—a monotypic genus, containing only that Japanese species just mentioned. | In order to make clear the systematic position of the new fossil, it will be well to give a brief sketch of the generic divisions of the family Palinurida, as accepted in modern zoology.t The family Palinuride contains seven recent genera: Palinurellus, Jasus, Palinurus, Palinustus, Linuparus, Panulirus and Puerulus. Indeed, some of these genera have not been admitted by some modern carcinologists, but I should say that the differences of these genera are so striking, that one would amply be justified in arranging them into three or * See de Haan, Fauna Japonica. Crust., decas 5, 1841, p. 157, pl. 39, 40. + Compare Ortmann, in Zoolog. Jahrb. Syst., vol. vi, 1891, pp. 13-38. I should mention here, that some of the generic names used by me in this revision do not comply with the rules of nomenclature accepted generally. Thus Avus should be Linuparus, Senex should be Panulirus, and Puer ought to be changed, since it has been preoccupied, (I should like to propose Puerulus for it.) Ortmann— Linuparus atavus. 291 four different families. - Only Palinurus and Palinustus on the one hand, and on the other Panulirus and Puerulus are more closely related to each other: the other genera differ so widely that they indicate as many lines of development within this family, which are separated since very old geological times. It may be possible to trace back the separation of these lines of development into the earlier Jurassic or even into the Triassie period. There are three chief groups, namely: 1, that of Palinu- rellus and Jasus; 2, that of Palinurus, Palinustus and Lin- uparus ; 3, that of Panulirus and Puerulus. According to the morphological characters the first may be called the more primitive, the second the typical, the third the more advanced group. But perhaps it would be well to place Palinurellus and Jasus in separate groups, since both— although agreeing in some characters not found in the other venera—are so widely different, that no closer genetic relation seems to be present. The most striking character of Palinurido is the connec- tion of the frontal parts of the carapace with the so-called segment of the antennule as well as with the epistoma, and, on the other hand, the fusion of the basal points of the stalk of the antenna with the epistoma.’ The frontal part of the carapace is always united with the segment of the antennule outside of the eyes, on either side, but in the two genera first named there is a median connection besides: the rostrum is ‘ bent downward and covers completely or partially the bases of the eyes, thus reaching and joining the segment of the anten- nula. These two genera—Palinurellus and Jasus—are further characterized by the lack of a stridulating apparatus, formed by the first free joints of the antenn& rubbing against the seg- . “ment of the antennul&, which seems to be present in all the other genera. The second and third groups are more closely related to each other, but they are distinguished by one important character: in the second the epistoma is divided longitudinally by a deep furrow, which no doubt indicates the former separation of the basal joints of the antenna fused into the epistoma. This furrow is wholly wanting in the third group, the epistoma being smooth and even medially. The disappearance of this indication of the primitive separation of the basal joints of the “antenna stamps the third group as a more advanced one than the second. Besides, there is another difference: in the second _ group the flagella of the antennule are always short, while in the third group they are very much longer. N Examining our fossil form, we see at once that it belongs to the second group. The larger specimen shows plainly the con- nection of the carapace with the epistoma and with the seg- ment of the antennule, outside of the bases of the eyes, while 292 Ortmann-— Linuparus atavus. no median connection is present. The epistoma shows the median longitudinal groove characteristic of the second group. The flagella of the antennule, however, are not preserved. There are three genera in the second group. The first is the type genus of the family, Palinurus (containing two liv- ing species); the others are Palinustus and Linupurus (con- taining only one species each). Palinustus was proposed by A. Milne-Edwards* for a deep-sea form from the West Indies. The description of it is very poor and even incorrect in some respects, and no figure of it has been published. I am, how- ever, enabled—through the kindness of Professor Alexander Agassiz, who lent me the type specimen for examination—to state, that Palinustus comes very near to Palinurus, and differs. only in the weaker “frontal horns,” which are placed on the outer edge of two very peculiar plates projecting horizontally from the frontal margin and truncated squarely at the apex. In Palinurus these projecting frontal plates are wanting and the “frontal horns” are formed by two large, compressed, nearly falciform spines placed close to the frontal margin on. either side of the rostrum. In all other respects Palinurus. differs only shghtly from Palinustus. The differences of both genera from Zinuparus are the following. In Palinurus and Palinustus the carapace, especially the part behind the cervical groove, is evenly arched from side to side, i. e. of sub-cylindri- cal shape, and it is covered by a multitude of spines and spiny tubercles, becoming scaly in the hinder part. The frontal horns are compressed and separated by a wide space. In Linuparus the hinder’ part of the carapace is distinctly cari- nate, three keels being present, a median one and two lateral ones. The surface is covered with granules, and a few small spines placed chiefly on the anterior part, thus differing strik- ingly from the spiny appearance of the carapace of the first two genera, and, further, the frontal horns of the living Linu- parus lie close together and are depressed (not compressed), forming two broadly triangular plates projecting from the middle of the frontal margin. Our fossil form comes very near to Zinuparus in the shape and armature of the carapace. There are three distinct longi- tudinal keels on the hinder part of the carapace, and only a few short spines distributed in a similar manner as in the living Japanese form. But there is a difference in the frontal horns. The latter are compressed, as in Palinurus, bnt nearer to the median line. The horns are smaller than in Palinurus and a little inclined, diverging from the bases outward, and thus they are exactly intermediate in shape and position between the living Palinurus and the living Linuparus: the distinct lateral compression comes near to that of the former genus, but the inclining direction looks like an incipient depression, and in * Bull. Mus. Compar. Zool., vol. viii, 1880, p. 66. Ortmann-—Linuparus atavus. 293 their eloser position to the median line, the horns approach also the condition seen in Linuparus.* There is no doubt that we are to place the fossil form in the genus Linuparus, and although the frontal horns form in some degree a connection with Palinurus, there are a couple of other characters of minor importance exhibited by our fossil which occur only in the Japanese Zinuparus trigonus, as will be pointed out in the following detailed description of the new fossil, which I propose to name Linuparus atavus, spec. nov. The two specimens of the Princeton Museum, both males, were collected by Mr. H. F. Wells in the Niobrara group (Upper Cretaceous) at the head of Cotton-Wood Creek, Mead Co., South Dakota. They were broken into numerous pieces, but have been put together again very skilfully by Mr. Gidley. The matrix being extremely hard, it was deemed dangerous to try to work out some parts of the body more completely ; thus some parts in either specimen are still imbedded in the matrix: but luckily the speeimens supplement each other in an admira- ble manner, so as to leave only a few details of minor import- ance unknown. See figures 1-4, p. 297. MEASUREMENTS. Of larger specimen (a). From anterior frontal margin to hinder lateral corner of a IR I NEL Sell SO. q Rm Length of 4 posterior abdominal segments+telson (hinder | part of the latter imbedded in the matrix)... ........ 77 Length of the three free basal joints of the antennz (outer BER uch ente DUE no o Sy ele oe tl lee 6100 ERRA Bontal margins==.m=== 2000200 >0mes0 02000: by 38 Enstanees between the frontal horns, 2:_ --:....--- ---- -2==- - 8 Eu sih. or carapace, posterior end... -.-- --.- .ı- ------=-- 36 Of smaller specimen (b). Msn eiapace = yop 2... A eo rele GOR Length of 4 anterior abdominal segments.._-.--- ------ -- 31 Allowing, in the larger specimen, for the first two abdom- inal segments one and a half of the length of the third seg- ment (14"®), the approximate total length of the body would Bell Tan, * This intermediate shape of the frontal horns settles the question, whether the triangular frontal processes of Linuparus are a bilobed rostrum (as de Haan be- lieves) or the homologues of the frontal horns found in other genera of Palinuride. They are frontal horns. 294 Ortmann— Linuparus atavus. Specimen (a) shows beautifully the frontal margin, the seg- ment of the antennule, the stalks of the antenna and parts of the flagella, the basal joints of the antennule, the epistoma, and the hinder part of the abdomen. The upper surface of the carapace is much crushed, and the place of the sternum is occupied by a large hole. Of the abdomen, the four last abdominal segments and the telson are present ; of the first and second segments only a few pieces are recognizable. In speci- men (6) the upper surface of the carapace is nearly complete, there is only a hole occupying the gastrical region and a few smaller ones; the frontal horns are better than in the first specimen. The anterior part of the abdomen and the sternum are complete in specimen (4), but the anterior part of the body (beyond the frontal margin) is imbedded in the matrix, and the posterior part of the abdomen is wholly absent. Parts of the max- illipeds, pereiopods, and pleopods are visible in both specimens. Description. — Carapace nearly rectangular in outline. Frontal margin truncate, nearly straight, connected with the segment of the antennul® on both sides of the eyes. Frontal horns approaching each other, compressed, but diverging from the bases outward, their anterior margin with a few small teeth, no median rostral spine being visible. Antero-lateral angles formed by spines. Cervical groove distinct. Anterior part of carapace (in front of the cervical groove) with two spines just behind the frontal horns, which are a little more distant from - each other than the latter, and with three tubercles forming a triangle. A curved, longitudinal series of three spines between the median line and the lateral margins. Hinder part of cara- pace tricarinate, each keel bearing a number of small spines. Otherwise the surface of the carapace is only granulate and punctate. (The arrangement of the spines on the anterior part is very like to that of the living Linuparus!) Abdominal segments in the median line provided with short, conical spines. (Similar spines are found in Linuparus tri- gonus on the anterior segments, but are wholly wanting in all other genera of Palinurid&, except in one species of Puerulus: here, however, they are of a different character!) The first segment has only one spine, the second has two simple spines, on the third segment the posterior one is provided, in specimen (a) with one, in specimen (0) with two additional tubercles, one behind the other. The fourth segment has two double- spined tubercles; the tips of the spines are placed one behind the other. The fifth segment has two simple spiniform tubercles. On the sixth segment, however, are two low double spines, placed side by side each near the median line, and on the posterior margin are two small spines placed close to the median line. The segments from the second to the fifth have each two sharp tubercles on each lateral part; the sixth has only one. The epimera are spined on the margins, but the Ortmann— Linuparus atavus. 295 exact number of the spines cannot be determined. Each abdominal segment has a transverse furrow passing across the back between the anterior and the posterior median spines ; these furrows are very distinct on the second, third and fourth segments, while they are obsolete on the first, fifth and sixth. Of the telson only a small part of the anterior portion is exposed; the posterior end, which was probably—as usual in this family—soft, is imbedded in the hard matrix. The segment of the antennule is very like that of Palinurus or Linuparus. It is narrow, elongate-triangular ; the lateral borders form a blunt, elevated ridge. The epistoma has a deep median longitudinal furrow, which is bordered anteriorly by a strongly elevated, oblong tubercle on both sides. The phyma- cerite (opening of the green gland) is visible only on the left side of specimen (a). The sternum, exposed beautifully in specimen (0), is elongate-triangular in outline. The lateral borders have three spiniform tubercles near the insertions of the second, third and fourth pereiopods, and a similar median tubercle a little in advance of the level of insertion of the fifth pereiopods. Of the antennule only parts of the basal joint are preserved. The antenne show the stont and enlarged form usual in the family. The stems have three free joints, the basal one being greatly enlarged and dilated on the inner margin, thus form- ing, with the segment of the antennule, that peculiar “stridu- lating apparatus” found in the genera of group 2 and 3 of the family. The two other basal joints of the antenna are nar- rower than the basal one, but still large and powerful. All three joints are furnished with a number of smaller and larger spines. Of the flagella only a couple of fragments are pre- served, but these show a very peculiar feature only found, among the living genera, in Linuparus: there exists dorsally and ventrally a distinct longitudinal furrow, so as to render the cross section oval with a constriction in the middle. Of the mouth parts, traces of the strong and powerful man- dibles are seen in specimen (a), of the second maxillipeds in specimen (4), and of the third maxillipeds in both. Of the latter the distal joints, carpus, propodus, and dactylus, are broken away. The interior margin of ischium and merus is spiny. No traces of an exopodite have been discovered, but it is probable that it is broken away or still imbedded in the matrix. Of the pereiopods (thoracic legs) the first seems to be the stoutest, the second the longest. In specimen (0) all the joints of the latter are preserved on the right side (but partly cov- ered by the matrix). The dactylus reaches as far as the end of the stalks of the antenne, and it is long and slender. The dactylus of the first periopods is nowhere visible, but in both specimens the propodus of the left sides, showing plainly that 296 Ortmann— Linuparus atavus. no chele were developed, as required by the diagnosis of the family. The following pairs of pereiopods decrease in size and thickness. The fifth pair shows plainly in both specimens the male sexual opening. The distal parts from the merus onward are not present in the fifth pair. Traces of abdominal appendages (pleopods) are discernable in both specimens; the right one of the fourth segment in specimen (q) is the best preserved, consisting of an oval plate, which is finely striated. Sexual appendages are wanting. Thus we see that the position of this fossil form with the genus Linuparus is warranted not only by the tricarinate cara- pace, but also by other characters of minor importance, such as the distribution of spines on the carapace, the armature of the abdomen (which in its general plan is exactly like that of Linuparus trigonus, and differs from Palinurus as well as from the other genera of the family), and the peculiar shape of the flagella of. the antenne. Only the frontal horns differ from those of the living species, but, as I have shown above, they are intermediate between that species and the condition seen in Palinurus, and this difference should be regarded as of only specific value: I do not think the shape of the frontal horns justifies the creation of a new genus, and this would be the only way left, if we do not wish to unite this fossil generically with the living Japanese species. Altogether, there is no-doubt that the fossil described above is the nearest relation of the living Linuparus trigonus, none of the other living species coming so near to that Japanese Crustacean. This fact is extremely interesting, since it proves that the genus Linuparus only slightly modified existed as far back as the Upper Cretaceous time, and, indeed, one might be induced to regard Linuparus atavus as the direct ancestor of . the living species. In conclusion, this new fossil gives a hint as to the origin of the geogr aphical range of the genus Linuparus. Linuparus is not--as might be supposed from its present exclusive distribu- tion in the Japanese seas—a form_indigenous to that part of the world: the Japanese seas are not the “ center of origin” of this genus, but the living species is to be regarded as the only “reliet” left from a former wider distribution. Probably this genus (like most of the other Mesozoic marine animals) possessed formerly a more or less cosmopolitan distribution, but it has been restricted gradually, and the only remnant left at the present time is the Japanese Zinuparus trigonus, which is to be regarded, accordingly, as a very ancient type among the living Decapods. Princeton University, February, 1897. win) pu! My PO yy yy ’ ty) " == == 7 == == yu N N MR EXPLANATION OF FIGURES. Linuparus atavus. FIGURE 1.— Upper view of larger specimen. 4 nat. size. (Some details of struc- ture of the carapace are supplemented from the smaller specimen.) FIGURE 2.— Frontal parts of carapace and base of antenn&, viewed from above, - and showing stridulating apparatus. Nat. size (large specimen). FIGURE 3.—do., viewed from below. Nat. size —a. Longitudinal groove, divid- ing the epistoma; b. Phymacerite; c. Basal joints of antennule. FIGURE 4.—Linuparus trigonus (dH.), living Japanese form, the same parts as in fig. 3, copied from the ‘‘ Fauna Japonica’ for comparison. size. 4 nat. e Wy ) da We Ltd, i E a 4 ee... a US AS) REVISTA “po Museu PAULISTA, N. II, 1897 A BR, a POR Dr. Arnold E. Ortmann RR EM PRINCETON N. J., U.S. A. No presente trabalho tentamos classificar de modo “claro os camarões da agua doce da America do Sul, (1) a “até agora conhecidos, tratando principalmente da possi- “bilidade de uma classificação d'estas- fórmas, feita com E — segurança e promptidão. | Br: E de eer que nossos conhecimentos systematicos é E. rea haja especies. ainda não encontradas, e além es fórmas ainda não descriptas de maneira eh pans, lacunas consideraveis: não conhecemos ponte a an geographica das diversas förmas, Bios. distribuição. Mo de tudo, a ee s de quasi toda noticia sobre as condições bionomicas Re Ro é sóa #. Müller que devemos informações a) Essa denominação geographica comprehende aqui tambem — notar que estes territorios, em relação 4 fauna dos crustaceos da “agua doce, não een ser vennledos da America do Sul propria- m nte dita. | America Central e as ilhas das Indias Occidentaes, convindo — Ace, ee | Fr SE CE. TEN el ny So AA A classificação systematica seguinte trata principal- mente das fórmas «bem conhecidas», (2) isto é, das fórmas cujos caracteres ja estudados permittem distinguil-as com segurança de todas as outras especies do mesmo genero, apresentando-se assim a base apropriada para mais amplos estudos. cujo primeiro fim seria a tentativa de explicar as fórmas «duvidosas». Quanto a estas ultimas, citei-as adduzindo pelo menos as necessarias Informações litterarias. E’ de presumir, que na America do Sul haja tambem algumas novas especies scientificamente ainda não conhecidas; descrevel-as e comparal-as com as espe- cies já conhecidas será tarefa de trabalhos posteriores. EK’ muito desejavel que se descreva todas as novas espe- cies comparando-as com as conhecidas, o que se fará. melhor apresentando uma tabella, destacando-se assim mais distinctamente os caracteres especificos. E” só por este methodo que auctores e monographos posteriores poderão formar opinião sobre uma especie sem ser obri- gados a estudar exemplares originaes. Até agora a tal - requisito, por mais natural e indispensavel que seja, em muitos casos infelizmente não se tem satisfeito, contentan- do-se muitos auctores em ter estabelecido para suas novas fórmas uma «diagnose» que não passa de uma descripção, insufficiente, abreviada e que muitas vezes não é compara- vel ás diagnoses de especies aparentadas. Demais lia aucto- res que no estabelecimento de novas especies muitas vezes seguem o methodo de dar uma descripção muito éxacta e minuciosa, preciosa sem duvida, em geral, mas dispen- savel muitas vezes para grupos bem conhecidos. | Fatiga procurar n'uma descripcao tão extensa. ps sa caracteres essenciaes frequentemente occultos. Comtudo é natural que a este ultimo methodo de descrever espe- (2) Em geral estas sao formas que eu tambem conheço bem _ e cujos exemplares foram examinados por mim e comparados | entre si. Em alguns casos, porém, ainda não cheguei a estudar |. representantes de certas especies 0 ave: me obrigou a recorrer - então só 4 respectiva litteratura. — 175 — cies caiba a preferencia, desde que se trate de grupos _ pouco estudados e, quanto á classificação, duvidosos, — havendo então mais esperança de não omittir-se nenhum “dos caracteristicos que por trabalhos monographicos pos- _ teriores se manifestarem como importantes para a dis- | tingezo das especies. E E preciso lembrar que a descripção de novas especies 4 “não póde mais ser o principal fim do estudo da fauna 4 — da agua doce da America do Sul; ao contrario, seria “muito proveitoso que não en outras formas além 2 das conhecidas. Mas como não é de suppör que assim. E 2 succeda, devemos primeiro procurar conhecer perfeita- x mente o verdadeiro conjuncto da fauna para ter uma _ base que nos permitta comprehender a origem e o des- "envolvimento da fauna da agua d-ce da America do Sul. 4 - E’ claro, porém, que isso exige estudos muito mais serios e que além da verdadeira distribuição geographica (cho- rag devemos tambem tomar em consideracäo a ma- | meira pela qual as diversas fórmas se apresentam em “vista das condições physicas de existencia as quaes in- fluem na distribuição dos animaes, assim como seus habitos > de vida eantes de tudo sua historia geologica. Faltando É finda quasi totalmente taes estudos sobre os grupos dé “animaes dos quaes trataremus aqui, qualquer trabalho, | Ee por mais modesto, sobre os crustaceos da agua doce da z America do Sul, pide um dia tornar-se precioso. | 4 Na America do Sul (com inclusão das Antilhas e da “America Central) encontram-se camarões de agua doce de duas familias differentes: dos Atyidae e dos Palaemo- ag aes pertencentes 4 divisäo dos Zucyphidea (3). Para (3) Veja-se ‘Ortmann: Das System der Decapoden—Krebse in : TES Jahrb. Abt. f. Syst. v. 9. 1896 p. 409-453.—Os Eucyphidea es correspondem ao antigo grupo dos Caridae («Garneelen>) com exclusão o Penaeidea. & Br comprehender a posicäo systematica e as relacöes de parentesco note-se o seguinte. O tronco dos Decapodes divide-se em dous grandes grupos: os Nalanlıa e os Reptantia, classificados em sub-ordens e separados uns dos outros já muito cedo, certamente ja no periodo ju- rassico. E’ de suppör que os ultimos tenham derivado dos primeiros, desenvolvendo-se depois cada um d'esses ramos principaes isoladamente. Os Natantia hoje são representados por tres divisões : os Penacidea, os Steno- pidea e os Hucyphidea, dos quaes os dous primeiros se. têm afastado menos dos typos primitivos, ao passo que os Zucyphidea se tem desenvolvido mais divergentemente, ainda que alguma das suas familias se juntem estreita- mente aos Penaeidea. A (familia da agua doce tropical) dos Atyidae é grupo primitivo entre os Zucyphidea : acham-se seus proximos par ntes na familia dos Acan- thephyridae, limitados 4s zonas mais profundas do mar, talvez a mais primitiva de todas as familias actuaes dos Eucyphidea. Os Palaemonidae, ao contrario, collocam-se na extremidade de um dos ramos mais extremos dos Zu- cyphidea, representando uma familia muito moderna, da qual muitas fórmas vivem no mar perto do littoral e só poucos generos, em parte, todavia, em grande numeró de especies, emigraram para a agua doce dos tropicos.. Evidente é que estes são um augmento novissimo e que a fauna da agua doce obteve só nos ultimos periodos geo- logicos, sendo até possivel que em nossos dias estejamos ainda no meio do periodo da immigracäo d'estas fórmas na agua doce. | A segunda sub-ordem dos Decapodes, os Reptantia, compõe-se d'uma parte dos antigos Macruros (excluindo os antigos Caridae e os Stenopidea), dos Anomuros e dos Brachyuros. Conforme ás differenças na edade phylogenetica e geologica as duas familias de camarões que tem repre- sentantes na America do Sul differem a fundo nos traços “principaes de sua distribuição geographica. E' verdade WEIT SS DR RS qe eee BEN ER BE, ; > as RE: ou A > E d E 2 é KR o 2 ‘J — 177 — que ambas as familias säo grupos verdadeiramente tro- picaes, mas os Atyidae, de accordo com a sua edade “consideravel, apresentam na sua distribuição particulari- dades notaveis, ao passo que a distribuição dos Palae- monidae, immigrantes muito modernos, chegados do lit- toral ás regiões da agua doce, se mostra ainda estreita- mente ligada ás condições zoologico-geographicas que dominam no littoral. Seria demais entrar aqui na materia d'este capitulo interessante ; quanto ä distribuição d’estas “duas familias, refiro-me a meus anteriores trabalhos monographicos (4). Mais abaixo, porém, em poucas pala- vras farei ainda uma menção dos factos da distribuição mais importantes. | A tabella seguinte póde servir a quem procurar distinguir facilmente dos outros Decapodes estas duas familias de crustaceos pertencentes á fauna da agua doce da America do Sul. Note-se porém que n'esta tabella figuram só os caracteristicos principaes e facilmente visiveis, além dos quäes existem tambem outros que se revelam só ao estudo mais exacto. As partes buccaes principalmente (a mandibula, as maxillas e as patas ma- xillares) assim como as branchias (a respeito da fórma e do numero) são muito importantes para a caracterização das divisões principaes dos Decapodes, sujeitam-se porém ao estudo só depois de preparadas com muito trabalho. _E’ por isso que nas tabellas seguintes eu não me referi a estes orgãos sinão em caso de necessidade. a’. A forma do corpo é mais ou menos comprimida, o abdomen bem desenvolvido. O rostro ás mais das vezes é comprimido, munido de dentes na margem superior “assim como na inferior, faltando raramente os dentes. O primeiro segmento do abdomen não é consideravelmente (4) Veja-se Zoolog. Jahrb. Abt. f. Syst. vol. 5. 1891, p. 744-748. — Proceed. Acad. Nat. Sc. Philadelphia 1894, p. 410-416. Revista do Museu Paulista 12 — 178 — menor do que os outros. As partes lateraes (chamadas epimeros) do segundo segmento do abdomen cobrem tanto as do primeiro como as do terceiro segmento. Das partes thoracicas, chamadas pereiopodes, só os dous primeiros. pares têm tenazes, sendo que estas ou são de igual tama- nho ou as tenazes do segundo par maiores do que as do primeiro. As patas abdominaes, chamadas pleopodes, apresentam um forte tronco com dous appendices « com- . pridos e apropriados para a natação. Divisão : Eucyphidea. bi. Os dous pares de tenazes não são consideravel- mente differentes. Os dedos das tenazes têm na ponta um singular pincel de cabello. Na coxa (5) dos quatro pri- meiros pares de pereiopodes acha-se uma mastigobran- chia rudimentar, chamada epipodite (6). As antennas in- teriores apresentam dous appendices filiformes terminaes. Familia : Atyidae. b. O segundo par de tenazes é sempre mais com- prido e äs mais das vezes tambem consideravelmente mais forte do que o primeiro. Os dedos das tenazes nao apresentam pinceis de cabellos na ponta. As coxas dos quatro primeiros pares de pcereiopodes não têm epipodites. As antennas interiores pu tres appendices fili- formes terminaes. Familia : Palaemonidae. a. A forma do corpo não é comprimida ; “não falta o abdomen que é bem desenvolvido ou reduzido e ver- Ed (5) Cada pata compõe-se de sete segmentos que começando da base até á extremidade são designados pelos nomes seguintes : coxa, base, ischium, mero, carpo, propodus, dactylus. _ (6) E” este um appendice curto, rectilineo, situado no lado. exterior do segmento e que se dirige de diante para traz. E’ o ultimo resto das mastigobranchias as quaes em outros re se extendem ainda até para dentro da cavidade branchial. aad UV “ER BA ad 4 3 e ae tel + 5 ur er TA do a DAN TB I Th TE s 4 ces RR | a ee Mere Sh Eee e go RS i EE ae Re SR dt ze E sy pe q E y í ¢ EHE va 5 . kr Fu i a E à Pere, \ Ba 4 - gado sob o sterno. O primeiro segmento do abdomen 4 _ é visivelmente menor (mais estreito) do que os outros; 4 À “seus epimeros não são cobertos pelos do segundo. Tres, “dous ou um dos pares de pereiopodes tem. tenazes, achan- a do-se raramente um par que não as tenha; mas cada = vez que se encontra mais de um par de tendes, as do primeiro são muito mais fortes do que as outras. As patas Es -abdominaes não são apropriadas para a natação. Sub-ordem : Reptantia. DO Familia ; ATYIDAE Kingsley. Sos Diagnose: a mandibula é forte, larga, indistincta- Es. “mente bipartida, sem synaphipode (palpo). Os quatro - - primeiros pares de pereiopodes apresentam epipodites. Os. _ dous primeiros pares de pereiopodes têm tenazes, são quasi de igual fórma; o carpo do segundo par não é arti- _ culado (7). As pontas das tenazes apresentam singulares — pinceis de cabellos. O rostro varia de comprimento, sendo _ munido de dentes ou sem dentes. Os Atyidae representam provavelmente uma velha “familia da agua doce espalhada pelos tropicos de todo o mundo. Nenhum dos generos americanos limita-se a este — continente, mas todos os quatro encontram-se tambem - em outras partes do mundo. O genero Xiphocaris possue > “ainda uma outra especie, talvez duas, na Asia Oriental “e na Australia. O genero Cariding chega a seu desenvol- = “vimento principal nos tropicos do velho mundo, antes - de tudo no archipelago indo-malaio. O genero Atyoida é representado por uma nova especie nas ilhas Sandwich — eem Tahiti. O genero Atya pre duas ou tres especies ma Indo-Malasia e nas ilhas pacificas. Outros dous a = (7) Ha de Eueyphidea que apresentam este segmento „Aiyigide em certo numero de pecas ae — 180 — “que não são americanos acham-se, sendo representados por uma especie cada um, como relictos muito singula- res na Europa do Sul. E’ muito provavel que justamente d'essa familia seja possivel encontrar ainda novas especies na America do Sul, principalmente dos generos Xiphocaris, Caridina e | Atyoida, comprehendendo estes todos só formas menores, de poucos centimentros de comprimento, que facilmente | escapam á vista. E’ de suppör que a especie Atyoida “potimirim, attribuido até agora a uma só localidade, "esteja mais espalhado. Outras fórmas são Atya gabonensis e crassa, que representam os gigantes da familia e cujo corpo tem um ou dous decimetros de compri- mento ; informações sobre estas formas seriam acolhi- das com satisfação: não se omitta, porém, a possibili- dade de serem estas fórmas velhos exemplares de Atya scabra. } E’ certo que todos os Atyidae se limitam á agua doce. Ha só poucas especies de Caridina indo-malaias encontradas tambem na agua salobra. N’isso, porém, reve- lam-se com certeza adaptações secundarias, visto como | as mesmas especies vivem tambem na agua doce. Fal- tam-nos informações sobre o desenvolvimento, o modo de vida, o alimento etc. 4 excepção de Atyoida potimirim, sobre o qual 7. Müller publicou uma serie de noticias. Quadro synoptico dos generos americanos dos Alyidae. a'. Em todos os pereiopodes o segundo segmento tem ; um exopodite (8). Os segmentos do carpo dos dous pri- meiros pares de pereiopodes não são excavados na extre-. midade distal ou são excavados só indistinctamente. O rostro é bem desenvolvido e munido de dentes. (8) Este expodite corresponde ao ramo exterior das «patas. bipartidas», que caracterizam por exemplo os Schizopodes. E’ este | “um característico muito primitivo que se tem conservado ainda . só em poucos Decapodes. eg Genero - Xiphocaris. Os pereiopodes não tem exopodites. P “O segmento do carpo dos primeiros pereiopodes — é aes na cos ARO distal, não sendo excavado o dos segundos peretopodes. (fig. 6). O rostro é comprido e na especie ee munido de dentes só na margem = ‚inferior. at | Genero : Caridina. 4 | Br 0s segmentos carpaes dos primeiros e dos segun- e “dos x säo se BRE na extremidade distal. O a Be e. O dedo pe ae tenaz é mais curto do que a ER parte immovel da mão (9),a ultima distinctamente divi- “di Rs n'uma ae palmar e um dedo immovel (fig.2e3). en k Be _ Genero : Atyoida. “Ambos os dedos são de igual tamanho articu- a um com o outro na sua extremidade posterior. 3 Nenhuma das partes palmares é desenvolvida (fig. 4). a E Re sper É Genero: Atya. = E = 4, “Genero: Xiphocaris v. Martens. 5 pa de Haan, Miersia Kingsley, el Miers. ER “Xiphocaris elongata (Guérin). | E — Bippolyte ee en Anim. Artic. em: de la E Bechkoeus americanus CESPE: Mem. Soc. PR E Nat. Ro vol, 14, 2. 1858, p. 472, E 4, fig. 31. do movel é o un o immovel é o din do Drobo e Ihe & opposto. A parte basal do propodus, na qual se insere Regio e é a DIR, BET, — 182 — Xiphocaris elongata, gladiator, var. intermedia, brevi- rostris Pocock, Annal. Magaz. Nat. Hist. (6) vol. 4, 1889. p..17 E plot 98. Xiphocaris elongata (Guér.) Ortmann, Proceed. Acad. Nat. Sci. Philadelphia. 1894, p. 400. | Diagnose : Faltam os espinhos supraoculares. O ros- | tro varia de comprimento, sendo mais curto do que os troncos das antennas interiores e às vezes mais comprido o que todo o cephalothorax. A margem superior apre- senta uma serie interrompida de dentes em fórma de serra, com 9 a 18 dentes sobre a base e 3 a 6 diante da. ponta, havendo 16 a 40 dentes na margem inferior. Pocock distinguiu tres especies e uma variedade, as quaes, porém, se caracterizam todas só pelo comprimento ' do rostro. Visto como estas suppostas especies vêm | todas da mesma localidade e no comprimento do rostro, começando de elongata até brevirostris, apresentam todas as gradações, é de suppör que ellas não passem de va- riações de uma só especie. Até agora esta especie foi encontrada só na agua doce das Antilhas (Cuba, Haiti, Dominica). | 2, Genero: Caridina ki à Caridina americana Guérin. | Guerin, 1. c. 1857, p. 52, pl. 2, fig. 13. — Pocock, lie. 1889, p. 16, pl. 2; fig. 3. Diagnose : A malen anterior do cephalothorax tem um espinho na altura das antennas exteriores. A margem . superior do rostro não apresenta dentes. O segmento carpal dos primeiros pereiopodes é só pouco Ro com- prido do que largo. Essa especie, espalhada nas ilhas de Cuba e de “Doc -minica, ainda não foi estudada com bastante exactidão, estando principalmente por constatar mais exactamente suas differencas de Caridina typus M. E. (veja-se Ort- mann, 1. c. p. 401) encontrada nas ilhas do Oceano Indico, “na Indo-China e na Indo-Malasia. NA 4 é E ai dio A e SR A JAR EN 183 —- Uma especie duvidosá é Caridina mexicana Saussure (l. ec. 1858, p." 463, pl. 4, fig. 26) encontrada no Mexico, talvez uma Atya de edade juvenil. 3. Genero: Atyoida Randall. Atyoida potimirim F. Müller. Estampa I, fig. 1—3. Arch. Mus. Nacion. Rio de Janeiro v. 8, 1892, p. 155 7 91.9.1); Diagnose: O rostro é curto, munido de dentes na margem inferior. O segmento carpal dos primeiros pereio- podes é mais comprido do que largo. Encontra-se essa especie em alguns lugares do Brazil: em Itajahy e perto de São Sebastião. Da ultima localidade mandou-me o Dr. von Ihering um exemplar pescado no mar; é possivel que elle só por acaso tenha entrado na agua salgada. Kingsley (Proc. Acad. Nat. Sei. Philadelphia 1878, p. 93) descreve uma Atyoida glabra da Nicaragua, talvez “uma Atya de edade juvenil. 4., Genero: Atya Leach. Tabella das especies de americanas Atya : a. O rostro é mais curto do que os troncos das antennas interiores, carece de dentes ou espinhos na margem superior, apresenta, porém, de cada lado uma quilha que termina para diante n'um curto espinho. b' O cephalothorax não é esculpturado, é lizo ou “um pouco escabroso. O terceiro par de pereiopodes não tem espinho na margem inferior do mero. A. scabra. b. O cephalothorax, principalmente na frente, é “fortemente esculpturado de listras e covas. O terceiro par EP SI q ge ERES ad O pa ra N, a mn N ve co OF N A ha ” ; + a — 184 — de patas tem um forte espinho na margem inferior do mero (10). A. gabonensis. o a. O rostro é tão comprido como as escamas anten- naes, a margem superior tem 6 a 8 espinhos. A parte anterior do cephalothorax apresenta grande numero de espinhos e quilhas espinhosas. A. (Evatya) crassa. Conhecemos individuos de Atya scabra de cerca de dez centimetros de tamanho, ao passo que gabonensis e crassa, principalmente a ultima, excedem essa medida consideravelmente. Das ultimas especies têm sido encon- trados até hoje só exemplares d’este tamanho considera- vel: não seria impossivel que não fossem outra cousa sinão individuos mais ou menos adultos da especie scabra. Atya scabra Leach. Atya scabra Leach, Zoolog. Miscell. 3, 1817, p. 29, pl. 131.—Melne-Ednards, Hist. Nat. Crust. vol. 2, 1837, p. 942, pl. 24, fig. 15—19. Especies synonymas: A. mexicana Wiegmann, 4° “sulcatipes Newport, A. occidentalis Newport, A. rivalis Smith, A. tenella Smith, A. punctata Kingsley. Veja-se as allegações mais exactas em Ortmann, Proceed. Acad. Nat. Sci. Philadelphia 1894, p. 409. | Diagnose : O rostro, mais curto do que os troncos das antennas interiores, apresenta de cada lado uma qui- lha lateral que termina para diante n'um espinho agudo, (10) Em outras especies, encontradas na Indo-Malasia acha-se bem desenvolvido esse espinho só no adulto macho, sendo muito provavel que elle falte tambem aos individuos novos de gabonensis. Dado o caso de não ser desenvolvida tambem a esculptura do cephalothorax, taes exemplares novos de gabonensis seriam, sem duvida, identicos aos de scabra. — 185 — “sendo no mais despido de espinhos. O cephalothorax é lizo, ponteado ou um pouco escabroso, mas não tem qui- lhas nem tuberculos ou espinhos. O terceiro par de pereio- podes, nos individuos novos, não differe visivelmente do quarto e do quinto, nos individuos adultos, porém, mostra-se muito mais forte e coberto de numerosos espi- nhos. A margem inferior do mero carece sempre de um espinho de tamanho consideravel. A. Milne-Edwards menciona duas especies da Nova Caledonia : A. margaritacea e robusta, as quaes, segundo diz, no primeiro e no segundo par de pereiopodes possuem meros cobertos de pellos. Mas 4 Atya scabra tambem “parece não faltar esse caracter, sendo possivel que aquellas “duas especies sejam identicas 4 ultima e a Nova Caledonia erradamente mencionada como ar onde foram encon- tradas. A especie Atya scabra Leach está espalhada na America Central (Mexico, Nicaragua) e nas Antilhas (Cuba, Haiti, Jamaica, Dominica, Martinica, Tobago), sendo possivel que se encontre tambem no continente sul-americano. ' Acha-se tambem nas ilhas de Cabo Verde (São Nicoläo, São Yago) pertencendo por conseguinte ao numero das fórmas da agua doce que existem tanto na America como nas costas occidentaes da Africa. Atya gabonensis Giebel. 2 Atya gabonensis Giebel, Zeitschr. f. d. gesamt, Naturw. pee), vol. 1L, 1875, p. 52. + Evatya sculptilis Kölbel, Sitz. Ber. Akad. Wiss. wien wor. 90, 1, 1884, p. 917, pl. 2, De. 8, pl. 3. Atya sculptata Ortmann, un Jahrb. Syst. vol. 5, “1890, p. 465. Essa especie distingue- se da precedente pelo tamanho que é mais consideravel, pelo cephalothorax esculpturado na parte anterior com quilhas e tuberculos irregulares, assim como pelo forte espinho na margem inferior do — 186 — mero dos terceiros pereiopodes. E’ possivel que essa especie só represente os individuos adultos da prece- dente. so Pelo que sabemos com segurança a Atya gabonensis até hoje foi encontrada só no Orinoco e no Gabon, rio da Africa Occidental. Atya crassa Smith. 2, e 3, Rep. Peabody Acad. Sci. 1871, p. 95. Diagnose : Essa especie distingue-se de todas as ou- tras do genero pelo rostro tão comprido como as escamas antennaes e munido na margem superior de 6 a 8 espi- . nhos. No mais é muito parecida com Atya gabonensis, tendo, porém, a esculptura do cephalothorax ainda — mais fortemente pronunciada e augmentada com espinhos pequenos. | Seria muito interessante ter mais informações sobre essa especie raramente encontrada para a qual Smith “estabeleceu um genero especial (Zvatya). Atya crassa está espalhada na Nicaragua e no Mexico (Presidio). | Uma especie duvidosa é Atya poeyi Guérin (1. c. 1857, p. 46, pl. 2, fig. 7), a qual, segundo dizem,-se encontra em Cuba e só representa provavelmente a fórma juvenil da especie ordinaria das Indias Occidentaes. | Familia : PALAEMONIDAE Bate. Diagnose: A mandibula é profundamente bipartida, quasi sempre munida d’um synaphipode (palpus). As terceiras patas maxillares têm a forma de pernas, sendo cylindricas, não foliaceas. Os dous primeiros pares de pereiopodes têm tenazes, sendo o segundo distincto e. muitas vezes consideravelmente mais forte e comprido RET) PIER eee es — 187 — do que o primeiro. O carpo do segundo par não é | articulado. Em todos os pereiopodes faltam os epipodites. As antennas interiores apresentam tres appendices fili- formes terminaes, dividindo-se o appendice exterior em "duas partes ás vezes ainda reunidas na base. O rostro "| é sempre comprimido, forte e munido de dentes. Ki ; an yo: £ 7 1 E _ Essa familiacomprehende formas marinhas assim como __ fórmas de agua salobra e de agua doce. Essencialmente pos. “marinhos são os generos Zeander e Palaemonella. Um ge- nero, Palaemonetes, acha-se não só no mar, mas tambem 'na agua salobra e na agua doce, dando-se o mesmo tam- Se “bem com Palaemon, o qual, porém, só excepcionalmente E se tem encontrado na agua meramente salgada; está espa- “lhado principalmente na agua doce assim como o genero . — Bithgnis. A 5 E "Destes generos Palaemonella e ado ainda : näo foram verificados como pertencentes á America do Sul, o que nos permitte deixal-os de lado aqui. Achan- do-se, porém, Zeander no mar perto da costa brazileira ‘meridional e encontrando-se ás vezes no mar tambem algumas fórmas de Palaemon, julgo necessario incluir Leander na tabella seguinte, para que se torne possivel. E beter, à primeira vista, com segurança, das formas de Leander verdadeiramente marinhas os exemplares de | — Palaemon talvez por acaso encontrados na agua salgada. Do Palaemon e Bithynis são parentes muito chegados. - Limita-se Bithynis ao lado occidental da America do Sul, — ao passo que Palaemon se encontra tanto na America, - do lado oriental dos Andes (11), como em toda a parte ame do velho mundo (na Africa, na Asia meridional, nd, catia nas ilhas pacificas). EK’ digno de nota que (11) Ha an especies que em certos lugares se encontram do lado pacifico dos Andes; como, ‚porem, estão mais espa- — lhadas a E’ste dos Andes, é ‘de presumir que ellas, atravessando a montanha, tenham transmigrado para o lado occidental. — 188 — as especies indo-pacificas (da Africa Oriental até as ilhas pacificas) sejam differentes das da America Oriental, ao passo que todas as especies de Palaemon da Africa Oceiden- tal até hoje conhecidas ou são identicas ás da America Oriental ou parentes muito chegadas destas. O territorio indo-pacifico (12) é extraordinariamente rico em fórmas; na America Oriental o numero das cspecies mostra-se: talvez um pouco mais limitado, mas comtudo ainda con- sideravel. Em geral, na America esse genero não se- encontra a Oeste dos Andes, sendo representado no declive pacifico d'esta montanha (no Chile, no Perú) por Bithynis. Para o Sul o genero não passa do territorio brazileiro (só perto do littoral o limite é conhecido um pouco mais exactamente), para 0 Norte extende-se até ao Mexico e ä Cuba, achando-se tambem na America do Norte, no territorio do Mississippi. Encontram-se exemplares de Palaemon dentro dos. tropicos nos arroios das montanhas, em todos os rios, nos estuarios, nas lagoas do littoral, na agua salobra e até na agua meramente salgada (13). Em cada um d'estes lugares diferentes, porém, não se acha sempre uma só especie: ainda que algumas, ao que parece, prefiram a visi- nhança do littoral e a agua salobra, outras habitam igualmente vastos territorios fluviaes desde a embocadura até ás regiões das nascentes. Não conhecemos as causas d'essa estranha distribuição duma mesma especie nem mesmo sabemos, se essas especies ficam permanentemente no territorio superior ou no inferior do rio ou fazem, em certos tempos, talvez na epoca da propagação. migrações subindo ou descendo o rio. O que é certo é, que certas (12) Considerado como região zoologico- geographica, RR ee, rio indo-pacifico pertence ao littoral marinho. Estabelecer das fórmas da agua doce um «territorio indo-pacifico» é cousa que só é admittida em vista do facto de ligar-se a distribuição d’estas fórmas de modo extraordinario á distribuição das formas indo- . pacificas do littoral. (13) Os ultimos casos däo-se raramente. — Veja-se Ortmann, | ‘Decapod. e Schizopoden der Plankton— Expedition. 1893, P- 48. Mee pe ze eee RESP a is e a E a a ARO a Pe & DRA, PL E inda ds BER ; ; 4 FA 89 a “especies demoram > permanentemente na agua doce (14): tanto mais estranheza porém causa o facto do que outras + “56 “encontrem perto do mar e no proprio mar. E As especies do genero Palaemon, por causa do tama- E - nhoaque attingem (é este de cerca de 100 a 200 "= sem contar as tenazes), representam nas diversas regiões um Re artigo de mercado importante e chegam em certos lugares = E E eßnlatnente ao mercado de peixes (na America do Sul o ee. por exemplo no Rio de Janeiro e no Pará). Não seria “ impossivel que dos pescadores se pudesse obter informa- - ções sobre o modo de vida d'estes camarões. Quanto ás “ informações de tal origem, evidente é, que é preciso sub- “mettel-as a um exame critico rigoroso. Comtudo não quero “deixar de chamar a attenção para esse meio que talvez nos. possibilitará fazer investigações has epocas e nos Bere mais apropriados. Be N nr e 8 Saar Caes dos. generos : | Na margem anterior do cephalothorax acham-se “de cad lado. dous espinhos: um d’elles, chamado espi- ce “nho antennal, na mesma altura das antennas exteriores, Er 0 Outro, RR a branchiostegal, Repara do par de patas 6 só. neues mais forte e somata: do que au Faro: | Ber. Genero: Leander. ng Na margem anterior do cephalothorax ees: Ê de cada lado um só espinho antennal; falta o espinho. _ branchiostegal. O segundo par de patas, no macho adulto. é consideravelmente mais comprido e forte do que o. u 19, a. F. Mite, Archiv. Mus. Ben Rio de Janeiro Ba b!. Ao lado do espinho antennal, collocado para traz e um pouco para baixo, acha-se nas partes lateraes ante- riores do cephalothorax um espinho chamado hepatical (fig. 7 6.11). _ Genero : Palaemon. 6. Falta este espinho hepatical. Genero: Bithynis. 1., Genero : Leander Desmarest. As especies d’este genero, ainda que pela maior parte marinas, entram, muitas vezes nos estuarios, acham-se na agua salobra e até na agua doce. E” justamente uma especie brazileira (potitinga) que pertence ao numero das fórmas da agua doce, e como, além d'esta fórma, até hoje foi descripta ainda uma só especie de Zeander bra- zileira marina, eu entretanto consegui estudar uma segunda especie que é nova, farei no seguinte uma tabella e breve caracterização de todas estas tres especies | de Leander sul-americanas. Estas são de pequeno tama- nho, mas distinguem-se entre si facilmente ja pela forma do rostro. Distinguem-se tambem facilmente das outras fórmas que não são americanas. As antennas interiores. parecem ser de muita importancia para a distincção das especies. E” conhecido que estas têm tres appendices filiformes terminaes («Geisseln»), os dous exteriores d'elles ainda reunidos na base; o numero d'estes segmentos soldados assim como o dos livres do mais curto d’esses dous appendices filiformes é muito variavel nas diversas “especies, parece porém ser constante para cada nma “destas especies. . Tabella das especies. a. O rostro é muito curto, apenas tão comprido como os troncos das antennas interiores. rectilineo, mu- nido emcima de 6 a 7, embaixo de 2 dentes. Os dentes | da margem superior têm igual distancia entre si. 2191. L. brasiliensis. DF a’. O rostro é mais comprido, tão comprido, mais ou menos, como a escama das antennas exteriores, ligei- ramente curvada para cima. 6. Q rostro, na parte basal, é embaixo ne da forma de lanceta. A margem superior apresenta 11, a margem inferior 5 dentes que tem igual distancia entre si. O corpo do segundo par de paias é pouco mais ou menos tão comprido como a palma da tenaz. L. paulensis. b’. O rostro não é alargado na base, rectilineo, estrei- tando-se para a ponta só imperceptivelmente. A margem superior é munida de 7 dentes, dos quaes seis tem igual. distancia entre si na parte basal, seguindo-se depois um trecho sem dentes e a pouca distancia da ponta ainda um dente. A margem inferior apresenta 5 ou 6 dentes. O carpo do segundo par de patas é consideravelmente mais comprido do que toda a tenaz. L. potitinga. Leander brasiliensis Ortmann.—Estamya I. flo. 12. Em: Zoolog. Jahrb. Syst. v. 5, 1890, p. 524, pl. 37, fio. 16. | O rostro & rectilineo e apenas täo comprido como os troncos das antennas interiores. A margem superior é munida de 6 ou 7 dentes que têm igual distancia entre si, estando o u:timo ainda no cephalothorax. A margem inferior apresenta 2 dentes. O segundo par de patas é tão comprido como a escama antennal, 0 carpo um pouco mais comprido do que a tenaz, a tenaz pequena € fraca, 0 dedo mais curto do que a palma, que não é intumecida. Os appendices filiformes terminaes exteriores são soldados em cerca de 9 segmentos; o appendice curto apresenta mais de 20 segments livres. — 192 — Pela curteza do rostro distingue-se esta especie de todos as outras do genero á primeira vista. Encontra-se no Rio Grande do Sul; faltam-me informações mais ex- actas sobre os lugares onde foi encontrada. Leander paulensis nov. spec.—Estampa 1, fig. 14. O rostro e tão comprido como as escamas antennaes, ligeiramente curvado para cima, da fórma de lanceta, na base alargado na margem inferior, estreitando-se depois até à ponta. A margem superior é munida de 11 dentes que têm igual distancia entre si, estando os dous ultimos ainda no cephalothorox. A margem inferior apresenta 5 dentes. O segundo par de patas sobrepuja com a mão a esca- ma antennal. O carpo é mais curto do que a tenaz, mais ou menos tão comprido como a palma. A palma é de forma oval alongada, um pouco intumecida, o dedo del- gado e tão comprido como a palma. Os appendices filiformes terminaes exteriores das antennas interiores são soldados em cerca de 8 segmentos; o appendice curto tem cerca de 12 segmentos livres. Esta especie approxima-se muito de algumas outras que não são brazileiras, principalmente do adspersus européo (veja-se Ortmann, 1890, p. 524) e do af/in.s en- contrado perto de Bermuda, na Australia e na Nova Ze- landia. O carpo porém mais curto, os dentes um pouco mais numerosos do rostro, emcima e embaixo, cheguem talvez para distinguir estas especies á primeira vista. L. adspersus tem nas antennas interiores 9 ou 10 seg- mentos soldados e 14 a 16 livres; Z. affinis apresenta cerca de 10 segmentos soldados e cerca de 14 livres, sendo por tanto pequenas as differenças. Não ha duvida “que todas estas tres especies estão em relaçõo de paren- tesco muito Intimo. Do Dr. von Ihering recebi tres exemplares d'esta especie pescados na agua salgada no canal entre 0 con- tinente e a ilha de São Sebastião (Estado de São Paulo) ] j + a : 3 + idee E Ss i A e a WA af , Es “O maior exemplar, uma femea com ovos, mede da ponta do rostro até 4 extremidade do telson 24 mm, Leander potitinga F. Müller.—Estampa I, fig. 18. Em : Zoolog. Anzeig. 3, 1880, p. 153 (sem descripcäo). O rostro é tão comprido como a escama antennal, distinctamente curvado para cima, rectilineo, não alar- gado na base, estreitando-se para a ponta só pouco a pouco. À margem superior apresenta na parte basal 6 dentes, que têm entre si mais ou menos igual distancia _ achando-se o ultimo ainda no cephalothorax. Segue-se na parte distal da margem superior, um trecho lizo e sem dentes, e immediatameute diante da ponta haainda um dente (raramente ainda um segundo, muito pequeno). A margem inferior é munida de 5 ou 6 dentes, achan- do-se o ultimo em frente do intervallo entre o quarto e o quinto dente basal da margem superior. No macho o segundo par de patas excede com a “tenaz 4 escama antennal, sendo na femea tão comprido, mais ou menos, como esta, esbelto e fraco. O carpo é consideravelmente mais comprido do que toda a tenaz * que mede, pouco mais ou menos, só dous terços do carpo. “A tenaz é fraca, curta e delgada, não mais espessa do “que o carpo, o dedo um pouco mais curto do que a palma. Os appendices filiformes terminaes exteriores das “antennas Interiores têm cerca de 9 segmentos soldados, Ri o appendice Run cerca de 20 segmentos “livres. Do Dr. von Ihering recebi 8 E omplnes d' esta a “especie colligidos pelo Dr. Fritz Müller nas proximidades de Blumenau (Estado de Santa Catharina) na agua doce. _ Refere-se portanto a caracterização acima feita a exem- _ plares authenticos d’esta especie conhecida até agora só _ pelo nome. O maior exemplar (uma femea com ovos) E mede 32." ._ | | Revista do Museu Paulista 13 fa er : ' E, O SS : ee f 27 \ 4 LA 2 é a . — 194 — A principio senti-me levado a crêr que esta supposta especie de Leander, peculiar 4 agua doce, pertencia ao genero Palaemonetes muito semelhante, que é um genero da agua doce e da agua salobra, encontrado na Europa e na America do Norte. Palaemonetes distingue- se de Zeander só pela mandibula a que falta o palpo. Tendo preparado as partes buccaes da especie potitinga achei que o palpo da mandibula é bem desenvolvido, que esta especie, portanto, é um verdadeiro Zeander. Pela fórma do rostro esta especie distingue-se exa- ctamente das outras duas especies brazileiras acima des- criptas. Parece porém approximar-se muito d'ella o Zean- der maculatus Thallwitz (veja-se Abh. Mus. Dresden. N.º 3, 1891, p. 19, pl. 1, fig. 4) da Africa Occidental, possuindo este tambem um segundo par de patas semelhante. Mas o ultimo tem na margem inferior do rostro só 3 dentes e os appendices filiformes terminaes exteriores das an- tennas interiores são soldados em 12 ou 13 segmentos, havendo no appendice curto só 8 segmentos livres: a parte soldada é portanto mais comprida aqui do que a livre o que só se encontra ainda em ZL. squilla dos mares européus. | No territorio indo-pacifico ha algumas especies que apresentam um carpo comprido semelhante no segundo par de patas e um trecho despido de dentes semelhante na parte distal da margem superior do rostro; todas ellas porém têm o rostro distinctamente mais comprido do que a escama antennale na ponta mais decididamente curvado para cima. Ha, porém, ainda grande incerteza sobre as especies indo-pacificas (veja-se Ortmann, Zoolog. Jahrb. v. 5, 1890, p. 515517). | E’ muito provavel que além das especies de Leander aqui mencionadas se encontrem outras mais na Ame- rica do Sul. are PD —:195.— é Genero : Palaemon Fabricius (sens. strict.). E’ muito difficil caracterizar as especies d’este genero. “De um lado, as especies mesmas parecem ser ainda bas- tante variaveis, encontrando-se numerosas fórmas de transição e fórmas locaes intermediarias o que se dá com tantos animaes da agua doce, de maneira que este ge- nero deve considerar-se como um dos chamados «poly- morphos». De outro lado, os carasteres distinctivos não se mostram bem desenvolvidos sinão nos machos adultos. Estes caracteres apparecem principalmente no segundo par das patas com tenazes e é justamente esse par de patas que só nos machos adultos chega a seu desen- volvimento perfeito, ao passo que os exemplares mais _ novos e em parte tambem as femeas apresentam caracter menos decidido. Distinguem-se assim os machos adultos muitas vezes consideravelmente pela formação d'esse par “de extremidades; ás vezes é completamente impossivel classificar exemplares novos das mesmas especies. Ainda - que a fórma do rostro eos dentes d'elle ds vezes apre- sentem caracteres importantes para a classificação, O _ rostro das diversas especies, em geral, não varia tão consideravelmente que n'elle se pudesse buscar uma clas- sificação com segnrança. | Para que se possa classificar especies deste genero, antes de tudo é preciso examinar machos adultos. Visto que as fórmas de edade juvenil muitas vezes têm sido descriptas como especies particulares, muitas vezes será “util ter 4 disposição todas as fórmas possiveis de qual- quer edade e sexo pertencentes á mesma localidade e ä mesma especie, tornando-se então ás vezes possivel clas- sificar taes especies fundadas em fórmas de edade juve- nil. Em geral, o estado dos conhecimentos que agora possuimos. não permitte classificar exemplares novos, principalmente os que vêm de localidades d'onde ainda não recebemos fórmas adultas. — 196 — Na tabella seguinte figuram primeiro as especies que eu proprio pude estudar em machos adultos, depois aquel- las tambem de que ha descripções fundadas no estudo de taes machos os quaes eu, por meio de comparação, pude verificar satisfactoriamente, formando assim uma opi- nião sobre as differenças d'ellas. Já ha annos (15) referi algumas formas de edade juvenil ás fórmas adultas, resta porém certo numero de fórmas qne não posso incluir na lista com segurança ; fiz a tentativa de classifical-as o melhor possivel. Essa tentativa, porém, termina muitas vezes sem resultado satisfactorio e para sempre será impossivel identificar algumas d'essas fórmas. Primeira tabella das especies sul-americanas do genero Palaemon. a‘. As grandes patas com tenazes dos machos adul- tos têm a palma cylindrica, muito raramente fracamente comprimida, sendo porem que no ultimo caso a palma sempre é quatro vezes mais comprida do que larga. A tenaz (mão) não é consideravelmente mais espessa do que o carpo, e toda a fórma do segundo par de patas é quasi cylindrica. A direita tenaz e a esquerda tem ás mais das vezes igual tamanho, sendo raramente uma mais forte do que a outra. b'. O carpo das segundas patas com tenazes é quasi regularmente cylindrico, ás mais das vezes distincta- mente mais comprido do que o mero, raramente (na es-. pecie P. appuni) só um pouco mais comprido ou do mesmo comprimento, nunca porém mais curto. À palma das patas com tenazes é quasi regularmente cylindrica. Sub-genero : Eupalaemon. c'. O carpo, nos exemplares de todas as edades, é distinctamente mais comprido do que o mero. (15) Veja-se Ortmann, Zoolog. Jahrb, v. 5, 1891, P..6932 87, = YO d'. O telson, a peça central da barbatana caudal, é na extremidade alongado e agucado, os espinhos lateraes collocados diante da ponta são curtos, moveis e não attin- gem de nenhum modo á extremidade do telson. O rostro é comprido, curvado para cima na ponta e mais comprido do que as escamas antennaes. Ha numerosos dentes (8 a _ 12) na margem superior e na inferior. O carpo das gran- 7 des patas com tenazes é nos individuos novos mais com- prido do que toda a mão, nos adultos, porém, mais curto do que esta. Nos individuos adultos a superficie do segundo par de patas torna-se escabrosa, cobrindo-se até de espinhos curtos, e os dedos cobrem-se d'um feltro curto de pello. 7 P. amazonicus. ad. O telson tem a extremidade obtusa ou com uma ponta curta e larga, os interiores dos espinhos lateraes sobrepujam ordinariamente a ponta. A margem inferior do rostro apresenta em regra menor numero de dentes do que a margem superior, havendo raramente mais de 7 dentes na margem inferior. e'. O segundo par de tenazes é espinhoso nos ma- chos velhos, muitas vezes escabroso tambem nos exem- — Pplares novos. jf. Ambos os dedos do ende par de tenazes säo “cobertos nos individuos velhos de um feltro espesso. Os espinhos d'este par de patas são fortes, dispostos em series longitudinaes. O rostro é um pouco variavel, rectilineo ou fracamente curvado para cima, tão comprido como as “escamas antennaes ou um pouco mais comprido do que “estas. Em cima ha 8 a 12, embaixo 4 a 7 dentes. Ocarpo do segundo par de tenazes nem nos individuos novos nem nos adultos é mais comprido do que a mão, mas mais comprido do que a palma. ne P. acanthurus. f. Os dedos das tenazes carecem de feltro. Os espi- nhos do segundo par de patas são delgados e collocados irregularmente, ás mais das vezes representados só por gräosinhos escabrosos. 1 I- antennaes, curvado para cima na ponta, munido em cima de 8 a lv, embaixo de 4 a 7 dentes. O carpo, nos exem- plares novos, é mais comprido do que toda a mão, nos O rostro é mais comprido do que as escamas velhos mais curto do que esta, mais comprido, porém, do — que a palma. P. mexicanus g. O rostro e mais comprido do que os troncos das antennas interiores, mais curto do que as escamas an- tennaes, munido em cima de 8 a 13, embaixo de 2 a 4 dentes. O carpo do segundo par de tenazes é, mais ou menos, tão comprido como a palma nos individuos novos, nos velhos, porém, mais curto do que esta. P. nattereri. > Vac ou escabroso. Os dedos das tenazes carecem de feltro. (Provavelmente fórmas de edade juvenil). P. desaussurei, P. consobrinus, P. fluvialis. o mero nos exemplares novos, nos velhos, porém, só um pouco mais comprido, sempre muito mais curto do que a mão e, nos machos velhos, até muito mais curto do que a palma. O rostro & curto, munido em cima de 7 a 12, embaixo de 1 a 3 dentes. Todo o segundo par das patas com tenazes é, nos exemplares velhos, escabroso e “até espinhoso, os dedos carecem de feltro. O segundo par de tenazes nunca é espinhoso. c’. O carpo é, mais ou menos, tão comprido como | ty P. appuni. b’. O carpo das segundas patas com tenazes é, na parte distal, um pouco espessado e sempre consideravel- mente mais curto do que o mero. À palma ê cylindrica, nos exemplares velhos, porém, iracamente comprimida, mas não consideravelmente mais espessa do que a extre- midade contigua do carpo. : Sub-genero : Brachycarpus. ci. O segundo par das patas com tenazes é esca- . broso nos individuos novos, nos velhos, porém, guarnecido de espinhos fortes. O rostro, mais ou menos tão comprido como os troncos das antennas interiores, apresenta em- cima 11 a 14, embaixo 3a 5 dentes. P. jamaicensis. c. O segundo par das patas com tenazes é fraco e lizo. O rostro apresenta em cima 10 ou 11, embaixo 6 dentes. (Provavelmente fórma de edade juvenil). P. montezumae. “4. As grandes patas com tenazes dos machos adul- tos têm a palma intumecida e comprimida, que é, quando muito, quatro vezes mais comprida do que larga. A pal- ma é mais espessa do que a extremidade distal espessada | do carpo. Toda a fórma d'este par de patas de nenhum modo é cylindrica, o carpo tão comprido, mais ou menos, como o mero. Uma das duas grandes tenazes é, em regra, “consideravelmente mais forte do que a outra. Sub-genero : Macrobrachium. b'. As tenazes dos machos adultos são escabrosas ou têm espinhos curtos. Os dedos das tenazes são bastante cerrados. A palma é tres ou quatro vezes mais comprida — 200 — do que larga, o rostro curto, não mais comprido do que os troncos das antennas interiores, munido em cima de o a 8, embaixo de 6 a 3 dentes. 1 c’. Os dedos das tenazes são tão compridos como a palma. P. potiuna. c. Os dedos das tenazes são mais curtos do que a palma. P. iheringi. b’. As tenazes dos machos adultos são espinhosas ; os espinhos do lado de flexão dos segmentos são collocados quasi como os dentes de um pente e ligeiramente curva- dos. As superfícies da palma são cobertas de pello e feltro. Os dedos das tenazes não são cerrados, o dedo movel é curvado (fig. 10). O rostro apresenta emcima 13 ou 14, embaixo 3 a 5 dentes. c'. A palma é apenas duas vezes mais comprida do que larga, o rostro mais curto do que os troncos das antennas interiores. P. olfersi. 2 c. A palma é mais de duas vezes mais comprida do que larga, o rostro tão comprido como os troncos das antennas interiores ou um pouco mais comprido. P. faustinus. Das especies mencionadas podemos considerar como bem caracterizadas as seguintes: amazonicus, acanthurus, nattereri, appunt, jamaicencis, potiuna, iheringi, olferst, faustinus. De todas estas, á excepção de naltereri, eu proprio cxaminei exemplares. Não é impossivel que 2. mexicanus seja uma forma de edade juvenil pertencente 7 = * oe bo x O WMA Ure Mr DP PME eae er NS Ona See LN. AS ee Benin > ‘ pepe we RR La es eee UNR a ne ae eee gt ee Pe KERN Sone 2 e se TE ; CERRO QUO ACO - es = Sere ree da PS; BEN FUN Te TIP o o . 5 os A sã st igh ad E ye ei pay aa a acanthurus, o que, porém, não quero affirmar positi- _ vamente. Seria possivel que P. montezumae pertencesse a Jamaicensis. As outras formas, desaussurei, consobrinus, Aluvialis, são exemplares de edade juvenil perfeitamente duvidosos. "Para facilitar a classificação dos machos adultos apresento aqui uma segunda tabella, na qual figuram só as fórmas de machos bem conhecidas e só os caracteres mais significativos. * Segunda tabella dos machos Palaemonidae adultos da America do Sul. a‘. Não falta o espinho hepatical. O rostro sobrepuja pelo menos ao segmento basal das antennas interiores. (America do Sul: o lado oriental dos Andes, o Equador, a Colombia, a America Central e as Antilhas). b'. Ambos os dedos das tenazes são cobertos de feltro. c'. O rostro é muito comprido, curvado para cima, e sobrepuja muito as escamas antennaes. O segundo par de patas é munido de espinhos delgados. P. amazonicus. 2 c. O rostro é mais curto, tão comprido como as escamas antennaes ou só um pouco mais comprido do que estas, rectilineo ou fracamente curvado para cima. “O segundo par de patas a espinhos fortes dispos- tos em series. ; | P. acanthurus. b’. Os dedos das tenazes sao despidos de feltro. c'. As superfícies da palma carecem de feltro. d'. As segundas patas com tenazes são cylindricas, principalmente o carpo é regularmente cylindrico. e'. O carpo do segundo par de patas é considera- velmente mais comprido do que o mero. — 202 — P. nattereri. e. O carpo do segundo par de patas é tão comprido. como o mero. P. appuni. d’. As segundas patas com tenazes não são cylin- dricas sendo principalmente que o carpo, na parte distal, é espessado. O carpo nunca é consideravelmete mais au do que o mero. A palma é mais de quatro vezes mais comprida do a larga, quasi cylindrica e muito pouco comprimida. O grande par de tenazes apresenta espinhos fortes. P. jamaicensis. \ e. A palma 6, quando muito, quatro vezes mais comprida do que larga e fracamente comprimida. O gran- de par de tenazes é escabroso ou munido de espinhos delgados. P. potiuna. Ji. A palma é quatro vezes mais comprida do que larga. Os dedos das tenazes são tão compridos como a palma. f. A palma é tres vezes mais comprida do que larga. Os dedos das tenazes são mais curtos do que a palma. P. iheringi. c’”. As superficies da palma, que é espessada e com- primida, são cobertas de feltro espesso e de pello com- prido. Os segmentos do segundo par de tenazes são intu- mecidos e munidos de fortes espinhos. d'. A palma é apenas duas vezes mais comprida do que larga. “sda — 203 — P. olfersi. d’. A palma € mais de duas vezes mais comprida do que larga. P. faustinus. a’. Falta o espinho hepatical. O rostro é muito curto, não mais comprido do que o segmento basal das antennas interiores. As grandes tenazes são muito desi- guaes e espinhosas, os segmentos intumecidos. (Só no Chile e no Perú). Bithynis gaudichaudii. E' digno de nota que 2. jamaicensis e olfersi não se encontrem só na America do Sul, mas tambem na “Africa Occidental e que alli mesmo 2. acanthurus seja substituido por uma especie (16) de parentesco muito chegado. Além destas tres especies de Palaemon não conhecemos mais outras da Africa Occidental e o facto “de existir essa estreita connexão entre a Africa Occidental e a America do Sul é tanto mais Interessante, quanto as especies de Palaemon da Africa Oriental apresentam cara- cter muito differente, ligando-se, como dissemos acima, ás fórmas indo-pacificas. Por este facto torna-se impossivel explicar n’este caso a semelhança de ambas aquellas fór- nas pela ligação que existia em tempos remotos entre a Africa e a America do Sul (17), o que não se admitte tambem em vista da origem provavelmente moderna de (16) Pal. macrobrachion Herklots, encontrado em Bontry e na Sierra Leone (veja-se Ortmann Zoolog. Jahrb. 5. 1891, p. 722). - (17) À existencia antiga de tal ligação parece-me estar fora de duvida, desde que o Dr. von Ihering repetidas vezes chamou a attenção para este assumpto. E” de presumir que esta ligação tenha existido no periodo mesozoico.—Veja-se v. Ihering, Berliner ' Entomolog. Zeitschr. vol. 39, 1894, p. 406, 432 u. 438 (Archhelenis). — 204 — toda a familia. A distribuição dos Palaemones refere-se tão evidentemente ás condições modernas do littoral, que é por isso tambem que somos levados a presumir que a immigracäo d'este grupo para a agua doce se tenha dado. nos tempos modernos e que o facto de concordarem as fórmas da Africa Occidental com as da America do Sul deve explicar-se pelas relações intimas que existem entre as respectivas faunas marinhas do littoral. Palaemon amazonicus Heller. P. amazonicus Heller, Sitz. Ber. Akad. Wiss. Wien. vol. 45, 1, 1862, p. 418, pl. 2, fig. 45. — PP. lamarrei de Man (não Milne-Edwards (18), Not. Leyden Mus. vol. 1, 1879, p. 166.—Ortmann, Zoolog. Jahrb. vol), 189L/p: MOL “pl 47, 00.2. P. ensiculus, Smith, Trans. Connecticut Acad. vol. 2, ES ido p: 26, ple ly go 2. P. jelsha Miers, Proc. Zool. ‚Soc. London leit, BO pH. 61, fig | Essa especie distingue-se de todas as outras especies americanas pela extremidade do telson alongada e agu- cada. Não menos caracteristicos são o rostro comprido, curvado para cima, munido em cima e em baixo de quasi igual numero de dentes assim como o carpo muito com- prido das segundas patas com tenazes, nos individuos (18) Seguindo o exemplo dado por de Man julguei antes o lamarrei de Milne-Edwards e de de Haan identico aesta especie americana. Henderson (Trans. Linn. Soc. London (2) vol. 5, 1893, p. 442) está convencido de ter recentemente reconhecido o verda- deiro lamarrei em exemplares de Ganjam (Indias Orientaes) con- siderando-o como förma de edade juvenil do P. carcinus Fabr. bem conhecido. Em todo o caso o lamarrei deve então conside- rar-se pelo menos como fórma duvidosa que se póde referir a diversas especies, e este nome não serve mais para a fórma americana, tendo de ser substituido pelo nome que se segue na edade, e este é amazonicus Heller. Le j aa E E RA q ; L q = 7 dg j Ee E E ong novos mais comprido do que toda a mão, nos velhos só um pouco mais curto do que esta. Nos individuos velhos as segundas patas com tenazes tornam-se escabrosas e cobrem-se de curtos espinhos, desenvolvendo-se nos dedos um feltro curto. | Essa especie está espalhada, sem duvida, por todo o territorio do Amazonas, desde a embocadura (o Pará) “até aos Andes do Perú (o Rio Huallaga) e do Equador “(o Rio Paute); encontra-se tambem no rio Oyapock (Gu- yana Franceza) e no Surinam. Palaemon acanthurus Wiegmann. PD. acanthurus Wiegmann, Archiv. für Naturgesch. Jahrg. 2 vol. 1, 1836, p. 150.—Ortmann, |. c. p. 720, pl. ER neo. P. forceps Milne-Edwards, Hist. Nat. Crust. vol. 2,. 1837, p. 397. Caracteriza-se esta especie principalmente pelo se- gundo par das patas com tenazes munido de modo sin- gular, nos exemplares velhos, de espinhos: os espinhos fortes principalmente os do lado interior e do inferior dos segmentos, são dispostos em series longitudinaes. Ambos os dedos das tenazes são cobertos de feltro espes- so. O carpo sempre é mais curto do que a tenaz, mas mais comprido do que a palma. O rostro é um pouco “variavel, em geral porém ainda bastante comprido, tão comprido como as escamas antennaes ou mais comprido do que estas, rectilineo ou curvado para cima. Varia tambem consideravelmente o numero dos dentes, haven- do em cima 8 a 12, em baixo 4 a 7. Esta especie encontra-se nos Estados brazileiros de “São Paulo (19) e do Rio Grande do Sul (São Lourenço), (19) A julgar pelos exemplares que eu recebi do Dr. von Jhering.— Note-se porém que meu direito de mencionar aqui as localidades meridionaes se funda só em exemplares novos, cuja classificação ainda não se póde considerar como perfeitamente correcta. . — 206 — perto do Rio de Janeiro, na embocadura do Parä, nas Antilhas, especialmente nas ilhas de Haiti e de Säo Martinho; acha-se tambem, segundo dizem, do lado oc- cidental dos Andes, perto de Guayaquil, no Equador e em Panamá. | | Esta especie parece habitar principalmente as pro- ximidades do littoral, encontrando-se occasionalmente tambem na agua salgada: Cunningham pelo menos. diz tel-a encontrado no porto do Rio de Janeiro (veja-se Trans. Linn. Soc. London. vol. 27. 1871. p. 497). Quanto a São Lourenço, afirma-se expressamente que esta espe- cie existe na agua doce. pole Palaemon mexicanus Saussure. P. mexicanus Saussure, Mem. Soc. Phys. Hist. Nat. Genéve. vol. 14, 2. 1858. p. 468. pl. 4. fig. 21.— Ortmann, fC Ol we P. dasydactylus Streets, Proc. Acad. Nat. Sci. Phila- délphia, LS] pes. pl 2. ie. 3. P. sexdentatus Streets, ibid. b. 226. pl! 2. fe 4. Essa especie é ainda um pouco duvidosa. Distin- zue-se da precedente só por seu tamanho, que é mais pequeno, pela ausencia de feltro nos dedos das tenazes, as quaes, porém, são cobertos de pellos, e pelos espinhos pequenos do segundo par de patas, os quaes, são pouco desenvolvidos, se assemelham mais a granulações. Não se manifesta tambem distinctamente a disposição dos espinhos em series longitudinaes, Além d'isso, nos exem- plares muito novos 0 carpo é mais comprido do que a mão. Nenhum d’estes caracteres prestar-se-hia a contestar que aqui se tratasse só de exemplares novos de P. acan- thurus. Visto como porém ainda não sabemos, si exem- plares adultos e bem desenvolvidos da especie P. acan- thurus já foram encontrados nas mesmas localidades da. especie P. mexicanus, será melhor deixar esta questão por emquanto indecisa. — 207 — A especie P. mexicanus está espalhada nas costas do Mexico, na embocadura do rio Coatzocoallcos, e nas aguas doces de Cuba. Palaemon nattereri Heller. P. nattereri Heller, Sitz. Ber. Akad. Wiss. Wien. vol. 45. 1. 1862. p. 414. pl. 2. fig. 36. 37.—Ortmann, |. c. po 410. P. brasiliensis Heller, ibid. p. 419. pl. 2. fig. 46. O grande par das patas com tenazes é escabroso ou munido de espinhos delgados. O carpo é mais comprido do que o mero, nos individuos novos mais ou menos - tão comprido como a palma, nos velhos mais curto do que esta. O rostro é mais curto do que as escamas an- -“tennaes, mas mais comprido do que os troncos das an- tennas interiores, munido em cima de 8 a 13, em baixo de 2 a 4 dentes. Os dedos das tenazes carecem de feltro. “Pelo carpo mais curto do que a palma, pela ausen- “cia de feltro nos dedos das tenazes assim como pelo rostro mais curto e que apresenta em baixo menor nu- “mero de dentes distingue-se esta especie do 2. acanthu- rus, com 0 qual parece em: outros sentidos ser apparen- tada intimamente. Está espalhada no Rio Negro, no Bra- zil, e no River St. Laurent, na Guyana. ~ Palaemon appuni v. Martens. Arch. für Naturgesch. Jahrgang 35. vol. 1. 1869. p. 31. pl. 2. fig. ».—Orimann |. c. p. 722 pl. 47. fig. 6. Dentro do subgenero Zupalaemon, isto é, dentro das especies que têm o segundo par de patas cylindrico, distingue-se esta especie de todas as ontras americanas pela curteza do carpo. Nos exemplares novos o mero, o . carpo e a palma são de quasi igual comprimento. Com o progresso da edade, porém, cresce principalmente a “palma, de modo que o mero e o carpo só pouco se dis- tinguem pelo comprimento, a palma porém se torna dis- — 208 — tinctamente mais comprida do que o carpo. Nos exem- plares velhos todo o segundo par das patas com tenazes torna-se escabroso e espinhoso, os dedos, porém, ficam sem feltro, seus córtes não têm maiores dentes. O rostro é curto, munido em cima de 7 a 12, em baixo de La 3 dentes. | A förma typica apresenta em cima 12, em baixo 3 dentes. Exemplares que eu recebera do Equador, tinham em cima só 7 a 10,em baixo 1—3 dentes: por esta razão e por encontrarem-se dos dentes da margem superior só 2 ou 3 collocados detraz dos olhos em vez dos quatro, que alli apresentam os exemplares typicos, separei 08 exemplares do Equador como variedade NIT (veja-se |. cp. 723). A especie P. appunt está espalhada na Venezuela, no Porto Cabello e no Equador; encontra-se tambem, (20) segundo dizem, em Dominica, o que, porém, não está fóra de duvida. Palaemon jamaicensis (Herbst). P. jamaicensis (Herbst) Milne-kdwards, Hist. Nat. Crust. vol. 2. 1837. p. 398.—Ortmann, |. c. p. 729. pl. 47. fig. 7 | | | brachydactylus Wiegmann, Arch. für Naturg. Jabre. 2. vol. 1. 1836. p. 148. P. punctatus Randall, Journ. Acad. Nat. Sci. Phila- delphia vol. 8. 1839. p. 144. P. aztecus Saussure, 1. c. 1858. p. 466. pl. 4. fig. 29. P. vollenhovenii Herklots, veja-se Ortmann, |. c. p. 731. Macrobrachium americanum Bate, Proc. Zool. Soc. Lon- don 1868. p. 368. pl. 30. O carpo do segundo par das patas com tenazes é mais curto do que o mero (medindo talvez */, do com- primento d'este) e muito mais curto do que a palma. pe / (20) Veja-se Pocock, Annal. Magaz. Nat. Hist. (6) vol. 3. 1889. _ 0. = “a E eee DR a » 4 E? » RR 2 dp A o e ini sd ndo a 0 RAS E ar E dé hei E we SRP I en eee me a 4 o = x ho ds Ye f 1 j er, « — 209 — E' tambem distinctamente espessado na extremidade distal. A palma é alongada, não consideravelmente mais espessa do que a parte contigua espessada do carpo, quasi cylindrica, mas, nos exemplares velhos, um pouco comprimida. Nos individuos velhos esse par de patas é munido de fortes espinhos, os dedos porém ficam sem feltro. O rostro é, mais ou menos, tão comprido como os troncos das antennas interiores, ligeiramente curvado para cima, munido em cima de ll a 13, em baixo de 3 a 4 dentes. Examinando machos adultos de Kamerum conven- ei-me de que o P. vollenhoventi da Africa Occidental é absolutamente identico a esta especie. Esta especie é talvez a mais espalhada da America do Sul. Encontra-se em muitos lugares do Brazil: no Rio de Janeiro (no lago do jardim botanico), em Pene- do, no rio São Francisco, no Estado da Bahia, em Cara- vellas e Pernambuco. Dentro do territorio superior do Amazonas encontra-se no Rio Paute no Equador, na Venezuela perto de Caracas, na America Central perto de Panamá, na Nicaragua (Polvon) e no lago de Ama: titlan na Guatemala. Acha-se tambem nas aguas doces da costa oriental do Mexico assim como da costa occi- “dental até ao cabo de São Lucas na California Inferior. “Nas Antilhas é espalhada em Dominica, São Martinho, Haiti, Cuba e Jamaica. Na Africa Occidental encontra-se esta especie nos rios Congo e Coanza, em Kamerum, no Niger, perto de Lagos e na Liberia. Palaemon potiuna F. Miiller. Estampa I fig. 9. Archiv. Mus. Nacion. Rio de Janeiro. v. 8. 1892. p. 19. fe ph 11. | O segundo par das patas com tenazes é desigual. O carpo da grande pata com tenaz é, mais cu menos, Revista do Museu Paulista 14 — 210 — täo comprido como 0 mero e vai-se espessando desde a base até ä extremidade distal. A palma é um pouco intumescida, mais espessa do que o carpo, mais ainda | quasi cylindrica, só muito fracamente comprimida, tal- vez quatro vezes mais comprida do que larga. Os dedos são do comprimento da palma, quasi cerrados, da mesma espessura desde a base até a parte immediata á ponta; cada um dos seus córtes apresenta um dente maior na parte proximal e alguns dentes menores e graniformes na parte distal. Toda a pata com tenaz é, nos indivi- duos velhos, fortemente granulada ou guarnecida de espinhos muito delgados, principalmente no lado interior dos segmentos; nos dedos os grãos não estão muito apertados; a palma carece de feltro. O rostro é, mais ou menos, tão comprido como os troncos das antennas interiores, munido na margem su- perior de 5 a 9, na margem inferior de O a 3 dentes. O carpo do macho mede 52°" de comprimento. Esta especie estabelece, em certo sentido, a transição das precedentes para as que seguem, não sendo a palma tão consideraveimente espessada e intumescida como na especie cheringi. Approximando-se das quatro primeiras especies pelo facto de espessar-se 0 carpo pouco a pouco e não consideravelmente, distingue se d'estas 4 primeira vista pela curteza do carpo. N’este ultimo caracteristi- co porém, e tambem em outros, assemelha-se ella ao P. appuni; mas este tem o carpo e a mão regularmente cylindricos, os dedos das tenazes mais curtos do que a mão e despidos de dentes maiores nos córtes. P. jamai- censis distingue-se sempre de potiuna pela palma mais esbelta, e exemplares velhos ainda mais consideravel- mente pelos fortes espinhos do segundo par de patas: A especie P. potiuna encontra-se nos afiluentes do rio Itajahy (21) (Estado de Santa Catharina, Brazil). (21) Examinei um exemplar authentico d’esta especie que fora ~ achado pelo Dr. F. Müller e que eu recebera do Dr. von Ihering E ky gar yy. ee Palaemon iheringi nov. spec. Estampa I. fig. 7 e 8 Recebi esta especie do Dr. von Ihering e julguei - primeiro reconhecer n'ella o P. potiuna. Estudando po- rém um exemplar typico do ultimo que mais tarde re- cebera, convenci-me de que a especie zhering? é differente de potiuna. P. iheringi assemelha-se perfeitamente ao P. potiuna excepto na fórma das grandes patas com tenazes, as quaes, ainda que parecidas com as do 2. potiuna, em geral se distinguem d'estas pelos segmentos distaes mais fortemente intumescidos e pelas patas com tenazes mais curtas. O carpo da maior das patas com tenazes não val engrossando, como na especie potiuna, symetricamente desde a base até á extremidade distal, mas espessa-se perto da base quasi subitamente, sendo tambem a es- pessura muito mais consideravel. A mão é distincta- mente mais larga do que a extremidade distal do carpo, a palma de forma oval alongada, talvez só tres vezes mais comprida do que larga, intumescida e fracamente com- primida: falta a essa especie completamente a fórma quasi cylindrica da palma do P. potiuna. Os dedos das tenazes são consideravelmente mais curtos do que a palma (me- dindo só *; do comprimento d'esta), quasi cerrados e vão diminuindo de espessura desde a base até á ponta. Cada um dos córtes apresenta um forte dente, ao lado d’este ha na parte proximal alguns dentes menores, 20 passo que na parte distal os córtes são perfeitamen‘e lizos. A superficie do mero, do carpo e da mão é fortemente eranulada, os grãos, principalmente nos dedos, estão mais apertados do que na especie potiuna, tomaudo, no lado de flexão dos segmentos, distinctamente a forma de espinhos curtos. O rostro assemelha-se perfeitamente ao do P. potiu- na, nos exemplares que eu examinei, apresenta a mar- gem superior 9, a margem inferior 2 dentes. BE BE E RL ne a an RR PRA a es ich EN re SE Leo É = dE eee ; See Para facilitar a comparacäo apresento aqui as dimensões do potiuna macho de iheringi femea de iheringi macho de potiuna Comprimento do carpo Hm 732" 5mm Grande pata com tenaz 53" Dae 5yum Coxa ia base Da {mm Zum Isch ium "pam gam À "mm Me ro Qmm Qmm gum Carpo ] Qmm 10m» Qmm er ot Palma l Dre mm ar ) mm Lore : 2 4mm Mão , Dedo gmia , 24 gm ) 22 ]Q=m , Na femea é o respectivo par de patas, principal- mente a tenaz d'elle, mais fracamente desenvolvido; o caracter geral, porém, accentua-se, principalmente nos dedos curtos, para revelar sufficientemente na femea tambem a differença especifica entre zheringi e potiuna. A especie iheringi. encontra-se no Estado de São Paulo; o macho que examinei, veio do Alto da Serra, a femea. do rio Tieté. Palaemon olfersi Wiegmann Estampa I. fig. 10 e 11 P. olferst Wiegmann, Arch. für Naturg. Jahrg. 2. vol. 1. 1836. p. 150.—Ortmann, Zoolog. Jahrb. Syst. v. 5. 1891. p. 733. pl. 47. fig. 8. | P. spinimanus Melne-Edwards, Hist. Nat. Crust. v. 2. 1837. p. 399.—v. Martens, Arch. f. Naturg. Jahrg. 35. Vids 2869. pi 26: ply 2: mes: O segundo par das patas com tenazes é muito desi- gual. A grande pata com tenaz é guarnecida de espi- nhos, que são muito fortes no lado de flexão do carpo e do mero e ligeiramente curvados para diante. O carpo é tão comprido como o mero, ambos os segmentos um pouco intumescidos. A palma é de fórma oval, intu- mescida e comprimida, mais ou menos duas vezes mais . comprida do que larga, mais larga do que o carpo e. ee “Ao ZH It ee PS | ig ta A qo té ee — 213 — mais comprida do que este, guarnecida de espinhos e em ambas as largas superficies munida de um feltro es- \ za re pesso e curto. Além d'isso, toda a pata tem ainda pellos bastantes compridos e setiformes. Os dedos das tenazes não são cerrados, o dedo movel é fortemente curvado. O rostro, munido em cima de 13 ou 14, em baixo de 3 a 5 dentes, não excede aos troncos das antennas interiores. Encontra-se essa especie nas Antilhas (Cuba, Domi- nica), dentro do territorio brazileiro n'um arroio perto do Rio de Janeiro e no Estado de São Paulo (22), tam- bem na ilha de São Thomé (pertencente á Africa Occi- dental). Palaemon faustinus Saussure. Saussure, Mem. Soc. Phys. Hist. Nat. Genéve v- 14. 1858. p. 469. pl. 4. fig. 30.—Ortmann, Zoolog. Jahrb. Syst. v. 5. 1891. p. 734. Esta especie, estreitamente aparentada com a prece- dente, representa talvez só uma fórma local d'aquella. Distingue-se da precedente pela palma mais esbelta, que é mais de duas vezes mais comprida do que larga, e pelo rostro um pouco mais comprido, que excede um pouco aos troncos das antennas interiores. Foi encon- trada até agora, pelo que sabemos, só em embocaduras de rios em Haiti e Cuba e perto de Vera Cruz, no Me- XICO. As especies seguintes são duvidosas e insufficien- _ temente conhecidas. Palaemon desaussurei Heller, Sitz. Ber. Akad. Wiss. Wien. v. 45. 1. 1862. p. 420. pl. 2. fig. 47.—Orimann, Zoolog. Jahrb. v. 5. 1891. p. 720.—Foi encontrada na Colombia. (22) A julgar pelos exemplares (um macho adulto e dous _ novos) que recebi do Dr, von Ihering. BRR Sl BE AR ld RS : an Od Palaemon consobrinus Saussure, Mem. Soc. Phys. Hist. Nat. Genóve. v. 14. 1858. p. 469. Fui encontrada no Mexico, na embocadura de um rio perto de Vera Cruz. Kk’ provavel que estas duas förmas pertençam ao numero des parentes do P. acanthurus. A primeira, po- rém, tem o rostro mais curto do que este e apresen- ta em cima maior (13 ou 14), embaixo menor numero de dentes (3 ou 4). A ultima está descripta de modo tão imperfeito que é impossivel identifical-a. Ambas são formas de edade juvenil, Palaemon fluvialis Streets, Proc. Acad. Philadelphia. 1871. p. 227. pl. 2. fig. 3.—Foi encontrada no Mexico, no rio Coatzocoallcos. “E” uma forma de edade juvenil que não se póde identificar. Palaemon montezumae Saussure, |. e p. 467. pl. 4. fig. 28.—Foi encontrada no Mexico, na embocadura de um rio perto de Vera Cruz. —E” talvez uma fórma de edade juvenil do 2. gamaicensis. : Genero: Bithynis Philippi. Deste genero conhecemos até hoje só uma especie encontrada exclusivamente nas aguas doces do lado oe- cidental dos Andes sul-americanos, onde substitue o genero Palaemon. Apresenta a mesma singularidade que este no crescimento das grandes tenazes, que só nos machos velhos chegam a perfeito desenvolvimento. Bithynis caementaria (Pôppig). Palaemon caementarius Pöppig, Arch. f. Nature. Jahrg. 2. v. 1. 1836. p. 148. Palaemon gaudichaudü Milne-Edwards, Hist. Nat. — Crust. v, 2. 1837. p. 400. \ — 215 — Bithynis longimana Philippi, Arch. f. Nature. Jahre. 20. w. |: 1860. p.'161. Macrobrachium africanum Bate, Proc. Zool. Soc. London 1868. p. 366. pl. 31. fig. 3. Bithynis gaudichaudü Ortmann, Zool. Jahrb. v. 5. 1891. p: 748. O rostro é muito curto, não mais comprido do que o segmento basal das antennas interiores, inclinado para baixo, munido na margem superior de 7 ou 8, na mar- gem inferior de O a 3 dentes. O grande par de tenazes é muito desigual, guarnecido de espinhos cujo tamanho vai augmentando com a edade. A maior pata com tenaz tem os segmentos intumescidos. O carpo é mais curto do que o mero e do que a palma. Os dedos são um pouco mais curtos do que a palma. Encontra-se esta especie, segundo dizem, no Chile e no Perú (no rio Aconcagua, norio La Ligua, em pan- tanos de agua doce perto de Coquimbo, no rio Tamba e em Lima). — N’um dos meus trabalhos anteriores citei « Ancon no Equador» como um dos lugares onde esta especie foi encontrada; hoje, porém, sou de opinião que eu devia ter citado « Ancon no Perú », O rotulo dos respectivos exemplares colligidos pelo Dr. Zeiss apresen- tou só a palavra «Ancon» sem dar mais esclarecimento —nota esta que agora supponho referir-se antes á cidade do mesmo nome situada no Perú. . > baw “Explicação das figuras (Estampa 1) Fig. 1. Atyoida potimirim F. Müller, femea, '/. (Segundo F. Müller, em: Arch. Mus. : Nac. Rio de Janeiro v. 8, 1892, DL.) | Fig. 2. ) » A tenaz do primeiro par de patas, “/. (Segundo W Mill x» Pointe olla KOS sous eB METER WON er 4 Sai Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. z 13. 14. — 216 — » » A tenaz do segundo par de patas, “4. (Segundo 7. Müller, Le pl. 10.0038). Atya moluccensis de Haan, da Indo-Malasia, tenaz do primeiro par de patas, en- grandecida. (Segundo de Man, em: Weber’s Reise in Niederländ Indien, v.. 2, 1892, pl. 21 tie an Caridına typus Milne-Edwards, tenaz do primeiro par de patas, engrandecida. (Se- gundo de Man, 1. c. pl. 21, fig. 22°). Wh ) tenaz do segundo par de patas, engrandecida. (Segundo de un Loc ple ve. 229, Palaemon iheringi nov. espec., macho adulto, '.. | » » » » tenaz deste, '/. Palaemon potiuna F. Müller, tenaz do macho adulto, '4. (Em parte segundo dr. Müller, ).:c. pl. Il, ne em parte segundo um exem- à» plar-typico). | Palaemon olfersi Wiegmann, tenaz do macho adulto, "4. (Segundo um ex- emplar de Sao Paulo). » » parte anterior do cephalo- "shorax ur. Leander brasiliensis Ortmann, parte anterior do cephalothorax, engrandecida. (Segundo Ortmann, em: Zoolog. Jahrb. v. 5, 1890, pl. 37, fig. 16). Leander potitinga F. Müller, rostro, “A. ae Leander paulensis nov. espec., rostro, “A. Revista do Museu Paulista II. 1897. E. I. 73 17 14 £ Sonderabdruck aus dem „Biologischen Centralblatt“. Bd. XVIII. Nr. 4. 15. Februar 1898. Ueber Keimvariation. Von Dr. Arnold E. Ortmann, Princeton University, N. J. OO SSS In einer vor Kurzem erschienenen Arbeit‘), die den Zweck hatte, meine Stellungnahme zu der Frage der „Entstehung der Arten“ zu 1) OnNatural Selection andSeparation. Proc. Americ. Philos. Soc., Aug.1896. 440 Ortmann, Ueber Keimvariation. kennzeichnen, habe ich vier Hauptprinzipien (Variation, Vererbung, Naturzüchtung und Separation) angenommen, die es uns ermöglichen, eine Vorstellung über die „Entstehung der Arten“ zu machen, d.h. über die allmähliche Umwandlung derLebewelt und die Entwicklung der jetzt lebenden Arten aus ihren geologischen Vorläufern. Ich habe dort ganz besonders betont, dass es nicht möglich ist, ein einzelnes dieser vier Prinzipien herauszugreifen, und es als das wichtigste oder gar alleinig wirksame hinzustellen, sondern dass alle vier zusammen- wirkend gedacht werden müssen, und dass jedes derselben in einer ganz speziellen, beschränkten Weise wirkt. Ich habe nachzuweisen gesucht, dass diese meine Ansicht eigentlich nichts Neues ist, sondern dass sie sich im Wesentlichen mit Darwin deckt, vielleicht nur mit den einzigen Ausnahmen, dass ich mit Pfeffer den Selektionsvorgang mir etwas anders vorstelle, und dass ich das Prinzip der Separation — das ich M. Wagner entnehme — in einem schärferen und etwas modifizierten Sinne fasse, und es für das Darwin'sche Prinzip der Divergenz — das bisher allgemein übersehen wurde — substituiere. Bei der Zusammenfassung meiner Ansichten !) habe ich mich in Bezug auf das erste Prinzip, die Variation, zu einer Doktrin bekannt, die der jetzt in gewissen biologischen Kreisen herrschenden durchaus entgegensetzt ist, nämlich zu der alten Lamarck-Darwin'schen Annahme, dass Variationen durch direkte Einwirkung äußerer Reize auf das Individuum während seiner Lebenszeit entstehen, und dass solche Variationen vererbt werden können. Ich habe ausdrücklich be- merkt, dass ich diese Annahme zunächst als , Arbeitshypothese“ auf- gefasst wissen will, habe mich aber gegen die gegenteilige Ansicht, dass nur „angeborene“ oder „Keimes“-Variationen vererbbar seien, sehr entschieden wenn auch ohne nähere Motivierung dieser Ansicht, geäußert 2). Es ist der Zweck der folgenden Zeilen, diese meine Ansicht näher zu begründen. Ich werde mich hierbei im Wesentlichen an die Schriften des Hauptvertreters der von mir bekämpften Richtung halten — Weismann — und wenn auch dieser schon von anderer und viel- leicht berufenerer Seite in ausgedehntester Weise kritisiert worden ist, so glaube ich doch, im Folgenden einigen Punkten in Weismann’s Theorien näher zu treten, die bisher noch nicht im Einzelnen geprüft worden sind. Ich muss bemerken, dass meine a. a. O. gegebenen Ausführungen über die Würdigung der drei letzten der genannten Prinzipien durch 1) loc. eit. p. 188. 2) Dieselbe Ansicht habe ich beiläufig schon früher ausgesprochen, vergl. Grundzüge der marinen Tiergeographie, 1896, p.30 und Americ. Journ. of Sci. July 1896, p. 69. Ortmann, Ueber Keimvariation. 444 die Vorstellungen, die wir uns über die Entstehung der Variation machen, durchaus nicht berührt werden. Und in der That können wir finden, dass alle nicht in Vorurteilen befangenen Descendenz- theoretiker — mögen sie nun sich mehr auf die Darwin’sche oder auf die Weismann'sche Seite neigen — es offen zugeben, dass beide Annahmen über die Entstehung der vererbbaren Variationen möglich und denkbar sind: die Entwicklung der Lebewelt geht genau nach denselben Gesetzen vor sich, mag nun das Material, das für die ver- schiedenen Agentien die Angriffspunkte bietet, die variierten Formen, durch Keimesvariation. oder durch Veränderung im Soma des Indivi- duums geliefert werden. Wir können also, ohne dass die Wirkungsweise der Vererbung, Selektion und Separation dadurch beeinflusst wird, beide Ansichten als gleichberechtigt neben einander bestehen lassen — so lange wir sie eben nur als „Ansichten“, als „Annahmen“ betrachten, die weder bewiesen noch widerlegt sind, resp. weder bewiesen noch widerlegt werden können. Sobald wir jedoch diese Ansichten näher analy- sieren, d. h. nach einer causalen Erklärung für die Variation in jedem Falle suchen, dann liegt die Sache anders, und ich glaube durch eine solche Analyse nachweisen zu können, dass die Annahme einer Keimes- variation teilweis gänzlich allen logischen Anforderungen zuwiderläuft, teilweis, wo sie äußerlich in eine logisch zureichende Form gekleidet ist, direkt auf den Thatsachen widersprechenden Voraussetzungen beruht. I. Zuallererst müssen wir den Begriff der Keimvariation und über- haupt des Keimes uns völlig klar machen. Es ist das durchaus nicht überflüssig, da wir sehen werden, dass Weismann selbst diese Be- griffe nicht klar fasst, ja selbst thatsächlich Dinge als „Keime“ be- zeichnet, die unmöglich Keime sein können. Was ist Keimesvariation, und wie unterscheidet sie sich von anderer Variation? Die Keimesvariation wird vielfach auch mit anderen Namen be- zeichnet: man nennt sie auch „spontane“ oder ,congenitale“, „ange- borene „Variation. Ersterer Ausdruck hebt aber gerade einen ange- nommenen Charakter derselben hervor, der, wie wir sehen werden, logisch sinnlos ist; der andere kann zu Missverständnissen Anlass geben: der Ausdruck ,Keimesvariation“ dürfte entschieden für die Sache vorzuziehen sein. Wie in diesem Namen liegt, und wie es auch Weismann ver- standen haben will, unterscheidet sich die Keimesvariation von anderer Variation, der „somatischen“, dadurch, dass sie im Keim, im Gegen- satz zum Soma, stattfindet. Es ist dies der fundamentale Unterschied, den Weismann zwischen den Somazellen und den Keimzellen, dem somatischen und dem Keim-Plasma, macht. Bei dieser Ansicht, die schon von verschiedenen Seiten bekämpft wurde, am erfolgreichsten ; * 442 Ortmann, Ueber Keimvariation. wohl von O. Hertwig'), halte ich mich nicht weiter auf, da es zu- nächst nicht von Belang ist, ob wir diese Unterschiede, die Weis- mann in das Keimplasma hineinlegt, anerkennen oder nicht. Was fiir uns hier wichtig ist, ist das, dass in der individuellen Entwicklung der Lebewesen ein steter Kreislauf sich vollzieht: vom Keim zum erwach- senen Geschöpf, das wieder Keime hervorbringt. Der Keim bildet so- mit in diesem Kreislauf ein gewisses Stadium, und zwar ist es beim Einzelwesen das allererste Stadium. Von dem elterlichen Individuum lösen sich beim Fortpflanzungsakt körperliche Teile ab, die entweder für sich allein, oder meist nach Vereinigung mit einem ähnlichen, von demselben oder anderen Individuen abgelösten Teil (sexuelle Fort- pflanzung), die Anfänge, die Keime zu je einem neuen Individuum bilden. Sobald diese Ablösung vollzogen ist, resp. sobald die Ver- schmelzung solcher abgelösten Teile stattgefunden hat, liegt ein Keim vor. Dieser Keim entwickelt sich nun weiter. Er geht durch eine Reihe von Umänderungen durch, bis er schließlich zu einem Indi- viduum derselben Art wird, das sich dann weiter fortpflanzt. Das Wesen der Weiterentwicklung liegt nun in der organischen Verände- rung des Keimes. Die Keimzelle teilt sich, vermehrt sich, und bildet allmählich den Körper des neuen Individuums. Wann hört der Keim nun auf, ein Keim zu sein? Offenbar, sobald die erste Veränderung auftritt, sobald er sich thatsächlich entwickelt. Da diese Weiter- entwicklung — abgesehen davon, dass Ruhepausen eintreten können — jedenfalls kontinuierlich sich an die Keimbildung anschließt, so können wir sagen: sobald ein Keim sich gebildet hat, verliert er auch seine Eigenschaft als solcher, insofern in ihm Vorgänge stattfinden, die seine Weiterentwicklung bedingen. Der Ausdruck Keim wird somit zu einem abstrakten Begriff, er bedeutet nichts als den „Anfang“ in einer Ent- wicklungsreihe, und wir können nur dann von Keimen im konkreten Sinne sprechen, wenn wir uns denken, dass die Entwicklung im Mo- mente der Keimbildung sistiert wird. Es ist dies die einzig mögliche Auffassung für den Begriff des „Keimes“, da es absolut undenkbar ist, den Keim an einer beliebigen anderen Stelle der individuellen Ent- wicklung aufhören zu lassen. Dies also müssen wir festhalten, dass ein Individuum nur beim allerersten Anfang, im Augenblicke seines Entstehens, als Keim an- gesehen werden kann: in jedem späteren Stadium ist es eben kein „Keim“ mehr! Was kann nun „Keimesvariation“ sein? Natürlich nur eine solche Variation, die mit der Keimbildung zusammenfällt, die vor- handen ist, sobald der Keim fertig ist, nicht vorher, die aber auch nicht erst später eintritt. Die Keimesvariation kann nur eine Variation 1) Zeit- und Streitfragen der Biologie, Heft 1, 1894, S. 75 ff. Hertwig sagt (S. 76): „Nach unserer Auffassung ist der hervorgehobene Gegensatz nur künstlich in sie hineinphilosophiert worden‘. | Ortmann, Ueber Keimvariation. 143 sein, die in dem Augenblicke auftritt, wo die Existenz eines neuen In- dividuums beginnt. Die Annahme einer Keimesvariation bedeutet also, dass wir ein beliebiges, abweichendes Verhalten eines Individuums von seinen Artgenossen darauf zurückführen, dass in diesem Individuum als Keim, d. h. in dem Augenblicke, wo seine Existenz begann, plötz- lich dieses veränderte Verhalten auftrat, wenn auch nur potentiell. Es schließt diese Annahme es ausdrücklich aus, dass vor der Ent- stehung des „Keimes“, d. h. in seinen Erzeugern, diese Aenderung bereits vorhanden war, und ebenso wird dadurch ausgeschlossen, dass diese Variation nach der Keimbildung in irgend einem Stadium der individuellen Entwicklung eintreten kann‘). Die Behauptung nun, dass es eine solche „Keimesvariation“ giebt, führt uns sofort zu der Frage, wie eine solche Variation überhaupt denkbar ist, wie sie entstehen kann. Diese Frage lässt sich auf drei- fache Weise beantworten, und ist auch thatsächlich auf dreifache Weise beantwortet worden. II. Viele Forscher, die die Existenz einer „Keimesvariation“ an- nehmen, drücken tiberhaupt keine Ansicht darüber aus, wie diese ent- stehen mag. Man begnügt sich damit, die Variationsfähigkeit als eine charakteristische Eigenschaft des Keimplasmas und überhaupt der lebenden Substanz, als einen Teil des allgemeinen Lebensgeheimnisses anzusehen, und es wird dabei die weitere Annahme gemacht, dass bei dieser Variation äußere Einflüsse nicht mitspielen. Es heisst das mit anderen Worten: es ist dies eine Eigentümlichkeit der lebenden Sub- stanz, dass sie dazu fähig ist, zu variieren, und diese Fähigkeit be- thätigt sich in thatsächlicher Variation, sobald durch den Vermehrungs- oder Fortpflanzungsakt der Anfang eines neuen Individuums gegeben wird: durch die einfache Thatsache, dass ein Keim sich bildet, va- riiert die lebende Substanz, die das Wesen des neuen Geschöpfes ausmacht. Dieser letztere Satz, der unmittelbar aus der scharfen Definition des Keimes sich ergiebt, wird im allgemeinen von den Vertretern der Keimesvariation (ich nehme hier Weismann ausdrücklich aus) nicht erkannt. Es wird einfach angenommen, dass die Thatsache, der Va- riation in einer inneren, uns unverständlichen Eigenschaft der leben- den Substanz begründet, dass sie „spontan“?) ist, ohne dass man versucht, näher hierauf einzugehen. Wir werden hier einfach vor das berüchtigte „Ignorabimus“ gestellt. Wenn aber schon hier die Grenze 4) Wir sehen jetzt auch, warum der Ausdruck „kongenitale* oder „an- geborene“ Variation unklar ist. „Angeboren* macht die Variation vom Augen- blick der „Geburt“ abhängig, der aber für gewöhnlich in eine spätere Zeit fällt, wie die „Keimbildung“. 2) Diese Auffassung wird eben durch den Ausdruck „spontane“ Variation gekennzeichnet. 144 Ortmann, Ueber Keimvariation des menschlichen Erkennens gezogen werden soll, und zwar nur einer willkührlichen Annahme zu Liebe!), so muss die Wissenschaft als solche energisch dagegen protestieren und muss verlangen, dass erst einmal der Versuch gemacht wird, die Frage der Entstehung der Va- riation von einer anderen Seite anzugreifen. Dazu kommt nun noch, dass eine derartige Annahme über den Ursprung der Keimesvariation logisch völlig widersinnig ist. Es handelt sich hier offenbar darum, die Erklärungsgründe für diese angenommene Thatsache der Keimes- variation aufzufinden. Die Erklärungsgründe zerfallen in zwei Haupt- kategorien: causae materiales und causae efficientes. Die hier be- sprochene Annahme behauptet nun, dass bei der Entstebung von Keimesvariationen nur die eine Kategorie mitspielt, die causwe materiales, nämlich die Eigenschaft der organischen Substanz, variieren zu können. Diese causa materialis — die ja von Jedermann als wirklich vorhanden angesehen werden muss — kann aber unmöglich die einzige sein, und es müssen unweigerlich causae efficientes ebenfalls mitwirken. Diese letzteren werden aber von den Vertretern dieser Ansicht überhaupt nicht berücksichtigt, ja sogar bisweilen ausdrücklich ausgeschlossen 2). 4) Diese Annahme wird vielfach nur gemacht, um sich mit der „herrschen- den“ Ansicht in der Biologie nicht in Widerspruch zu setzen, oder weil sie von anderen Autoren als Axiom aufgestellt wurde, die als „große Zoologen“, „geistreiche Denker“ einen Ruf haben! 2) Ein typisches Beispiel hierfür liefert F. v. Wagner in dem Artikel: Einige Bemerkungen zu O. Hertwig's Entwicklungstheorie (Biolog. Central- blatt, Nov. 1895, S. 777—784). Hertwig hatte den Unterschied der causa materialis und efficiens an einem Beispiel dargelegt (ohne jedoch diese termini techniei anzuwenden). Wagner sah sich nun dazu veranlasst, gerade dieses Beispiel, das an Klarheit nichts zu wünschen übrig lässt, zu kritisieren, wobei er zu dem überraschenden Resultat kam, dass diese Unterscheidung eine falsche sei, dass nur die causae materiales als Ursachen anzusehen seien! Auf diese „vortreffliche Klarlegung“ durch Wagner bezieht sich nun Weismann in einer Anmerkung zu seiner Schrift „Ueber Germinalselektion“ (1896, S. 48, Anm. 2), indem er außerdem im Haupttext die Bemerkung macht: Hertwig habe die „Bedingungen“ und die „Ursachen“ der Entwicklung „verwechselt“, während doch thatsächlich Hertwig sein Beispiel nur anführt, um den Unter- schied, den Weismann hier zwischen „Bedingung“ und „Ursache“ entdeckt hat, dem Leser anschaulicher zu machen! — Dieselben nichtssagenden und unverstandenen Schlagworte („cause* und „condition*) gebraucht v. Graff in dem Artikel: „Zoology since Darwin“ (Ann. Rep. Smithson. Institut, 1896, p. 486) und sucht so glauben zu machen, dass Hertwig widerlegt sei. — Uebrigens führt Weismann (Aeußere Einflüsse als Entwicklungsreize, 1894, S. 3) ein gauz analoges Beispiel an (Winterschlaf des Murmeltiers), indem er aufs Haar genau denselben Fehler macht, wie Wagner, und die Existenz von causae efficientes leugnet! Dass es ihm thatsächlich gänzlich entfallen ist, was eigentlich „causae efficientes“ sind, geht aus einer anderen Stelle der letzteren Schrift (S. 24) hervor, wo er die „causae efficientes“ für verschieden erklärt von dem „auslösenden Reiz“!!! Ortmann, Ueber Keimvariation. 145 Das ist aber ein grober Verstoß gegen alle Grundsätze der Logik, und gerade auf diese Annahme, dass Keimvariation nur durch die Konstitution des Plasmas bedingt sei, bezieht sich meine in der Ein- leitung ausgesprochene Behauptung, dass diese „allen logischen An- forderungen zuwiderläuft“. Ä III. Ich habe schon oben angedeutet, dass Weismann — ohne sich indessen klar dessen bewusst gewesen zu sein!) — in den eben gerügten Fehler nicht verfallen ist. Er führt nämlich wirklich außer der causa materialis, der Konstitution des Keimplasma, eine causa efficiens bei der Keimesyariation ein. Er fragt sich, wie bei der von ihm angenommenen komplizierten Struktur des Keimplasmas es er- möglicht werden kann, dass thatsächlich Variationen entstehen, und kommt zu der unter seinen Voraussetzungen jedenfalls zulässigen An- nahme, das nirgends anders die Ursache zu suchen ist, als im Keim- bildungsorgane selbst: er führt die Entstehung der Variation auf die Fortpflanzungsvorgänge, und zwar zunächst auf die „Amphimixis“, (Kreuzung, Amphigonie) zurück. Ich werde jedoch hier nachzuweisen suchen, dass die von ihm angenommene Wirkungsweise der Amphimixis vollständig unrichtig ist, dass sie den Thatsachen widerspricht, kurz, dass die Amphimixis gerade das Gegenteil von dem bewirkt?), was Weismann von ihr verlangt, und ferner, dass selbst diese von ihm angenommene Wirkung unzureichend ist, die Entstehung der Variation zu erklären?). Weismann’s Vorstellung von der Wirkungsweise der Amphimixis ist die folgende. Mehrfach hebt er es ausdrücklich hervor, dass es sich bei der Konjugation oder Befruchtung „um eine Vermischung der Vererbungstendenzen zweier Individuen handelt“. Aus diesem Satz*), dessen Richtigkeit wohl von Niemandem in dieser allgemeinen Fassung bestritten werden dürfte, leitet nun Weismann die Folgerung ab, dass durch diese Vermischung gerade neue Verschiedenheiten hervor- gerufen werden. Dieser letztere Satz, der nach der populären An- wendung der Begriffe „Vermischung“ und „Verschiedenheit“ geradezu absurd erscheint, ist aber, wie Weismann behauptet, die ganz natür- 1) Das geht zur Genüge aus der vorigen Anmerkung hervor! 2) Ich habe dies in der im Eingange erwähnten Schrift: 1. c. 5. 181 An- merkung, und schon früher, in: Grundzüge der marinen Tiergeographie, 1896, S. 30, angedeutet. | 3) Dessen war sich Weismann wohl bewusst, und er giebt auch in späteren Arbeiten (vgl. unten S. 151 ff.) diese Auffassung der Amphimixis als „Quelle“ der Variation auf. Indessen ändert er nichts an seiner Ansicht über ihre Wirkungsweise, und es ist deshalb angezeigt, hierauf im Folgenden etwas näher einzugehen. 4) Vergl. Amphimixis oder die Vermischung der Individuen, 1891, S. 127, und ebenda: S. 10 und 14. 146 Ortmann, Ueber Keimvariation. liche Folgerung aus dem ersteren. Er schließt nämlich folgendermaßen: da die bei der Befruchtung sich vermischenden „Vererbungstendenzen“ der elterlichen Teile in jedem Individuum verschieden sind, so dass es kaum zwei Individuen geben dürfte, die dieselben Vererbungs- tendenzen enthalten, und da ferner auch die von jedem Individuum produzierten Sexualprodukte unter sich verschieden sind, so muss jedesmal das Resultat der Kreuzung ein anderes sein, d. h. die einzelnen fertigen Keime sind sämtlich von einander verschieden, und durch den wiederholten Vorgang der Amphimixis müssen immer wieder neue Keime mit neuen Variationen auftreten, so dass dieser Vorgang that- sächlich zu einer Variationsquelle wird. Weismann schließt dies Argument dann damit, dass er noch eine „causa finalis“ einführt‘): die Aphimixis erweist sich durch diese ihre Wirkungsweise für das Bestehen der Art als nützlich, und deshalb ist sie zu einer in der Organismenwelt so weit verbreiteten Erscheinung geworden. Beide Ansichten Weismanns, die über die Wirkungsweise der Amphimixis einerseits, und die über ihren Nutzen andererseits, sind grundfalsch. 1. Nehmen wir an, dass alle Voraussetzungen Weismann’s über den Bau des Keimplasmas, besonders die Verschiedenheit der Vererbungstendenzen, richtig seien, und fragen wir uns dann, was wird wirklich geschehen, wenn Amphimixis einsetzt? Es ist sehr wohl denkbar, dass dann durch diesen Vorgang die verschiedenartigen Keim- plasmen in verschiedener Weise „durcheinander gemischt“ werden. Können aber so „neue“ Verschiedenheiten entstehen? Wie haben wir uns überhaupt das „Durcheinandermischen“ vorzustellen ? Offenbar so, dass durch die Verschiedenheiten der elterlichen Sexualzellen und die verschiedenen einzelnen Kreuzungsakte die Möglichkeit von ver- schiedenartiger Kombination der Vererbungstendenzen gegeben wird die fertigen Keime enthalten die Vererbungstendenzen der Eltern in den verschiedensten Kombinationen. Dabei ist aber hervorzuheben, dass sie nur solche Vererbungstendenzen enthalten können, die auch in den Eltern vorhanden waren. Finden sich die elterlichen Tendenzen zu solchen Kombinationen zusammen, so müssen diese Kombinationen 1) Es scheint Weismann völlig unbekannt zu sein, dass die causa finalis durchaus nicht genügt, das Vorhandensein einer Erscheinung in der Natur zu erklären. Das „Nützlichkeitsprinzip“ hat ja in seiner übertriebenen Selektions- lehre eine so ausgedehnte Anwendung gefunden, dass er sich völlig dabei be- ruhigt, wenn er die „Bedeutung“ eines Vorganges, d. h. seine „Zweckmäßig- keit“ erkannt zu haben glaubt: er übersieht es fast durchgehends, dass diese causa finalis nur das Bestehen einer Einrichtung erklärt, nicht aber deren Ent- stehen. — Vergl. hierzu (in Bezug auf den „Zweck“ der Amphimixis) Pfeffer, Die inneren Fehler der Weismann’schen Keimplasma-Theorie (Verh. Naturw. Ver. Hamburg, 1894), S. 14 ff. Ortmann, Ueber Keimvariation. 147 stets zu den möglichen gehören, d. h. sie können keine Elemente ent- halten, die vorher nicht auch in den Eltern vorhanden waren. Mit anderen Worten: die durch die Amphimixis herbeigeführten neuen Kombinationen müssen innerhalb der Grenzen der gegebenen Möglich- keit liegen, und die letzteren werden bestimmt durch die thatsächlich in den Eltern repräsentierten Verschiedenheiten. Für jede Kreuzung stellen also die beiden Eltern die äußersten Enden einer Kombinations- reihe dar, zwischen denen alle neuen Keimeskombinationen liegen müssen: die Keime sind intermediär zwischen den von den Eltern markierten Extremen. Sie sind allerdings neu, aber nur in einem be- schränkten Sinne, insofern sie neue Kombinationen von gegebenen Elementen darstellen: neue Elemente enthalten sie aber nicht. Wieder- holte derartige Kombinationen können nur ein Resultat haben: dass die extremen Formen der Kombination, die nahe den beiden Enden der Reihe liegen (d.h. dem einen oder dem anderen der beiden Eltern sich am stärksten nähern), allmählich immer seltener werden, dass dagegen diejenigen Kombinationen, die ungefähr in der Mitte zwischen beiden Extremen liegen, am zahlreichsten werden: diese letzteren ähneln sich untereinander ausserordentlich und müssen sich allmählich immer ähnlicher werden. Das Resultat der Amphimixis ist demnach, dass die reine Vererbungstendenz des Vaters oder der Mutter mehr und mehr verschwindet, dass an ihre Stelle eine gemischte Tendenz tritt, und dass bei fortgesetzter Amphimixis an Stelle der ursprünglich vorhandenen Extreme eine Reihe von Kombinationen tritt, die aller- dings von zahlreicheren unter einander verschiedenen Individuen ge- bildet wird, die aber sich unter einander viel näher stehen, als die Eltern sich unter einander standen. Es wird also allerdings die Zahl der Variationen vermehrt, aber die Stärke der gegenseitigen Ver- schiedenheit wird vermindert, und das bedeutet nichts anderes, als dass Amphimixis die bei den Eltern vorhandenen Verschiedenheiten auszugleichen sucht. Das ist aber gerade das Gegenteil von dem, was Weismann annimmt! Blicken wir uns in der Natur um, und untersuchen wir, ob dieser theoretisch abgeleitete Satz sich bestätigt! Da sehen wir, dass überall das Kind ein intermediäres Verhalten gegenüber den elterlichen Ver- schiedenheiten verkörpert: es neigt sich zwar bisweilen bald mehr nach der einen, bald nach der anderen Seite, wo aber bei den Eltern wirklich gegensätzliche Verschiedenheiten vorhanden sind, bildet das Kind stets eine Vermittelung derselben. Die besten und einleuchtendsten Beispiele hierfür finden wir bei der Bastardbildung, wo die Ver- schiedenheit der „Vererbungstendenzen“ der Eltern offenbar das Maximum erreicht, bei dem überhaupt noch Amphimixis möglich ist. Was ist nun das Resultat der Amphimixis, z. B. von Pferd und Esel? Doch wohl stets ein Maultier oder Maulesel! Niemals etwas anderes! 148 Ortmann, Ueber Keimvariation, Nun ähneln sich doch aber diese Kreuzungsprodukte sicher mehr unter einander, als Pferd und Esel sich ähneln; das ist es aber, was wir nach unserer theoretischen Betrachtungen verlangen müssen. Der Unterschied zwischen Pferd und Esel wird durch Vermischung beider abgeschwächt, es entstehen intermediäre Geschöpfe, die ja allerdings neu sind, die aber alle unter einander sich ähnlicher sind, als die Eltern es waren, und die alle etwas Gemeinsames haben, dass sie nämlich intermediär zwischen den Eltern sind. Eine fortgesetzte und allgemeine Kreuzung der Pferde und Esel der Welt würde bald die reinen Stammformen verschwinden lassen, an deren Stelle dann eine Mischform tritt. Ist es etwa denkbar, dass aus der Kreuzung von Pferd und Esel etwas „Neues“ entstehen könnte, etwas, das nicht Maultier oder Maulesel ist, und das dann, wie Weismann es will, von der Selection ergriffen und weiter gezüchtet werden kann, weil es eventuell befähigt sein mag, an andere Lebensbedingungen sich anzupassen, wie die sind, auf die Pferd und Esel angewiesen sind? Kann aus der Kreuzung der letzteren ein Zebra, eine Kuh oder ein Pegasus hervorgehen? Kann bei der Kreuzung eines Weissen und eines Negers ein Eskimo oder Neuseeländer entstehen? Die Thatsache, dass Amphimixis nur eine Abschwächung der Verschiedenheiten der Eltern bewirkt, und dass sie stets ein bestimmtes, zwischen den Eltern in Bezug auf deren Verschiedenheiten intermediäres Produkt hervor- bringt, ist jedenfalls über jeden Zweifel erhaben, und im vollsten Um- fange durch die wirklich in der Natur vorkommenden Beispiele erhärtet!). Die Weismannsche Ansicht über die Wirkungsweise der Amphi- mixis widerspricht also den Thatsachen. Es muss ferner noch darauf hingewiesen werden, dass sich Weismann auch mit sich selbst in Widerspruch setzt, und zwar in einer Weise, die für seine Gewohnheit zu denken ganz charakteristisch ist. Nach ihm wirkt die sogenaunte Panmixie so, wie ich es oben für die Amphimixis angegeben habe: gewisse variierende Charaktere werden unter gewissen Umständen durch die Wirkung der Kreuzung mehr gleichmäßig gemacht. Weismann stellt es so dar: wenn Plus- und Minus-Variationen eines Charakters unter gewissen Umständen zur Kreuzung kommen, so verschwinden allmählich die Plus-Variationen, „sie sinken von ihrer Höhe herab“, und wenn noch mehr Minus- Variationen vorkommen, die in die Amphimixis eintreten, so tritt in Bezug auf den betreffenden Charakter eine Reduktion ein: er sinkt immer tiefer. Das ist genau dasselbe, was wir oben für die Amphimixis festgestellt haben, nur in anderen Worten ausgedrückt. Ich halte des- halb auch diese Auffassung der Panmixie im Weismann’schen 1) Vergl. Proc. Americ. Philosoph. Soc., Aug. 1896, p. 181 Anmerk., und das ebenda gegebene Citat aus Darwin. Ortmann, Ueber Keimvariation. 149 Sinne für durchaus richtigl). Wie unterscheidet sich die letztere nun aber von der Amphimixis? Weismann sagt selbst?): „Ich verstehe bekanntlich unter Panmixie die Wirkung des Aufhörens der Selektion in Bezug auf einen Teil“. Wo liegt denn hier nun der Unterschied ? Nach Weismann’s eigner, und mehrfach wiederholter?) Versicherung im Selektionsvorgang! Aber nicht in der Form der Kreuzung, der Amphigonie! Die Amphimixis soll also nach Weismann durch die Kreuzung aus gegebenen Verschiedenheiten neue Verschiedenheiten bilden, die Panmixie dagegen durch Kreuzung gegebene Verschieden- heiten abschwächen, und letzteres soll deshalb möglich sein, weil gewisse Individuen, die im ersten Fall in Folge von Charakteren, die ihre Vernichtung bedingen, nicht an der Kreuzung Teil nehmen, im letzteren Falle zugelassen werden! Im ersteren Falle werden ge- wisse Variationen von der Kreuzung ausgeschlossen, im zweiten werden sie zugelassen, und deshalb hat in beiden Fällen die Kreuzung selbst eine gegenteilige Wirkung! Der Kreuzungsvorgang an sich ist in beiden Fällen absolut derselbe, nur ein vorangehender Vorgang, der der Selektion, der mit der Kreuzung sonst gar nichts zu thun hat, war verschieden! Weismann kommt also thatsächlich hier dazu, folgende Absurdität als richtig anzunehmen: Amphimixis wirkt, wenn eine gewisse, durch Naturzüchtung beschränkte Zahl von Variationen vorhanden ist, eben durch die Kreuzung solcher Variationen, die da sind, als Erzeugerin von neuen Variationen; wenn dagegen durch Aufhören der Naturzüchtung, bei der Panmixie, noch weitere Variationen zur Kreuzung zugelassen werden, dann tritt die gegenteilige Wirkung ein, dann werden — anstatt dass nun noch mehr „neue“ Variationen entstünden, wie man erwarten sollte — jene nunmehr vorhandenen Variationen ausgeglichen! | 2) Wie steht es nun mit dem angeblichen Nutzen, der nach Weismann's Annahme in der Amphimixis liegt? Er sagt, dass diese für die Existenz der Art, für ihre Anpassungsfähigkeit an neue Existenz- bedingungen von Wichtigkeit ist*). Das heißt weiter nichts anderes als: für die Existenz der Art ist es vorteilhaft, wenn sie sich an neue Existenzbedingungen anpasst, und deshalb ist es für sie nützlich, wenn möglichst viel Individuen und diese in möglichst mannigfacher Weise vom normalen Verhalten abweichen, da diese abweichenden 1) Es liegt aber immerhin noch in den Ausführungen Weismann’s über die Panmixie ein Fehler: er unterscheidet nämlich nicht das Optimum und Maximum, an einer Stelle sagt er sogar direkt, dass das Maximum auch stets das Optimum sei. 2) Neue Gedanken zur Vererbungsfrage, 1895. S. 7. 3) Vergl. ibid. S. 14; Ueber Germinal - Selektion, 1896, S. 34. 4) In: Bedeutung der sexuellen Fortpflanzung, 1886, S.55, spricht er von dem „unermesslichen Vorteil der Anpassungsfähigkeit der Art an neue Existenz- bedingungen“. 150 Ortmann, Ueber Keimvariation. Exemplare gerade die sind, die sich eventuell an die neuen Be- dingungen gewöhnen, und dann durch Selektion erhalten bleiben können. Es setzt dies voraus, dass solche neuen Bedingungen stets vorhanden sind, dass gewissermaßen für die Art die Notwendigkeit vorliegt, sich umzuändern. So haben wir uns die Lage der Dinge doch wohl nicht vorzustellen. Für den Bestand einer Art ist es zu- nächst wichtig, dass die äußeren Existenzbedingungen, denen dieselbe angepasst ist, bestehen bleiben und letzteres ist im Allgemeinen der Fall, d. h. die Veränderungen in der Umgebung sind — wie ja jetzt von kompetenter Seite allgemein angenommen wird — ausserordent- lich langsam. Eine zweite Bedingung für die Fortexistenz einer Art ist es, dass ihre Individuen an diese Bedingungen angepasst sind, d. h. dass sie eine gewisse Summe von Merkmalen zeigen, die eben diese Anpassung kennzeichnen, und dass diese Merkmale möglichst unverändert bleiben, da eventuell irgend eine Abweichung schädlich werden könnte. Und ferner ist es wichtig, dass jede Art aus einer möglichst großen Zahl von solchen gleichmäßig angepassten Individuen besteht: eine Art, die in zahlreichen Individuen vorhanden ist, ‘ist eben eine blühende, kräftig existierende; gerade die Individuenzahl ist eines der Kriterien der Existenzfähigkeit, und ein Zurückgang der Art, ein beginnendes Aussterben zeigt sich zuallererst an der Ab- nahme der Zahl der Individuen!). Somit gelangen wir gerade zu dem Gegenteil von dem, was Weismann für vorteilhaft für den Bestand der Art ansieht, und wohl Jedermann dürfte es zugeben, dass es für die Fortexistenz irgend einer Tierform am vorteilhaftesten ist, wenn sie von möglichst vielen und gleichmäßigen Individuen repräsentiert wird, und dass es schädlich sein würde, wenn möglichst viele Indi- viduen durch Keimesvariation in Folge von Amphimixis von dem normalen Verhalten abweichen. Der Weismann’sche Satz von dem Nutzen, der in der Amphimixis liegen soll, ist also völlig ungerecht- fertigt, und dies springt noch mehr in die Augen, wenn man ihn in eine etwas andere Form fasst. Weismann sagt nämlich thatsächlich mit diesem Satz: Für die Existenz einer Art ist es am vorteilhaftesten wenn sie sich verändert, oder: das Bestehenbleiben einer Art wird am besten gesichert, wenn die Art nicht bestehen bleibt! Zu solchen Ab- surditäten führt die Analyse gewisserW eismann’scher Behauptungen!?). Nach dem, was wir oben gesehen haben, bewirkt die Amphimixis gerade das Gegenteil, nämlich ein Ausgleichen von etwa vorhandenen Abweichungen, und gerade hierin liegt ihre „Bedeutung“. In der „Er- 1) Gelegentlich kann gerade die Abnahme der Zahl die Ausrottung herbei- führen. Vergl. Stejneger’s Ansicht über das Aussterben der Labradorente (Camptolaimus labradorius), zitiert von Lucas, in: Rep. U. S. Nation. Mus. for 1889, 1891, p. 637. 2) Vergl. Pfeffer 1. c. S.15: „in dem gegenwärtigea Kampf ums Dasein sollen die Eigenschaften der zukünftigen Nachkommenschaft Vorteil bringen“! Ortmann, Ueber Keimvariation. 451 haltung des Durchschnitts“!) liegt der Nutzen, die causa finalis der Amphigonie, die Ursache, warum die sexuelle Fortpflanzung in der Organismenwelt eine so weit verbreitete Erscheinung ist. Weismanns Einführung der Amphimixis, um das Entstehen der Keimesvariation zu erklären, beruht also auf falschen Voraussetzungen über das Wesen der Amphimixis. Hierzu kommt aber dann noch, dass die Annahme des Entstehens der Keimesvariation durch Amphimixis, die Bezeichnung letzterer als „Variationsquelle“, logisch mangelhaft ist: Es handelt sich hier um die Erklärung von Verschiedenheiten, wir wollen wissen, wie die Verschiedenheiten der Keime entstehen, und wenn dann Weismann uns sagt, dass die Amphimixis diese Verschiedenheiten dadurch erzeugt, dass sie mit verschiedenem Material arbeitet, so müssen wir dann sofort weiter fragen: wo kommt dieses verschiedene Material her. Nach Weismann’s Ansicht kann die Amphimixis nur bereits vorhandene Verschiedenheiten benutzen, kann sie verändern, komplizieren, vermehren, jedenfalls aber erzeugt und schafft?) sie dieselben nicht. Die Frage nach dem Entstehen der Variationen bleibt also bei dieser Annahme völlig ungelöst, und schon aus diesem Grunde ist die Amphimixis-Theorie Weismann’s zu verwerfen. IV. Es ist schon oben darauf hingewiesen worden, dass Weis- mann sich dieser Unzulänglichkeit seiner Amphimixis-Theorie bewusst geworden ist. Alle seine Ansichten beziehen sich auf seine fundamentale Annahme, dass vererbbare Variationen nur im Keim auftreten, und dass dieselben niemals auf Veränderungen des Soma der Eltern zurück- zuführen seien, oder anders ausgedrückt: dass die Ursache der Keimes- variation nicht in den Eltern, in der Beeinflussung der Eltern durch äußere Einflüsse liegen könne. Dass diese Annahme thatsächlich die Grundlage seiner ganzen Theorie ist, giebt Weismann selbst direkt zu3). Aber diese Ansicht hat sich bei ihm im Laufe der Zeit ganz erheblich geändert. Es ist interessant, zu sehen, wie er dem Gegen- teil mehr und mehr Konzessionen macht, und schließlich sich in einem 1) Vergl. Grundzüge der marinen Tiergeographie, S. 32. 2) Der Anfang einer der neuesten Schriften Weismann’s (Germinal- Selektion, 1896, S. 1) lautet: „Wie viele... . Einwiirfe sind nicht gegen die Selektionstheorie erhoben worden... . Von dem .... Poltern Richard Owen’s an.... bis zu der Opposition unserer Tage hin, die da meint, Selektion könne nicht schaffen, sondern nur verwerfen, und die nicht zu sehen vermag, dass sie eben gerade durch das Verwerfen wirklich schaffend wirkt“. In den letzten, von mir hervorgehobenen Worten — die ja allerdings eine schöne rhetorische Wendung bilden — liegt aber derselbe, oben schon ange- deutete Fehler, und es ist charakteristisch, dass Weismann mit einem solchen Fehler glauben machen will, er habe jene Einwürfe gegen seine Selektionslehre vernichtet! 3) Neue Gedanken zur Vererbungsfrage, 1895, Vorwort S. IV. 452 Ortmann, Ueber Keimvariation. Gedankengang bewegt, der absolut auf Lamarck-Darwin’schem Boden steht!): allerdings versucht er dabei stets noch den Schein zu wahren, als handele es sich dabei um seine alte Theorie der Keimesvariation. Den ersten Schritt in dieser allmählichen Aenderung seiner Mei- nung that Weismann bereits im Jahre 1886. Er deutet nämlich an?), dass äußere Einflüsse direkt die Keimzellen treffen und Ab- änderungen des Keimplasmas hervorrufen können. Er widmet diesem Gedanken jedoch keine besondere Diskussion, sondern begnügt sich mit dem sehr subjektiven Urteil, dass er dies „nicht ganz in Abrede“ stellt, aber „glaubt“, „dass sie (die äußeren Einflüsse) am Zustande- kommen erblicher individueller Ckaraktere keinen Anteil haben“. Dieser Satz, der an und für sich äußerst unklar ist, ist indessen in einer Hinsicht interessant; er schließt hier ausdrücklich die Wirksam- keit der „äußeren Einflüsse“ aus. Eine viel bestimmtere Ansicht spricht Weismann dann in seinem großen Werke: Das Keimplasma, 1892º%), aus. Zunächst ändert er hier ausdrücklich seine Meinung in Bezug auf die Amphimixis als » Variationsquelle“: sie ist jetzt nur noch für die „Erhaltung und stete Umgestaltung“ (der individuellen Variabilität) „zu den für die Selektion erforderlichen Mischungen“*) von Bedeutung. Die „letzte Wurzel“ der individuellen Variabilität liegt indessen „in einer direkten Einwirkung der äußeren Einflüsse auf die Biophoren und Determinanten“ >). Zu dieser Ansicht kommt er auf Grund seiner Experimente über Wärmewirkung auf Schmetterlinge, und er giebt zu, dass es hier thatsächlich das „Ansehen“ habe, als ob sich erworbene Eigenschaften des Soma vererben, d. h. das Soma wird durch gewisse äußere Ein- wirkungen verändert, und die folgenden Generationen zeigen dieselben Veränderungen. Nach seiner Meinung beruht aber das Auftreten dieser selben Veränderungen in folgenden Generationen nicht darauf, dass die somatischen Abänderungen der Eltern direkt auf die Nachkommen übertragen werden, sondern dass®) „der abändernde Einfluss“ sowohl „einen Teil des Somas“ als auch „das Keimplasma der in dem Tier enthaltenen Keimzellen“ trifft. Jene Abänderungen des Somas über- tragen sich nicht, wohl aber die des Keimplasmas. Es variieren also Soma und das Keimplasma der Keimzellen unabhängig von einander, aber parallel und gleichzeitig mit einander, aber nur die Variation des Keimplasmas ist für die Veränderung der Nachkommenschaft maßgebend. 1) Ich sehe davon ab, dass er die Vererbbarkeit erworbener Eigenschaften für einzellige Organismen voll und ganz zugiebt, vergl. Die Bedeutung der sexuellen Fortpflanzung für die Selektionstheorie, 1886, S. 38. 2) Ibid. S. 26. 3) Besonders Kapitel 14 ff. AYA e. 9. Dad: 5) 1. c. S. 544. 6) 1. c. 8. 526. Ortmann, Ueber Keimvariation. 153 Es ist schon früher, durch Lester Ward, behauptet worden, dass diese Ansicht Weismann’s auf dem Boden der Lamarck- Darwinschen Theorie steht. Weismann verwahrt sich allerdings hiergegen'), indem er einfach sagt, dass Lester Ward „sich irre“. Trotzdem halte ich diese Ansicht durchaus für richtig, und werde dies hier beweisen. Was die Lamarck-Darwin'sche Theorie behauptet, ist weiter Nichts, als dass äußere Einflüsse, die auf ein Individuum wirken, Aenderungen in der organischen Beschaffenheit desselben herbeiführen können, und dass diese Aenderungen vererbbar seien, d. h. in den folgenden Generationen wieder auftreten können. Dies ist aber jetzt genau die Ansicht von Weismann. Um sein Beispiel anzuführen?): Bei dem Schmetterlinge Polymmatus phaeas bewirkt erhöhte Tempe- ratur (äußerer Einfluss) ein Auftreten von schwärzlicherer Färbung (Aenderung der organischen Beschaffenheit), und Weismann glaubt ferner, dass diese Eigenschaft (schwärzere Färbung) bei den folgenden Generationen infolge jener Temperaturerhöhung wieder auftreten kann. Soweit deckt sich Weismann’s Ansicht absolut mit der Lamarck- Darwin’schen Theorie. Sie ist indessen doch nicht völlig identisch mit ihr, da nämlich Weismann einen Schritt weiter geht. Die Theorie von der Vererbung erworbener Eigenschaften behauptet weiter nichts, als dass die Wirkungen solcher äußeren Einflüsse bei der folgenden Generation wieder erscheinen können; wie dies möglich ist, darüber sagt sie zunächst nichts weiter aus, als dass „Vererbung“ hierbei im Spiele sei. Die Weismanns’che Annahme behauptet genau dasselbe, nur geht sie weiter, und sagt etwas über das „Wie?“ aus, indem sie eine Theorie darüber giebt, wie wir es uns zu denken haben, dass diese „Vererbung“ vor sich geht. Weismann setzt sich also durchaus nicht mit der Theorie der Vererbung erworbener Eigenschaften in Widerspruch, sondern nimmt sie voll und ganz an, dagegen wider- spricht er anderen Theorien, die über das „Wie“ der Vererbung auf- gestellt worden sind, und zunächst würden wir hier an die Pangenesis- Theorie Darwin’s zu denken haben, und ferner widerspricht er durch- aus seiner älteren Ansicht, die ausdrücklich die Wirksamkeit äußerer Einflüsse als Ursachen der Veränderung in Abrede stellt. Nach dieser Ansicht findet zuerst Variation der Keime statt, und dann erst erfolgt eine Anpassung der Variationen (durch Selektion); jetzt sind die äußeren Verhältnisse die direkte Ursache der Variation. Wir müssen hierbei noch etwas verweilen, da dieses Ueberein- stimmen Weismann's mit einer Theorie, die er von Anfang an ver- worfen hatte, und die er immer noch bekämpft, trotzdem er sie voll und ganz acceptiert hat, höchst interessant ist. Weismann leugnete die Vererbung erworbener Eigenschaften, er leugnete es, dass die 4) 1. €. Si 530. 2) Vergl. 1. c. S. 524. 154 Ortmann, Ueber Keimvariation. Veränderungen, die wir bei irgend welchen Tieren erblich auftreten sehen, als Wirkungen äußerer Einflüsse anzusehen seien. Dies war der Grundgedanken aller seiner Theorien. Die Frage nach der Ent- stehung vererbbarer Variationen beantwortete er dann dahin, dass er eine Keimesvariation annimmt. Nach ihm variieren zuerst die Keime, und dann erst erfolgt durch Selektionsprozesse die Anpassung an die äußeren Existenzbedingungen, eine Annahme, die der anderen Theorie, die die äußeren Existenzbedingungen zur Ursache der Variation macht, direkt entgegengesetztist. Was nun Weismann unter Keimesvariation versteht, sagt er nirgends ausdrücklich. Es ist äusserst wichtig, dies zu konstatieren, da in der ungenügerden Klarheit hierüber der ganze Fehler versteckt ist, wie wir gleich sehen werden. Aus Weismann’s Amphimixis-Theorie haben wir indessen zu entnehmen, dass er that- sächlich den Begriff des Keimes so fasste, wie wir ihn oben definiert haben, d. h. als den Anfang eines neuen Individuums. Durch die Amphimixis sollen die Keime gebildet werden, und zwar soll 'es in der Wirkungsweise der Amphimixis liegen, dass verschiedene, variierte Keime produziert werden, so dass thatsächlich mit dem neuen Keim der Anfang eines neuen Individuums und eine neue Variation gegeben wird. Diese letztere Ansicht wurde aber schließlich für Weismann selbst unhaltbar, und nun giebt er es zu, dass äußere Einflüsse bei der Entstehung einer vererbbaren Variation von Wirkung sein können; bei dieser vererbbaren Wirkung darf aber nun und nimmer das Soma der Eltern beteiligt sein, das würde einem Teil seiner grundlegenden Annahme widersprechen, und Weismann sucht sich nun aus diesem Dilemma zu retten, indem er behauptet, die Wirkung der äußeren Einflüsse erstrecke sich auf das Keimplasma der in dem Muttertier enthaltenen Keimzellen. Dieses Keimplasma ist nun von ihm genügend definiert worden, und wir wissen genau, was er sich darunter vor- stellt. Wir wissen aber auch, dass dies „Keimplasma“ sich durchaus nicht mit den „Keimen“ deckt, und dass die „Keimzellen“ auch nicht mit den „Keimen“ im obigen Sinne identifiziert werden können. Aus der „Keimesvariation“ wird jetzt eine „Keimplasmavariation“! Im Gegensatz zur ersteren, die nur im Keim, d. h. beim Anfang eines neuen Individuums stattfinden kann, kann die letztere jederzeit, also auch in dem im elterlichen Tier vorhandenen Keimplasma eintreten, denn nach Weismann ist ja dies Keimplasma kontinuierlich, geht ununterbrochen, aber auch unabhängig und unbeeinflusst vom Soma durch die Reihen der Generationen hindurch. Hiermit hat Weismann seine Ansicht vollkommen geändert. Nicht mehr die Keime variieren, die Variationen sind nicht mehr „an- geboren“, sondern dieselben können zu jeder Zeit in einem Individuum auftreten, indem sich das in ihm befindliche „Keimplasma“ ändert. Und ferner sind die Variationen nicht mehr „spontan“, nicht mehr unabhängig von den äußeren Verhältnissen, sondern sie werden durch Ortmann, Ueber Keimvariation. 155 die letzteren direkt verursacht und geleitet. Durch diese Aenderung seiner Ansicht stellt sich Weismann vollkommen auf den Boden der Lamarck-Darwin'schen Theorie, denn er nimmt jetzt den Grund- gedanken der letzteren an, dass nämlich die äusseren Einflüsse als Ursachen der Veränderungen anzusehen sind, und dass diese Verände- rungen bei den Nachkommen wieder auftreten können. Die letztere Erscheinung, die für gewöhnlich durch das Wort „Vererbung“ charak- terisiert wird, wird nun von Weismann weiter erklärt, und zwar mit Hilfe seiner Keimplasmatheorie, die somit — wie es auch der Titel seines großen Werkes angiebt — eine „Theorie der Vererbung“ ist, sonst aber auf die Theorie über die Entstehung der Variation keinen weiteren Einfluss hat. Weismann ist sich offenbar über die Schwenkung, die er that- sächlich ausgeführt hat, durchaus nicht klar geworden. Er hebt es allerdings hervor, dass er nunmehr den „äußeren Einflüssen“ eine ‚gewisse Rolle zugesteht, aber die Substitution der „Keimplasmavaria- tion“ für die „Keimesvariation* geschieht ganz unversehens, und somit hat es äußerlich den Anschein, als ob noch seine ursprüngliche Ansicht unverändert oder nur schwach modifiziert beibehalten wäre. Ja, in einer der allerneuesten Arbeiten!) geht er direkt auf seine alte Auf- fassung zurück. Dort giebt er nämlich die Wirkung äußerer Einflüsse auf die Eltern zu, aber er erklärt die Vererbbarkeit derartiger Aende- rungen dadurch, dass „auf solche Reize der Organismus vorher ein- gerichtet“ (S. 16) ist, und dass „der Schein einer Umwandlung durch äußere Einflüsse entstehen kann, während dieser Einfluss... . doch nur die Rolle des auslösenden Reizes spielt“ (S. 18), während „die eigentliche Ursache in der Abänderung der Keimesanlagen, hervor- gerufen durch Selektionsprozesse“ liegt. Nun, dies ist eben seine alte Ansicht, nur etwas konfus?) ausgedrückt. Dann spricht Weismann wieder in seiner „Germinalselektion“?) durchweg von Vorgängen, die im Keimplasma, während der Entwicklung, stattfinden, aber nicht mehr von der Keimesvariation, wie sie oben definiert wurde. Hier steht er also wieder auf dem Standpunkt, den er im „Keimplasma“ (1892) ver- trat. Aus dem allen dürfte aber hervorgehen, dass — obgleich sich Weismann über seine eignen Ansichten noch nicht recht klar ge- worden ist — er doch, trotz aller Schwankungen, neuerdings sich ent- schieden dahin neigt, die Wirksamkeit der äußeren Einflüsse auf die Entstehung der Variation anzuerkennen, und dass er somit sich in 1) Aeußere Einflüsse als Entwicklungsreize, 1894. 2) Die Konfusion liegt in dem Gegensatz von „auslösender Reiz“ und „eigentlicher Ursache“: erstere würde also eine „uneigentliche Ursache“ sein, die in der Logik unbekannt ist. Wie er sich die Abänderung der „Keimes- anlagen“ (hier ebenfalls ein unklarer Ausdruck!) durch cken denkt, ist vollkommen unverständlich. 3) Ueber Germinalselektion, 1896. 156 Ortmann, Ueber Keimvariation. Uebereinstimmung bringt mit der Lamarck-Darwin'schen Theorie. Dies berührt seine Vererbungstheorie nicht, und dieselbe würde even- tuell neben der Lamarck-Darwin'schen Theorie, die sich auf die Entstehung der Variation bezieht, bestehen können. Ihre Annehmbar- keit hängt aber davon ab, ob wir Weismann’s Vorstellungen über das Keimplasma acceptieren. Ich gehe auf diese Frage hier nicht weiter ein, verweise jedoch auf Hertwig’s Diskussion!) derselben, in der die „Keimplasmatheorie“ schwer erschüttert wird. Wir sind zu einem, fast möchte man sagen, unerwartetem Ergebnis gekommen. Wir haben gesehen, dass der Hauptvertreter der Theorie von der Keimesvariation seine Ansichten mit der Zeit so umgeändert hat, dass er schließlich thatsächlich mit der von ihm so lange und so heftig bekämpften Theorie der „Gebrauchsvererbung“ in Ueberein- stimmung gekommen ist. Allerdings sträubt er sich dagegen, diese Thatsache anzuerkennen, ich habe aber oben nachzuweisen gesucht, dass nur in Betreff der Frage der „Vererbung“, aber nicht mehr in Betreff derjenigen der „Entstehung der Variation“, Weismann sich von den älteren Theoretikern (besonders Dar win) unterscheidet. Weis- mann giebt es vollkommen zu, dass äußere Einflüsse („bionomische Einflüsse“) derartig ein Tier verändern können, dass die Abänderungen bei den Nachkommen wieder erscheinen. Wie dies geschieht, dafür hat er seine eigne Theorie. Zu dieser Meinungsänderung wurde offenbar Weismann dadurch gedrängt, dass er die Unhaltbarkeit seiner Amphimixis-Theorie einsah, und ich habe oben ausführlich auseinandergesetzt, dass diese Theorie die Entstehung von Variationen nicht erklären kann. Es bleibt also nur noch die einfache Annahme der Existenz von „spontaner“ Keimes- variation übrig, die auch thatsächlich von einzelnen Autoren gemacht wird, und von dieser habe ich gezeigt, dass sie unserem logischen Bedürfnis nicht genügen kann, ja gerade ein wesentliches logisches Erfordernis ausdrücklich ausschließt. Wie wir die Sache auch drehen und wenden, die Idee der Existenz einer Keimesvariation, des Auftretens von neuen Abänderungen in den Keimen neuer Individuen, unabhängig von einer eventuellen Beein- flussung der Eltern, ist ein Unding, und sie bewegt sich entweder in einem logisch unzureichenden Gedankengang, oder — wo man formell versucht hat, dem Bedürfnis unserer Denkgesetze zu genügen — da beruht sie auf ganz verkehrten, den Thatsachen widersprechenden Voraussetzungen. Das heißt mit anderen Worten: nach dem Stande unserer jetzigen Kenntnis und auf Grund unserer Regeln des Denkens ist der Begriff der Keimesvariation, des ersten Auftretens von Varia- tionen im Keim, eine Unmöglichkeit. Es bleibt uns also nichts weiter übrig, als zu der anderen Theorie zurückzukehren, die aussagt, dass 1) Zeit- und Streitfragen der Biologie, Heft 1, 1894. Ortmann, Ueber Keimvariation. 157 neue Variationen dadurch entstehen, dass die äußeren Existenzbeding- ungen die Individuen während ihrer Lebenszeit umändern, und dass diese Veränderungen auf die Nachkommen übertragen, d. h. vererbt werden können. Wie dies geschieht, das ist eine andere Frage. Ich will zum Schluss versuchen, die obigen Resultate in aphoristi- scher Form zu kondensieren, indem ich nochmals betone, dass es sich um die Frage nach der Entstehung der Variationen handelt, der Variationen, die durch Vererbung fixiert, durch Naturzüchtung erhalten, und durch Separation zu getrennten Arten ausgebildet werden kénnen'). 1. Jede neue Abweichung eines Individuums vom normalen Ver- halten der Art ist zurückzuführen auf eine Reaktion des Organismus auf äußere Einflüsse (bionomische Bedingungen), denen das Individuum während seiner Lebenszeit ausgesetzt ist. 2. Gleiche Eltern produzieren gleiche Nachkommen. 3. Sind in den Keimen bereits Verschiedenheiten vorhanden, so muss die Ursache hierfür in den Eltern liegen: es fand also schon Vererbung statt. Eine spontane Keimesvariation, ohne entsprechende vorangehende Beeinflussung der Eltern ist unmöglich. 4. Die Möglichkeit einer Vererbung der von den Eltern erworbenen Veränderungen muss zugegeben werden. Princeton University, October 1897. 4) Vergl. Proc. Americ. Philos. Soc., Aug. 1896, p. 188. K. b. Hof- und Univ.-Buchdruckerei von Fr. Junge (Junge & Sohn) Erlangen. a En © ect | ogia pre ih ash abe ' weh Pt em pi ao POI N Ro Pt ee a ania’ EN vs rm vu je * ‘Haiwilye al ofotlnaed aegide sil ‚nenne aaiiliio® axis: | ih ocated, abunda doi wahr art A AS : ME: j E Ha E RR Do BD wetonnemt ab {usted ine aan 9 erent ik Tater doe nh Pitt aig OT VA Rd oo ow debito aire: WIR nase BR noite re: E an roteiro TOY sigam Di wihul: “as SHAW ooo | f ak aod: Rah ie seio Weleda ei au ond (iram nated odoetmomond) oul wv Ooo aia: HONALOE: ya E A “glo oly ugiixebory i N OR Bobi: tov wotisdasboidsee atrotod womisgh genes Hong oalie Sarg) dao rar eet HO dob che aid! oh ohanisangatna oie ‚sollen. eetusteronpo su sr deinen: dee a garen a uadaon 19 well ash gay ab. auudhora" yt MANN E * ay a ou en guten 3. ee 4 pa A L 7 . | (Separat-Abdruck aus dem »Zoologischen Anzeiger« Bd. XXII. No. 587 vom 18. Mai 1899.) G. Pfeffer und die »Bipolarität«. Von Dr. Arnold E. Ortmann. Es ist bereits über anderthalb Jahr her, daß G. Pfeffer im Zoo- logischen Anzeiger (13. Sept. 1897) »in wenig verbindlicher Form« auf meine Ansichten über seine Bipolaritäts-Theorie hingewiesen hat. Ich gebe dies die »Form« betreffende Compliment zurück und zwar mit mehr Berechtigung, denn in der kurzen Notiz, auf die Pfeffer sich bezieht (Zool. Jahrb. Syst., Vol. 10. 1897. p. 217), finde ich keine einzige Außerung, die diesen Vorwurf rechtfertigen könnte, da daselbst in äußerst knapper Fassung lediglich Thatsachen constatiert sind, einer- seits zoogeographische, andererseits die, daß J. Murray meine Aus- führungen nicht berücksichtigt hat, sondern einfach von den von mir nachgewiesenen Verhältnissen das Gegentheil behauptet. Der Mangel an Verbindlichkeit auf Seiten Pfeffer's liegt einmal in dem sich überhebenden Ton, in dem der ganze Artikel abgefaßt ist, dann aber darin, daß er in einer Weise von meiner Ansicht spricht, die bei jedem in die Sache nicht Eingeweihten eine ganz falsche Mei- nung über den Stand der Frage der Bipolarität erwecken muß. Er stellt es so dar, als ob meine zoogeographischen Ansichten sich im Gegensatz befänden zu den in der » Wissenschaft« angenommenen, als ob ich mich darüber beschwere, daß die » Wissenschaft« sich wei- gere, meine Ideen anzunehmen; ferner giebt er mir den nur wenig versteckten Rath, mich nicht weiter mit Dingen zu befassen, deren Lösung den Bearbeitern des Materials der » Hamburger Magelhaensi- schen Sammelreise « vorbehalten sei, die dieselbe auf » sachlicher Grundlage« unternehmen werden, was die Andeutung enthält, als ent- behrten meine Arbeiten einer derartigen Grundlage; und schließlich enthält der Artikel — nicht ausdrücklich, aber wie die Thatsache, 215 daß er überhaupt geschrieben wurde, schließen läßt — die weitere Andeutung, daß die ganze Frage wohl schließlich zu Gunsten der Pfeffer’schen Theorie entschieden werden dürfte. Was den ersten Punct anbetrifft, so gebe ich zu, daß ich betreffs der Bipolarität anderer Ansicht bin wie Pfeffer. Die Pfeffer’sche Ansicht hat nun außer ihm selbst nur noch einen Vertreter, der es ernstlich versucht hat, diese Theorie zu stützen, nämlich J. Murray, der unter dem Plural »die Fachgenossen« zu verstehen ist. Wenn ich mich demnach in Widerspruch mit der » Wissenschaft« setze, so sind die Vertreter der letzteren Murray und Pfeffer, während meine Wenigkeit, sowie alle die weiteren Autoren, die sich später auf meine Seite geschlagen haben, außerhalb der Wissenschaft stehen. Zweitens: daß die Bearbeiter der H. M. S. die Frage auf » sach- licher Grundlage « entscheiden werden, und jetzt zum Theil bereits ent- schieden haben, darüber hege ich nicht den geringsten Zweifel: das soll mich aber nicht bestimmen, wie Pfeffer es von sich selbst in Aussicht stellt, diese Bearbeitungen alle erst abzuwarten; und das wird mich nicht abhalten, schon jetzt, wie ich es seit 1894 thue, die Bipolaritäts- theorie auf Grund meiner eigenen »sachlichen« Untersuchungen als falsch zu bezeichnen. Ich glaube nämlich, in der Behandlung dieser Frage mich auf sehr »sachliche Grundlage« gestellt zu haben, wenn- gleich sich meine Untersuchungen nur auf eine einzige Thiergruppe erstrecken. Letzteres kann man kaum von Pfeffer's Arbeiten über dasselbe Thema behaupten, da sich bei ihm eine ganze Reihe thatsäch- licher Irrthümer finden, die nicht immer entschuldbar sind. Zum dritten: insofern bin ich jedoch, wie Pfeffer mit Genug- thuung constatieren wird, seinem Rathe gefolgt, als ich zur Beant- wortung seiner Notiz mir über ein Jahr Zeit genommen habe: ich habe einige Resultate der H.M. S. erst abwarten wollen, und es liegen solche nunmehr vor, die die Frage der Bipolarität ganz besonders berücksich- tigen. Außerdem sind von anderer Seite — offenbar angeregt durch meinen Protest — einige Arbeiten in gleicher Richtung erschienen, so daß wir zur Zeit eine ganze Liste einschlägiger Arbeiten aufstellen können. Die folgenden sind es: 1) Chun, Die Beziehungen zwischen dem aan und ant- arktischen Plankton. Stuttgart, 1897. 2) v. Ihering, Zur Geschichte der marinen Fauna von Pata- gonien. Zool. Anz. 27. Dec. 1897 (Mollusken). 3) Breitfuß, Die arktische Kalkschwammfauna. Arch. Naturg., 1898. Heft 3. 4) Herdman, Note on the Tunicate Fauna of the Australian Seas. Ann. Mag. Nat. Hist., Ser. 7. Vol. 1. 1898 and Descriptions of some simple Ascidians collected in Puget Sound. Tr. Liverpool Biol. Soc., Vol. 12. 1898. 5) D’Arcy W. Thomson, On a supposed resemblance between the marine faunas of the Arctic and Antarctic regions. Proc. Roy. Soc. Edinburgh, 1898. (Fische, Isopoden und Amphipoden.) Aus der H.M. S.: 6) Ludwig, Holothurien, 1898. 7) Lud wig, Crinoideen, 1899. 216 8) Ludwig, Ophiuroideen, 1899. 9) Bürger, Nemertinen, 1899. Es sind somit die planktonischen Formen als Ganzes, sowie 10 litoral-abyssale Thiergruppen von zusammen 7 Autoren behandelt worden. Das Resultat aller dieser Arbeiten in Bezug auf die Vergleichung der beiden polaren Faunen ist ein übereinstimmendes und bestätigt voll meinen seit 1894 eingenommenen Standpunct, daß — im Gegen- satz zu Pfeffer undMurray — Fälle von Bipolarität von Gattungen oder Arten außerordentlich selten sind, daß also demnach von einer Bipolarität als Characteristicum der polaren Faunen nicht im entfern- testen die Rede sein kann. Ich halte es für unnöthig, hier auf Einzelnheiten einzugehen, da ein Überblick über die betreffenden Arbeiten ziemlich gleichzeitig hier- mit im » American Naturalist« erscheinen wird. An dieser Stelle will ich nur die Thatsache constatieren, daß trotz der wenig »verbindlichen « Kritik Pfeffer’s im September 1897 meine Ansichten jetzt von sieben anderen Forschern in sehr verschiedenen Thiergruppen bestätigt wor- den sind, daß dagegen Pfeffer’s Theorie überhaupt noch keine »sach- lichen« Grundlagen zu erlangen im Stande war. Das komische Mo- ment, das aber jetzt in dieser Niederlage, die die Bipolaritäts-Theorie erlitten, liegt, hätte der Begründer der Theorie vermeiden können, wenn er jene formell und sachlich wenig angebrachte Notiz unterdrückt hätte. University of Princeton, April 1899. NE O wo vee tdcte wie tar EINEM HESS amd EMEA Er E ME Hd O OA Erste + als WYN AT THE AMERICAN NATURALIST A MONTHLY JOURNAL DEVOTED TO THE NATURAL SCIENCES IN THEIR WIDEST SENSE Rife RINT FROM VoL. XX XIII, No. 391. JULY, 1899. BOSTON GINN & COMPANY The Atheneum Press 1899 A e van Er \ y u q vê Cats ds à RE ei + 1 : me ‘ee 656: Qa ON NEW FACTS LATELY PRESENTED IN OPPO- SITION TO THE HYPOTHESIS OF BIPOLARITY OF MARINE FAUNAS. ARNOLD E. ORTMANN. BIPOLARITY in the distribution of marine animals, indicated by Théel as early as 1886, has been proposed as a theory by G. Pfeffer." Later, J. Murray? accepted the theory and tried to support it by a careful collection of facts. From the beginning the present writer, chiefly relying on the investigation of the distribution of decapod crustaceans, vigorously objected to the theory, and expressed his views as early as 1894 and 1895,? contending that the cases introduced by Pfeffer were not cor- rect. In 1896, after the publication of Murray’s paper, the writer published an article* dealing with the subject more closely, and arrived at the conclusion that bipolarity does not exist as a general law of distribution among the decapod crustaceans, and that it seems very improbable that such a law may prevail among other groups of animals. J. Murray disregarded these objections, and on different occasions ? continued advancing bipolarity as a distributional fact, which called forth repeated objections on the part of the writer® Since then (1897) other zoölogists have taken part in I Versuch über die erdgeschichtliche Entwicklung der jetzigen Verbreitungs- verhältnisse unserer Thierwelt, p. 38. Hamburg, 1891. 2 Trans. Roy. Soc. Edinburgh, vol. xxxviii (1896), No. 2, p. 494. 2 Jenaische Denkschr., Bd. viii (1894), p. 76, and Grundzüge der marinen Thier- geographie, p. 52. (This latter book was issued in December, 1895, but bears the date 1896 on the title-page.) 4 Zool. Jahrb., Syst., Bd. ix (1896), pp. 571 f. 5 Nature, vol. lv (1897), No. 1430, p. 500, and in The Geograph. Journ., vo). xii (1893), No. 2. 6 Zool. Jahrb., Syst., Bd. x (1897), p. 217, and Science, vol. viii (1898), p. 516. Pfeffer (Zool. Anzeig., Bd. xx, September, 1897) has referred to the first of these objections; but since he does not discuss the matter at all, and only doubts the ability of the writer to investigate this topic, it is better not to consider this note. 583 584 THE AMERICAN NATURALIST. [VoL. XXXIII. the discussion, and at present we possess the results of a num- ber of investigations in special groups of animals, dealing with the relations of the Arctic and Antarctic faunas. All the results obtained tend to show that the original contention of the writer, derived from a study of the decapods, is fully sup- ported by the facts found among other groups, so that the theory held by Pfeffer and Murray, that both polar faunas are more closely related to each other than to any of the inter- mediate ones, is without support. In fact, there have been added very few cases of bipolarity of genera to the single case established by the writer in 1895,! and one case of a bipolar species, discovered by Chun, is to be looked upon with some suspicion, for he himself suggests an explanation. All this points to the confirmation of the opinion of the writer, that, although some cases of bipolarity may exist, such cases are extremely rare, and may be explained in one of the ways indi- cated in his paper of 1896, while the greater part of each polar fauna consists of peculiar forms, which show no closer connec- tion with each other than with forms found in tropical latitudes. We will now review the chief results of the papers recently published, and then draw conclusions as to the theory of bipo- larity. However, it is well to observe that some of the authors referred to did not give all the necessary data. Especially is there a lack of information as to the distribution of genera found in both polar seas, outside of their polar range. The writer has tried to supply this deficiency by consulting other papers, but as he cannot claim to be a specialist in the respec- tive groups, he has in some cases failed. Further, a misunder- standing seems to exist on the part of some authors as regards the term “bipolarity’”; they sometimes call a species or genus that is found in both polar areas bipolar, although it is also present in intermediate localities. But “ bipolarity,” as under- stood by Pfeffer and Murray and the present writer, implies that a bipolar form is wanting in the intermediate tropical parts of the seas, and the chief difficulty in the discussion is the explanation of such cases of discontinuity in distribution. The first paper to be discussed is an investigation of the 1 Proc. Acad. Philad. (1895), pp. 189-197. No. 391.] BIPOLARITY OF MARINE FAUNAS. 585 pelagic faunas of the Arctic and Antarctic, by C. Chun.! He collects the records of the occurrence of the animals constituting the plankton of the polar regions (Protozoa, Medusz, worms, crustaceans, mollusks, Tunicata, and fishes), and although he complains in many cases of a general lack of information, especially as to the Antarctic pelagic life, he reaches some very important conclusions. He recognizes a general simi- larity of both faunas, which finds its chief expression in the prevalence of certain groups in both areas and the absence of others; and, further, he mentions the presence in both polar seas of two identical species, one a worm (Sagitta hamata), the other a Tunicata (/ritzllaria borealis). The first case, that of Sagitta hamata, is treated more in detail, and Chun shows (after Steinhaus and Lohmann) that this species, which has been found near the surface in both polar seas, crosses the Atlantic Ocean. It is not, however, found there near the surface, but at consid- erable depths (300-1500 m.). Thus, for this pelagic species, a connection of the Arctic and Antarctic range through the trop- ics, but in deeper water, is established (analogous to the con- nection of littoral polar forms along the bottom of the deep sea), and Chun concludes that this connection, once having been proved, is sufficient to explain other cases, and that there is no need to have recourse to theories which, like Pfeffer’s and Murray's, go back to former climatic conditions of the earth. Yet in the writer’s opinion this conclusion is not satisfactory. We do not want to know how an individual case may be explained, but we want to know how it can be explained cor- rectly, Although we must appreciate the value of the case represented by Sagitta hamata, still there remains the question to be settled, whether other cases of bipolarity, which may be discovered, are really cases of bipolarity, where there is no connection of both ranges, and whether such cases are to be explained by the Pfeffer-Murray theory, or by other means, as indicated by the present writer. But at any rate Chun's paper shows plainly that cases of bipolarity among pelagic organisms seem to be very rare. 1 Die Beziehungen zwischen dem arktischen und antarktischen Plankton. Stutt- gart, 1897. 586 THE AMERICAN NATURALIST. ([VoL. XXXIII. All the other papers under consideration discuss littoral and abyssal animals. In an article on the history of the marine fauna of Patagonia, H. von Ihering! compares the Antarctic mollusks with those of the Arctic. He mentions 9 species that are found in both polar seas, but at the same time he says that this list comprises almost exclusively such species as are of a very large or universal distribution. The connection of the polar localities of these forms is chiefly through the deep sea. There are no true bipolar species, and if we regard the genera present or wanting in the Arctic and Antarctic molluscan faunas, both differ considerably. | Breitfuss ? has published a study of the distribution of the calcareous sponges of the Arctic seas, and incidentally compares them with those of the Antarctic. Of 42 Arctic species only a few (6) cross the equator, and a single one extends its range into the southern polar regions (Grantia capillosa). The rich Calcispongiz fauna of the Australian and New Zealand coasts is very distinct from that of the Arctic, and from the Magellan, South Georgian, and Kerguelen regions only 6 species (belong- ing to 4 genera) are known, which, with the exception of Grantia capillosa, are different from the northern species; and of these genera one (Leucetta) is missing in the Arctic Ocean, while, on the other hand, numerous Arctic genera (6 out of 11) are not known from the Antarctic. No case of bipolarity, either of a species or genus, is mentioned, and the author says nothing about a resemblance of faunas of both seas. Herdman® refers to the extra-tropical southern tunicate fauna of Australia, and, without going into further detail, states that there is no special relationship between it and the tunicate fauna of the northern hemisphere. As to Mur- ray's extracts, from his report on the distribution of the Chal- lenger-Tunicata, he says that the distributional data given in this report are not complete, and, he says, “have to be added 1 Zur Geschichte der marinen Fauna von Patagonien, Zool. Anzeig., Bd. xxvii, December, 1897. 2 Die arctische Kalkschwammfauna, Arch. f. Naturg., Bd. i (1898), Heft 3. 3 Ann. Mag. Nat. Hist., Ser. 7, vol. i (1898), and 7rans. Liverpool Biol. Soc., vol. xii (1898), p. 251. No. 391.] BIPOLARITY OF MARINE FAUNAS. 587 to or modified in such a way as to entirely change the nature of their evidence, and show that there is no such close resem- blance between the northern and southern polar faunas as Dr. Murray and others have supposed.” In fact, he states plainly that among the simple ascidians no cases of bipolarity are known. D’Arcy W. Thompson! has reéxamined the list of bipolar animals given by J. Murray. This list contains nearly 100 species, but d'Arcy W. Thompson shows (p. 347) that there are among them “more than one-third in which grave doubt as to their identification was expressed by the original describers, or in which the identification has been doubted or denied by later writers. In somewhat more than another third the evi- dence of identity is inconclusive or even inadmissible by reason of the nature of the examination to which the specimens were subjected, or by reason of the small size of the objects and lack of adequate marks of characterization. Of the remaining forms, about a dozen find their northern representatives in the Japanese seas, where they form part of a fauna predominantly southern in its relations, and where at least the occurrence of any par- ticular form cannot be taken, zpso facto, as evidence of a boreal center of distribution.’ After deducting these forms the list shrinks into very little. There remains, aside from 12 deep-sea species, only a single littoral annelid species (Terrebellides stremit), and 2 pelagic species, a mollusk, Janthina rotundata, and a copepod, Calanus finmarchicus; but even these last two hardly seem to be bipolar, since neither of them is recorded from further south than 35° S. L., and the latter seems to be rather a cosmopolitan form (see note on p. 340, /oc. cıt.). Further, d’Arcy W. Thompson gives an examination of the Antarctic fishes, isopods, and amphipods, with special reference to bipolarity. He finds no species in any of these groups to inhabit both the Arctic and Antarctic Oceans, and he sees no signs of a likeness of both faunas. A valuable series of monographs has been published by 1 On a Supposed Resemblance between the Marine Faunas of the Arctic and Antarctic Regions, Proc. Roy. Soc. Edinburgh (1898), pp. 311-349. 588 THE AMERICAN NATURALISTEN [(VOLrx oe H. Ludwig,! treating of the distribution of the holothurioids, crinoids, and ophiuroids, with special reference to their polar ranges. The part on the holothurians is especially interesting, since it was this group that first suggested to Théel the idea of bipolarity. According to Ludwig there are no bipolar species, and, in respect to the genera, there is not a single instance that shows the slightest indications of bipolarity. Out of 10 genera found in both polar regions, 5 (Stichopus, Cucumaria, Thyone, Phyllophorus, Chirodota) have been found abundantly in the littoral parts of the tropics, and 4 (Bathyplotes, Mesothuria, Trochostoma, Ankyroderma) are connected in the deep sea; and the same seems to be true of Psolus, which has been reported from tropical latitudes, although it seems to be rarer there. Aside from these 10 genera mentioned, there are 9 genera peculiar to the Antarctic, and 6 peculiar to the Arctic (but some of them extend into the tropics), thus giving a different character to the two faunas. The general result in the other two groups studied by Ludwig is practically the same; there are no bipolar species, and the number of genera peculiar . to each fauna is larger than the number of genera common to ‚ both. Among the crinoids there is only 1 genus (Antedon) found in both areas, while 3 are peculiar to the Antarctic (2 of them abyssal) and 1 peculiar to the Arctic, and among the ophiuroids 6 genera are common to both areas, while 9 are peculiar to the Antarctic and 8 to the Arctic. The genus Antedon found in both polar seas is very interest- ing. Both the Antarctic and Arctic species belong exclusively to two sections of the genus, A. eschrichti and A. tenella. The Tenella group is found in all parts of the world, so that there is nothing remarkable about its distribution. The Eschrichti group, however, contains 4 littoral Antarctic species and 3 littoral Arctic species (2 of them also abyssal), the latter all from the North Atlantic. Now it is very significant that some kind of a con- nection is afforded by one of the Antarctic species, namely, A. rhombotdea. This species has been found in the littoral of the southern end of America, and its range extends northward 1 Hamburger Magalhaensische Sammelreise. Holothurien, 1898; Crinoideen, 1899; Ophiuroideen, 1899. No. 391.] BIPOLARITY OF MARINE FAUNAS. 589 along the western coast of America to 22° N. L., but there it has been dredged at greater depths (1200-1400 m.). Although no species of this group has yet been found in the northern Pacific, it is very probable, nevertheless, that such species do exist. In that case we would here have again an instance of a connection, along the western coast of America, of an apparently bipolar group of marine animals. Examples of this kind have been pointed out, by the present writer, among the decapods. Of the 6 ophiuroid genera common to both the polar seas, 4 (Ophioglypha, Ophiactis, Amphiura, Ophiacantha)are also repre- sented in the littoral of the tropics. The 2 remaining genera (Ophiocten, Gorgonocephalus) are chiefly abyssal genera, and, as far as the writer could determine, Ludwig does not give any information — at least, Ophiocten is also found in tropical latitudes. Thus in these three groups we have again the same result: that bipolarity, if present at all, is extremely rare, and that the most prominent feature of the respective faunas of the polar seas consists in their dissimilarity. Yet Ludwig calls attention to a certain general likeness of both faunas, expressed by the mutual prevalence of certain genera and the mutual lack of others as compared with the tropic faunas. This is not to be regarded at all as a remark- able fact, and has no connection with the question under dis- cussion ; indeed, it would be very strange if other conditions prevailed. When, out of a number of genera present in the tropics, a certain number disappears as we approach either pole, while a certain number does not, this shows only that the latter are not affected by the change of conditions, —chiefly climatic, —while the former are, and of course by the disappear- ance of a number of types the percentage of the remaining must increase, if the deficiency is not made up by other genera making their appearance in the colder regions. This is again an instance where statistics give a wrong idea of the true con- ditions; the increase of the percentage of certain genera in the polar seas is not due to an actual increase of species and a more vigorous development, but only to the lack of species of other genera. 590 THE AMERICAN NATURALIST. [Voz XXXII Lastly, we have a paper, by O. Buerger,! treating of a group of worms, the nemertines. Buerger does not go much into detail, but we must attribute this chiefly to our scant knowl- edge of this group. Again, there are no bipolar species; the only two species which have been found in corresponding lati- tudes on both hemispheres are circum-tropical, and enter extra- tropical parts only on the northern and southern limits of their range. As regards the genera, all Antarctic genera (9) are also found in the Arctic. Buerger says that a general simi- larity of both polar faunas is thus indicated, but the lack of 12 Arctic genera in the Antarctic does not support this view; and since he says, further, that neither of the faunas seems to possess very characteristic types, as do the tropics, it is evident that these 9 genera common to both polar faunas are also repre- sented in the tropics. There is, however, one genus that seems to be bipolar; Carinoma, which has been found on the coast of England (C. armandı) and in the Straits of Magellan (C. patagonica). There is no doubt that the facts presented here do not at all support the theory of bipolarity. The contention of Pfeffer and Murray is that bipolarity forms a very striking feature of the polar faunas. This has been denied by the present writer with regard to the decapod crustaceans, and now von Ihering has confirmed this latter opinion for the mollusks, Breitfuss for the Calcispongise, Herdman for the tunicates, d’Arcy W. Thompson for the fishes, isopods, and amphipods, Ludwig for the holothurians, crinoids, and ophiuroids, Buerger for the nemer- tines, and Chun for the entire bulk of the pelagic fauna. Two cases of bipolarity of species and one of genera have been discovered, and when we add these to the single case previously established (Crangon), we have altogether four cases of true bipolarity which are to be explained by a theory. In all other cases the supposed bipolar range of a species or group has been connected by intermediate localities, and these con- nections are of two kinds: (I) connection along the bottom of the deep sea or in deeper strata of the tropical parts of the open 1 Hamburger Magalhaensische Sammelreise. Nemertinen, 1899. No. 391.] BIPOEARIIVY OF MARINE FAUNAS. 591 sea (Ortmann, von Ihering, Thompson, Chun, Ludwig); (2) con- nection along the western shores of the continents, mostly con- nected with a descending of the respective forms into deeper water (Ortmann, Bouvier, Thompson, Ludwig). It is possible that by these ways cases of true bipolarity may develop, provided these connections become discontinued. The writer has explained a true case of bipolarity (Crangon) by one of these ways. But, on the other hand, it is also possible that bipolarity is to be explained by the Pfeffer-Murray theory in some cases by former conditions of the earth’s history, espe- cially those existing at the beginning of the Tertiary period. Yet we do not know any concrete case of this kind, and we must wait for further investigation to show whether bipolarity as a velic of older times is realized in the geographical distribu- tion of any marine animals. i she a, po E. rn nu.“ er) m” u 2 ’ TBE GEOGRAPHICAL DISTRIBUTION OF FRESHWATER DECAPODS AND ITS BEARING UPON ANCIENT GEOGRAPHY. BY DR. A. E. ORTMANN. (Read April 3, 1902.) INTRODUCTION. During the last decennium Zoogeography has developed in a very peculiar direction, which, in a large part, is directly opposite to the methods introduced by Wallace. The professed aim of the latter was the creation of a zoogeographical division of the earth’s surface into regions, realms and the like, the purpose of which was the subordination of the facts of animal distribution under a fixed scheme; and since it was self-evident from the beginning that the distribution of animals ought to express the physical conditions of the earth’s surface, it was assumed that the proposed zoogeographi- cal divisions correspond to the chief features of the distribution of the conditions of life. | Soon, however, it was discovered that it is impossible to give a division of the earth’s surface that could claim general recognition. It is true that each of the proposed schemes was actually supported by more or less numerous instances of distribution, and that in many cases the physical factors influencing and explaining these divisions were easily understood ; but there was always alongside of the supposed normal conditions a number of exceptional cases, where the actual distribution of certain animals or animal groups was directly the opposite. One of the chief causes of this fact has already been recognized and carefully studied by Wallace. It is Reprinted from Proceedings American Philosophical Society, Vol. XLI, No. 171 268 ORTMANN— DISTRIBUTION OF DECAPODS [April 3, the difference of the means of dispersal of the various groups of animals. On account of these anomalies Wallace constructed his regions chiefly for Mammals and Birds, excluding all the rest of the animal kingdom.! This method, however, can never be satisfactory. It amounts to nothing but the creation of an arbitrary scheme which may corre- spond to some of the facts; but if there are any other facts that do not fit into it—as very often happens—they are simply thrown out and neglected. But this is not all. Even the restriction of Wallace’s regions to a single group of animals proved insufficient to cover all cases within this group. ‘This is true also of all other schemes that have been proposed by other writers for the same or other smaller groups. In every single instance there were exceptions to the rule, and for some time it seemed difficult or even impossible to deal with these apparent anomalies; in fact, none of the proposed divisions into regions can be applied to all cases, even within smaller groups. The correct understanding of this fact, that a large number of animals does not submit to any of the proposed schemes that profess — to comply with the present distribution of the condition of life, was made possible by the consideration that the actual distribution of any animal must have originated in the past. Although there are some animals the history of which does not go very far back, ina geological sense, there are others which do, and, generally speak- ing, we may say that the farther back we go in geological history the more different were the conditions of life from what they are now, and the present distribution of the respective forms must nec- essarily appear the more strange and anomalous. Wallace, indeed, tried to remove this difficulty in a very peculiar way. He simply propounded his principle of the permanency of the continents, which means to say that the present distribution of land and water (and in general of the physical conditions of life) did not change materially during the earth’s history, and that the external features of the earth’s surface have remained practically identical from time immemorial up to the present. That this principle is without 1 This exclusive restriction to the higher forms of life (Mammals, Birds) is a principle of Wallace and has been expressly maintained by him as late as in 1894 (see Mature, Vol. xlix, 1894, p. 610). 1902.] AND ANCIENT GEOGRAPHY. 269 proper foundation has now been recognized and the opposite opinion begins to prevail, that abnormal conditions of distribution are due to just such changes of the physical conditions during a geological past, and that cases of this kind may often enable us to draw con- clusions as to the reconstruction of the old conditions. We may safely assume that the character of the physical conditions of the earth’s surface has changed continuously and variously in the past and that we possess among living animals many forms which express - in their present distribution not only the Tertiary state, but which may also represent Mesozoic or even Paleozoic conditions. Thus it is evident that investigation of the present distribution cannot be used as the starting point for the construction of any scheme. This has. been done, however, not only by Wallace—who entirely disre- _ garded the above fact—but also by others, who paid due attention to it. Indeed Osborn * has pronounced it the purpose of Zoogeog- raphy to unite past and present distribution into one scheme, and the same idea has led Jacobi’ to attempt practically this union. But if we study the most prominent differences between past and present we see that they are chiefly found in the different distribu- tion of land and water, and that frequently in past times land con- nections existed between parts which are now separated, or vice versa; and thus it is self-evident that the solution of Osborn’s problem is simply impossible, since there is no way to express separation and connection of the identical parts in one and the same scheme.’ We consequently arrive at the following three conclusions: 1. Any division of the earth's surface into zoogeographical regions which starts exclusively from the present distribution of animals, without considering its origin, must be unsatisfactory, since always only certain cases can be taken in while others remain outside of this scheme. 2. Considering the geological development of the distribution of 1H. F. Osborn, « The Geological and Faunal Relation of Europe and America During the Tertiary Period, etc.,” in Ann. N. Y. Acad, Sci., Vol. xiii, 1900, p. 48, and in Science, April 13, 1900, p. 563. 2 A. Jacobi, «Lage und Form biogeographischer Gebiete” (Zeitschr. Ges. fuer Erdkunde, Berlin, Vol. xxxv, 1900). > This, of course, does not dispose entirely of Osborn’s problem. On the con- trary, it remains “the” problem of Zoogeography, only we have to change its formal expression and to say that the Azstorical union of past and present distri. bution is the purpose of zoogeographical study. i 270 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, animals, we must pronounce tt impossible to create any scheme what- ever that covers all cases. 3. Under these circumstances it is incorrect to regard the creation of a scheme of animal distribution as an important feature or purpose of zoogeographical research. Thus we are justified in saying that zoogeographical study, as introduced by Wallace, is not directed in the proper channels, and we are confronted with the question, If the creation of regions of animal distribution is not a matter of first importance, which is the vital point in this branch of research ? This question has been practically answered by many writers. I name the following: G. Pfeffer, E. von Ihering, H. A. Pilsbry, R. F. Scharff, :C.. Medley, W. Kobelt, H. F. Osborn, A Jarobı (besides others), and these we may take as representatives of the modern tendency in Zoogeography. According to these authors the chief aim of zoogeographical study consists—as in any other branch of biology—in the demonstration of its geological develop- ment. We have to designate this most emphatically, as the final goal of Zoogeography: the retracing of the present animal distri- bution to its beginning in the past, and a corollary of this is the reconstruction of the ancient physical features of the earth’s surface, since these in the first place have guided the development. In the latter respect the distribution of land and water in past times is all- important and the easiest to be traced. Thus Zoogeography becomes a very important aid not only to physical Geography itself, but also to historic Geology. The above introductory remarks seem necessary, because the purpose and methods of the new tendency in Zoogeography have been frequently misunderstood, and especially because it was not seen that in this way the fruitless discussions on the limits and value of the different zoogeographical regions, etc., have been ren- dered unnecessary. Yet it is a habit among zoogeographers to create or discuss zoogeographical regions according to Wallace’s ideas, and this is done not only by writers who, like Wallace and Sclater, are principally opposed to any progress in Zoogeography, but also by those who are familiar with the new ideas about the geo- logical development of animal distribution. The old method has become an integral part of this branch of science to such a degree 1902.] AND ANCIENT GEOGRAPHY. 27% that any research in this direction is deemed incomplete that is not finished by the creation or discussion of ‘‘ regions.” In opposition to this, we wish to emphasize that we consider it entirely a matter of indifference whether we accept any regions or not, since none of the possible schemes can be satisfactory. Only in a very limited degree and in a modified sense we believe it ad- visable to divide the earth into regions, and we have proposed such a division for the marine life districts.! This scheme, however, is not intended to represent or to express the actual distribution of any animals, but it is a scheme of the distribution of the conditions of existence in the oceans of the present time without consideration of the past or of any definite group of animals. The only purpose of these regions is to single out those marine animals which corre- spond to the normal conditions of life and to separate them from the abnormal cases ; under ‘‘ normally distributed," consequently, we mean those animals which shape their distribution according to the present features of the earth's surface and which belong in their origin to recent time. All the rest differs and does not fit into these regions; but instead of leaving them out of consideration we know that just these cases are the most interesting, since they demand closer investigation. In most cases we find that these in- stances of ‘‘abnormal’’ distribution are to be traced back into the geological past in order to be properly understood, This latter study is the most important branch of Zoogeography, and we see that the introduction of ‘‘regions’’ in our method is only the means by which we discover the more interesting and important cases, but it is not the final aim. Of course the same method may also be used for land and fresh- water animals, and it may here be incidentally remarked that the regions proposed by Wallace are in this respect superior to any modifications introduced by later authors, since they generally are well limited and isolated by physical boundaries given on the sur- face of the earth. But if we are satisfied with the simple statement of the fact that some animals fit into these regions while others do not, we do not approach the solution of the question as to how the actual distribution originated: we are to advance one step further and investigate those cases which do not submit to the scheme. The final aim of this investigation is to compare and group together 1 Ortmann, A. E., Grundzuege der marinen Thiergeographie, Jena, 1896. 272 ORTMANN— DISTRIBUTION OF DECAPODS [April 3, those abnormal cases which resemble each other. Thus we gain certain general views as to ancient geography, and we are finally enabled to trace the distribution of land and water, of climatic con- ditions and the like in the geological past. Most prominent among the groups of animals that are available for these investigations are the Mammals, and they have actually been used for just this purpose by various authors (Doederlein, Zittel, Lydekker, Scharff, Osborn). The palsontological material within this group is the most complete of all. But there is one im- portant drawback: since the history of the Mammals hardly goes back beyond Tertiary times, at any rate since the palzontological record of this group is more or less complete only within the Ter- tiary, we can only draw conclusions from them as to the geographi- cal conditions of this period, while we have to refrain from an investigation of those of the Mesozoic times. This is a very different matter with the land and freshwater Mo/- lusks. According to what we know, it is apparent that many of these forms can be traced back to Mesozoic times, sometimes even to Pal&ozoic, and, indeed, it is this group of animals that has fur- nished the material for the studies of von Ihering, Pilsbry, Hedley, Kobelt, and we are to expect that further investigation in this direc- tion may yield interesting results. Other groups have also been used. Von Ihering introduced the study of Anis, and there may be other promising groups among the Insects (for instance Spiders). But since the majority of the Insects possess unusual means of dispersal (power of flight) that are apt to obscure the original conditions of distribution, Insects in general are not well adapted to this kind of research. Of other animals the Earthworms have been studied in this respect (by Beddard), and of the Vertebrates, Reptiles, Amphibians, and freshwater Fishes are very likely to prove good objects, since their history in many cases goes back to the beginning of the Mesozoic or even to the Palzo- zoic time. In the following treatise I wish to call special attention to certain groups of Decapod Crustaceans that live in fresh water. In part these have been discussed previously by other writers as well as by myself, but it is worth while to go more into detail, since we shall find them very interesting in this respect. 1902.] AND ANCIENT GEOGRAPHY. 21a The following groups of freshwater Decapods are known: FAMILY: Alyıde. Palemonide (in part). Potamobide. Parastacide. igleide (monotypic). Potamonide. There are, scattered among other families, other forms of fresh- water Decapods, but the above are the inost important groups. These are found either exclusively in fresh water or possess the largest number of their members there, and are found only in rare cases in the sea. As regards the Azide, the present writer has collected the cho- rological material in a previous paper.” This is no doubt one of the oldest groups of freshwater Decapods, and their origin, as is very likely also according to their morphological characters, is to be sought for possibly in Jurassic times, although fossil forms are not positively known. The chief features of their distribution are excessively abnormal and even confusing, and therefore the extreme age of the group is again confirmed. On the other hand, there are smaller groups within this family, the distribution of which was apparently formed in later times. Since there is every reason to believe that our knowledge of the actual distribution of the Azyide is still more or less defective, we shall refrain from discussing it and refer only to the latest summary given by the present writer.? In the family of the Palemonide the genus Palemon forms a group that possesses numerous species which are found chiefly in fresh water. Their distribution, which has also been previously investigated by the present writer,* points distinctly to the fact that this genus is a very recent one, which is at the present time just in the act of immigrating into fresh water, and that this process is by no means completed. The different species depend in their dis- 1Compare Ortmann, A. E., in Bronn’s Klassen und Ordnungen des Thier- reichs, Vol. v, 2, 1899, p. 1185. We leave out of consideration the families Cenobitide and Gecarcinide, which are more properly land animals. See zdzd., pp. 1183 and 1184. 2 Ortmann, in Proc. Acad. Philadelphia, 1894, p. 397 ff. 3 In Bronn’s Klassen und Ordn., !. c., 1901, p. 1286 f. 4In Zoot. Fahrb. Syst., Vol. v, 1891, pp. 744-748, and in Bronn’s Klassen und Ordn., À. c., 1901, p. 1291 f. 274 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, tribution largely on the conditions prevailing in the littoral waters, and generally they follow the physical regions which we have pro- posed for the marine littoral district of the present time. To this there are only a few exceptions, due to special means of dispersal (crossing over continental divides, for instance). For the investi- gation of ancient Geography this genus has no value." In the following we shall treat of the remaining four families: Potamobiude, Parastacide, Egleid« and Potamonide. PART I. CHOROLOGICAL MATERIAL. A. CHOROLOGY OF THE FAMILIES POTAMOBIIDE AND PARA- STACIDE. (See Fig. 1.) BIBLIOGRAPHY. (a) General Discussions and Systematic Revisions. HuxLEY, TH.: Zhe Crayfish, London, 1879. Faxon, W.: “A Revision of the Astacide” (Mem. Mus. Harvard, Vol. 10, 1885). 1 Coutiere, H. (“Sur quelques Macrures des eaux douces de Madagascar,” in C. R. Acad. Sci. Paris, Vol. cxxx, 1900, pp. 1266-1268), discussing the Palz- mons of Madagascar, has advanced some views as to their distribution and con- cludes by putting the (unanswered) question whether this distribution has formed under conditions similar to the present ones or not, This question, how- ever, has been answered in detail by the present writer in the paper quoted above (1891), with which Coutiere seems to have been unacquainted. This is also evi- denced by the fact that some of the peculiarities of distribution in this genus; emphasized by the present writer, are not mentioned by Coutiere—for instance, the relation of the West African species to those of America. Coutiére holds that the West African (not South African) Palemon vollenhoveni Herkl. is most closely allied to 2. drevicarpus Haan from Japan, while I regard the relationship to the American 2. jamazcensis (Hbst.) as more important. As regards Bithynis hildebrandti Higdf. (1893) from Madagascar, I believe it is hardly possible to connect this species genetically with the type species of this genus from Chile. I think this is a case of convergency. The opinion of Coutiére, that the theory of a Posttriassic connection of Madagascar with India and Africa is to be abandoned, has no support whatever. The distribution of Palemon, which, according to Coutiére himself, does not go back beyond Miocene times, is absolutely irrelevant to this question, and even the Miocene age of Palamon seems to be doubtful. The presence of identical species on the eastern and western sides of the Cordilleras ın South America is no evidence for this, since this distribution is not discontinuous, and the respective species have apparently crossed this chain of mountains, and are actually found in the moun- tains high up in the headwaters of the Anazonas river, for instance. 275 v Sa wes \ ey o a \ \ { \ ' > \ AND ANCIENT GEOGRAPHY. 192] Distribution of the Crayfishes of the families Zutamodiide and Zurastaridg, 276 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Faxon, W.: « Notes on North American Crayfishes, Family Astacid@” (Pr. U. S. Mus., Vol. 12, 1890). FAxon, W.: “ Observations on the Astacide in the U. S. National Museum and in the Museum of Comparative Zoology, with Descriptions of New Species ” (Pr. U. S. Mus., Vol. 20, 1898). ORTMANN, A, E.: “ Ueber Bipolaritaet in der Verbreitung mariner Thiere”’ (Zool. Fahrb. Syst., Vol. 9, 1896, p. 588-594). ORTMANN, A. E., in Bronn’s Klassen und Ordnungen des Thierreichs, Vol. 5, Part 2, 1901, pp. 1288-1290. (6) Special Literature, published after Faxon's Revisions (1885, 1890, 1898), or not embodied in them. BERG, C.: “ Datos sobre algunos crustaceos nuevos para la fauna argentina ” (Commun. Mus. Buenos Aires, Vol. I, 1900). COCKERELL, T. D. A., and PORTER, W.: “ A New Crayfish from New Mexico” (Pr. Acad, Philadelphia, 1900). DorLEIN, F.: « Weitere Mitteilungen ueber dekapode Crustaceen der k. bayer- ischen Staatssammlungen ” (5. B. Ak, Muenchen, Vol. 30, 1900, p. 132). Hay, W. P.: « Description of Two New Species of Crayfish” (Pr. U. S. Mus., Vol. 22, 1899). Hay, W. P.: Synopses of North American Invertebrates--6. The Astacida of North America” (Americ. Natural., 1899). Lenz, H.: « Die Crustaceen der Sammlung Plate” (Zool. Fahrb. Syst., Suppl. 5, 1902, pp. 736, 737). NosiLt, C.: “ Contribuzioni alla conoscenza della fauna carcinologica della Papuasia, della Molucche e dell’ Australia” (Anum. Mus. Genova, Ser. 2, Vol. 20, 1899). PHILIPPI, R. A.: ( Descriptions of Three Species of Crayfishes from Chile) (Annales Univers. Chile, Vol. 61, 1882, pp. 624-628, with plate). PHILIPPI, R. A.: “ Dos palabras sobre la sinonimia de los Crustaceos, Decapo- dos, Braquiuros o jaivas de Chile” (Ann. Univers. Chile, 1894). For the intended publication of the Decapods in the “ Thier- reich,’ edited by the German Zoological Society, the present writer was obliged to make a complete collection and a critical review of the systematic literature of these two families. Of course, . the results of these studies are embodied in the following portion of this article, although it is not possible to refer to this work, the manuscript of which has just been finished. 1. Family: PoramosiiDa Huxl.? The family Potamobide is divided into two genera: Potamobius Sam. and Cambarus Er. The latter is no doubt the more special- 1 Of this rare paper I possess a handwritten copy and sketches of the figures, through the kindness of Dr. F. Philippi, of Santiago. 2 Those authors (Faxon, Rathbun) who retain for the European crayfish the = 1902.) AND ANCIENT GEOGRAPHY. DT ized one, and its distribution is more sharply limited than that of Potamobius, it being found only in the eastern parts of North America, Mexico and Cuba. Genus: Cambarus Er. The genus Cambarus contains at present sixty-six well-known species ; of a sixty-seventh, the group to which it belongs is doubt- ful (C. clypeatus Hay, Missouri). The species form five groups within the genus. Sixteen species belong to the first group, namely : 1. dlandingi (Harl.). 9. versulus Hag. 2. hayı Fax. 10. spiculifer (Lec.). 3. fallax Hag. 11. pellucidus (Tell.). 4. clarki Gir. 12. acherontis Loennb. 5. troglodytes (Lec.). 13. wiegmanni Er. 6. lecontei Hag. 14. allent Fax. 7. angustatus (Lec.). 15. evermanni Fax. 8. pubescens Fax. 16. genicillatus (Lec.). Eight species belong to the second group: 1. cubensis Er. 5. gallinus Cock. and Port. 2. carinatus Fax. 6. gracilis Bund. 3. mexicanus Er. 7. carolinus Er. 4. simulans Fax. 8. advena (Lec.). To this group possibly belongs clypeatus Hay. Thirteen species belong to the third group: 1. acuminalus Fax. 8. whlert Bar. 2. bartoni (Fabr.). 9. setosus Fax. 3. longulus Gir. 10. extraneus Hag. 4. latimanus (Lec.). II. jordant Fax. 5. dubius Fax 12. cornutus Fax. 6. diogenes Gir. 13. hamulatus Cope and Pack. 7. argillicola Fax. generic name of Astacus M. E., claim that Latreille (Consider. génér., etc., 1810; see Faxon, 1898, p. 662) has made this species, Astacus fluviatilis Fabr., the type of the genus Astacus Fabr. This statement of Latreille, however, is erroneous, since Astacus of Fabricius is a genus without type, and remained such until Samouelle (7h Entomologists Useful Compendium, 1819, p. 95) separated Astacus and Potamobius (Lobster and Crayfish). See Faxon, 1885; Ortmann, es Das System der Decapodon Krebse” (Zool. Fahrb. Syst., Vol. 9, 1896, p- 430), and Stebbing (in Natural Science, Vol. 12, 1898, p. 239 ff.). 278 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Twenty-six species belong to the fourth group: I. mississippiensis Fax. 14. virilis Hag. 2. immunis Hag. 15. nais Fax. 3. medius Fax. 16. pzlosus Hay. 4. lancifer Hag. 17. longidigitus Fax. 5. palmeri Fax. 18. sloanei Bund. 6. difheilis Fax. 19. rusticus Gir. 7. alabamensis Fax. 20. mecki Fax. 8. compressus Fax. 21. harrisoni Fax. 9. propinguus Gir. 22. forceps Fax. 10. neglectus Fax. 23. spinosus Bund. 11. digueti Bouv. 24. erichsonianus Fax. 12. afınis (Say). 25. putnami Fax. 13. indianensis Hay. 26. hylas Fax. Three species belong to the fifth group: I. montezume Sauss. 3. shufeldti Fax. 2. chapalanus Fax. In discussing the distribution, it is best we take up the single groups. The species of the first group are restricted chiefly to the southern parts of the United States and Mexico, and we observe that all, with two exceptions (dlandingi and pellucidus), are found in the region of North America formed by Mexico, Texas, Louisiana, Mississippi, Alabama, Florida, Georgia and South Carolina. C. blandingi possesses the widest range; in the States named it is wanting only in the farthest southeast, in Florida and Georgia'; but on the other side it extends beyond those limits along the. Atlantic coast, passing through North Carolina, Maryland and New Jersey into the neighborhood of New York, and in the Mississippi- Ohio basin it extends northward through Arkansas, Tennessee, Missouri, Illinois and Indiana into Ohio and southern and eastern Iowa. Westward, it has been found as far as Indian Territory. €. pellucidus is a blind cave species which is restricted to certain localities in Indiana and Kentucky. It is apparent that the centre of this group is in the Gulf States and in the southern Atlantic States, while the region of the eastern mountains (Allegheny system) is left unoccupied by it, and only one species advances northward along the Atlantic coast and in the 1 It is very likely to be discovered in Georgia. u a. EEE EEE VE a 1902.] AND ANCIENT GEOGRAPHY. 279 Mississippi valley to the neighborhood of the Great Lakes. To this latter extension of the range also belongs C. gellucidus. South- ward, this group goes through Texas (here it has been found near the Mexican boundary line), and is found in the neighborhood of the city of Mexico (C. wiegmanni). Whether this latter locality is connected with the localities in Texas or not is unknown. The centre of distribution of the second group is to be found in the Southwest. We know two species from Mexico, two from New Mexico, Texas and Kansas. Another species (C. gracilis) extends from these parts northward (in the prairies), and is found in Kansas, Iowa, Illinois, as far as Wisconsin. In the South we have, more or less isolated, C. clypeatus in Mississippi, and absolutely isolated are C. carolinus and advena in South Carolina and Georgia and C. cubensis in Cuba. Within this group we observe a very striking discontinuity ; not only the Mexican localities are separated from those in the United States, but also in the Gulf States, the southern Atlantic States and in Cuba there are representatives of this group, separated from the rest in the Southwestern and Central States. Very different is the range of the Zhzrd group. Here we have complete continuity, and the centre is evidently in the system of the Allegheny mountains and in the East. The species are very numerous in the mountainous parts of Tennessee, Kentucky, North Carolina, Virginia and West Virginia, Maryland, Pennsylvania, and in the adjoining parts of Ohio and Indiana. This group is also well represented in Illinois, and extends, gradually decreasing in density, westward into Wisconsin, Minnesota, Iowa, Missouri (in the eastern part only), Arkansas and the Indian Territory. It is very rare in Texas, Louisiana, Mississippi; is slightly represented in Alabama, Georgia and South Carolina, but is wanting in Florida. In a northeasterly direction, a single species (C. bartoni) extends over New York and New England across the Canadian boundary into New Brunswick, where it reaches the Restigouche river, a tributary of the Gulf of St. Lawrence. The same species is found in the northern affluents of Lake Ontario (Toronto) and the St. Lawrence river in Quebec (St. John’s Lake), where it marks the northern boundary of the genus. In Michigan this group is repre- sented in the neighborhood of Lake Huron, but it has not been found north of the Great Lakes in Canada. The northeastern extension of the range of this group, on the one hand, is very 280 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, remarkable, while, on the other hand, we have a scarcity of it south of the Allegheny system and west of the Mississippi. With the exception of one isolated station of C. argillicola in Texas, this group is not represented in the Southwest. The largest number of species is found in the fourth group. In certain respects it corresponds, in its distribution, to the third, namely, in its exceeding scarcity in the South and Southwest. It is wanting in Florida, in the low parts of the Carolinas, of Georgia, Alabama and Mississippi. It is also wanting in Louisiana, and in Texas it is found only in the northeastern corner (near the bound- aries of the Indian Territory and Arkansas). Beginning here, it extends northward over the Mississippi-Missouri-Ohio basin, becoming more abundant, the centre being situated, in this region, in the States of Missouri, Tennessee, Kentucky, Indiana, Illinois, Iowa and the southern parts of Michigan and Wisconsin. East- ward this group enters Ohio, Pennsylvania, Virginia, Maryland, New Jersey and New York, reaching its northeastern limit north of Lake Ontario, near Toronto and Montreal. In Wisconsin it extends to Lake Superior, and one species (C. virzlis) reaches from Minne- sota, including the northeastern corner of North Dakota, to Lake Winnipeg and the Saskatchewan river, the most northern locality known for the genus. Westward, the range of this group includes Kansas and Nebraska (southern and eastern part only) and the southeastern corner of Wyoming: this is the most advanced point for the genus in a northwesterly direction. Entirely isolated from the range of this group, thus far described, we find a species (€. digueti) in Mexico (Pacific side, State of Jalisco), and another species (C. immunis, known from the prairies of Michigan, Indiana, Illinois, Wisconsin, Iowa) is said to be present near Orizaba, Mexico. Therefore we may say, generally, that the centre of this group is situated in the central part of the United States, about in that region where the three large rivers, Missouri, Mississippi and Ohio, unite. Thence it extends into the eastern and southeastern moun- tains, but hardly across them; northward, it reaches the St. Lawrence and the Saskatchewan rivers and westward Wyoming. In a southwesterly direction it hardly reaches Texas, and the Mexican localities seem to be isolated from the rest. Of the three species of the %#/%% group, two are found in Mexico and one near New Orleans. E" Zu ln, o COM <— po ——— o ee hea 1902.] AND ANCIENT GEOGRAPHY. 281 Taking together the distribution of the five groups, we find that the range of the genus Cambarus extends over the following parts of North America: In Mexico, the respective species are reported from the following States: Vera Cruz (near Vera Cruz and Orizaba), Pueblo, Mexico, Michoacan. This line would represent the southern boundary of the range.! Further, the genus has been found in the States of Jalisco and Sinaloa (Mazatlan) (in the drain- age of the Pacific Ocean) ; on the central pleateau, in Guanajuato, San Luis Potosi (Santa Maria) and Coahuila (Parras). This latter locality forms in a certain degree the connection of the Mexican part of the range of the genus with that of the United States, since the Mexican State Coahuila extends northward to the Rio Grande del Norte, and just across this river, on its left bank, there is, in Kinney county, Texas, a locality for C. c/arki. ‘Thence the range of the genus is apparently continuous, and reaches eastward to the sea (Gulf of Mexico and Atlantic Ocean).” ‘Toward the west and north it is circumscribed by the following line: from Kinney county, Texas, to New Mexico (including its eastern part), then receding toward Indian Territory and leaving out Oklahoma, farther, including Kansas, the southeastern corner of Wyoming (possibly a part of Colorado), the southern and eastern part of Nebraska, crossing here the Missouri, including Iowa and Minne- sota and possibly parts of the Dakotas, at any rate the northeastern corner of North Dakota, crossing over into Canadian territory and including the region of Lake Winnipeg and Saskatchewan river (northernmost point). Thence this line recedes in a southeasterly direction, reaches Lake Superior, and follows the Great Lakes as far as Lake Erie. At Lake Ontario it advances again northward and follows at a certain distance the St. Lawrence river, reaching at the Lake St. John in Quebec the northernmost point in the East. Then it turns southward, crosses the St. Lawrence and includes, in New Brunswick, the drainage of the Restigouche and Miramichi rivers (emptying in the St. Lawrence Gulf) and also the St. John river (emptying in the Bay of Fundy). ‘Thus the largest part of New Brunswick seems to belong to the range of this genus, while 1 The genus is said to be represented near Alta Vera Paz, in Guatemala (Faxon, 1885, p. 173). This would advance the range southward beyond the Isthmus of Tehuantepec. This locality, however, needs confirmation. é - 2Tn Florida, only in the northern half are localities known, southward as far as Orange, Lake and Hillsboro counties. 282 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Nova Scotia is excluded. Isolated from the continuous Mexican . and United States ranges is the Island of Cuba, where C. cubensis has been found. It is hard to say where the centre of the whole genus is situated. Judging from the number of species represented in the different parts, it seems to be more in the East than in the West, but for the rest the genus is pretty evenly distributed in the Southeastern States, in the region of the Alleghanies and the central basin, and decreases markedly only in a westerly direction, disappearing before it reaches the foothills of the Rocky Mountains. In the Southwest, in Texas and New Mexico, the genus is less abundant, and in northern Mexico it is found only near Parras, in the State of Coahuila ; but then again it becomes more abundant in the central part of Mexico. Whether this apparent scarcity in northern Mexico and Texas corresponds to the actual conditions, or whether it is due to defective knowledge of these parts, cannot be decided. One result, however, is very evident: the. genus is preéminently characteristic of the central and eastern parts of the United States, there attaining its highest development as regards the number of species. Now, what is the origin of this distribution of Cambarus? Did this genus originate in these parts, or whence did it come, and which are its ancestors ? In order to answer the first question, we learn much by recalling to our mind the distribution of the single groups as stated above. We have seen that the centre of the first group is in the Southeast ; the range of the second group—although somewhat discontinuous— centres in the Southwest. The third group has evidently its centre in the mountainous regions of the Allegheny system, the fourth group in the central basin and the fifth in Mexico. The second and fifth groups are strongly represented in the Southwest, the first group has distinct relation to these parts, the fourth group only a few isolated stations, while the third group is entirely wanting there.! 1 Faxon (1885, p. 178) expresses this in the following way: in the South (Mexico, Cuba, Gulf States and Atlantic States south of North Carolina) species of the first, second and fifth groups prevail, while comparatively few species of the third and fourth groups are present; in the North (Atlantic States north of South Carolina, Central States and Canada) species of the third and fourth groups prevail, whilz only a few species of the first and second advance into the northern provinces. 1902.] AND ANCIENT GEOGRAPHY. 288 As regards the morphological relations of the five groups, we are to consider first Faxon’s view (1885, p. 19), that the species of the first group are morphologically the most primitive ones. He draws this conclusion chiefly from the shape of the male copulatory organs. If we compare, however, certain species of the second group (simulans, mexicanus, cubensis) with those of the first group in this respect, we see that they chiefly differ from the latter only in the smaller number of hooks on the pereiopoda of the male (only on the third pair, not on the third and fourth, as in the first group). On this account I should prefer to regard the species named as the most primitive forms of the genus, although, on the other hand, I agree with Faxon (1885, p. 47) in believing that the other species of the second group more nearly approach the third group. That the third and fourth groups, compared with the others, are more advanced forms is also my opinion. As the most specialized species I regard those of the third group which have acquired burrowing habits (diogenes, argillicola, dubius). ‘The species of the fifth group differ from ail the rest in the presence of hooks in the second and third pereiopods of the male, and thus I think they represent an early separated side branch. The copulatory organs of the male in this group resemble in certain respects more those of the first and second groups than those of the third and fourth, and the more primitive character of these species is also suggested by the general shape of the body. Thus we see that the more primitive forms of the first, second and fifth groups belong chiefly to the South and point distinctly to a connection with Mexico, while among the more advanced and specialized forms of the third and fourth groups this latter connec- tion is hardly expressed or not at all. Their origin and main dis- tribution belong to the more northern parts. This points to an origin of the genus in the Southwest, and we believe that the genus came from Mexico and immigrated into the United States in a northeasterly direction. A few additional distributional facts tend to support this conclu- sion. It seems that in those groups which possess a large represen- tation in the Southwest the distribution is rather discontinuous. This is most evident with the second groúp. Now discontinuity in distribution of any animal is very often a sign of the breaking up of a former continuous range by unfavorable physical conditions. In the present case it appears that at a certain time the immigra 284 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, tion of Cambarus from Mexico into the United States did not meet with serious obstacles, but that later in the intermediate regions (northern Mexico and Texas) more unfavorable conditions arose which separated the United States more distinctly from Mexico, and this is possibly due to a more decided development of the desert character of these parts. Thus the Mexican representa- tives of the first, second, fourth and fifth groups became more or less separated from those in the United States, the first and fourth groups developed more abundantly in the United States, while the third originated there, possibly out of the second group, which in these parts did not make any marked progress and was suppressed and restricted to a few more or less isolated stations, probably on account of its primitive character. An interesting light is thrown upon this question by the presence of one species of the second group (C. cubensis) in Cuba. This species is closely related to C. mexicanus (Pueblo, San Luis Potosi), while it has no closer rela- tions in the United States, and thus its Mexican origin is most dis- tinctly indicated. Therefore we may safely say of the second group that it is a very primitive one and that Mexico, not the United States, is to be taken as its centre of origin. The character of discontinuity is more or less noticeable also in the southwestern part of the range of the first, fourth and fifth groups. The first possesses an isolated species (wegmannz) in Mexico, and the stations of C. dlandingt and clarki in Texas are very scattered. In the fourth group we have an isolated species (digueti) in Mexico (Jalisco), while C. zmmunis, a species found elsewhere in the northern central basin, has been reported from Orizaba, in Mexico.’ The fifth group has two species in Mexico and, widely separated from them, a third near New Orleans. If we compare with this the northern part of the ranges of the first, third and fourth groups we see everywhere perfect continuity. In every direction from the centre, except toward the Southwest, the intensity of distribution decreases gradually. This is especially true for the first group, the centre of which is in the Southern States, in the directions northward along the Atlantic coast and upward in the Mississippi Valley. In the third group, whose centre is in the Allegheny system, there is a regular decrease in intensity in all directions, and in the fourth group a very regular decrease is 1 We have to accept this record, however, very cautiously. 1902.) | AND ANCIENT GEOGRAPHY. 285 noticeable from its centre in the middle Mississippi basin toward the East, North and West. Thus we are to recognize the fact that the different groups, chiefly the first, third and fourth, express in their distribution a regular, continuous advance in a northeasterly direction. Toward the North and East is continuity, which represents a more recent stage in distribution, while in the opposite direction, toward South- west, we observe discontinuity, which characterizes generally a more ancient stage. In the second group we have a very remark- able discontinuity, and this group is a comparatively primitive one, and the fifth group, which is also primitive in some degree, is chiefly found in the Southwest. All the foregoing considerations tend to justify our conclusion that the migration of the genus Cambarus into the United States started in the Southwest, on the Mexican plateau, and advanced in a northeasterly direction. Taking up now the second point to be considered, the question of the origin and the ancestral forms of the genus Cambarus, we shall be satisfied—for the present—with the opinion of Faxon (1885, p. 16), which is also that of the present writer, that this genus is the most highly specialized within the family Potamobiide, a corollary of which is that it must have originated from forms of a lower type, which probably corresponded to the genus Potamobius ; in fact, it is easy to imagine that Cambarus is derived directly from Potamobius by the suppression of the single posterior pleuro- branchia and the high specialization of the copulatory organs. However, before entering into a more detailed discussion of the relation of Cambarus and Potamobius, we shall give a sketch of the chorology of the latter genus. Genus Potamobius.* It is advisable here to go more into detail, since, on the one hand, a synopsis of the more recent publications in this group is desirable, and since, on the other, the number of species in this genus is comparatively small and our knowledge of them excellent. The genus is divided into two subgenera: Potamobius sens. strict. Ortm. (Astacus sens. strict. Fax.) and Cambaroides Fax. ! The following facts have not been put together since Faxon's review (1885). I shall use here chiefly the revision of this group which I have prepared for the “ Thierreich.” 286 ORTMANN—-DISTRIBUTION OF DECAPODS [April 3, I nu Subgenus Potamobius—twelve species: European group: . pallipes (Lereb.). South and West Europe: Central Spain, France, England, Ireland, Southwest Germany, Italy south- ward to Naples, Dalmatia, Greece. . torrentium (Schrk.). Central Europe: Switzerland, South Ger’ many, Bohemia. . astacus (L.). West Russia (northward to Finland), Austria, Germany, Denmark, South Sweden and Norway (possibly in- troduced), France, southward to Northern Italy. . leptodactylus (Eschz.). Ponto-Caspian basin: Hungary (Danube, Theiss), South and Central Russia, northward to the White Sea; in Siberia in the region of the Caspian Sea. Further, in West Siberia in the basin of the rivers Obi and Irtish, intro- duced, as reported, but possibly indigenous (see Faxon, 1885, POT): . pachypus (Rthk.). Estuaries of the Black and Caspian Seas. ..colchicus (Kessl.). ‘Transcaucasia (upper Rion river). 7. kessleri (Schimk.). Turkestan (Sir Darja). IO. II. I2. American group: . leniusculus (Dan.). Washington, Oregon (lower Columbia river), California (San Francisco). . trowbridgei (Stps.). Washington, Oregon (lower Columbia TINER). ; nigrescens (Stps.). California (San Francisco), Washington, Alaska (Unalaska). klamathensis (Stps.). British Columbia (east of Cascade Moun- tains), Idaho, Washington, Oregon, Northern California (mountain rivers). gambeli (Gir.). In the Rocky Mountains: on the Pacific slope in Utah, Idaho, Wyoming and Yellowstone Park ; on the At- lantic slope; mouth of Yellowstone river (eastern State line of Montana). Subgenus Cambaroides—four species: I. 2. 3. 4. ‚schrenki (Kessl.). Lower river Amur. dauricus (Pall.). Upper river Amur. japonicus (Haan). North Japan: Yesso. similis (Koelb.). Korea. 1902.] AND ANCIENT GEOGRAPHY. 287 Generally speaking the range of the genus Potamobius exhibits a striking discontinuity, which has often been discussed. One group of species occupies a continuous area in Zuroße (and Western Asia); another in Zas? Asia; a third in Western North America. It has been said that it is another remarkable fact that the American species resemble the European more than they do the East Asiatic, and that the latter more approach Cambarus, which idea is ex- pressed by their position in a separate subgenus named Camba- roides. But as regards the gills and the general form of the body,’ Cambaroides belongs without question to Potamobius. ‘The male copulating organs are as different from those of Cambarus as they are from those of the typical species of Potamobius, and the only character that points decidedly to Cambarus is the presence of copulatory hooks on the ischiopodites of certain per&opods. But also in this respect Cambaroides is rather peculiar, since these hooks are found on the second and third pair, which case is represented among Cambarus only in the fifth group (containing only three species), while all the rest of the numerous species of this genus possess these hooks either on the third and fourth or only the third pair. I am of the opinion that the resemblance of Cambaroides to Cambarus does not express very close blood relationship, but is due to convergency. ‘The development of hooks on the perzeopods of the male, which serve, as is now known, the purpose of taking hold of the female in copulation, is easily understood, if we remember the manner in which copulation is performed, and it is also easily intelligible that this device has possibly developed independently in Cambaroides and Cambarus. The shape of the copulating organs, which shows no doubt in Cambaroides a certain similarity to the Cambarus type, can be explained in the same way, since it is quite clear that if they are used in the same manner they may 1 To the latter area belongs an isolated locality of P. migrescens in Alaska. According to Hay (1899) this species is found all along the western coast of North America, from California to Alaska. To my knowledge intermediate locali- ties between Washington and Alaska have not been published. * Faxon (1885, p. 126) calls the shape of the body «“subcylindrical,” and says that it resembles that of Camdarus. I cannot concur with him in this opinion; the form of the carapace in Cambaroides is decidedly rather oval, as in Zotamo- dius, and besides there are variations also in this respect within the genus Cam- darus. 288 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, assume the same or a similar form. If, finally, Faxon says that the shape of the chele in Cumbaroides resembles those of Cambarus, he means apparently only the general weak development of them, and we must bear in mind that many Cambari are more like typical Potamobii in this respect." Thus the view seems supported that Cambaroides is not so very closely related to Cambarus, as has been hitherto supposed, and that the similarities which were emphasized are due only to con- vergency. If we peruse the comparison of the characters of Camba- roides, Potamobius and Cambarus given by Faxon (1885, pp. 126, 127), we find that Cambaroides is in some of them more isolated, and that it resembles in others even more the West American species of Potamobius. (For instance, the lack of a transverse suture of the telson; the shape of the second male abdominal ap- pendage ; the lack of the first abdominal appendage in the female.) The conclusion drawn from the foregoing is that in certain respects (telson, second pleopods of male, first pleopods of female) Cambaroides represents a type that points to the West American Potamobit, while the European species are more divergent from it, and there is nothing that opposes the view that this subgenus (which might as well be regarded as a separate genus) forms the starting point on the one side for the European FPotamodz and on the other for the American Potamobii, while subsequently it has changed itself and become different from both (in the male copula- tory organs). The subgenus Cambaroides is restricted to the northeastern parts of Asia (region of Amur river, Korea, North Japan). The exact boundaries of its range have nowhere been located positively, and it is not impossible that in the Siberian and northern Chinese mountains other representatives of it may exist. For the present “the area from which species of Cambaroides are known is absolutely separated from the European area of Potamobiws. As regards the latter, its centre is apparently in Southern and Central Russia. From these parts the different species extend into Western Europe, southward to Central Spain, Middle Italy and Greece, and in Russia one species passes southward across the Caucasus Mountains, Eastward a species is found as far as Turke- 1 Some other characters of Cambaroides indicate that this subgenus differs from Potamobius as well as from Cambarus, and these are characters which approach it to the crayfishes of the southern hemisphere. Compare below. 1902.] AND ANCIENT GEOGRAPHY. 289 stan, and northward the area reaches the White Sea. East of the Ural Mountains the genus is said to be lacking, but it is found (the widely-distributed species 2. /eptodactylus) introduced in the river Obi and its affluents. Some observations, however, have been made which render it possible that P. /eptodactylus is an original inhabitant of these parts. As Huxley (1879) and Faxon (1885, p. 140) believe, the different forms of Potamobius have immigrated into Europe from the East, and we can distinguish an older immigration on the part of the group formed by the species 2. pa/lipes and Zorrentium and a more recent one on the part of P. astacus and its allies. And even within the latter group it seems that ?. astacus is older than the other species and that it is pushed gradually westward by 2. depéo- dactylus, which is spreading in a westerly direction. The writer is of the same opinion, and we shall see below that this is the only theory that is admissible, if we consider the origin of Europe as a continental mass. ‘The occupation of Europe, after it had lost the character of an archipelago and become part of the Eurasiatic con- tinent, was possible for these animals only in a west-easterly direc- tion. This corresponds also to the fact that those forms allied to the European otamobiz, which are the nearest geographically, are found to the east of them. They are the forms of Cambaroides in Eastern Asia, and we can readily imagine that from the area of dis- tribution of Cambaroides an extension existed formerly in a westerly direction across Central Asia, which connected with the European area of Polamobius, and this connection represents the direction of the migration. The forms of Potamobius which are found in Western North America possess a continuous area of distribution ! which is separated from the rest of the genus. Huxley and Faxon, as has been men- tioned above, believe that these American species are more closely related to the European, but I think we have reason to accept a different view. My opinion is that a primitive group, which was ancestral to all three of the living groups, formerly existed in Eastern Asia, which is to be regarded as the centre of origin of the Potamobiide. This group sent out a branch in a westerly direction, which finally reached Europe, and it also sent out a branch in an easterly direc- tion, which migrated apparently along the northern shores of the 1 Possibly with the exception of the isolated station near Unalaska. 290 ORTMANN—DISTRIBUTION OF DECAPODS [April 3 Pacific Ocean and finally immigrated into Northwestern America. A trace of the direction of this route is preserved in the presence of Potamobius nigrescens near Unalaska. After the final geographical separation of the European and American descendants from the original group in Eastern Asia each of the three groups developed independently, and the Asiatic group acquired several more advanced characters (copulatory organs and hooks) which otherwise are found only in Cambarus, but which do not point to a closer affinity to the latter genus, but are only due to parallelism. Further, the West American Potamobii possess a character that is found also in Caméarus. Faxon mentions that the second pleopods of the male resemble not only those of Cambaroides, but also those of Cambarus, while the European species are different in this respect. This would bring the genus Cambdarus into closer relation to the West American Potamobii, and although this similarity would hardly be of much value by itself, we have to regard it as significant, since it agrees well with the distributional facts. The tracing back of Cambarus to Cambaroides is geographically impos- sible, and just this latter difficulty has induced the writer to exam- ine more closely the supposed resemblance of both, and the result is as has been discussed above. A closer connection of the Euro- pean species of Potamobius with Cambarus is out of the question," and thus only the third group is left, the West American Potamobii. From the latter group Cambarus is very sharply distinguished though and no transitional forms are known. Probably this is due to the fact that the connection of the area of both is far remote geologically—that is to say, that the migration of Potamobius into Mexico is very old and that the separation of both genera took place in very early times, the one becoming restricted to North- western America (southward to California), the other developing on the Mexican plateau out of the old Potamobdius stock that origi- nally immigrated thither from the North. Thus the differential characters of Cambarus became well fixed and no transitions to the old stock are found any more. Thus for the family of the Pofamobüde we may express the fol- 1 Faxon (1885, p. 176) thinks that in former times Camdarus and Potamobius occupied about the same area, and in order to support this he mentions the sup- posed existence of a blind Camdéarus in the caves of Carniola, Austria. How- ever, this latter record is entirely erroneous. There exists no Carzdarus in the caves of Carniola (see Haman, Zurofeische Hoehlenfauna, 1896). 1902.] AND ANCIENT GEOGRAPHY. 291 lowing opinion as to the origin of its distribution, founded exclu- sively upon systematic and chorological studies. The oldest home of the Potamobiide and their centre of origin is somewhere in Eastern Asia. This ancestral stock spread chiefly in two directions: a western extension of the range crossed Central — Asia, finally reaching Europe, while an eastern extension went across Bering Strait and reached the western parts of North Amer- ica. The continuity of this wide area, which was once wholly occupied by the genus Potamobius, was interrupted subsequently in Central Asia and where there is now Bering Sea, and thus three isolated areas were formed—in Europe, in Eastern Asia and North- west America. In each one of these parts the genus Potamobius continued to develop separately. From the West American stock of Potamobius finally issued the genus Cambarus, which probably originated in Mexico and thence invaded the central and eastern parts of North America. The origin of Cambarus probably lies far back in time, since it shows no marked special affinities to any of the three groups of Potamobius, and probably it was'separated from the latter genus before it was divided up into those three groups. 2. Family Parastacide Huxl. A systematic revision of this family has not been published hith- erto. The present writer has tried to collect the necessary data for a review in the “ Thierreich,’’ and although it is not possible to give acomplete synopsis, based upon careful criticism of the existing descriptions as well as upon actual specimens, he has obtained a fair general idea of the various forms which make up this family. According to these studies the present state of our knowledge of the distribution of this group is the following: 1. Genus Cheraps Er. em. Huxl. Species: 1. guinquecarinatus (Gr.). West Australia: Swan river. . 2. quadricarinatus Mrts. North Australia: Cape York. 3. Stcarinatus (Gr.). North and East Australia: Port Essington, Cape York, Rockhampton, Burnett river, Sydney, Melbourne, Murray river. | 4. pretsst Er. Southeast Australia: Victoria. 292 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Doubtful species: australiensis (M.-E.). Sydney.' 2. Genus Astacopsis Huxl. Species: 1. franklini (Gr.). N.S. Wales and Tasmania. 2. serratus (Shaw). N. S. Wales: Murray river, Murrumbidgee river, Richmond river, Brisbane Water and Paramatta river near Sydney. The following species represent probably young stages of A. serratus: paramattensis Bate and sydneyensis Bate, both from Sydney. Doubtful species: Zasmanicus Er. ‘Tasmania. 3. Genus Zngeus Er. Species: 1. fossor Er. ‘Tasmania. 2. cunicularius Er. ‘Tasmania. 4. Genus Paranephrops White. Species: 1. planifrons White. New Zealand, North Island and northern part of South Island. , 2. zealandicus (White). New Zealand, South Island: Dunedin, Oamaru (Otago). 3. setosus Hutt. New Zealand, South Island: Canterbury. This genus possibly is also represented in the Fiji Islands (Huxley). A doubtful genus, which perhaps belongs in this N... is genus Astaconephrops Nobili. Species : 1. albertist Nobili. Southern New Guinea: Katau. 5. Genus Zarastacus Huxl. Species : 1. pilimanus (Mrts.). Southern Brazil: Rio Grande do Sul. Northern Argentina: Provinces Corientes, Entrerios, Cata- marca. 1 By Nobili (1899, p. 246) this species is classified with Astacopszs, and is recorded from the Island of Sorong, west end of New Guinea. It is very doubt- ful whether this is correct. 1902.] AND ANCIENT GEOGRAPHY. 293 2. brasiliensis (Mrts.). Southern Brazil: Rio Grande do Sul. hassleri Fax. Chili: Talcahuano, Tumbez. defossus Fax. Uruguay. Brazil: Rio Grande do Sul.’ saffordi Fax. Uruguay. Brazil: Rio Grande do Sul.! . varicosus Fax. Reported from Colima, Mexico.’ nicoleti (Phil.). Chili: Tumbez. agassizi Fax. Chili: Talcahuano, Llanquihue (Puerto Montt), Tumbez. Argentina: Lake Nahuel Huapi. Doubtful species: chilensis (M.-E.), spinifrons (Phil), dimacu- Zatus (Phil.), all three from Chili. This genus is also found in Sta. Catharina, Southern Brazil, according to Fr. Mueller. ou Dn pw 6. Genus Astacoides Guér. Species: 1. madagascariensis (M.-E.). Madagascar. As regards the detailed limits of the range of the single species and genera we are very poorly informed, and, further, it is quite possible that our knowledge of the Australian and South American crayfishes is very incomplete also on the systematic side, and it is very likely that there are many unknown species. It is evident at the first glance, however, that the distribution of the Parastacide is divided into four absolutely isolated areas: Australia (including Tasmania and possibly New Guinea); New Zealand; part of South America; Madagascar. Within each of these areas are peculiar genera: in Australia, Cheraps, Astacopsis, 1] have received these two species, defossus and sajfordi, from Rio Grande do Sul through Dr. H. von Ihering. 2 This locality most emphatically needs confirmation. It is very surprising that this species has never been rediscovered anywhere in Mexico, although large col- lections of freshwater Crustaceans from these parts have lately reached the United States Museum. 3 Through Prof. W. B. Scott, of Princeton, I have received from the La Plata Museum two males and one female of this species from this locality which agree well with the description, with the exception that in the larger (adult) male the right (larger) chela is more elongate, with almost parallel margins, and that the squamiform granules of it are more strongly marked. The smaller male and the female agree perfectly with P. agassizi. The lake Nahuel Huapi is situated in the Cordilleras, at the southern extremity of the Argentinian province Neuquen. It drains into the Atlantic through the river Limay Leofu, which finally forms the Rio Negro. This locality is directly east of Llanquihug, in Chili, but on the opposite slope of the Cordilleras. 294 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Engeus; in New Zealand, Paranephrops; in South America, Parastacus ; in Madagascar, Astacoides. All these forms are more or less closely related to each other, only Astacoides from Mada- gascar is rather isolated morphologically, since its branchial formula shows peculiar reductions (only one pleurobranchia on the fifth seg- ment of the thorax, while in all the rest four pleurobranchis are present). In this respect Aszacoides resembles the Potamobiide of the northern hemisphere. If it should prove to be correct that the genus Astaconephrofs of Nobili, from Southern New Guinea, as its author believes, is most closely related to the New Zealandian Paranephrops, this, together with the occurrence of Paranephrops in the Fiji Islands reported by Huxley, would indicate a distinct direction of the communication between New Zealand and the rest of the world. This would have been over the Fiji Islands in the direction toward New Guinea. As to the connection of the South American Parastaci with the rest of the family, we have hardly any systematic or chorological facts which permit more detailed conclusions. We can only venture to express the opinion that some kind of a connection between South America on the one side and Australia or New Zealand on the other must have once existed. In order to get an adequate idea as to the geographical relations of the genus Astacoides we have to recall to our mind a few facts concerning the morphological relations of the Parastacida and the Potamobüde (see Ortmann, 1901, p. 1289). According to Faxon (1885, p. 126 f.), among the crayfishes of the northern hemisphere it is only the subgenus Cambaroides which approaches those of the southern. Not only the characters mentioned above, the absence of a suture on the telson and the absence of the first pleopods in the female, are common with the southern forms, but there is alsoa peculiarity in the arrangement of Leydig’s olfactory organs on the external flagellum of the antennules which is found in Cambaroides as well as in the Parastacide. Moreover, if we consider the fact that among the Parastacide it is just the genus Astacoides from Madagascar which shows, in the branchial formula, a similarity to the Potamobiide (although in other respects the gills are peculiarly developed), it is easy to imagine, in trying to construct a connec- tion between both families—and such a connection must have once existed—that this was located between the area of Cambaroides (Northeast Asia) and that of Astacoides (Madagascar). This would 1902.] AND ANCIENT GEOGRAPHY. 295 be over India and China, generally over Southern and Eastern Asia. Under this assumption, that crayfishes formerly existed in Southeastern Asia, it also becomes clear by which way the rest of the Parastacide were geographically connected with the Potamo- bide, namely, by way of the Indian Archipelago, from the conti- nent of Asia over the Sunda Islands,. New Guinea to Australia. Looking over the various connections between the different isolated areas of distribution of the different groups of crayfishes, which have been suggested by the above chorological and system- atical discussions, we may itemize them in the following way: 1. A connection of East Asia with North America by way of Bering Sea. 2. A connection of Cuba with Central America (Mexico). 3. Aconnection of New Zealand with Australia, possibly over the Fiji Islands and New Guinea. 4. A connection of Australia or New Zealand with South Amer- ica. . 5. A connection of Southeastern Asia with Madagascar and with Australia. We need further explanation of the following remarkable facts: 1. The absence of Potamobiide in Central Asia. 2. The absence of crayfishes in Southeastern and Eastern Asia. 3. The remarkable geographic restriction and isolation from each other of the crayfishes of the genera Potamodius and Cambarus in North America. 4. The remarkable boundaries of the area of Parastacus in South America. B. CHOROLOGY OF THE FAMILY /EGLEIDE! (See Fig. 2). Here we shall leave for the present the crayfishes of the families of the Potamobiide and Parastacide and shall take up the small group formed by the Zgleida of Dana. This seems to be a mono- typic family, consisting only of one genus and one species, g/ea levis (Latr.). The following localities are recorded for it: Chili: Valparaiso, and between Valparaiso and Santiago ; Lake Llanquihue, near Puerto Montt.” Argentina: Provinces Jujuy 1 See Ortmann, 1901, p. 1290. 2 Doflein, 7. SB. Akad. Muenchen, V. 30, 1900, p. 135. 296 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, (this is the northernmost point, near the Bolivian boundary), Tucu- man, San Luis,’ Buenos Ayres.” Uruguay. Southern Brazil: Rio Grande do Sul and Santa Catharina. As may be seen, the extremities of the range on the Atlantic side, Sta. Catharina and Uruguay, and the | southernmost locality in Chili, near Puerto Montt, are also mentioned for the genus Parastacus, and in fact the distribution of Parastacus and _Eglea are almost identical (see figs. ı and 2), only glea seems to ex- tend a little more to the north (Jujuy). This similarity is the more striking, since in both cases the chain of the Cordilleras, which crosses the Fic. 2. Distribution of Zglea : ; levis (Latr.). area of distribution from north to south, has absolutely no effect; both genera are found on either side of this mountain range, and in the case of “glee levis and Parastacus agassizi the identical spe- cies is found east and west of the Cordilleras. This fact is very significant, and important conclusions may be derived from it. C. CHOROLOGY or THE FRESHWATER CRABS OF THE FAMILY POTAMONIDE (See Figures 3 and 4.) BIBLIOGRAPHY. (a) Revisions, more or less complete. MILNE-EDWARDS, A.: “Revision du genre Thelphuse” (Nouv. Arch. Mus, Paris, V. 5, 1869, pp. 161-191). HENDERSON, J. R.: “A Contribution to Indian Carcinology ” (77. Zinn. Soc, London, Ser. 2, Zool., V. 5, 1893, p. 380 ff.). Here a revision of the Indian species. ORTMANN, A. E.: “ Carcinologische Studien ” (Zool. Jahrb, Syst., V. IO, 1897, Ppp. 296-329). Revision in part, chiefly for the subgenera Potamonautes, Geothelphusa, and the subfamilies Potamocarcinine and Trichodactyline. ! Nobili, G. Boll. Mus. Torino, V. 11, No. 265, 1896. 2 I have received from the Museum in La Plata specimens that are labeled - Ensenada, Rio de la Plata. AND ANCIENT GEOGRAPHY. 297 1902.] Fıc, 3. Distribution of the Crabs aci a SS ae DE Do 2 O O Ya 298 ORTMANN—DISTRIBUTION OF DECAPODS [April 3 RATHBUN, M. J.: “A Contribution to a Knowledge of the Freshwater Crabs of America. The Pseudothelphusine” (roc. U. S. Nat. Mus., Vol. 21, 1898, PP. 507-537)- Revision of the subfamily Pseudorhelphusine — Potamocarcinine. DE MAN, J. G.: “ Notes sur quelques especes des genres Parathelphusa et Potamon, recueillies par M. Leonardo Fea pendent son voyage en Birmanie ” (Ann. Mus. Genova, Ser. 2, Vol. 19, 1898, pp. 384-440). Here a nominal list of the described species of Potamon, with localities. (6) More recent systematic papers, not included in the above revisions. BORRADAILE, L. A.: «On a Small Collection of Decapod Crustaceans from Fresh Waters in North Borneo” (77. Zool. Soc. London, 1900, pp. 93-95). DorLEIN, F.: “ Amerikanische Dekapoden der k. bayerischen Staatssamm- lungen ” (SB. Akad. Muenchen, Vol. 29, 1899, pp. 187-188). —— “Ueber eine neue Suesswasserkrabbe aus Columbien ” (Zbid., Vol. 30, 1900). —— « Ostasiatische Dekapoden ” (4bh. k. bayerischen Akad. Wiss., Vol. 21, 1902, pp. 626-628, 662-663). HILGENDORF, F.: “Die Land- und Suesswasser-Dekapoden Ostafrikas ” (in Meebius, K. Deutsch Ostafrika, Vol. 4, 1898). LANCHESTER, W. F.: “On Some Malacostracous Crustacea from Malaysia in the Collection of the Sarawak Museum” (Ann. Nat. Hist., Ser. 7, Vol. 6, 1900, pp. 255-257). DE MAN, J. G.: “ Note sur quelques Thelphusides recueillies par M. Pavie dans VIndo-Chine” (Bull. Soc. Philom. Paris, Ser. 8, Vol. 10, 1898, pp. 36-52). —— “ Description d'une espéce nouvelle du genre Potamon Sav. provenant du pays des Somalis” (Ar. Mus. Genova, Ser. 2, Vol. 19, 1898). — “ Zoological Results of the Dutch Scientific Expedition to Central Borneo. The Crustaceans. Part 2” (Not. Leyden Mus., Vol. 21, 1899, pp. 67-132). —— “Description of a New Freshwater Crustacean from the Soudan’’ (Pr. Zool. Soc. London, 1901, pp. 94-104). NosiLi, G.: “ Viaggio del Dott. A. Borelli nella Republica Argentina e nel Paraguay. Crostacei Decapodi” (Goll. Mus. Torino, Vol. 11, No. 222, 1896). —— “Di uma nuova varieta della Thelphusa dubia racolta a Kazungula ” (Zbid., No. 262, 1896). I —— “Viaggio del Dr. Enrico Festa nella Republica dell’ Ecuador. Decapod! terrestri e d’acqua dolce” (/bid., Vol. 12, No. 275, 1897). —— “ Decapodi e Stomatopodi racolti dal Dr. Enrico Festa nel Darien, etc.” ( Zbid., No. 280, 1897). —— “Supra alcuni Decapodi terrestri e d'acqua dolce” (Ann. Mus. Genova, Ser. 2, Vol. Ig, 1898, pp. 9-14). —— “ Intorno ad alcuni Crostacei Decapodi del Brasile” (Doll, Mus. Torino, Vol. 14, No. 355, 1899). —— ‘ Contribuzioni alla conoscenza della fauna carcinologica della Papuasia, 1902.] AND ANCIENT GEOGRAPHY. 299 delle Molucche e dell’ Australia” (Ann. Mus. Genova, Ser. 2, Vol. 20, 1899, pp. 261-264). NoßiL1, G.: “ Decapodi e Stomatopodi Indo-Malesi ’’ (/did., Ser. 3, Vol. 20, 1900, pp. 499-504). —— “ Decapodi raccolti dal Dr. Filippo Silvestri nell’ America meridionale ”’ (Boll. Mus. Torino, Vol. 16, No. 402, 1901). —— “Viaggio del Dott. Enrico Festa nella Republica dell’ Ecuador. Decapodi e Stomatopodi ’’ (/bid., Vol. 16, No. 415, 1901). RATHBUN, M. J.: “ Descriptions de nouvelles especes de Crabes d’eau douce appartenant aux collections du Muséum d’histoire naturelle de Paris” (Bull. Mus. Paris, 1897, pp. 58-61). —— « Descriptions of Three New Species of Freshwater Crabs of the Genus Potamon ” (Pr. Biol. Soc, Washington, Vol. 12, 1898, pp. 27-30). — “The Decapod Crustaceans of West Africa” (Pr. U. S. Mus., Vol. 22, 1900, pp. 282-285). —— “The Brachyura and Macrura of Porto Rico” (Bull. U. S. Fish Comm. Jor 1900, Vol. 2, 1901, p. 23). —— “ Description des nouvelles especes de Parathelphusa appartenant au Muséum de Paris’ (Bull. Mus. Paris, 1902, p. 184 ff.). WEBER, M.: «Die Decapoden Crustaceen des Suesswassers von Sued-Afrika ” (Zool. Fahrb. Syst., Vol. 10, 1897, p. 156). According to Ortmann (1897) the family of Potamonide Ortm. (= Thelphuside Dan.) is divided into four subfamilies: Potamonine Ortm., Deckeniine Ortm., Potamocarcinine Ortm.,' and Tricho- dactyline Ortm. The first two belong to the Old World, the last two inhabit the New World.’ 1. Subfamily: POTAMONINE. . The subfamily Potamonine is in very poor condition, systemati- cally. Not only our knowledge of the very numerous species is rather incomplete, but also their arrangement into genera and sub- genera is by no means satisfactory. Generally, it seems that we can distinguish two genera: Parathelbhusa M.-E. and Potamon Sav. (= Thelphusa Latr.), to which possibly a third one is to be added, 1 _.. Pseudothelphusing Ortmann and Rathbun (1898, p. 508). The division into genera varies considerably with Ortmann and Rathbun respectively (see below), and the name of the subfamily depends on the classification accepted. 2 According to Alcock ( Fourn. Asiat. Soc. Bengal, Vol. 69, 1900, p. 279), also Gecarcinucus (one species in the peninsula of India), which was placed hitherto with the family Gecarcinide, belongs to the Thelphuside (= Pota- monide). If this is so, we ought to create, possibly, a separate subfamily for this genus. 300 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, the very incompletely known Zrimetopus of Rathbun. The value of a few other genera, created by various authors, is extremely doubtful. Parathelphusa is represented by typical species in the northern parts of India, in Burma, Siam, Anam, Malacca, Southern China (Hongkong and Canton), and in the Sunda Islands: Sumatra, Borneo, Java, extending to Timor and New Guinea. With the same genus some other forms have been classified which are found in certain parts of Africa (Congo basin and Nile river) ; but these have been placed by the present writer in a subgenus (Acanthothel- phusa) of Potamon, since they differ in their general shape very strikingly from the Asiatic species of Parathelphusa. Unfortunately these African species are very poorly known; only of the Nile species figures have been published (Milne-Edwards and Hilgen- dorf), and according to these it is impossible to unite this species and its supposed allies with Parathelphusa.* As regards the genus Pozamon, it is divided into several sub- genera, which, however, are not very sharply defined. Aside from the doubtful subgenus Acanthothelphusa just mentioned, there are three of them which are generally recognized: Potamon (sens. strict.), Potamonautes Macl., and Geothelphusa Stps. The centre of the subgenus Petamon is, no doubt, in India and Farther India. Thence it extends eastward to the greater Sunda Islands (Sumatra and Java); it is found in the Philippine Islands, but does not advance any farther in this direction. Northward it enters China, where it is known from the Yang-tse-Kiang (see Doflein, 1902, p. 662). It does not seem to pass beyond the Himalaya Mountains to the north, but extends considerably west- ward (possibly in a single species), going through Persia to the Transcaspian countries, crossing the Caucasus Mountains and extending to the Crimea ; from Mesopotamia it extends to Syria and Asia Minor, where it reaches the Mediterranean countries, and here it is found in Northern Egypt, Turkey, Greece, Italy, Sicily, and 1 Possibly Platythelphusa A. M.-E. (see Hilgendorf, 1898, p. 21) from Lake Tanganyika also belongs here. 2] disregard, for the present, the subgenus Perithelphusa de Man (1899, p. 70), which contains apparently rather primitive forms of Geothelphusa, and, on account of its exclusive occurrence in Borneo, may be left united with Geothelphusa. As to Platythelphusa, see the last note. As to Hydrothelphusa A. M.-E., see below. 1902.] AND ANCIENT GEOGRAPHY. 301 farther in Algiers as far as Oran.* It is a remarkable fact that this subgenus is entirely absent from Africa proper, z.e., the part of it that lies to the south of the Sahara Desert. The subgenus Potamonautes, on the contrary, has its chief centre of distribution in tropical Africa. It has been found, beginning at Liberia, all along. the western coast as far as Mossamedes. It is found in the interior, in the region of the upper Zambesi (Kazun- gula), extends over Transvaal to the Cape Colony, and northward all along the eastern coast (Natal, Mozambique) to German East Africa. Also in the eastern part of the interior it is represented, for instance, in the headwaters of the Nile (Victoria Nyanza) and in the Somali country. From the upper Nile it extends down the Nile valley as far as Bahr-el-Gebel in the Egyptian Soudan. It is also found on the Island of Socotra and in Madagascar, although “the species of the latter island do not seem to belong to the typical form of this subgenus.’ ; 1A. Milne-Edwards reports a species that is identical with an Indian (2. Ze- schenaudi (M.-E.)) from Mauritius: this locality, however, lacks confirmation. As regards the Madagassian species of Zotamon, their systematic position is doubtful, and they possibly do not belong to this subgenus. Compare next note. 2 Three species of Potamon are known from Madagascar. PP. goudoti (M.-E.) (see A. Milne-Edwards, 1869, p. 172, Pl. 8, Fig. 4) is a peculiar form, but its postfrontal crest distinctly points to Putamonautes. A. Milne-Edwards compares “it with 2 odesum A. M.-E. from Zanzibar, and indeed it seems to be closely related to it. The latter species is also an abnormal type of Potamonautes, and forms with several others a group that is peculiar to East Africa; but there is no reason to separate this group from /ofamonautes, and thus we may safely regard P. goudoti .as a Potamonautes. The second species is P. madagas- cariense (A. M.-E.) (Ann. Sci. Nat. Zool., Ser. 5, Vol. 15, 1872), As to this form, the diagnosis of which is very brief, and which has not been figured, its author says that it is a true 7e/phusa (2.e., subgenus Potamon), but this seems hardly correct according to the descrip'ion of the postfrontal crest, which is said to be simply interrupted in the middle, while the median parts of it are not advanced beyond the rest. This would better agree with Potamonautes. The third species is regarded by A. Milne-Edwards (/ézd., 1872) as the type of a separate genus, Zydrothelphusa (H. agilis A. M.-E.). This genus is said to be characterized by the flat carapace, which is scarcely dilated and almost quad- rangular, and by the horizontal front. The postfrontal crest is distinct and interrupted. Since no figure is given, it is hard to form an opinion as to the “relation of this form to others, but it seems to be very peculiar. Thus it seems that the Madagassian species of /otamon show, in some respects, a distinct relation to East Africa and the subgenus Pofamonautes, while in others they appear quite peculiar. (This is opposed to the opinion expressed by myself in I901, p. 1290, footnote.) 302 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, The main range of Potamonautes in Africa seems to be almost continuous, but absolutely isolated from it is a secondary centre in South Asia. Here this subgenus is represented in India, and thence it extends to Farther India, and reappears on some of the islands: Pulo Condore on the coast of Cochin China, in the Philip- pine Islands, Celebes and New Guinea. These latter localities are distinctly discontinuous. | The third subgenus, Geothelphusa, undoubtedly has its centre in the extreme East, and it is most characteristic for the Malaysian Islands. On the Asiatic continent it seems to be absent ; but it is found abundantly in Sumatra, Java, Borneo, and extends eastward over Aru Island and New Guinea to North Australia, where it is found on the Cape York Peninsula, and in Queensland as far as Port Mackay." Northward this subgenus ranges over the Philippine and Loo-Choo Islands to Japan, where it reaches its northernmost station in the neighborhood of Tokyo. On the continent of Asia typical species of this subgenus have not been found ; indeed a few small species from India have been described which might be united with this subgenus, but this is by no means sure. | But this identical subgenus, Geothelphusa, is apparently found in another locality isolated from the rest of the range: this is P. berardi (Aud.) from Egypt (Nile river). This species, however, is also morphologically isolated from the rest; and further, this subgenus is recorded by Rathbun from Liberia (2. macropus Rthb., 1898), and some species from East and Central Africa, related to P. obesum, mentioned above, resemble, in the reduction of the postfrontal crest, the subgenus Geothelphusa,*? while on the other hand they are undoubtedly related to the subgenus Potamonautes. It is quite possible also that P. derard: from Egypt (Kairo south- ward to Mount Elgon) belongs to this East African group. In my opinion, all these species do not properly belong to Geothelphusa, and we have to deal here again with a case of convergency: the 1 According to de Man, an Australian species (P. transversum (Mrts.)) is also found in the Fiji Islands; but this lacks confirmation. 2These are P. obesum (A. M.-E.), Zanzibar; P. emini Hlgdf., P. new- manni Hlgdf., P. pilosum Hilgdf. (Hilgendorf, 1898), all three from East Africa and the region of the Great Lakes. Possibly P. socotrense Hilgendorf (1883, Zeitschr. d. Naturw., Ser. 4, Vol. 2) = P. granosum Koelbel (SB. Akad, Wien, Vol. 90, 1885) belongs here. o E Sagas Pa 1902.] AND ANCIENT GEOGRAPHY. 303 tendency to reduce the postfrontal crest has developed in the East African forms independently from the typical Geothelbhusce, and the East African (possibly also the Liberian) species form a pecu- liar branch of Potamonautes. The genus Zrrimetopus of Rathbun is found so far only in the Congo basin. Considering the distribution of the subfamily Potamonine in general, we see that it is continucus over the whole of tropical Africa, then it extends through the Nile valley into the Mediterranean regions and connects with the Asiatic range, which . goes from Syria over Mesopotamia, Persia to India, China and the Malaysian archipelago, over which it finally reaches Northern Austra- lia and Japan. This whole range is practically continuous, only the larger continental islands (disregarding the smaller ones), Mada- gascar and the Sunda Islands, the Philippines, New Guinea and Japan, constituting breaks in the continuity. Within this large area, however, we are able to distinguish two main divisions: an African, characterized by the prevalence of the subgenus Potamonautes, the complete lack of the subgenus Potamon (and possibly of Geothelphusa), and an Asiatic- Australian division, characterized by the prevalence of the subgenus Pofamon, the pres- ence of Geothelphusa (in its eastern part), and the scarcity of Potamonautes. Both divisions are practically connected by the Nile valley ; this connection, however, does not seem to represent the original condition, but suggests a secondary one, since different types are here associated which are not at all related to each other. Species of Potamonautes, to which subgenus, according to our opin- ion, P. berardi also belongs, migrating northward from the Soudan, have met here in Lower Egypt a species of the subgenus Po/amon (P. fluviatile), which had migrated westward from India. Both subgenera entered the Nile valley from different directions and accidentally became occupants of the same territory, but the Nile valley is not the route of migration by which African species migrated into Asia or vice versa. Aside from this narrow connection, the fauna of freshwater crabs of tropical Africa is very sharply characterized and isolated from Asia," and the fact is worth special mention that North Africa 1 The peculiarity of the African fauna is emphasized by the doubtful forms of Parathelphusa (or Acanthothelphusa), and by Erimetopus. 804 ORTMANN— DISTRIBUTION OF DECAPODS [April 3, (Lower Egypt and Algiers) points, like the whole of the Mediter- ranean region, to India, from which locality the species present there, P. fluviatile (Latr.), has apparently migrated in an east-westerly direction over Persia, Mesopotamia and Syria. P. fluviatile has been actually recorded from western India; at any rate the most closely allied species to this one are found in India and China. Other remarkable facts in the distribution of this subfamily may be summed up thus: 1. The Asiatic as well as the African part of the range is occu- pied by the subgenus Potamonautes. It is impossible to say which was the original home of Potamonautes, but this much is evident, that it must have been present in both parts at a comparatively early time, it being probably older than Potamon sens. strict. In Africa Potamonautes attained its highest development, being the prevailing type there and showing great variety. 2. Madagascar, while belonging distinctly to Africa in its fauna, possesses some rather peculiar types. 3. The subgenus Potamon originated in Asia, apparently at a time when there was no connection any more with tropical Africa or Madagascar. The immigration of Potamon into the Mediterranean countries, across Persia, etc., is probably a comparatively recent one, since the route of immigration is easily traced and occupied by one single species. 4. The Malaysian and Philippine Islands, Japan and North Austra- lia possess in Geothelphusa a very peculiar group. This distribution of Geothelphusa does not correspond to that of Parathelphusa, Potamonautes and Potamon sens. strict., which are also found in the Malaysian Islands. Potamonautes and Parathelphusa are similar in this respect, possessing on the Sunda Islands only scattered stations (as far as New Guinea), which by their discontinuity express an ancient condition. Pofamon points directly to an Indian origin, extending only to Sumatra, Java and the Philippines, but going not any farther to the east. 5. The position of Parathelphusa is hard to understand. If it is really absent in Africa, as we believe, its distribution in Asia is rather eastern than western, being chiefly found in Farther India. Its extension over the Sunda Islands to New Guinea points to old conditions. Since the morphological relations of Parathelphusa to the rest of the subfamily are not well understood, it is better to exclude it from our further consideration. 1902.] AND ANCIENT GEOGRAPHY. 305 Supposing that this subfamily must have had once a more or less continuous distribution, we are to draw from this the following conclusions as to the geographic conditions of the past: 1. Africa and India must have been connected once. This connec- tion, however, was not by way of North Africa, Arabia and Persia, and ts possibly identical with that from Africa over Madagascar to India, discussed above (see No. 5, p. 295). 2. Madagascar must once have been a part of Africa. 3. Lhe Indo-Malaysian Islands, including the Philippine Islands, Loo-Choo Islands and Japan, must have been once connected not only between themselves, but also with New Guinea and North Australia (as indicated by Geothelphusa). On the other hand, the distribution of the typical forms of Potamon indicates that some of these tslands (Sumatra, Java, Philippines) were once connected with the continent of Asia. Then, again, by Potamonautes (and Parathelphusa) the former continuity of the whole region from India to New Guinea is indicated (see p. 295). Ltisevident that here repeated and important changes of the mutual connections have taken place at different periods of the past. The history of the subfamily of Potamonine would then be this: Its centre liesin an Afro-Indian continental mass, which was divided subsequently into two parts, tropical Africa and India. From India the subfamily extended at a very early period over the Sunda Islands, Philippine Islands, which consequently must have formed a part of the continent, and this continental connection extended as far as New Guinea and Australia, but not without repeated inter- ruptions and changes. Inthe region of unstability and change lies the home of the subgenus Geothe/phusa, which was able at a certain time to go as far north as Japan. A separate branch of the sub- genus Potamon was sent out from India westward, which finally reached the Mediterranean countries, where it met in the lower Nile valley a branch of the African subgenus Potamonautes which came down the Nile from the south. 2. Subfamily: Deckeniine. The second subfamily of the Oid World, the Deckenzine, contains only one genus, Deckenia Hlgdf. (see Ortmann, 1897, p. 314), of which three species have been described : D. imitatrix Higdf. Interior of British East Africa: Taro (Hil- 306 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, gendorf, 1898, p. 23) and Somali country (de Man, 1898, p: 270): D. mitis Hlgdf. (1898, p. 24). German East Africa and British East Africa (Mombas). D. alluaudi A. M.-E. and Bouv. (= cristata Rthb.). Seychelle Islands. The Derckentin« are, as is expressed by their morphological char- acters (Ortmann, 1897, p. 297), a highly specialized group of the family which may be connected without hesitation with the genus Potamon, and possibly with the African branch of it. This sub- family is a group localized in East Africa, and the presence of one of the species in the Seychelles indicates a former connection of these islands with East Africa. It is quite probable that this con- nection is an additional proof for that old Afro-Indian landbridge discussed above, which included Madagascar (see No. 5, p. 295, and No. I, p. 305). 3. Subfamily: Potamocarcinine. The subfamily Potamocarcinine (= Pseudothelphusine) is re- stricted to America and is wanting in the Old World. The syste- matic arrangement of it is a matter of discussion, since the two revisions published by Rathbun and Ortmann do not agree as to the principles of division. Regarding the subfamily as a whole, its range comprises the following parts: West Indies—Greater Antilles: Cuba (including the Isle of Pines), Hayti, Porto Rico (including Santa Cruz); Les- ser Antilles: Guadeloupe, Dominica, Martinique, Sta. Lucia. On the continent its range begins in Mexico; the northern boundary is marked by a line beginning in Tepic Territory, running through the States Jalisco and Guanajuato to Vera Cruz. ‘Thence the range covers the southern parts of Mexico, Guatemala, Nicaragua, Costa Rica and Colombia, and extends eastward over Venezuela (includ- ing Trinidad) and Guyana. In a southerly direction it passes from Colombia into Ecuador, Peru and to Northern Bolivia. In the lat- ter region it is found in the Cordilleras and the tributaries of the upper Amazonas river. An isolated locality is Para, on the southern side of the mouth of the Amazonas river (Pseudothelphusa agassizi Rthb.). In order to get an idea of the distribution of the different genera 1902.] AND ANCIENT GEOGRAPHY. 307 of this subfamily, it is necessary to discuss the systematics of it. Ortmann distinguishes four genera: Potamocarcinus, Epilobocera, Aypolobocera and Kingsleya, while Rathbun accepts the following : Lipilobocera, Potamocarcinus, Pseudothelbhusa and Rathbunia. Generally, Ortmann's Potamocarcinus corresponds to the genera Potamocarcinus and Pseudothelphusa of Rathbun, and the close affinity of these two is also admitted by Rathbun, so that their union (under Po/amocarcinus) is well supported. But in this case, we are to exclude from Pozamocarcinus the species sinuatifrons Kgsl. (and Ortm., nec A. M.-E.) = haytensis Rthb., which be- longs to Epilobocera. If we add this latter species to Ortmann’s Lpilobocera, this genus corresponds exactly to Zpilobocera Rath- bun. Zypolobocera of Ortmann isclassed by Rathbun with Pseudo- thelphusa (Potamocarcinus of Ortmann), and rightly so, as we now believe. Kings/eya Ortmann is put by Rathbun with Potamocar- cimus (sens. strict.); this, however, does not seem to be justified, ‚since then the very peculiar shape of the orbita is neglected. While in all other forms of the subfamily the lower orbital margin pos- sesses on the inner end a suborbital lobe, which may unite with the front, in Äings/eya the lower orbital margin itself joins the front, while the suborbital lobe is hidden. This character, connected with the extremely reduced condition of the exopodite of the third maxilliped, which also does not find its like in the whole subfamily, fully warrant, in our opinion, the creation of aseparate genus. The genus ARalhbunia of Nobili is founded upon a single species, and its chief character is taken from the shape of the meropodite of the third maxilliped, which is narrower than usual at the proximal end. In all other respects this genus agrees absolutely with Pseudothel- phusa (resp. Potamocarcinus of Ortmann), and a generic separation does not seem to be necessary. As a compromise between both generic divisions I should like to suggest the following: Genus: XLpilobocera Stps. (corresponding fully to pzlobocera Rathbun). Genus: Potamocarcinus M.-E. (== Potamocarcinus Ortm. (ex- cluding sinuatifrons Ortm. = haytensis Rthb.) + Zypolobo- cera Ortm.). 1. Subgen. Potamocarcinus M.-E. (genus, according to Rathbun, excluding the species /azifrons Rand.). 308 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, 2. Subgen. Pseudothelphusa Sauss. (= genus Pseudothel- phusa Rthb.). 3. Subgen. Rathbunia Nobili (= genus Nobili and Rathb.). Genus Azngsleya Ortm. It is entirely a matter of taste whether one prefers to regard Potamocarcinus, Pseudothelphusa and Rathbunia as genera or sub- genera. This much, however, is evident, that they are much more closely allied to each other morphologically than to either Zpi/obo- cera or Kingsleya. Judging from the third maxillipeds (which furnish a good criterion in this respect), Zpzlobocera should be re- garded as the most primitive form, Potamocarcinus (in the largest sense) would be typical and Kingsleya the most specialized. This division into three genera corresponds well to the geographi- cal distribution of the different forms (see Rathbun, 1898, pp. 532-537). Lipilobocera contains six species which are restricted to the Greater Antilles: Cuba, Isle of Pines, Hayti, Porto Rico and Santa Cruz Island. Potamocarcinus (in the widest sense) contains 47 species!, which cover the whole continental range of the subfamily from Mexico to Bolivia and Parä, the Lesser Antilles and of the Greater Antilles, Cuba and Hayti. The subgenus Pseudothelphusa has the same range, while of the two species of Potamocarcinus (sens. strict.) one is found in Guyana, the other in Costa Rica. Aathbunia is known only from Darien. This only partly agrees with whe: we know about the history of Jamaica. 348 ORTMANN —DISTRIBUTION OF DECAPODS [April 3, It seems that part of the freshwater Decapods (the identical spe- cies) found their way from Central America to the Greater Antilles during the Pleistocene connection, while the genus Zprlebocera reached the same parts in much older times, in the beginning of the Eocene or even at the end of the Cretaceous. How all these forms were able to get into Central America we shall discuss below. To which of the two immigrations Cambarus cubensis belongs remains doubtful. I am inclined to classify it with the older (Eocene) immigration. The freshwater crab of the Windward Islands, Potamocarcinus dentatus, confirms the view of Simpson that these islands and their fauna have little to do with the Greater Antilles, but rather that they are related to South America. But, while Simpson believes that the (late Tertiary) population of the Lesser Antilles was ac- complished by drift, I believe that a land connection is indicated. 7. CONNECTION OF SOUTH AMERICA AND AFRICA. The presence of freshwater crabs belonging to the family of the Potamomde in the Old World (subfamilies Potamonine and Deck- entin®), as well as in the tropical parts of the New World (subfamily Potamocarcinin«), has led us above (p. 310) to the assumption that there was once a land connection between South America and the West Indies on the one side and Africa on the other. Similar zoogeographical facts have been emphasized chiefly by von Ihering (1891, p. 438, and 1894, p. 406), and, according to him, “all affinities of the freshwater fauna of northern South America direct us to Africa.’’ He believes (we shall discuss this later) that the Hill (Bull. Mus. Harvard, Vol. 34, 1899) says that at the end of the Cretaceous and the beginning of the Eocene there was an extensive continental period, but that there was a subsidence at the end of the Eocene and in the Oligocene, and then again an uplift at the end of the Oligocene and in the Miocene. The latter is just the opposite movement from what is known for Cuba. It is quite likely that a different fate is to be assumed for the different islands, and it seems that Spencer’s idea of contemporaneous subsidence or elevation of the whole region between North and South America is entirely wrong; the orogenetic movements and the changes of level connected with them were, after the first great subsi- dence of the Caribbean basin, more or less local and affected only limited parts, so that at the same time we may have had opposite movements in different sec- tions of this region. 1902.] AND ANCIENT GEOGRAPHY. 349 northern parts of South America (Archiguiana) once formed, during Mesozoic times, a part separated from the rest of South America, which, however, continued eastward across the Atlantic Ocean connecting with Africa. Fernando Noronha and St. Helena are remnants of this land-bridge, which he calls by the name of Arch- helenis. This connection was destroyed, according to von Ihering, in the Eocene, or, at any rate, not later than in the Oligocene. To the numerous instances quoted by von Ihering in support of his theory the distribution of the family of the Potamonide adds another one, and the fact that two different subfamilies are found in the Old and the New Worlds, and that the affinities of the Ameri- can forms with those of Africa and Asia are somewhat obscure, indicates that the connection of both is to be regarded as an old one and that it has been severed long ago. Therefore its existence in Mesozoic times and destruction in the beginning of the Terti- ary, as maintained by von Ihering, has much in its favor. Taking up the geological side of this question, we first have the broad Jurassic connection between Africa and South America assumed by Neumayr (1890). According to this author, and also according to Suess (1888, p. 677 ff.), the whole of the southern Atlantic Ocean did not exist neither during the Jurassic nor during the older Cretaceous (Naumayr, /. c., p. 376), since no traces of deposits belonging to these periods are found in West Africa or on the eastern shores of South America It was not until the beginning-of the Upper Cretaceous that sea washed the eastern parts of Brazil (7. c., p. 389). But the connection of both conti- nents persisted even then, although in a limited degree, and dis- appeared entirely as late as after the beginning of the Tertiary (/. c., p. 397). Its last remnant (Z. c., p. 493) was formed by a chain of islands which extended in the Oligocene from tropical Africa to South America and the West Indies. This view, however, is not accepted by Koken. In his map (1893, pl. 1) the Cretaceous continents of South America and Africa are absolutely separated in the earlier as well as in the later part of this period, and the Atlantic coast lines of both generally agree with the present ones. In the older Tertiary Koken (pl. 2) draws an island chain (Brazilo-Ethiopian islands) from the West Indies to Africa. As far as it refers to the Cretaceous period, Koken seems to be mistaken. Although formerly it was supposed that Lower Creta- 350 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, ceous deposits are found in West Africa, it was soon recognized * that the respective beds are younger, and are certainly not older, than the Middle Cretaceous (in Cameroon) ; and especially Kossmat (1895) has demonstrated that the Cretaceous beds of West Africa (Angola, Elobi Islands, etc.) belong to the Middle and possibly the Upper Cretaceous (Cenomanian and Lower Senonian), and that they unmistakably possess a South Indian character, being connected probably around the Cape of Good Hope with the Indian Ocean. According to Kossmat, also the Brazilian Upper Creta- ceous deposits in Sergipe, Pernambuco, etc.,” are of the South Indian type. Farther’ north, on the coasts of Morocco and Algiers, typical Mediterranean Cretaceous beds are present. ‘The upper- most Cretaceous beds of Angola, however, are said to exhibit traces of the influence of the Mediterranean province (Kossmat, p. 465). According to these facts we are to form the following idea as to the destruction of the old Brazilo-Ethiopian continent: It existed in its full development during the Jurassic and in the beginning of the Cretaceous time, being the western remnant of the old’ Paleo- zoic Gondwana Land, and probably it had the extension assigned to it by Neumayr—that is to say, it connected Africa with the north- ern as well as with the southern parts (Brazil) of South America. In the middle of the Cretaceous time the southern Atlantic Ocean was formed and the sea extended from the south (connected around the Cape of Good Hope with the Indian Ocean) toward the equator. About the same time, or rather a little later (inzene Upper Cretaceous), a branch of the new South Atlantic extended into what is now the valley of the Amazonas river, separating the southern part of the Brazilian mass from the northern (Guiana) (compare below). But Guiana remained connected with Africa 1See Koenen, A. von,in 40h. Ges. Wiss. Goettingen, Ser. 2, Vol. I, 1897, 1898. ? Described by White (Arch. Mus. Rio Janeiro, Vol. 7, 1888). Although some of these beds (marine beds in Sergipe and Parahyba) are without any doubt Upper Cretaceous, Branner (Canadian Meeting Americ. Instit. Min. Engin., 1900, p. 17 f., and Bull. Geol. Soc. America, Vol. 13, 1902) has lately demonstrated that other marine sedıments in Sergipe, Alagoas, Pernambuco Parahyba, Rio Grande do Norte and Pará belong to the Eocene Tertiary (1902, pp. 47, 64, 85, 91,96), and also that the freshwater deposits of the Bahia basin are probably Eocene (1900, p. 18). 1902. ] AND ANCIENT GEOGRAPHY. 301 and this restricted land-bridge going across the middle part of the Atlantic existed probably during the rest of the Cretaceous time and was not destroyed until the beginning of the Tertiary, a chain of islands remaining as late as the Oligocene. This means, with respect to our freshwater crabs, ¢hat their age goes back at least to the Upper Cretaceous. During this period the last remnant of the continental connection between Africa and Guiana still existed, and the absence of Potamonide in South America south of the Amazonas valley further substantiates this assumption, that these crabs did not reach South America prior to the Upper Cretaceous, when the main part of Brazil also took part in this old continental connection. Aside from this fact, we have the consideration that it is not very likely that the age of the fresh- water crabs goes far back in Cretaceous times. Although we have no definite information as to the latter point, we may say, from a morphological standpoint, that the Zozamonida represent a pecu- liarly specialized side branch of primitive Cyclometopa. Cyclome- topa existed in the beginning of the Cretaceous, but were rare. Thus an Upper Cretaceous age of the Potamonide is admissible. The subsequent fate of the Pozamonide in South and Central America, after they immigrated (or originated) in these parts in the later Cretaceous, will be discussed in the next chapter. 8. THE MUTUAL RELATIONS. OF NORTH, CENTRAL AND SOUTH AMERICA. Aside from the peculiarities in the distribution of the freshwater _Decapods of America, discussed above, there are several other features which need explanation. They are the following (see pp. 295, 296, 309): t. The remarkable restriction of the genus Potamobius to the western parts of North America, while Camdarus is found in the east and south (Mexico). 2. The southern limit of the range of Cambarus. 3. The distribution of the Potamocarcinine over the West Indies, “Central America and the northern parts of South America; their presence in the mountains of Ecuador and Peru and their absence in Brazil south of the Amazonas. 4. The peculiar shape of the areas of Parastacus and -Zglea, which are almost identical, and extend, in the subtropical and tem- 352 ORTMANN—DISTRIBUTION OF DECAPODS _ [April3, perate parts of South America, from the Pacific to the Atlantic Ocean, but do not extend into the tropical parts. In order to arrive at an understanding of these points it will be necessary to investigate the history of the origin and the mutual relations of North, Central and South America. It is generally conceded that these three parts have undergone various changes, but as regards the details there is much discussion and erroneous ideas prevail. It will hardly be possible in the following to give satisfactory answers to all of these questions, but we shall endeavor to collect all that is known as relating to the geological history, and we shall thus try to get an idea of the most prominent features of the history of the origin of the Americas.’ That America consists of three masses differing tectonically is. well known. The nucleus of North America is formed by an old northern and eastern mass—the “‘ Canadian shield’’ and the folded ranges to the south of it. The parts to the west of these were sub- ject to various oscillations during Paleozoic and Mesozoic times, and finally the elevation of the chain of the Rocky Mountains, | running in a north-southerly direction, resulted in the present con- figuration of North America. Central America (including the northern coast of South America) consisted in older times of asystem of old ranges with east-westerly strike, forming probably an old Paleozoic and Mesozoic continent (Antillean continent), which was destroyed at the end of the Meso- zoic time. Since then Central America and the West Indies are composed only of the remnants of this continent, which in turn have undergone various changes. South America consisted formerly of the old Brazilian plateau, which probably was part of old Gondwana Land (Australia, Africa, South America). The high moun:ain chains of the Cordilleras in the west did not exist for a long time, and this region was covered by sea probably up to near the end of the Mesozoic time. The elevation of the Cordilleras began at the end of the Cretaceous and continued during the Tertiary. The present connection of the three Americas did not always. 1.We shall disregard all those questions which are not connected with and illustrated by the distribution of the freshwater Decapods—for instance, the sup- posed former connection of North and Northeast America with Europe, 1902.) AND ANCIENT GEOGRAPHY. 359 exist, and was not brought about until the mutual relations had gone through various and entirely different stages. a. North America. If we want to get an idea of the configuration of North America during Mesozoic times, we have to consult in the first line Neu- mayr's well-known map (1890). According to this, in the Jurassic, the northern and eastern parts of North America formed a conti- nental mass, which extended well to the west (Utah peninsula), while the northwest was covered by the sea that separated America from Northeastern Asia. At the same time this continent (Nearc- tic) was bounded by sea to the south, Mexico and the West Indies being submerged.! This representation, however, needs correction, chiefly as regards the West Indies, as we have seen above. Differing but little from the view taken by Neumayr is that of Koken (1893, pl. 1) with respect to the Lower Cretaceous period ; but here the land extends considerably to the northwest and includes parts of Mexico, a conception which is also to be modi- fied, as we shall presently see. The general history of North America during the Cretaceous period is best represented by Dana (1895, pp. 813, 874, 881). According to him, Western North America was largely land during the Lower Cretaceous and continuous with the rest. In the Upper Cretaceous, however, chiefly in its earlier part, a central depression became evident, which extended from the south (Gulf of Mexico) northward and possibly reached the Arctic Ocean, dividing the continent into an eastern and a western half. The western half, as we have seen above (p. 318), became connected across Bering Sea with Asia at about this time.” At the end of the Cretaceous (Laramie) and in the beginning of the Tertiary an extended eleva- tion began, which culminated in the formation of the Rocky Moun- tains, and by this process the interior Cretaceous sea became land again, which resulted in the reconnection of Western and Eastern ' North America. But, although there was a geographical union, Eastern and Western North America remained separated bionomi- 1 Compare, also, Logan, W. N., in Journ. of Geology, Vol. 8, 1900, but here the Jurassic ocean of the Northwest is considerably reduced in size and repre- sented only by a shallow bay. 2 Temporarily the Cretaceous sea of the interior was connected in British Co- lumbia with the Pacific (see Kossmat, 1895, p. 474). 394 " ORTMANN--DISTRIBUTION OF DECAPODS [April 3, cally, the Upper Cretaceous sea barrier being replaced by a barrier formed by the Rocky Mountains.’ Looking now toward Mexico and its continuation southward, we shall refer in the first place to the papers of Hill (1893 and 1898). The history of Mexico in Pre-Cretaceous times is very obscure. Possibly it was covered by sea, as is also assumed by Neumayr, in the Jurassic, at least in part (Hill, 1898). But it seems to be well established that in the Lower Cretaceous (Hill, 1893) almost all of Mexico was submerged from the Atlantic to the Pacific side. This Lower Cretaceous sea was limited on the north by the southern coast of the North American continent, which extended from the old Appalachian region across the present Indian Territory and New Mexico to the Mexican province of Sonora.” In the middle of the. Cretaceous period (at the end of the Comanche series, Gault) a large part of Mexico became land, forming a southern continuation of the western part of North America, which was separated in the Upper Cretaceous from the eastern, and which therefore extended from British Columbia * to the Isthmus of Tehuantepec. This strip of land formed during this period a very important barrier, separating the marine faunas of the Pacific and Atlantic Oceans. While both faunas were more or less connected during the Lower Cretaceous across Mexico, they became separated later and never again communicated in this region. | The Isthmus of Tehuantepec consists, according to Spencer,‘ of the identical Lower Cretaceous deposits found in Mexico, and, further, according to Sapper,’ Cretaceous rocks are found in the 1 This barrier was probably emphasized by the development of desert condi- tions in and at the foot of this mountain range. Compare Scott, W. B., Ar Zn- troduction to Geology, 1897, p. 500: “ Probably the upheavals at the end of the Bridger and at the end of the Eocene had made the climate much drier by cut- ting off the moisture-laden winds.” 2 In 1898 (pp. 243 and 259) Hill qualifies his views, and says that it is doubt- ful whether the whole country (Mexico) was entirely submerged at any one time during this period. He thinks it was a mere shifting of the barrier between the Atlantic and Pacific. Compare, also, Stanton, T, W., in Four. of Geology, Vol. 3, 1895, p. 861. 3 And these parts must have been connected, as we have seen above, with Northeastern Asia. 4 Bull. Geolog. Soc. America, Vol. 9, 1897. 5 Boll. Instit. Geol., Mexico, Vol. 3, 1896. — 1902.) AND ANCIENT GEOGRAPHY. 355 Mexican State of Chiapas, which adjoins Guatemala. As regards Guatemala, we know that here old rocks appear which belong to the system of the Antillean continent (see above, p. 342). Thus we have reason to assume that, while Mexico was covered by the Lower Cretaceous seas which separated North and Central America, this whole region became land at about the middle of the Cretaceous, thus effecting a connection of Western North America with Central America (Guatemala) or with the old Antillean continent. This seems to be also the view of Hill, and he likewise believes that this connection was never subsequently interrupted.’ The result of the foregoing discussion is that during the Jurassic, and especially during the Lower Cretaceous, North America formed a unit, which was separated from Asia and which was also circum- scribed by a shore line in the south, being disconnected from Central America. In the middle part of the Cretaceous Mexico was elevated, and this new-formed land connected the western part of North America with the Anrillean continent. At about the _ same time a connection of Western North America with Northeast- ern Asia was established (by way of Bering Sea), and the Mexican Gulf extended northward, separating Western from Eastern North America. | Thus we have, in the Upper Cretaceous, a strip of land extending from Northeastern Asia over Bering Sea and over the western side of North America to Mexico and the Antillean continent. Eastern North America was separated from this strip. In the beginning of the Tertiary Eastern North America became reumited to this western section. At the end of the Tertiary the Beringian connechon with Asia was interrupted (see above, p. 317). This would lead us for our Crustaceans to the following conclu- sions: We have seen above (p. 319) that at any time, beginning in the Upper Cretaceous, Potamobius may have invaded the western parts of North America. This is again supported by the preceding ! See Hill, 1893, p. 323. Spencer (1897) assumes that there was a reéstab- lishment of the connection of the Atlantic and Pacific Oceans across the Isthmus of Tehuantepec in late Tertiary times. The evidence for it, however, is entirely insufficient. The gravels found on the passes of the isthmus are of no value, since their marine character has not been demonstrated. Compare, also, Hill, 1898, p. 262, footnote. 350 ORTMANN — DISTRIBUTION OF DECAPODS [April 3, considerations, in so far as it is confirmed that Po/amodrus cannot have been present in North America during the Lower Cretaceous, otherwise the remarkable restriction to the west would be inexplic- able. But the genus must have immigrated during the Upper Cre- taceous, since fossil remains of Potamobicde! are known from the Eocene of North America. This latter fact, therefore, narrows down the time of immigration to more definite limits (those of the Upper Cretaceous), and at the same time explains its restriction to the west. During this period the western parts of the country were separated from the eastern by sea. At the same time there was a possibility for the crayfishes to reach Mexico, and it is easily understood that Pofamodzus then senta branch southward, which subsequently developed on the Mexican plateau into Cambarus. After this, in the beginning of the Tertiary, Cambarus had a chance to migrate by way of Texas into Eastern North America, where it reaches its culmination in the present time. The morphological differentiation of Cambarus from Potamobius probably took place in the beginning of the Tertiary, after the ranges of these genera had become separated. This separation is apparently due to a climatic change in the region between Mexico and central California, where desert conditions developed. This desert climate is not so pronounced on the eastern side of the con- tinent, near the Atlantic coast in Texas, and, consequently, the area of Cambarus is not here interrupted between Mexico and the United States. A subsequent connection of the ranges of Potamo- dius and Cambarus in the interior of North America (in the region of the Rocky Mountains and the plains adjacent to their eastern slope) was impossible on account of the topographic and climatic barrier existing there in Tertiary times, which has been mentioned above (p. 354). The Rocky Mountains themselves and the arid regions are not favorable for the freshwater crayfishes. Thus the areas of both genera remained separated, and only in one case a species (P. gambeli) has crossed the continental divide in the region of the Yellowstone National Park. ‘This, however, is very likely due to the capturing of streams that originally belonged to the Pacific slope by the Yellowstone river. d. Central America. The tectonic unity of the old Archaic and Paleozoic rocks known 1 Cambarus primevus of Packard, from the Eocene of Western Wyoming, which is, however, according to Faxon (1885, p. 155), rather a Zotamobiws. 1902.) AND ANCIENT GEOGRAPHY. 301 from Guatemala to Venezuela is also emphasized by Hill (1898, p. 239 ff.), and he also thinks that, during Mesozoic times, a continu- ous continental mass may have existed here, which reached as far as Trinidad. We have seen above that the destruction of this con- tinent was probably due, in the first place, to the formation of the Caribbean depression, at the end of the Cretaceous. This also agrees with Hill's view (1898, p. 260 f.) that during the whole of the Cretaceous, or at least during the larger part of it, the Atlantic and the Pacific Oceans were separated in the region of Central America—that is to say, that there was a land connection between the northern parts of Central America and northern South America. But, according to Hill, this connection is not identical with the present isthmian region, but was situated chiefly to the west of it. We have nothing to say against a western extension of this Cretaceous land (which probably extended as far as the Galapagos Islands), but we believe that the isthmian region and the present Caribbean Sea also were land during this time ; the main point is, that there was a connection between Guatemala, Honduras, Nica- ragua, and the Greater Antilles on the one side, and northern Venezuela on the other. These conditions changed considerably during the Tertiary. First, the Caribbean Sea was formed, and possibly it extended farther to the west and southwest than it does now. At least, parts of the present land-bridge, the Isthmus of Panama, were covered entirely by sea in the earlier Tertiary, and that this sea reached from the present Caribbean Sea across to the Pacific is beyond doubt. In the first line, the part through which the Panama canal is to be built is composed entirely of deposits that are not older than Eocene and Oligocene (Hill, 1898, p. 236), and this well agrees with the investigations of Douvillé,! and Bertrand and Zurcher :? the Old Tertiary sea (Eocene and Oligocene) must have here extended entirely across the isthmus, from the Atlantic to the Pacific. The same seems to be true for the Nicaragua canal. According to Hayes,’ there are no rocks along this route that are older than Tertiary, and the Tertiary deposits probably belong to the Eocene and Oligocene. The remarkable discovery has been made that ı CR. Soc. geolog. France, 1898. 2 Bertrand, M. et Zurcher, O. Etude géologique sur l’ Isthme de Panama, 1899. 3 Hayes, C. W., « Physiography and Geology of Region Adjacent to the Nic- aragua Canal Route” (Bull. Geol. Soc. America, Vol. 10, 1899). i 306 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, sediments on the Pacific side contain the same fossils as. the corre- sponding ones on the Caribbean side, which is an important addi- tion to Hill’s observations. | Between these depressions of the isthmian region, filled out by older Tertiary deposits, there are Archaic rocks at various places ; we know of such not only from Guatemala and Honduras, but also from northern Nicaragua (Hayes), Costa Rica (Hill, Hayes), and even farther east, beyond the Panama canal, in the Cordilleras of San Blas. Thus it seems that the present isthmus, from Nicaragua to Colombia, consisted during the older Tertiary of a series of islands separated by ocean straits. , - According to the unanimous opinion of Hill, Hayes, Bertrand and Zucher and others, these straits (Nicaragua and Panama) became dry in the Middle Tertiary, z.e., in the Miocene, and, con- seguently, the connection of North and South America was then established, Although this Eocene and Oligocene communication of the oceans is admitted by Hill, he is inclined to minimize its import- ance. Moreover, he assumes (1898, p. 263) that to the southward and westward, toward the Pacific, a large land mass must have existed, from which the material of the marine deposits of the isthmus was derived, and, further, he believes that this land mass chiefly extended in a north-southerly direction, probably connect- ing North and South America. I think we do not need this land, and even if we accept its existence,’ it hardly formed, in the earlier Tertiary, a connection of the Americas. Be that as it may, the insular elevations of the isthmus, and the masses of old rocks to the north of it, in Nicaragua, Guatemala, Honduras, and in the - supposed connecting land with Jamaica and Cuba (see above, p. 347), were in our opinion sufficient to furnish material for those Old Ter- tiary sediments in the isthmian region.” On the other hand, any 1 Since we need, as I most emphatically believe, a connection with Galapagos Islands; this subject, however, is outside of the present. question. 2 Hill himself (1898, p. 263) discusses the idea that the land to the north of the isthmus may have furnished the material, but dismisses it, since here «‘we are confroated by great depths.” Now, in my opinion, great depths are no funda- mental objection, and just in this case the character of the sea bottom in the region between Honduras, Jamaica, Cuba and Hayti indicates that important disturbances have occurred here, and, in the first place, the deep submarine rift valley, known as “ Bartlett deep,” may be of a very recent age. Be: Pe Pr A 1902.] AND ANCIENT GEOGRAPHY. 354 land mass to the south and west of the isthmus cannot have formed an Old Tertiary barrier completely separating both oceans, since we need an interoceanic communication during this time, as we shall presently see. Our opinion is, that during the Cretaceous there was a connection between northern Central America and northern South America, the Antillean continent still being more or less intact. At the beginning of the Tertiary, however, and after the formation of the Caribbean Sea, an oceanic connection existed between the Atlantic and Pacific in the isthmian region, and this communication existed up to the Miocene, separating North and South America. But afterward, beginning in the Miocene, the isthmus was elevated, reconnecting the separated chief remnants of the Antillean continent, and at the same time North and South America. The Atlantic and Pacific Oceans were separated, and never again communicated, either here or else- where.“ We here arrive at a result which differs considerably from von Ihering’s ideas as to the relations of North and South America: von Ihering believes (1894, p. 405) that both continents were sepa- rated by Cretaceous sea, and that Central America was entirely submerged at this time ; the origin of the Isthmian land-bridge is also placed by von Ihering in the Miocene. For our Crustaceans, we are to draw from this the following con- clusions : The presence of Potamocarcinine in the present continental parts of the old Antillean continent, in Nicaragua, Guatemala (to which we must add the southern parts of Mexico), the isthmian region and Venezuela, is due to the Cretaceous connection of these parts; the presence of the genus Zzlobocera in the Greater Antilles is due to the former connection of these islands with the mainland, and belongs to the same land period, or to the continuation of it in the earlier part of the Tertiary. After the separation of the Greater 1 This idea well agrees with the character of the present Atlantic and Pacific marine littoral faunas in the Central American region. These faunistic facts arz often incorrectly represented and understood, and Hills argument against the importance of the interoceanic communication in older Tertiary times is based upon such a misunderstanding. I have studied this question chiefly with refer- ence to the marine Decapod Crustaceans, and shall give below a correct repre- sentation of the actual conditions of the faunal relations of both oceans. See Appendix. 360 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Antilles from the mainland, there was left on these islands an iso- lated stock of primitive freshwater crabs, now known under the name of Zpilobocera. On the mainland, these primitive forms dis- appeared, or changed into what is now known as the genus Potamo- carcinus, and although in the beginning of the Tertiary the conti- nental range of this genus was much cut up, chiefly in the region of the isthmus, the different parts were reunited in the Miocene, form- ing a unit that extended from northern Central America to Trinidad and Guiana. “This explains the uniform distribution of Potamocar- cinus over this region. In the later Tertiary we had a second union of the Greater Antilles with northern Central America, which explains the immigration of identical species of Potamocarcinus from Mexico into Cuba and Hayti. The Lesser Antilles were probably connected, in the later Tertiary with Venezuela, and a species of freshwater crabs reached them by this way. c. Relation of Venezuela to the rest of South America. The Orinoco Valley. The northern coast range of’ Venezuela belongs, as has been stated, to Central America. To the south, on the slope toward the Orinoco, it is fringed by extensively developed Cretaceous deposits, which are also known from Trinidad in a similar position. These deposits are said to belong to the Lower Cretaceous (Suess, 1885, p. 688), and to extend westward far into Colombia. To the south of this zone, in Venezuela, there are (Suess, zézd.) younger Tertiary marine beds, which, in part, enter this region through a depression extending southward from the Bay of Barcelona on the northern -coast of Venezuela. This would indicate that during the Lower Cretaceous, the old Antillean continent was bounded on the south by sea (see above, p. 343), which separated it from the old granitic masses of Guiana. The apparent lack of Upper Cretaceous deposits, with the excep- tion of asmall region of western Venezuela, points to the assumption that at the end of the Mesozoic time (Upper Cretaceous) both regions were connected. Then again, in the later Tertiary, they were separated, at least in part, by sea that entered into the Orinoco valley (Suess, 1888, p. 161). The Lower Cretaceous sea not only separated Venezuela and Guiana, but apparently continued westward, into Colombia, Ecuador and Peru. Indeed, there are in the western chain of the 1902.] AND ANCIENT GEOGRAPHY. 361 Cordilleras in Peru and Bolivia many exposures of old (Archaic and Paleozoic) rocks ; but the fact that in this region (from Colombia to Bolivia) Lower Cretaceous of the Mediterranean type has been discovered right in the Cordilleras,' renders it possible that those older rocks were originally covered by Mesozoic deposits, which were removed subsequently by erosion ; and this is also the view of Suess (1885, p. 684, and 1888, p. 683), since he takes it for granted that the Cretaceous beds of the Upper Amazonas (and Orinoco) valley once continued across the whole continent to the Pacific Ocean. | Thus there would result, in Lower Cretaceous times, a complete separation of Central from South America bya sea, which extended from the region of the mouth of the Orinoco westward to Ecuader and Peru, connecting the Atlantic and Pacific Oceans: in the Upper Cretaceous, however, Guiana was united with Venezuela. The Potamocarcinine, which, as we have seen above (p. 351), arrived in Guiana in the Upper Cretaceous (by way of the connec- tion with Africa), found at this same time a land connection with the northern parts of Venezuela, and generally with the Antillean continent, and this explains their general distribution over Central America and the West Indian region, as set forth above (p. 308), and the origin of this distribution consequently falls in the Upper Cretaceous. d. South America. “The separation and isolation of South America from Central, resp. North America during Mesozoic times as well as in the begin- ning of the Tertiary, forms the fundamental idea of von Ihering’s Archiplata and Archhelenis theory (1891). But, according to him, the line of separation was situated in the present Amazonas valley, and existed during the Jurassic, Cretaceous and the Eocene; in the Oligocene the elevation of the Cordilleras began, and Archiplata (the southern part) was united with Archiguiana (Guiana and Venezuela), and it was not until the beginning of the seond half of the Tertiary (Miocene) that these latter parts became united with North America by the formation of the Isthmus of Panama. We can accept this view only in part, since the very important 1 Hyatt, A., in Proc. Boston Soc. Nat. Hist., Vol. 17, 1875, p. 365 ff.; Stei- mann, in NY. Fehr. Mineral., etc., 1881, 2 p. 130 ff., 1882, 1 p. 166 ff., and Gerhardt, zbid., Beil,, Bd. 11, 1897. ; 362 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, interoceanic connection through the Orinoco valley, discussed above, is not taken account of, and since, as we shall see presently, the relations between Guiana and Brazil and between Guiana and Venezuela are much more complex than v. Ihering assumes. Considering the tectonic configuration of South America, we are to mention, in the first place, that the whole eastern part is formed by the so-called Brazilian mass (Suess, 1885, p. 655 ff.): this is an old Archaic-Paleozoic plateau, which was possibly connected, from very early times up to the Lower Cretaceous (see p. 350), with Africa. Part of this mass is formed by the mountains of Guiana (Suess, 1885, p. 658), and the present valley of the Amazonas is a symmetrical syncline within the old plateau, in the centre of which are Carboniferous beds and, on top of the latter, Upper Cretaceous deposits. Thus the Amazonas valley was apparently land during most of the Mesozoic time, and Guiana was connected with Brazil ; but in the Upper Cretaceous it was a wide sea, the northern and southern shores of which were formed by Paleozoic rocks (Suess, 1885, p. 660). This sea extended from the Atlantic westward into the region of the Upper Marafion, in the Cordilleras, and probably connected with the Pacific Ocean (Suess, 1888, p. 683), which is very likely, since the western shore of the old Brazilian mass hardly extended to the eastern foothills of the Cordilleras (in a certain region, the present river Madeira marks the western boundary), and since it is quite sure that the Cordilleras were sea during the. Jurassic as well as the larger part of the Cretaceous. This results in an Upper Cretaceous interoceanic connection between the southern Atlantic and the Pacific, which was situated about where the Amazonas valley now is. Zus Upper Cretaceous strait agrees with the sea that separated von Lhering’s Archiplata and Archi- guiana, but it is well to emphasize the fact that it is restricted, as a separating s/rait, to the Upper Cretaceous period: during previous times, especially the Jurassic and Lower Cretaceous, it did not exist at all, and later it was changed into a bay, as we shall see below. ‘The interoceanic connection during the earlier Cretaceous was not situated here, but went by way of the Orinoco valley (see above, p. 360). The directions of both straits converge to the westward, and it is possible that they actually met, if they coéxisted at any time: but generally, we are to maintain ¢hat the separation of Central and South America during the Lower Cretaceous was effected by the Orinoco Strait, and that at this time Guiana was 1902.] AND ANCIENT GEOGRAPHY. 363 united with Brazil, to which it belongs tectonically, while, in the Upper Cretaceous, Guiana was united with Central America, and was separated from Brazil by the transgresston of the Atlantic Ocean in the Amazonas valley. This latter strait thus formed a continuation of the South Atlantic Ocean, which came into existence, as we have seen above (p. 350), at about the middle of the Cretaceous. The Upper Cretaceous conditions were generally preserved in this region during the beginning of the Tertiary, and the Eocene and Oligocene sea extended, in the Amazonas transgression, far to the west (brackish Oligocene deposits are known near Pebas, Peru). But during this time (older Tertiary), the elevation of the Cordilleras must have become evident ' in the western parts of this interoceanic connection, since older Tertiary deposits are wanting in this region. Thus those parts which now comprise Colombia, Ecuador, Peru and Bolivia became land, and the Amazonas Strait was shut off from the Pacific Ocean, being transformed into a deep bay, which occu- pied the Amazonas valley as far as the foothills of this new eleva- tion (Cordilleras). Therefore, this interoceanic connection was interrupted in the beginning of the Tertiary, the main part of South America, or the old “* Archiplata ”” of von Ihering, becoming united with northern South America (Venezuela and Guiana). But we have seen above (p. 344) that at the same time (earlier Tertiary or uppermost Cretaceous) another interoceanic connection had formed in the isthmian region, and this replaced the Amazonas connection of the Upper Cretaceous era. The old connection of the Brazilian mass with Africa continued in part as we have seen (p. 350) during the Upper Cretaceous, for its northern portion, Guiana. That is to say, an intermigration of the faunas of Guiana and Africa was yet possible in the Upper Cretaceous. The fact that during this time (and in the beginning of the Tertiary) a strait or bay extended along the region of the Amazonas river as far as the Pacific Ocean (or as far as the Cordilleras), furnishes the explanation for the zoogeographical fact that animals immigrating from Africa into Guiana during the Upper Cretaceous could reach Central America and the West Indies, but not those parts of Brazil which are to the south of this - old Amazonas Strait: this seems to apply to our Potamonide, and 1 The first signs of an elevation belonz to the Upper Cretaceous. 364 ORTMANN-—- DISTRIBUTION OF DECAPODS [April 3, explains their general absence south ofthe Amazonas. The exten- sion of the range of these freshwater crabs into Colombia, Ecuador and Peru was not obstructed during the older Tertiary, since during this time these parts became land and were connected with Venezuela. Regarding the extension of the old Brazilian mass (Archiplata) to the south, we know that the old Archaic, Paleozoic and Old- Mesozoic rocks continue in southern Bolivia and northern Argen- tina, into the eastern Cordilleras (Suess, 1885, p. 661); in Argen- tina, these rocks prevail in the northern parts: they are also found in the Pampean Sierras,’ but do.not seem to extend southward beyond the province of Buenos ‘Ayres (Suess, 1885, p. 664). To the south of these parts the whole of Patagonia was apparently covered by the Cretaceous sea (Suess, 1888, p. 683, and above, p. 338). The Brazilian continent was also surrounded in the west by Jurassic and Cretaceous sea, as is demonstrated by the presence of the respective deposits in the region of the Chilian-Argentinian Cordilleras (see p: 338). As we have seen above (zézd.), it is very probable that during the Jurassic and a larger part of the Cretaceous era, the Brazilian mass was separated by this sea, which occupied present Patagonia and the site of the Cordilleras, from another continental mass lying to the west, southwest and south of it, which was formed by the present Chilian coast range and its southern continuation, which belonged, at least during the Cretaceous, to the Antarctie continent. At the end of the Cretaceous a land period began in these regions which culminated in the Eocene, and which effected a connection of the old Antarctica with Archiplata, chiefly in the region of the Chilian-Argentinian Cordilleras. This connection made possible the immigration of Parastacus into the southern parts of Archiplata (Argentina, Uruguay, southern Brazil), and it has remained up to the present time, although parts of Patagonia were again submerged during the course of the Tertiary. The results obtained in the foregoing concerning the history of the American continent may be summed up as follows. 1. America originally consists of three parts : North America (its nucleus being in the East), the Anzillean continent (comprising the West Indies, Central America and the northern coast of Venezuela) and the old Braziliar mass (Archiplata). Also a fourth part enters ! Valentin, J., Dosgue7o geologico de la Argentina, 1898. 1902.] AND ANCIENT GEOGRAPHY. 365 the present boundaries of South America, which is formed by the Chilian- Fuegian coast range, once a part of Antarctica. 2. North America was separated during the Lower Cretaceous from Central America. During the Upper Cretaceous it was divided ‚into an eastern and a western portion ; the western was definitively connected at this time with Central America. In the beginning of the Zer/zary the eastern portion was reunited with the western, and thus the whole of North America, from the Arctic Ocean to the Gulf of Mexico and the Caribbean Sea, became a unit. 3. Central America existed as a continental mass up to the end of the Cretaceous. Being originally separated from North America, it became united with it in the Upper Cretaceous. By the formation of the Caribbean Sea it was broken up and consisted, in the degin- ning of the Tertiary, of two main parts: a northern, belonging to North America, and a southern, which became united with South America, then undergoing the process of construction. Both parts were separated by the Old Tertiary interoceanic connections at Panama and Nicaragua. The southern part of Central America was originally (Lower Cretaceous) bounded on the south by sea, which occupied the region from the Orinoco valley westward. Inthe Ufer Cretaceous Guiana was connected with Venezuela, and thus Central America was connected also with Africa. To the south of these parts was the Upper Cretaceous interoceanic connection of the Amazonas valley. In the beginning of the Tertiary, what was left of Central America in the south (Venezuela and Guiana) was united with the Brazilian mass by the beginning of the upheaval of the Cordilleras, by which parts of Colombia, Ecuador and Peru became land. In the middle of the Tertiary (Miocene) the interoceanic connec- tion in the isthmian region became land, and thus North America and the northern remnants of Central America were united with the southern remnants of Central America and South America. 4. South America consisted in the beginning (Jurassic and Lower Cretaceous) of the Brazilian mass (Archiplata), which included Guiana, and a smaller part which is perhaps of Cretaceous age, rep- resented now by the Chilian coast range. Archiplata was con- nected with Africa up to the middle of the Cretaceous. Inthe Upper Cretaceous, Guiana was separated from Brazil by the interoceanic connection of the Amazonas valley and Archiplata became an island. At the end of the Cretaceous, and chiefly during the 366 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Eocene, Archiplata became united with the Chilian coast range by the elevation of the Cordilleras, and it was thus connected with Antarctica. And, further, in the beginning of the Tertiary, Archi- plata connected, by way of Peru and Ecuador, with Central America. This resulted in the final formation of South America (in its rough outlines) which, however, was still in communication with Antarctica. Finally, in the mzddle of the Tertiary, South America was united with North America (in the isthmian region) and was severed from Antarctica, and this represents the chief features of the present conditions. We have seen that during the geological development of the Americas 7n/eroceanic connections, which were directed east-westerly, and united the waters of the Atlantic and Pacific Oceans, have repeatedly played a part. These connections being extremely important for marine zoogeography, have often been referred to by various authors, but have generally been misunderstood, the value of a determination of the exact time of their existence being neglected. So it will be worth while here to put them together by themselves. Interoceanic connections of the Atlantic and Pacific Oceans.” 1. In the Lower Cretaceous there were ‘wo connections: a. across Mexico, and 6. through the Orinoco valley. Both probably united the marine fauna of the Mediterranean province with that of the (Indo-) Pacific. 2. In the Upper Cretaceous we have the connection through the Amazonas valley. This united the South Atlantic fauna, which, in this period, formed part of the Indo-Pacific, with the identical fauna of the eastern Pacific. 3. In the Older Tertiary there existed the Panamic connection, which united the fauna of the Atlantic, the chief element of which is Mediterranean, with that of the Indo-Pacific. 4. In the Later Tertiary no interoceanic connection existed, the Atlantic and Pacific faunas being sharply separated. These condi- tions continued up to the present time. It is impossible to say at present whether there were any transi- tions between these different stages. A coéxistence and union of the connections 1 and 2, at about the beginning of the Upper Cre- taceous, is possible in the region of the Upper Orinoco and Upper 1902.) AND ANCIENT GEOGRAPHY. 367 Amazonas. But we have no evidence for this, the Geology of the respective countries being too incompletely known. Q. THE RELATIONS OF AFRICA TO THE REST OF THE WORLD. We have seen (p. 303) that for the two main divisions of the range of the Potamonine in the Old World Egypt and the Nile valley form an actual connection; but examining this more closely we find that this subfamily cannot have migrated along this route from Africa to India (or vice versa), but entered Egypt from two opposite directions, from the south (Central Africa) and the north (resp. northeast) over Persia, Mesopotamia and Syria. The causes why this way was not open in former times have been briefly mentioned above (p. 333), and we shall here try to investi- gate the relations of Africa and Asia with respect chiefly to this northern connection. For this purpose we are to discuss also the northern boundaries of Africa with reference to Europe. This is the more important, since we have to consider the alleged fact that fossil forms of the Potamonina have been found in Miocene fresh- water deposits of Oeningen (Switzerland), Sigmaringen (Southern Germany) and Northern Italy.! Very important for a study of these questions is the former exist- ence ofa Central Mediterranean Sea, as Neumayr calls it (1890, pp. 332, 333, and map p 336), or the Zezhys of Suess (1894). This ancient sea goes back to Paleozoic times and covered in Mesozoic times the whole of Middle and Southern Europe, the present Medi- terranean Sea, Northern Africa and extended eastward over Asia Minor, Syria, the Caucasus Mountains and Mesopotamia as far as Northern India. In the east a large bay extended southward along the East African coast, which separated the Indo-Madagassian peninsula (Lemuria) from Africa. In a westerly direction the Tethys was broadly connected with the Atlantic Ocean, leaving only the island of Spain (Meseta) uncovered. In these general outlines the Tethys existed in Jurassic as well as in Cretaceous times, thus completely circumscribing the African continent toward the north and northeast. Europe did not then exist at all as a continental mass and Africa was separated from the Sinic continent by an eastern continuation of the Tethys, the 1 Thelphusa spectosa Mey. and Th. quenstedti Zitt,, see Zittel, Handbuch d. Faleontol., Vol. 2, 1885, p. 714. These forms have a remote resemblance to the subgenus Potamonautes, if they belong here at all. | 368 ORTMANN-- DISTRIBUTION OF DECAPODS [April $, Strait of Bengal.“ The only connection of Africa during these times was with South America, the old Archiplata (Jurassic and Lower Cretaceous) and the old Archiguiana (Archhelenis, Upper Cretaceous). On the southern margin of the Tethys, as sketched above, there is a zone in the desert region of North Africa and Arabia, where Jurassic deposits are wanting and Cretaceous directly overlies Paleozoic beds. This indicates a farther extension of Afiica northward in Jurassic times and a transgression of the sea southward in the Cretaceous (Neumayr, 1890, p. 386). The deposits of the Cretaceous sea can be traced very distinctly in a broad belt from Syria over Arabia, Persia, Afghanistan and Beluch- istan to Northern India. Also in the Older Tertiary (Neumayr, p. 480) the Central Medi- terranean Sea reaches from the Atlantic Ocean to India, and it was. not until after the end of the Oligocene that its unity was de- stroyed. In the beginning of the Miocene Western Asia became largely land, and thus a broad connection was established from Asia to Africa (India to Arabia), and at the same time from Asia to Europe, which was then forming (Neumayr, 1890, p. 501 f.). In detail the processes in the northeastern part of Africa were the following: Arabia during Mesozoic and the greater part of Tertiary times was broadly connected with Africa. The Red Sea did not exist, according to the unanimous opinion of all writers (Neumayr, Suess, Gregory, Blankenhorn and others). The origin of the Red Sea falls late in Tertiary times, after the connection of Africa with India was long established, and thus, in the second half of the Tertiary, a regular exchange of the faunas of Africa and india could take place, for which we possess ample evidence. The Red Sea is a rift valley, which is tectonically connected with the valley of the Jordan river in Palestine? The most de- tailed investigations on this question have been published by Blankenhorn.* According to this author, the Mediterranean Sea (the western part of the old Tethys) in Miocene times sent a wide bay to the southeast, which extended as far as the southern end of the Gulf of Suez, which, of course, did not then exist, and the Nile 1 Which, however, was temporarily interrupted during the Upper Cretaceous. See above, p. 330. 2 See Gregory, J. W., in Proc. Zool. Soc. London, 1894, p. 165. 3 Blankenhorn, M., in Centralbl, f. Mineral., etc., 1900, p. 209 ff. 1902.] AND ANCIENT GEOGRAPHY. 369 valley... The latter and the Red Sea originated in the Pliocene. Into the Nile valley entered the Pliocene Mediterranean Sea. It then changed into a series of inland lakes, and finally, in the middle Diluvial time, it became a river valley. The depression of the Red Sea was occupied first (Pliocene) by inland lakes, and finally, toward the end of the Pliocene, by the Indian Ocean, which entered it from the south.” The present separation of Africa and Arabia (Asia), which is nearly complete, belongs, therefore, to a very recent date. In the later Tertiary Southern Asia and Africa were not distinguished zoogeographically, while in older times (Pre-Miocene) there was a complete separation of Africa (including Arabia) from the Sinic continent, and only during the second half of the Cretaceous was there a limited connection by way of Mada- _ gascar and the Indian peninsula.? The old isolation of Africa was ended not only in these eastern parts during the Tertiary, but also in the northwest changes occurred which extended Africa and brought it into contact with Western Europe. The Cretaceous sea covering Northwestern Africa was no doubt considerably reduced in the Tertiary. Indeed, there are Tertiary deposits in this region, and according to Suess (1888, p. 155), the Middle Tertiary sea probably also covered the Western Sahara. But about this time apparentlya land connection was formed to the north toward the old Spanish Meseta. According to Bergeron,* the Algerian Sahara possesses deposits from the Senonian to the Plio- cene, but these are bounded in the west by a Cretaceous mountain 1 In the region of the Nil: valley there was a river, but this was not the Nile, but came from the west out of the Libyan desert, 2 An actual connection of the Red Sea and the Mediterranean Sea is very doubtful, but was possibly established for a short time in the beginning of Diluvial times, when the Mediterranean Sea became cold. The improbability of a connection of both seas is especially emphasized by Jousseaume (Ann. Sct. Nat., Ser. 7, Vol. 12, 1891). According to him, the Red Sea is Quarternary (Diluvial). 3 The oceanic connection from the Gulf of Aden across the Sahara desert to the Atlantic (Senegambia), advarced by Jousseaume (7. c ), has no geological support. Itis founded upon an alleged similarity of the Mollusk faunas of both parts, which, however, needs closer inves igation and might possibly find its explanation in the configuration of the Pre-Miocene Tethys, which reached from the Persian Gulf to the Mediterranean Sea and Atlantic Ocean. 4 In Mem. Soc. Ingen. civ. France, 1897. 370 ORTMANN—DISTRIBUTION OF DECAPODS [Apri 18, range running north-south. In Algeria we have, according to Lap- parent,’ deposits of Cretaceous and Eocene age, but only traces of Oligocene, and thus we can place the upheaval of these parts at the end of the Eocene, and probably at this time the connection with Southwestern Europe began to develop. The mountain range along the northern coast of Algiers, as far as the Strait of Gibraltar, consists of rocks which (see Suess, 1883, p. 293 ff.) are also found in the so-called Betic Cordilleras (z4zd., p. 298) in Southern Spain, and the tectonic unity of these ranges of Algiers and Spain is especially emphasized by Suess, as well as their tectonic connection with the Apennines and the Alps. The origin of all these moun- tain chains was near the end of the first half of the Tertiary, about the Oligocene time. But this connection of the northwestern parts of Africa and of Southern Spain with the rest of Africa did not constitute a com- plete union with Europe. We know that the central and northern region of Spain, the Iberian Meseta, is an old land, but that to the south and north of it, on the one side along the valley of the Guadalquivir river in Spain, on the other in the region of the Garonne riverin France, connections of the Mediterranean Sea with the Atlantic Ocean existed. According to Suess (1885, p. 381 ; see also Neumayr, 1890, p. 516), in the valley of the Guadalquivir there are Tertiary deposits, reaching from the Atlantic to the Medi- terranean Sea, which belong to the first and second Mediterranean stage—that is to say, to the Miocene—while deposits of the third Mediterranean stage (Pliocene) have not been found. Conse- quently this strait (Betic Strait) became dry at the end of the Miocene, and by this process the northern part of Spain was united with the southern and with Algiers and Africa. The disappearance of this strait was the last step which resulted in a definitive connection of Africa with Europe, since the strait in the region of the Garonne river, in Southern France, became prob- ably land a little earlier, namely, at the end of the Oligocene (see Suess, 1885, p. 382 ff., and Neumayr, 1890, p. 516). But it is to be borne in mind that possibly the conditions were not so simple as has been represented above. According to Lap- parent (/. c., pp. 1291 and 1313), the Betic Strait (détroit bétic, also called Andalusian connection) was dry during the Oligocene, 1 Tyaile de Geologie, Vol. 2, 1893, p. 1291. ne Ze ne qa EEE ND 1902.) AND ANCIENT GEOGRAPHY. 371 while sea again occupied it in the Miocene, and thus we would have a chance for the African fauna to reach Northern Spain as early as the Oligocene. This connection, however, scarcely amounted to a complete communication of Africa and Europe, since at that time the Oligocene strait to the north of the Iberian Meseta was still in existence, forming a barrier to the further advance of the African fauna. Thus, even under this assumption, a final connection of Africa and Europe was not established until the end of the Miocene, after the second obliteration of the Betic Strait. Subsequently the connection of both continents was again interrupted by the formation of the Strait of Gibraltar; but this belongs to very recent times.’ Another tectonic line goes from Northwestern Africa to Sicily and Italy, and is marked by the eastern continuation of the same mountain range that curves in the west from Africa into Southern Spain. This system belongs to Post-Oligocene times, and as a land-bridge apparently underwent repeated changes. Moreover, it is doubtful whether it existed at any time as a complete and solid bridge, but it is represented as such by Scharff (1895, maps pp. 465 and 470) for the Pliocene time, while Neumayr (1890, Vol. 1, p. 330), for the Zower Pliocene, gives only a series of islands. From the above discussion we are to draw the conclusion that— aside from a connection with the Sinic continent during the Upper 1 Kobelt, W. (Studien zur Zoogeographie—“ 2. Die Fauna der mediterranen Subregion,” 1898), arrives at a different conclusion. According to him, the Mediterranean Sea was separated from the Atlantic Ocean in the Older Tertiary _ by a connection of Czntral Spain with the Atlas mountains (the Sierra Nevada or Betic Cordilleras did not then exist). The Miocene Tethys reached from India to Spain and Central France, but did not communicate with the Atlantic, the connection along the valley of the Guadalquivir being of Pliocene age. This result is contrary, however, as we have seen, to what is known .of the Geology of these parts. Just the opposite is the case. In the Older Tertiary the Tethys and the Atlantic were broadly connected, and in the Miocene they still communicated through the Andalusian or Betic Strait, as is positively shown by the presence of Miocene beds there. But in Pliocene times this strait was dry land. 4 According to Scharff (in 1897, pp. 461 and 466), this bridge belongs to the Upper Pliocene and Gla:ial times. We shall become acquainted below with the evidence for its existence as an actually connecting bridge. . 872 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Cretaceous— Africa, for a very long time, was isolated from the rest of the Old World. After it had become disconnected from South America, at the beginning of the Tertiary, it was absolutely isolated, but soon during the course of the Tertiary it became united with Asia and the new continent of Europe. The most impor- tant stages in this process were that of the elevation of Western Asia, in the Miocene, and the elevation of the northwestern parts of Africa and southwestern parts of Europe at about the same time. This has the following bearing upon the origin of the distribution of our freshwater Crustaceans: The African types of the subfamily Potamonine (chiefly the subgenus Poramonautes) could not reach Europe before Miocene times, and, on the other hand, an immigra- tion of the Asiatic types (subgenus Po/amon) into Africa (and Europe) was also impossible before the Miocene and after the de- struction of the Madagassian land-bridge in the earlier Eocene. Whether the alleged fossil species of Potamon from the Miocene of Europe indicate this Miocene connection of Asia, Africa and Europe remains doubtful. The lack of African types in the Medi- terranean region of the present time, as well as the general absence of a northerly and easterly advance of them (except in the Nile valley, where the immigration no doubt belongs to a very recent period), is opposed to the above assumption, and it is quite possible that these fossil forms do not belong to relations of the Potamonine. It seems that the desert zone of the Sahara already existed in Miocene times, at least that it began to develop at the same time that Western Asia became land, since just this process furnished the conditions for the origin of an arid climate in North Africa and West Asia. On the other hand, we see that a species of the sub- genus Potamon, belonging to the Indian fauna, advanced in a west- erly direction across the new land areas formed in Miocene time, and that it reached by this route Northern Africa (Egypt and Algiers). But the distribution of this species (Potamon fluviatile) needs further explanation, since it is also found in certain parts of Europe, and we shall discuss this question in the next chapter. IO. RELATIONS OF EUROPE TO ASIA. In discussing the distribution of Potamon fluviatile in Southern Europe, just referred to, we are also to consider the presence of the genus Potamobius in Europe, the area of which is separated from that of the rest of the genus (in Northeast Asia and Northwest 1902} AND ANCIENT GEOGRAPHY. 373 America). The essential point in this respect is the investigation of the geological relation of Europe to Asia. Europe did not exist as a continent—z.e., as a continuous mass— from the beginning of the earth’s history up to about the middle of the Tertiary. Indeed, there was anumber of larger and smaller islands in the old Tethys, but they never were connected so as to assume continental shape. To the north, however, we had the large Scandinavian mass, which probably was connected over Greenland with North America, but we shall disregard this possible junction, since our present material, the Decapod Crustaceans, do not furnish additional facts which bear upon it. The Tethys, as we have seen (p. 367), covered the whole region of the present Mediterranean Sea and extended over Western Asia, reaching, in the older Eocene, not only as far as the Indian Ocean, but in an easterly and northerly direction as far as the eastern side of the Kuen-Lun mountains and the Gobi desert.’ Subsequently, in the Miocene, the western parts of Asia (from Asia Minor and Syria to India) became land (Neumayr, p. 501), and the Tethys was cut into a western (the present Mediterranean Sea) and an eastern section (forming part of the Indian Ocean). But during this time, and even afterward, the northern and northeastern parts of the old Tethys persisted. The Miocene Mediterranean Sea (Neumayr, 1890, p. 516) sent a strait from the basin of the Rhone river (France) through Switzerland into Austria, which there widened out into the Pannonian basin and in the Upper Miocene became a huge inland sea, the Sarmatian, which was cut off from its former western connection with the Mediterranean and reached from Austria over Southern Russia into the region of the Caspian and Aral Seas (Neumayr, p. 523). To the south of this sea the present Balkan Peninsula, the Atgean Sea and Asia Minor were largely land, but in Eastern Asia Minor a continuation of the Mediterranean Sea approached almost to the Black Sea. The region of the Caucasus mountains was probably sea up to Miocene 1 In the Kuen-Lun mountains there are, according to Bogdanowitsch (Geolog. Untersuch. im oestlichen Turkestan, 1892, Russian. Review in Neues Jahrb. f. Mineral., ete., 1895, Vol. 2,p. 110), Archaic and Paleozoic rocks and traces of Jurassic deposits (coal bearing strata), and then again marine Cretaceous beds, Thus it seems that these mountains were land since beginning of the Mesoz>ic times and formed part of the Sinic continent. During the Cre- taceous there was a temporary transgression of the sea. 374 ORTMANN=—DISTRIBUTION OF DECAPODS [April $, times, as is shown by a continuous series of sediments lying upon Azoic rocks. Here! has been found Jurassic, Cretaceous, Eocene, Oligocene and Miocene. The latter deposits (Miocene) belong to the Sarmatian inland sea. Beginning with the Pontic stage, the sea recedes on the southern side of the Caucasus (freshwater deposits), while on the northern side marine deposits, belonging to the Ponto-Caspian Sea, continue. The latter disappear after the Glacial period. The map, given by Neumayr, of the Eastern Mediterranean countries during the Lower Pliocene (1890, Vol. 1, p. 330, see also Vol. 2, p. 526) exhibits a much more extended development of land than at the present time. Especially striking is the direct connection of Asia Minor with the Balkan Peninsula and Central Europe. The corresponding map for the Later Pliocene, given by Scharff (1895, p. 465, and 1897, p. 461), indicates an additional land connection from Dalmatia over Southern Italy and Sicily to Algiers (see also 1895, p. 470, and 1897, p. 461), which is repre- sented in Neumayr’s map only by a series of islands. Thus we obtain a continuous land connection from Asia Minor to North- western Africa, belonging to the Pliocene age. In the Pleistocene (Glacial) time, according to Scharff (1897, map p. 466), this connection is still present. In the northern parts of Europe we have no land connection in an easterly direction during the Cretaceous time. According to Koken (1893), however, North Asia was connected with Scandi- navia in the Upper Cretaceous, forming part of a huge circumpolar Arctic continent; but the evidence for its existence seems to be very doubtful. For the Older Tertiary, Koken again indicates a separation of Northern Europe from Asia. In subsequent times, up to the Later Pliocene, the Sarmatian Sea covered the whole of Northeast Europe (Scharff, 1897, map p. 461), thus perpetuating the separation from Asia. During Glacial times this separation was maintained by the ice sheet covering Northern Russia and by the existence of the Aralo Caspian basin, and it was not until Interglacial times that a communication of Asia and Central I See Fournier, in Ann. Fac. Sci. Marseille, Vol. 7, 1896. 3 The Jarge extension of the Mediterranean Sea to the south of Algiers over. the Sahara desert in a westerly direction, as shown by Scharfl’s map (p. 470), is probably erroneous. RE Cs 1 > > En 1962. } AND ANCIENT GEOGRAPHY. Europe was established north of the Aralo-Caspian basin over Southern Russia (Scharff, 1897, map p. 466). The gradual origin of Europe, beginning with the formation of the chief mountain chains in the Oligocene, its connection first of the southern and central parts with Western Asia across the Balkan Peninsula (Miocene and Pliocene) and with Northern Africa over Spain (end of the Miocene), and subsequently the connection of the central and northern parts with Siberia (over Russia), by which processes Europe assumed the shape of a continent (part of Asia), have been largely used by previous authors for the explanation of the zoogeographical conditions of Europe. Osborn (1900, p. 569) mentions a repeated immigration of Mammals into Europe and indicates the Upper Eocene, the Miocene and the Pliocene times as most important in this respect. . But we must always bear in mind that during the Older Tertiary Europe was not a unit at all—in fact did not exist as a zoogeo- graphical section. The Old Tertiary Mammalian faunas of Europe (chiefly in the Northwest, in France) probably belong to the British- Scandinavian mass, which was connected, as has been mentioned incidentally, with North America." Then, in the Miocene, we have in Europe, which assumes a more consistent shape, a fauna of new character, the origin of which is to be sought in the East and Southeast (Asia), and possibly during this time the first African types reached Europe, either by the roundabout way over Western Asia or more directly over Algiers and Spain. Kobelt (1897) also assumes an isolation of Europe at the begin- ning of the Tertiary, and discusses the immigration of an Indo- Chinese fauna from the East in Pliocene times, while the Nile valley formed a route by which freshwater animals immigrated from the South (Africa).? The most detailed investigations on this question have been pub- 1 As to this connection, which is not treated here, I refer the reader to Neu- mayr (1890, Vol. 2, pp. 497 and 504) and to Scott (Az /ntroduction ts Geology, 1897, P. 505). 2 Contrary to this, Pilsbry (1894) is inclined to assume, for the Ze/ices, a Cre- taceous immigration from Southeastern Asia into Europe and Africa, But according to the present state of our knowledge, as set furth above, the history of the development of Africa and Europe, as well as of Asia, does not warrant this _assumption. There was no possibility, on geological grounds, for the old Sinic fauna to reach Europe and Northern Africa before the Miocene. , 376 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, lished by Scharff (1897). He distinguishes—aside from an Arctic migration—two main routes of immigration into Europe during the Later Tertiary period: 1, a southern one during Miocene and Pliocene, which was directed from Western Asia over Asia Minor, the Balkan Peninsula, Italy, Sicily, Algiers and Spain (and which apparently sent a branch from the Balkan Peninsula into Central Europe), and 2, a Siberian migration from Western Siberia through Southern Russia to Central Europe, which belongs to the Pleisto- cene (see map, /. c., p. 466) and was impossible before this time (in Miocene and Pliocene), the Sarmatian and Ponto-Caspian Sea forming barriers. Comparing our freshwater Decapods with the above, we see at the first glance that the present distribution of the European fresh- water crab, Potamon fluviatile, unmistakably agrees with that land connection which began in the Miocene and culminated in the Pliocene and which extends from Asia Minor over the Balkan Peninsula to Italy, Sicily and Algiers. Even the minor features of it are traceable. Potamon fluviatile is found everywhere in West- ern Asia, in the Caucasus region and in the Crimea, but is missing in the rest of Southern Russia. This corresponds to the fact that the Crimea was connected in Pliocene times with the Caucasus and was not in communication with the rest of Russia (see Scharff, 1897, map p. 461). Potamon fluviatile is found in Asia Minor, Syria, on the island of Cyprus and in Egypt. All these parts were then con- | nected. Along the tract of the land-bridge, from Asia Minor to Italy and Algiers, this crab has been everywhere found." This relation of the supposed Pliocene land extersion with the distribu- tion of Potamon fluviatile is so close that there is no objection whatever to the assumption that the immigration of this species falls in the Upper Pliocene, when this land connection was fully de- veloped, and not in the Lower Pliocene, when there was only a series of islands (see p. 374). Turning now to the crayfishes of Europe, we see that the centre of the range of the group of Polamobius astacus (the Russian cray- fishes) is just in that region which, during Miocene, Pliocene and 1 That this species extended, in former times, farther to the north from the Balkan Peninsula is shown by the discovery of it in fossil state in diluvial cal- careous tufa near Süttö, Com. Komarom, Hungary (see Loerenthey, E., Mat. Hefte Ungar. Nat. Mus., 1898. Review in Neues Jahrb. f. Mineral., ete., 1900, Vol. 2, p. 473). wie Oe 1902. ] AND ANCIENT GEOGRAPHY. 871 the beginning of the Pleistocene, was covered by the Sarmatian and Ponto-Caspian Sea. This group consequently can only have reached these parts at a later period, namely, in Interglacial or Postglacial times, and its immigration no doubt corresponds to the Siberian of Scharff (7. c., pp. 448 and 466). In regard to the other group formed by the two species, P. pallipes and Zorrentium, which occupy the South and West of Europe, we have to call attention to the important fact that this group is found not only in Southern and Western Europe, but also in England. Now we know that England was connected with the continent in Preglacial and even during Glacial times, and that this connection existed up to the beginning of the Siberian migration (Interglacial). It was interrupted later— according to Osborn (1900, p. 572), at about this time (Middle Pleistocene) and possibly even later.* The fact that Potamobius astacus is found in France, but not in England, while ?. Zallipes passes over into the latter country, points to a difference in time of the immigration of either species. P. pallipes arrived in these parts before the end of the Glacial time, P. astacus at the end of it or even later. The latter consequently without doubt belongs to the Siberian migration, but rather to the later part of it. 2. pallipes may belong to the earlier Interglacial part of the Siberian migration and have come from East and Cen- tral Europe; but it is also possible that it belongs to Scharff’s southern migration and came from Asia Minor over the Balkan Peninsula. It is true, forms of the 4a///pes group have not been found in Asia Minor nor in Algiers, but it is not impossible that such may be discovered in these parts, or that they once existed there and have now disappeared. We shall see below why this latter assumption is admissible. The crayfishes in Asia Minor, Southern Italy and Algiers may have been exterminated by the freshwater crabs subsequently occupying these parts. Until this question is finally settled it is impossible to decide whether the group of P. pallipes has reached its present area by the southern route (Miocene-Pliocene) or by the route of the Siberian migration (end of the Pleistocene); but however that may be it arrived in Europe before the group of P. astacus. The connection of the European crayfishes with the Sinic conti- 1 Suess (1888, p. 528) thinks it possible that this happened in historic time or shortly before the beginning of it. 318 ORTMANN—DISTRIBUTION OF DECAPODS (April 3, nent, where presumably their original home was located, is not yet established. It must necessarily have gone over Central Asia. Cray- fishes of the European type are found eastward as far as Turkestan. It is doubtful whether crayfishes are absolutely lacking in the region between Turkestan and the Amur river. None are reported, but these parts are very poorly known. For the present I cannot imag- ine any reason for their disappearance in this region, in which they must have once existed, and therefore it is well to suspend judgment until these parts have been properly investigated.” SUMMARY OF RESULTS OF PART I. A. HISTORY OF THE CONTINENTS. a. Lower Cretaceous. (See Fig. 5, p. 379.) I. During the Lower Cretaceous there existed a Sino-Australian continent, comprising eastern Asia, the Lndo-Malaysian Archipelago and Australia, and which was continued to Antarctica. We may retain for this continent the name SINO-AUSTRALIAN, although it is larger than that drawn by Neumayr for the jurassic time. We are justified in doing this, since probably the Jurassic Sixo-Austra- ka also included Antarctica. II. Besides, we have a Nearctic continent: this consists of the larger part of present Vorth America, and extended probably across Greenland to the Scandinavian mass of North Europe. This con- tinent also corresponds closely to Neuinayr's NEARCTICA of Jurassic times, and consequently we have retained this name for it. III. A third continent was formed by Central America, and we shall call this by the name ANTILLIA. Its remnants are now found in Central America, the West Indian Islands and northern South America (excluding Guiana). This continent is not given by Neumayr for the Jurassic, but probably existed then. IV. A fourth continent was formed by the western portion of old 1 A theory lately propounded by C. F. Wright (see Science, Vol. 16, Aug. 15, 1902, p. 262 f.) would go far toward an explanation of the causes leading to the destruction of the Central Asiatic crayfishes ıf properly supported. Wright be- lieves that Northern and Central Asia was largely covered by water in recent geological time, but the evidence introduced for this is, in my opinion, entirely inappropriate. Of the five points mentioned by Wright two (Nos. 3 and 4) have no bearing at all upon this theory, and the value of the other three, espe- cially of the fifth, is highly questionable, ‘pottod 5720370734) 43M07 oY) SuLIMp Xojem pue pur] Jo uoynquasta 1902.] So AND ANCIENT GEOGRAPHY. 3 9 380 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, Gondwana Land. It comprises the Brazilian mass (including Guiana) and Zropical Africa with the Lemurian Peninsula (Mada- gascar-India). This continent corresponds, generally, to Neu- mayr’s Jurassic Brazilo-Ethiopian continent, but comprises a smaller part of South America (also, for Jurassic times, the section of South America that entered it, according to Neumayr, is too large). It agrees to a certain degree with what v. Ihering has called Archhelenis, although it is larger, and it may be permitted in this sense to modify the conception of ARCHHELENIS. Thus in Lower Cretaceous times we have the following four con- tinental masses: Sino-Australia, Nearctica, Antillia, Archhelenis, which were mutually isolated. Besides, there were smaller islands, chiefly in the region of present Europe. b. Dbper Grelaceous. | (see: Fig. (6, p. 382.) The following changes took place: Sino-Australia was divided into a Szzic (Asiatic) and an Australian part, the latter comprising Australia and Antarctica. The Srnze section of Sino-Australia became united, across Bering Sea, with the western part of Nearctica. The western part of Nearctica was separated from the eastern. The western part of Nearctica became united with Anzıllia. Guiana became united with Andlha and separated from the Brazilian mass. Brazil became disconnected from Africa. The Zemurian bridge was connected with the Szxic continent. The result of this is: I. An irregular ring of land around the earth, which, generally, encircles it in the direction of the equator, but curving far to the north in the region of the Pacific Ocean. This ring, beginning at the Sinic land, goes across Bering Sea to western North America, thence to Antillia, Guiana, Africa and the Lemurian land bridge, which latter completes it by its union with the Szzzc land. We may call this ring-shaped continent MESOZONIA. Aside from Mesozonia we have, separated from it, the following continental masses : Il. Upper Cretaceous NEARCTICA. Smaller than the Lower Cretaceous continent of the same name, since its western part is cut off and enters Mesozonia. AND ANCIENT GEOGRAPHY. 881: 1902.] a Datum RETNA Fic. 6. Distribution of land and water during the Upper Cretaceous period, 382 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, III. ARCHIPLATA of von Ihering, comprising Brazz/, south of the Amazonas, and northern Argentina. IV. ARCHINOTIS, comprising Australia and Antarctica. As will be noticed, the term Archinotis (as used by von Ihering and others) does not exactly correspond to the meaning given to it here, but we think it convenient to define this term in this way, applying it only to the truly notal regions; aside from Australia and Antarctica, a part of South America belongs to Archinotis, namely the western (Chilian coast range). Note—The existence of this ring-shaped continent Mesozonia in Upper Cretaceous times is extremely important for marine zoogeo- graphy. The distinction of two types of marine faunas, the MEDI- TERRANEAN and the Paciric, is well known among geologists, and this continent furnishes an explanation for this differentiation: all parts of the oceans lying to the zorth of Mesozonia—as far as the present knowledge goes—possess the Mediterranean type, all parts to the south of it exhibit the Pacific type! In subsequent times both types of marine faunas frequently communicated, but there was never a complete fusion of both elements, and finally they developed into the Atlantic and /ndo Pacific types of the present marine fauna, the AZ/antic being a continuation of the Mediterra- nean. In later Tertiary and recent times the differences of both were again emphasized, chiefly on account of the development of an Arcrıc and ANTARCTIC TYPE through the action of climatic agencies, which prevented their communication in the northern and southern regions of the earth. At present both original types which, as we have seen, go back to the Cretaceous, are restricted to the circumtropical belt, and are absolutely separated. ¢;, Lower Tertiary. (see Fig: 7, p. 383.) The following changes appear : The ring formed by Mesozonia was interrupted at three places: 1. between Guiana and Africa; 2. in Central America (Panama region); 3. between Africa and Southeast Asta. This latter inter- 1 Of course, there are apparent exceptions. The Lower Senonian deposits of western Venezuela possess Mediterranean character (see Gerhardt, V. Fahré. Miner., etc., Berl., B. 11, 1897), but this is possibly explained by the assumption that they formed part of the Caribbean Sea just formed (see above, p. 343). The Mediterranean character of the Lower Cretaceous of Colombia, Ecuador and Peru is easily explained by the Orinoco strait. 389 AND ANCIENT GEOGRAPHY. 1902.] Fic. 7. Distribution of land and water during the Zower Tertiary period. 7" ~ ETTEPFFTTT 384 ORTMANN— DISTRIBUTION OF DECAPODS [April 3, ruption is a double one, the Lemurian bridge between Madagascar and Zndia being destroyed and Zndia becoming again disconnected from the Sinzc land. The southern part of Antillia (with Guiana) becomes united with Archiplata. Archiplata becomes connected with Antarctica. Antarctica is cut off from Australia. This results in the following five isolated continental masses : I. Sino-Nearctic continent. Composed of the whole of North America (including possibly the Scandinavian mass in Europe), the northern parts of Central America and of Eastern Asia (Sinic land). SINO-NEARCTICA comes very near to what von Ihering has called Archiboreas, with the exception that Europe does not belong to it. Von Ihering’s Archiboreas is almost identical with the “ Holarctic region,’ only from the latter the “ Sonoran region" (southern North America) is excluded. | Il. OLD TERTIARY Arrıca. This mass nearly approaches to present conditions, but still includes Madagascar and Arabia. Ill. THe INDIAN ISLAND. A very small part, hardly worth the name of a continent, but here so-called in order to emphasize this important stage in the development of southern Asia. IV. AUSTRALIA, which closely resembles its present form. V. Archinotis and Archiplata, together with the southern parts of old Antillia (northern South America). “This largely represents present South America with the addition of the Antarctic land. If we are to choose a name for it, we should like to propose NEONOTIS, in allusion to its relation to the older (Upper Cretaceous) Archinotis and the Neotropical continent of recent times. d. Upper Tertiary. (See Fig. 8, p. 385.) The following are the most important changes: ‚Sino-Nearctica is greatly enlarged, and becomes connected with the following parts: 1. in the Old World, with the island of /ndia, with Africa, with the Zuropean Archipelago, and with Scandinavia ; 2. the Nearctic part of Sino-Nearctica becomes connected, in the region of the Isthmus of Panama, with Veoxotis (South America). Madagascar is cut off from Africa. Antarctica becomes separated from South America. 335 AND ANCIENT GEOGRAPHY. 1902.] Fic. 8. Distribution of land and water during the Upper Tertiary period. 386 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, The result is : I. One large, continuous, continental mass, comprising almost all of the O/d and Mew Worlds. We may call it Hotocma. It is composed, not only of the Old World, together with North America (Arctogea of previous authors), but also of South America (Neogea of previous authors). Separated from it, we have only the following smaller parts of old continental masses: II. AUSTRALIA, which may be regarded as a second continent. III. MADAGASCAR, which is merely an island. IV. ANTARCTICA, which, on account of the deterioration of the climate, loses its character as a centre for the origin of life. Note—Here we have the greatest continusty of land masses of the earth that ever existed : practically all parts of the world that are important zoogeographical centres were mutually connected, with the exception of two comparatively small sections, Australia and Madagascar, and the barren regions of Antarctica." This union of old centres of radiation had a very important result: we must attribute to it the fact that the distribution of many continental forms of life has been rendered confused, and the difficulty at the present timein tracing the origin of the different groups. Of course, Upper Cre- taceous Mesozonia and other connections of Pre-Miocene times have had their share in effacing many of the original features of distribu- tion, but Late Tertiary Hologea ts the chief cause of uniformity in distribution : in most cases ‘*cosmopolitan ’’ distribution, with the exception of Australia and Madagascar, may safely be referred to these Upper Tertiary conditions. e. Recent time. The most important changes that brought about the present dis- tribution of the continents is the separation of North America from Asia by Bering Strait, and of North America from Europe. Thus we obtain a recent zoogeographic division into parts that represent important centres of distribution : I. Old World (Europe, Asia, Africa). This agrees partly with Sclater’s Arciogea, except that North America is excluded. We may choose for it the name Euc@a. 1] think that in Late Tertiary times Antarctica was not so desolate and desti- tute of life as it is now, but there is no doubt that the present character began to develop. 1902.] AND ANCIENT GEOGRAPHY. 387 II. New World (America). This is North America and Sclater’s /Veogea. I think there is no objection to use NEoG#A for the whole of the ““ New World.” HI. Australia. This is Sclater's Norocaa. IV. Manacascar. Although of small size, the historical development warrants a consideration of Madagascar as a separate centre. In fact, it is—aside from Australia—the oldest isolated part of the world. V. Antarctica. This is no longer a centre of radiation ; it is now barren of continental life. WVote—We claim that this division solves the problem of zoogeographi- cal research as indicated by Osborn, and amended in the introduc- tion (see p. 269, footnote 3): zt unites historically and genetically past and present conditions of distribution of continental life—that is to say, it gives a division that is founded upon the present physical features of the earth’s surface as related to life, and pays due atten- tion to the past history of the earth. But this division takes into consideration only the chief Zupographical characters; yet there are others, especially those connected with c/imatic differentiation, which are apt to furnish additional points of view in dividing the earth in zoogeographical units. By using the latter we shall arrive, with only slight changes,’ at Wallace’s regions, which, as we have mentioned above (p. 271), are well supported by physical characters, although Wallace constructed them according to entirely different principles. B. History OF THE DISTRIBUTION OF CRAYFISHES. (Compare Bis T, p. 275.) t. In the Lower Cretaceous we are to assume that the ancestors of the Potamobide and Parastacide lived in Sino-Australia, possi- bly extending to its southern extremity, Antarctica. 2. During the Middle Cretaceous, Astacoides reached Madagascar by way of the Lemurian land-bridge, coming from the Sinic conti- nent. Shortly after this, in the Upper Cretaceous, the separation of eastern Asia and Australia took place, resulting in the differen- tiation of the families Potamobide (in the Sinic continent) and Parastacide (in Archinotis). At the same time, the Potamobiide extended their range into western North America, going as far as Central America. ‘Thus, in the Upper Cretaceous, the Potamobiida 1 This refers to Madagascar. 388 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, extended over a great part of Mesozonia, from southeastern Asia over northwestern America to southern Mexico, and, in more primitive forms (approaching Astacoides), extending even from southern Asia across India to Madagascar." 3. In Zower Tertiary times, the genus Potamobius gives origin, in Mexico, to the genus Cambarus, and this spreads over the eastern parts of North America. The Parastacide of Archinotis extend from Chili to northern Argentina and southern Brazil, and the family is divided into an Australian group (which splits up in several genera) and a group belonging to Neonotis (Parastacus). 4. In Upper Tertiary times (and later), the Pofamobiide from eastern Asia reach western Asia and Europe, and the Parastacide become restricted to Australia, New Zealand and South America.’ C. History OF THE DISTRIBUTION oF FRESHWATER CRABS. (Compare Fig. 3, p. 297.) 1. In the Upper Cretaceous, freshwater crabs of the family Potamonide existed in parts of Mesozonia, beginning in India (possibly going eastward to the Malaysian islands), and extending over the Lemurian bridge to Africa, Guiana and Central America.’ 2. In the beginning of the Lower Tertiary, we find this area divided into two main portions. The one comprises farts of America: the northern parts of Neonotis and the southern parts of Sino-Nearctica (northern Central America), which are again sepa- rated from each other. These regions are inhabited by the sub- family Potamocarcining. ‘The second main portion, occupied by the subfamily Zotamonine, is formed by Africa and /ndia, and this, during this time, is again divided into two sections, an African (including Madagascar) and an /ndian. | 3. Inthe Upper Tertiary (and later), the two sections of the range of the Potamocarcinine become reunited, so that this subfamily now occupies the West Indian region, Central America and northern South America. Also the immigration in the Zesser Antilles 1 The possible cause of the check to the farther distribution of the crayfishes over Mesozonia, westward beyond Madagascar and south- and eastward beyond Central America, will be discussed below (see p. 391). 2 The Madagassian form, Astacoides, therefore does not belong to this stock, but should form a group by itself. 3 It will be noticed that the distribution of crayfishes and crabs in Mesozonia is almost mutually exclusive: they came into contact only in Lemuria (and South Asia) and northern Central America. See below, p. 391. 1902.] AND ANCIENT GEOGRAPHY. 389 occurred at this time. The 4jfricar stock of the Potamonine remains practically unchanged, the Madagassian forms alone becoming separated from it; the /ndian stock spreads over the Malaysian islands to North Australia and Japan,’ and further, sends out a westward branch over western Asia, reaching Southern Europe and Northern Africa. D. DisrRrRIBUTION OF ZEGLEA AND THE TRICHODACTYLINA. (Compare Fig. 2, p. 296, and Fig. 4, p. 311.) 1. The remarkable resemblance of the range of g/ea to that of Parastacus suggests identity of origin. This would mean that Eglea, in the beginning of the Tertiary, inhabited Chili, and migrated, at this time, into norzhern Argentina and southern Brazil. Since there are no closer relations to this peculiar genus in any other part of the world, 4g/ea apparently is indigenous to Chili, 2.e., to the northern extremity of the American part of Archinotis, and subsequently extended only into the southern part of Archiplata. Of course, the opposite direction of migration also is possible. 2. As we have seen above (p. 312) the distribution of the 77zcho- dactyline offers no remarkable feature. It belongs to the Atlantic slope ot present South America (the WVeotropical region of Wallace) and seems to have formed under the recent conditions. Possibly, this subtamily is a new addition to the freshwater fauna, and immi- grated from the marine littoral of the Atlantic. Further investiga- tion of this question, together with a closer study of the morpho- logy and systematic relations of this group are very desirable.’ PART III. CLIMATIC AND BIOCOENOTIC? BARRIERS TO THE DISTRIBUTION OF CRAYFISHES AND CRABS. In the foregoing discussions we have repeatedly called attention to some distributional facts which we were unable to explain. For 1 This extension began possibly as early as the Upper Cretaceous and Lower Tertiary, 2 Everything here depends on the systematic position and affinity of this group. If it should be a primitive one, and really belong to the Potamonide, it is possible that it reached Brazil in Lower Cretaceous times, when it formed part of Archhelenis. Its isolation in Upper Cretaceous Archiplata, which was not fully destroyed when it became a part of Lower Tertiary Neonotis, would explain its isolated morphological position. In the Tertiary this subfamily would then have extended its range northward. 3 As to the term “ Biocoenotic barrier,” compare Ortmann, Grundzuege der marinen Thiergeographie, 1896, pp. 41 and 70. 390 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, convenient study we may put them together here under the follow- ing heads: 1. Explanation of the absence of Potamocarcinina in Brazil south of the Amazonas river. 2. Explanation of the absence of Parastactde in Middle and Northern South America. 3. Explanation of the absence of Aszacoides-like forms in Africa. 4. Explanation of the absence of Pofamobiide in Central and South America. 5. Explanation of the absence of crayfishes in Central and South Asia and on the Malaysian islands. We can dispose of the first point with ease; indeed, we have in- dicated above the chief cause of it. The Potamocarcinine originally (in the Upper Cretaceous) occupied only the region to the north of the Amazonian interoceanic connection. In the Tertiary we have a connection of northern South America with the Brazilian mass (Archiplata) in the west (region of the Cordilleras), and we see that the crabs availed themselves of this opportunity and spread over the mountainous regions of Ecuador, Peru and Bolivia, possi- bly here reaching a climatic southern boundary. The Amazonas valley, however, remained sea during a much longer time and was gradually and slowly filled by the deposits carried down from the mountains. Thus, up to a comparatively recent time, it was im- possible for the Potamocarcinine to cross this depression. That there now exists a possibility of crossing this old barrier is shown by the existence of at least one species on the southern banks of the mouth of the Amazonas near Para. In regard to the second point—the absence of Parastacida in the main (tropical) part of Brazil—I can offer no explanation, They must have immigrated into Southern Brazil early in Tertiary times, and possibly we have to deal here with a climatic barrier. We may take together the other three points, since they appar- ently are subject to identical causes. Looking at the original dis- tribution of the crayfishes and crabs in Upper Cretaceous times, we have to note the very remarkable fact (see p. 388, footnotes 1 and 3) that both together occupied the whole of Mesozonia, but each different parts of it almost to their mutual exclusion. The crayfishes seem to have existed in the Asiatic part of this conti- 1902.] AND ANCIENT GEOGRAPHY. 391 nental ring and in the North American as far as the northern sec- tion of Central America. ‘There they gave place to the freshwater crabs, which extended thence to Northern South America, Africa and Lemuria, where they came again into touch with the cray- fishes. The same fact, namely, that crayfishes and crabs are mutually exclusive, holds good for their distribution in recent times. This fact was first pointed out by Milne-Edwards; it has also been men- tioned by Faxon, and the present writer! has used it for the expla- nation of some of the features in their distribution. It seems, therefore, that the crabs are more vigorous and active than the crayfishes, and that wherever they came into actual contact the latter were exterminated by the former. It is true there are some countries from which both types of Decapods have been reported, namely, Mexico, Northeastern Australia and Madagascar; but we have no report that both are found associated in the same localities and in the same rivers, streams, ponds or lakes, and it is very likely that just in these regions crabs and crayfishes inhabit stations of a different character. The closer investigation of these conditions would be most interesting. If we apply this idea, that the presence of crabs forms a biocoen- otic barrier to the crayfishes in the former distribution of both, we obtain the following result: The crayfishes are geologically older than the crabs. They ex- isted, in Lower Cretaceous times, in Sino-Australia, and conse- quently also in the region of Southeastern Asia and the Malaysian islands. In the Middle Cretaceous they sent a branch (4s¢acozdes) across India to Madagascar. But in the Upper Cretaceous the freshwater crabs arrived (or originated) in the same region (Lemu- ria) and extended into Southern Asia and the Malaysian Archipel- ago, everywhere exterminating the crayfishes, namely, in India, Southeastern Asia (Farther India and China) and on the islands. They not only acted as a check to the distribution of the cray- fishes, but directly annihilated them. Only in Madagascar Asta- codes survived, probably because in this island it inhabits parts that have not been occupied by the crabs.” On the other hand, 1 See Ortmann, in Zool. Jahrb. Syst., Vol. 9, 1896, p. 593 f., and in Bronn’s Klassen und Ordnungen, Vol. 5, 1901, p. 1289. 2 Possibly the large size of Astacozdes has something to do with its survival. Astacoides is—aside from some South Australian species—by far the largest type of all crayfishes. 392 ORTMANN—-DISTRIBUTION OF DECAPODS [April 3, the original presence of crabs in Africa at about the middle of the Cretaceous would explain the fact that no crayfishes are found on this continent ; but, on the other hand, there is the possibility that crayfishes once existed there, but have become extinct on account of the increase of crabs in this country. Then, again, after the crayfishes had, in Upper Cretaceous times, occupied western North America and Mexico, they met here with the crabs which came from the south, and their farther advance was checked by this biocoenotic barrier. The question remains, why did the crabs not advance beyond their present (and old) boundaries in China, Australia and Mexico? If it is correct that the existence of crabs forms a barrier to the ex- tension of the crayfishes, the opposite cannot be the case. The presence of crayfishes would not put a stop toa farther dispersal of crabs. But here, I think, we have to deal with climatic barriers. All freshwater crabs are truly tropical animals, entering in only a few cases subtropical countries, but never temperate or cold regions, and thus it seems that the northern boundaries of the Potamonide in China and Mexico and the southern in Australia are due to the climate of these respective parts. The same seems to be true in Europe, Western Asia and in Bolivia, where the northern, resp. southern boundaries are apparently given, in a large part, by some features of the climate. It will be noticed that in applying this principle to the past dis- tribution of the crabs it is necessary to assume the existence, in earlier Tertiary and even Pretertiary times, of climatic differences on the continents, although we do not believe in a climatic differen- tiation of the oceans of the Mesozoic period. But this is entirely in keeping with our opinion expressed in a previous paper." And, further, I do not mean to say that the present climatic boundaries of the crabs are identical to those of former times. On the con- trary, it is quite possible, for instance, that in China the crabs formerly extended farther north, and in Europe we know positively that the European species did so in Diluvial times, reaching as far as Hungary, where it does not now live (see above, p. 376, foot« note). The southern boundary of the crabs in Australia, however, seems to be original and has not retreated equatorward, since these 1 Ortmann, A. E., “An Examination . .. of Climatic Zones in Jurassic Times,” in Amer, Journ. Sci., Vol. 1, 1896, p. 270, foctnote, 1902.] AND ANCIENT GEOGRAPHY. 893 crabs arrived there presumably in a very recent period. Only the boundary in Mexico needs investigation, but possibly here it is not temperature that puts a stop to the northern advance of the crabs, but another climatic factor, namely, the arid or semiarid character of the country lying to the north of the actual boundary, which possibly has existed from the beginning of the Tertiary. The above considerations would sufficiently explain the third, fourth and partly the fifth points (see p. 390), namely, the absence of crayfishes in Africa, the absence of Potamobiida in Central and South America and their absence in South and Southeast Asia and on the Malaysian islands. They could not enter Africa and could not go beyond Mexico on account of the presence of crabs in these parts, and in Southeastern Asia and Malaysia they must have once existed, but, have succumbed under the onslaught of the crabs. This latter cause seems also to control the distribution of the crabs and crayfishes in Southern Europe (see p. 377). It does not explain, however, the absence of crayfishes in Central Asia, and, as regards this point, we are unable to offer any reasonable explanation (see p. 378 and footnote). CONCLUSION. Although we have tried to advance explanations for many of the puzzling facts in the distribution of the freshwater Decapods dis- cussed here, we are to bear in mind that the ideas brought forward are largely hypothetical and tentative. In many respects we have found a wonderful agreement between the distributional facts and what is known about the geology and tectonics of the respective parts, and it was one of my chief purposes to point out that it zs possible to more closely correlate zoogeography and geology. But, nevertheless, I am fully aware of the danger that lies in our incom- plete knowledge, not only of the geological configuration of the different countries here discussed, but also in the deficiency of the chorological facts at hand. I wish most strongly to emphasize that I do not believe in all cases to have correctly revealed the ancient relations of land and water, and I think that my ideas of the old continents need con- firmation and probably modification. I have only tried to give a representation of what I think of the changes that have taken place during the earth's history, as tar as the present state of our knowl- edge permits of any conclusions in this respect, and I earnestly 39+ ORTMANN—DISTRIBUTION OF DECAPODS [April 3, wish that my opinions may be investigated by other authors and compared with material furnished by other groups of animals, as well as with more complete and reliable geological observations to be made in future. The way in which such investigations should be carried on has been indicated in this paper. Finally, I want to point out that most of the ancient continental connections here discussed are not treated for the first time, but have been hinted at or more or less closely investigated by previous authors, zoogeographers as well as geologists. But, unfortunately, the former have not generally paid much attention to the results obtained by the latter, and vice versa. Just this lack of a broader view, chiefly among zoogeographers, has induced me to attempt to harmonize both sets of facts, and the results here presented are pos- sibly apt to serve as an apology for having undertaken this task although much preliminary work remains to be done. APPENDIX. RELATION OF THE MARINE DECAPOD FAUNAS OF THE EASTERN AND WESTERN SIDES OF TROPICAL AMERICA. We have mentioned above (p. 359, footnote) that the facts fur- nished by the characters of the marine faunas of either side of Cen- tral America are frequently misunderstood or misrepresented. In order to get at a proper understanding of the relations of the Atlantic and Pacific Oceans, as revealed by these facts, I shall endeavor here to give a (incomplete) list of identical, resp. closely allied forms of Decapod Crustaceans, which are especially apt to throw a light on this question. I have made it a point to include in this list only such forms as give plain and unmistakable indications in this respect, that is I have used only those cases in which the relations between the Panamic and Caribbean region are the closest known, which, gen- erally, is self-evident only when the respective forms (mostly species of the same genus) are not known outside of American waters. In genera or groups, where representatives are also known from other parts (especially the Indo-Pacific region), it is not always easy to determine the relation of the different forms, and the question whether the West and East American forms are the most closely allied ones remains unsettled: therefore I shall disregard such instances. 1902.] AND ANCIENT GEOGRAPHY. 395 Nevertheless, I am able to offer here a list that is quite large.’ PACIFIC SIDE. ATLANTIC SIDE. REMARKS. Panulirus interruptus (Rand.). CALCINUS TIBICEN (Hbst.), Ecuador (Nobili, Boll. Mus. Torino, Vol. 16, 1901, p. 26). PETROLISTHES THINUS (Bosc.). GALA- PACHYCHELES PANA- MENSIS Fax, (see No- Bil, 2. 2. p:. 19). Genus Lepidopa. Remipes strigillatus Stps. Albunea lucasia ( Sauss.). HiIPPA EMERITA (L.). Hypoconcha panamen- sts Sm. ETHUSA AMERICANA A. P. argus (Latr.). C. TIBICEN (Hbst.). P. GALATHINUS (Bosc.). P. PANAMENSIS Fax. Genus Lepidopa. R, cubensts Sauss. A. gibbesi and pareti. H. EMERITA (L.). H. sabulosa (Hbst.). H. arcuata Stps. E. AMERICANA. The Californian species is the most closely allied form, although the genus is circumtropical. We exclude P. armatus Gibb. as a circumtropical species. Number of species doubtful, but exclusively found in the West Indies and Low. California. The species on both sides different. Also in West Africa. This group of the genus is found nowhere else. The genus is circumtropical. No other species of the genus are so closely allied, although the genus is cir- cumtropical. Genus circumtropical. Genus found nowhere else. Genus cosmopolitan. 1 Where no references are given, the facts are taken from Ortmann, in Bronn’s Alass. u. Ordn., Vol. 5, 1900, p. 1275, and from my unpublished revis- ion of the respective groups for the « Thierreich.” | Identical species-are printed in SMALL CAPITALS; the most important forms, where the genus is not found outside of American waters, are printed in zzalies. 396 ORTMANN—DISTRIBUTION OF DECAPODS [April 3, PACIFIC SIDE. Ranilia angustata Stps. R. fornicata (Fax.). Lithadia cumingi Bell. L. digueti Bouv. Uhlias ellipticus Stps. Persephona subovala (Rthb.). P. orbicularis Bell. P. edwardsi Bell (=? townsendi (Rthb.)). Hepatus chilensis M.-E. Hepatella actua (Stps.). ff, levis (Rthb.). Hi, lata (Fax.). FA. amica Sm. ATLANTIC SIDE. muricata M.-E. R. stimpsoni (A. M.- EI R. constricta (A. M.- Ba): (AE va . cariosa Stps. . miersi Ortm. . cadaverosa Stps. . cubensis Mrts. . pontifera Stps. ss sy U. limbatus Stps. | P. punctata (L.). H. epheliticus (L.). H. annularis (01.). H. tuberosa (Stps.). REMARKS. Ranilia M.-E. includes Not- opus d. H. and Raninops A. .M.-E. ~The species mentioned here form a natural group, which is not found elsewhere. This genus is found nowhere else. Genus found nowhere else. Of one species (P. lichten- steini Leach) the habitat is unknown, but it is cer- tainly from America. The genus is not found else- where. Several doubtful species, but none outside of American waters. Hepatella = Osachila. One species, H. stimpsoni (Stud.), at Ascension Is- land. No other species from any other part of the world. The following are 15, 1892: Pericera triangulata Rthb. A contigua Rthb. Othonia nicholst Rthb. Mithrax (4 species). taken from Rathbun, UV. S. Nat. Mus., Vol. P. cornuta (Hbst.). P. atlantica Rthb. Othonia (4 species). Mithrax (14 species). Genus found nowhere out- side of America. Genus not found outside of America. Genus not found outside of America, 1902.] AND ANCIENT GEOGRAPHY. 397 The following are taken from Rathbun, U. S. Nat. Mus., Vol. 16, 1893: PACIFIC SIDE. ATLANTIC SIDE. REMARKS. Libinia macdonaldi L. spinimana Rthb. Other species known from Rthb. both sides, and possibly from other parts of the world, but these two are especially closely allied. Pelia (2 species), Pelia (2 species). Genus found nowhere else. EPIALTUS BITUBERCULA- | E. BITUBERCULATUS, There are four other species TUS. | on the Pacific side. The genus is found nowhere else. The following is taken from Rathbun, zézd., Vol. 18, 1896, and Proc. Biol. Soc. Wash., Vol. 10, 1897: Callinectes (4 species). | Callinectes (6 species). | All Pacific species different from the Atlantic. Three of the Atlantic species also found in West Africa. Genus not found else- where. | The following is taken from Nobili, Zoll. Mus. Torino, Vol. 16, 90%. D.,32: CRONIUS RUBER (Lmck.) | C. RUBER. E his species also in West | Africa, but nowhere else. In this list we see there are seven identical species. The rest are more or less closely allied, but the affinity is always so close that it is not equaled in any other’ part of the world, with the exception of West Africa, where some of the types have been found that are common to the east and west sides of America, but are lacking everywhere else. This affinity of the West African littoral fauna is a well-known fact, and there is nothing remarkable about it, since a communication between both sides of the Atlantie is possible in many cases even at present times. 398 ORTMANN--DISTRIBUTION OF DECAPODS [April 3, Aside from this, a close relation of the western and eastern faunas of the Central American shores is revealed at a glance.* Hill says (2. c., p. 267) that the recent faunas of the opposite sides of the isthmus are so distinct that the communication of waters must have belonged to a very remote time, and that there has been probably no communication since Miocene. We may modify this a little and say that the affinities of the Decapod fauna of the Atlantic and Pacific are unmistakable, and zZhat we have ample and convincing evidence that there must have once been a connection. ‘The scarcity of identical forms (which in part are not beyond doubt), and the demonstrated fact that generally one (or more) species of the re- spective genera replace each other on either side of America, being distinctly different, although closely allied, shows conclusively that this connection cannot have been of a very recent date. Ithink that the Decapods confirm Hill’s opinion that Zhere was no com. munication whatever of both oceans since Miocene time, and we may add that probably the similarity of both faunas is to be referred in most cases to the Eocene and Oligocene interoceanic connection across the isthmus. After this had been closed sufficient time has elapsed to generally change the characters of the once identical Pacific and Atlantic stock and to render them different species, while only a few have preserved their original characters and are to be regarded as identical species. Of course it is possible that some of the similarities of the Pacific and Atlantic faunas go back to earlier (Mesozoic) times, when the ! In speaking of a close resemblance of these faunas, I wish to avoid being misunderstood. There are cases that show a close resemblance, but this does not mean that both faunas are closely related in a// respects; on the contrary, there are other elements on both sides of Central America that are peculiar to only one of them. The Panamic fauna, for instance, contains Indo-Pacific elements and a very peculiar element that belongs to the whole western coast of America (from the Western United States to Chili). I have called attention to this element in a former paper (Zool. Jahrb, Syst., Vol. 9, 1896, p. 582 ff.), but I have been entirely misunderstood by von Ihering, who says (ev. Mus. Paul- ista, Vol. 2, 1897, p. 379) that my theory of a migration along this coast ıs dis- proved by the fact that different faunas succeed each other along this coast from the south to the north. This is quite true, but it does not disprove my theory, since I never meant to say that the whole of the West American fauna has reached these parts by migration from north to south or vice versa. On the con- trary, only a part of it belongs to this category, and there are other components ' of the West American fauna which came from quite different sources. 1902.] AND ANCIENT GEOGRAPHY. 399 Mexican, Orinoco and Amazonas interoceanic connections existed. But this would not influence our general result that the communica- tion of the oceans was interrupted definitively in the Miocene. We have, beginning in Mesozoic times, a differentiation of two types of marine faunas, a Mediterranean and a Pacific, but these faunas communicated with each other at certain points and were completely separated for a comparatively short period in the Upper Cretaceous by the continent of Mesozonia (if this separation was at all complete at any time).* Generally the Mediterranean fauna belongs originaily to the northern hemisphere, the Pacific to the southern, except that the latter largely encroached upon the former in the region of the Northern Pacific. This arrangement was completely upset during the Tertiary, so that at present the Atlantic fauna (containing chiefly the descendants of the old Medi- terranean types) and the Pacific fauna are divided, not by a line running east and west, but by two lines running generally north and south (in America and in the Old World). Besides, the Arctic and Antarctic types have been added, the former being an offshoot of the Mediterranean, the latter of the Pacific type.” While in former times, in the Mesozoic and Lower Tertiary, a decided tendency prevailed to mix the marine faunas of the world and make them more or less uniform, which tendency was checked only temporarily, we have, from the Miocene upward, a complete separation of two marine types of fauna,” which, however, still possess certain features in common that are due to conditions pre- vailing in earlier times, and with respect to Central America these conditions (interoceanic connections) were present for the last time in the Older Tertiary (Eocene and Oligocene). 1 We possess evidence that Mesozonia was interrupted for shorter periods within the Upper Cretaceous, for instance, in the region of British Colombia (see Koss- mat) and in Western Venezuela (see above, p. 343). 2 In opposition to the belief of some authors (Pfeffer, Murray) that both Polar faunas are strikingly similar, I have always held the opinion (see review of the literature in Americ. Natural., Vol. 35, 1901, p. 139 ff.) that this is not so. We see here also that the origin of these faunas is different, the one being derived from the old Mediterranean, the other from the old Pacific fauna, the differences of which, although obscured during the earth’s history by frequent interchanges, go back to Mesozoic times. 3 The complete separation was brought about not only by topographical factors, but chiefly by the additional action of climatic differentiation. See Ort- mann, Grundzuege der marin. Thiergeograph., 1896, p. 40. 400 ORTMANN—DISTRIBUTION OF DECAPODS. [April 8, It is a very remarkable fact that the interoceanic connection of the Mediterranean and Pacific type of marine faunas, existing in Western and Southern Asia (Tethys and Strait of Bengal), was ended at about the same time, in the Miocene, by the elevation of Western Asia and its union with Africa and Europe. PRINCETON UNIVERSITY. Crustacea and Pycnogonida Collected During the Princeton Expedition to North Greenland. By Dr. A. E. ORTMANN. From the Proceedings of The Academy of Natural Sciences of Philadelphia, February, 1901. Issued April 30, 1901. W142 a “u 43” to OR CRUSTACEA AND PYCNOGONIDA COLLECTED DURING THE PRINCETON EXPEDITION TO NORTH GREENLAND. BY DR. A. E. ORTMANN. A preliminary but not quite complete list of the species collected during the Princeton Expedition to North Greenland (Peary Auxiliary Expedition, 1899) has been published in The Princeton Bulletin, Vol. 11, No. 3, February, 1900, pp. 38-40; in the same periodical, Vol. 11, No. 2, December, 1899, pp 25-26, a list of stations has been gievn. It seems hardly necessary to repeat this jist here, since under each species not only the number of the station, but also the location of the latter and the depth is given. Most of the localities are situated on the coast of North Green- land, between Cape York and Foulke Fjords (ca. 76-79º N. L.); a few are situated on the opposite side of Smith Sound (Ellesmere Land, Payer Harbor); the rest is farther south, on the coast of West Greenland (Upernavik, Waigat Channel, and Godhavn, Disco Island), and the coast of Labrador (Domino Run and | Battle Harbor). Only a few expeditions have previously collected material in these parts (North water of Baffin Bay, Smith Sound and Grinnell Land). The following reports on Crustacea have been pub- lished : Hayes’ Expedition, 1860-G1 (see J. J. Hayes, The Open Polar Sea, 1867), published by W. Stimpson: ‘‘ Synopsis of the Marine Invertebrates collected by the Late Arctic Expedition under Dr. J. J. Hayes.’’' Nares’ Expedition, 1875-76, published by E. J. Miers, in G. S. Nares, Narrative of a Voyage to the Polar Sea, Vol. 2, 1878, Appendix 7. Expedition of the Academy of Natural Sciences of Philadelphia, connected with the Peary Expedition of 1891, published by J. E. 1 Proc. Acad. Nat. Sci. Phila., 1863. 1901. ] NATURAL SCIENCES OF PHILADELPHIA. 145 Ives: ‘‘ Echinoderms and Crustaceans collected by the West Greenland Expedition of 1891.’’? Peary Auziliary Expedition of 1894, published by A. Ohlin: Bidrag till Kaennedomen om Malakostrakfaunan ı Baffin Bay och Smith Sound, Lund, 1895. A number of species has been mentioned by Hansen from near Cape York in H. J. Hansen, ‘‘ Maiacostraca marina Groen- landiz occidentalis.’’ ° “The collections described here have been made by Prof. William Libbey and the writer, by means of small hand dredges and a larger beam-trawl, surface and dip nets. Since the chief value of the material collected lies on the zoögeographical side, I shall take particular pains to give an account of the pretas known facts of distribution in every species. CRUSTACEA. 1. Branchinecta paludosa (Mueller). Packard, 12th Ann. Rep. U.S. Geol. Surv. Terr. for 1878 part 1, 1883, p- 336, Pl. 9, 10, figs. 1-5. Station 13. Payer Harbor, Eilesmere Land. Fresh-water ponds (several hundred). Station 46. Northumberland Island. Fresh-water ponds (many hundred). Distribution. — Finmark, Lapland, North Siberia (Taimyr), Point Barrow (Alaska), Cape Krusenstern (Arctic America), Labrador, Grinnell Land, North and West Greenland. Grinnell Land: Discovery Bay (Miers) ; North Greenland: Polaris Bay (Packard). 2. Lepidurus glacialis (Kroeyer). Packard, 1. c., p. 316, Pl. 16, fig. 1. Station 46. Northumberland Island. Fresh-water ponds (46). Distribution. —Lapland, Novaja Semlja, Spitzbergen, South and West Greenland, Cape Krusenstern, Point Barrow. There are Cladocera (a fresh-water Daphnia, possibly rectispina Kr., from Stations 13 and 46) and a number of marine Ostracoda and Copepoda in the collection which have not yet been identified. 3 Proc. Acad. Nat. Sci. Phila., 1891. 3 Vidensk. Meddel. fra den naturh. Foren. à Kjoebenhavn, 1887. 146 PROCEEDINGS OF THE ACADEMY OF [Feb., 3. Balanus porcatus Costa. Darwin, Monogr. Cirrip. Balan., 1854, p. 256, Pl. .6, fig. 4; Weltner, Arch. f. Naturg., 1897, p. 267; Weltner, Die Cirripedien der Arktis (Fauna Arctica, Vol. 1), 1900, p. 292. Station 26. Cape Alexander, 27 fathoms (1). Station 45. Barden Bay, 10-40 fathoms (8). Station 51. Robertson Bay, 35-40 fathoms (6). Distribution.—England, Denmark, Norway, Iceland, Maine, Massachusetts, Novaja Semlja, Spitzbergen, Bear Island, East and West Greenland, Grinnell Land, Lancasier Sound, Japan, New Zealand and Campbell Island. Depth: to ca. 200 fathoms. Grinnell Land: Cape Napoleon, Franklin Pierce Bay, Richard- son Bay and Discovery Bay.‘ 4, Balanus crenatus Bruguiére. Darwin, 1. c., p. 261, Pl. 6, fig. 6; Weltner, !. c., 1897, v. 268; Weltner, 1. c., 1900, p. 298. Station 57. Sarkak (Waigat), 9 fathoms (1). Distribution. — Mediterranean, West Indies, Cape of Good Hope, England, Scandinavia, New England coast, Spitzbergen, Kara Sea, West Greenland, Labrador, Baffin Bay, Lancaster Sound, Grinnell Land, Bering Straits, North Japan. In deeper waiter. Grinnell Land: Discovery Bay (Miers, /. c., 1881). 5. Balanus balanoides (Linne), Darwin, 1. c., p. 267, Pl. 7, fig. 2; Weltner, !. c., 1897, p. 269; Weltner, . l. c., 1900, p. 302. Statiun 3. Godhavn, Disco Island. Between tides (4, and several broken). I have seen also oa the rocks of the shores of Foulke Fjord remains of a Balanus (bases only) which may belong to this species. Distribution.—Azores, Portugal, England, France, Norway, Atlantic coast of the United States, Novaja Semlja, White Sea, Bear Island, Iceland, West and North Greenland, Labrador. Within tidal limits. North Greenland: Port Foulke (Stimpson). 6. Nebalia bipes (O. Fabricius). Kroeyer, Naturhist. Tidsskr. (2), Vol. 2, 1849, p. 436; Grube, in Arch. f. Naturg., 1853, p. 162; Buchholz, Zweite deutsche Nord- polfahrt, Vol. 2, 1874, p. 388. Station 9. Saunders Island, 5-10 fathoms (1). * Miers, Journ. Linn. Soc. London, 15, 1881, pP. 73. / 1901. ] NATURAL SCIENCES OF PHILADELPHIA. 147 Distribution. —England, Labrador, East and West Greenland, North Greenland. Depth : to 150 fathoms. North Greenland: Cape Dudley Digges (Ohlin). 7. Hyperia galba (Montague). G. O. Sars, An Account of the Crustacea of Norway, Vol. 1, 1895, p. 7, PL. 2, 3, fie. 1. Station 29. Olriks Bay, 7-25 fathoms (1). Distribution. —France, England, Sweden, Norway, Kara Sea, Murman coast, Spitzbergen, West Greenland, Point Barrow. Pelagic. 8. Euthemisto libellula (Mandt). Sars, 1. €., 1895, p. 13, Pl. 6. fig. 1. Station 6. Melville Bay, surface (4). Station 29. Olriks Bay, 7-25 fathoms (1). Station 41. Whale Sound, surface (2). Station 42. Barden Bay, surface (7). Distribution. —Finmark, Novaja Semlja, Spitzbergen, Jan Mayen, East, West and North Greenland, Ellesmere Land, Point Barrow. Pelagic. North Greenland: Melville Bay (Ives), Inglefield Gulf on Ellesmere Land: Cape Faraday (Stimpson). 9, Socarnes bidenticulatus (Bate). Lysianassa bid. Bate, Ann. Mag. Nat. Hist., Ser. 3, Vol. 1, 1858, p. 362; Lys. nugax Bate, Catal. Amphip. Brit. Mus., 1862, p. 65, PI. 10, fig. 3; Anongya bid. Miers, Ann. Mag. Nat. Hist., Ser. 4, Vol. 19, 1877, p. 138; Socarnes ovalis Hoek, Niederl. Arch. Zool. Suppl., 1881, p. 42, Pl. 3, fig. 29; Soc. bid. Sars, Den Norsk. Nordhavs Exp. Crust., 1, 1885, p. 139, Pl. 12, fig. 1; Hansen, Malac. mar. Groenl. occ., 1887, p. 62. Station 11. Northumberland Island, 10-15 fathoms (2). Station 45. Barden Bay, 10-40 fathoms (2). Station 52. Robertson Bay, 5-15 fathoms (4). Distribution. — Spitzbergen, Jan Mayen, West Greenland, North Greenland, Ellesmere Land ; 4-160 fathoms. North Greenland: Cape Dudley Digges; Ellesmere Land: Cape Faraday (Ohlin). 148 PROCEEDINGS OF THE ACADEMY OF [Feb., 10. Anonyx nugax (Phipps). Cancer nug. Phipps, Voy. North Pole., Append., 1774, p: 192, Pl. 12, fig. 2; Lysianassa lagena and appendiculata Kroeyer, Dansk. Vid. Selsk. Afh., 7, 1838, pp. 237 and 240, Pl. 1, figs 1, 2; Anonyx am- pulla Kroeyer, Naturh. Tidssk. (2), Vol. 1, 1845, p. 578; An. lagena Bate, Catal. Amph. Brit. Mus., 1862, p. 77, Pl. 12, fig. 7; An. nugaz Miers, Ann. Mag. Nat. Hist., Ser. 4, Vol. 19, 1877, p. 135; Ives, Proc. Acad. Philad. 1291, p. 480; Sars, Crust. Norway, 1895, p. 88, Pl. 31. Station 45. Barden Bay, 10-40 fathoms (5). / Station 47. Northumberland Island, surface (1). Distribution. — Shetland Islands, Norway, northeast coast of North America, Labrador, Northumberland Sound, Ellesmere Land, Grinnell Land, North, West and East Greenland, Spitzber- gen, Franz Joseph Land, Kara Sea, North Siberia (East Taimyr and Tchukchee coast), Bering Straits, Sea of Ochotsk; 2-658 fathoms. Ellesmere Land: Gale Point (ten miles below Cape Isabella). (Stimpson); Grinnell Land: Floeberg Beach and 83° 19’ N. L., Discovery Bay (Miers); North Greenland: Murchison Sound (Ohlin), McCormick Bay (Ives). 11. Pseudalibrotus littoralis (Kroeyer), Alibrotus litt. Sars, Crust. Norway, Vol. 1, 1895, p. 102, Pl. 35, fig. 2. Station 14. Payer Harbor, Ellesmere Land, mouth of small fresh-water stream (1). | Station 42. Barden Bay, surface (2). Station 44. Barden Bay, sandy beach (17). Station 47. Northumberland Island, surface (several hundred). Station 53. Littleton Island, surface (2). The generic name Pseudalibrotus has been proposed by Stebbing, ° Distribution.—Finmark, Spitzbergen, Jan Mayen, East, West and North Greenland, Baffin Bay, Point Barrow. Surface to 100 fathoms. North Greenland: Murchison Sound (Ohlin), 12. Onesimus edwardsi (Kroeyer). | Sars, 1. c., 1895, p. 105, Pl. 36, fig. 1. Station 39. Granville Bay, 30-40 fathoms (3). Station 40. Granville Bay, 20-30 fathoms (2). Station 49. Olriks Bay, 15-20 fathoms (4). Distribution. —Kattegat, Norway, Labrador, West Greenland, > Ann. Mag. Nat. Hist., Ser. 7, Vol. 5, 1900, p. 15. 1901. NATURAL SCIENCES OF PHILADELPHIA. 149 Grinnell Land, Iceland, Jan Mayen, Spitzbergen, Murman coast, Franz Joseph Land, Kara Sea, eastern part of Siberian Polar Sea ; 2-60 fathoms. Grinnell Land: Discovery Bay and Floeberg Beach (Miers). 13. Byblis gaimardi (Kroeyer). _ Sars, I. c., 1895, p. 183, Pl. 64. Station 43. Barden Bay, 20-25 fathoms (11). Distribution. —Kattegat, Norway, Finmark, Labrador, West Greenland (northward to Disco Island), Iceland, Spitzbergen, Murman coast, Kara Sea; 2-280 fathoms. 14. Stegocephalus inflatus Kroeyer. Sars, 1. c., 1895, p. 198, Pl. 69. Station 12. Foulke Fjord, 35 fathoms (2). Station 29. Olriks Bay, 7-25 fathoms (2). Station 39. Granville Bay, 30-40 fathoms (11). Station 40. (rranville Bay, 20-30 fathoms (1). Station 43. Barden Bay, 20-25 fathoms (19). Station 49. Olriks Bay, 15-20 fathoms (65). Station 50. Karnah (Inglefield Gulf), 30-40 fathoms (1). Distribution. — Norway, Shetland Islands, Nova Scotia, North- umberland Sound, Berry Island, North, West and East Green- land, Spitzbergen, Murman coast, White Sea, Franz Joseph Land, Kara Sea, eastern part of Siberian Polar Sea ; 7-150 fathoms, North Greenland: Cape Dudley Digges and Murchison Sound (Ohlin). 15. Parcedicerus lynceus (M. Sars). G. O. Sars, 1. c., 1895, p. 292, Pl. 103, fig. 2, PL 104, fig. 1. Station 37. Saunders Island, 5 fathoms (1). Station 52. Robertson Bay, 5-15 fathoms (1). Distribution. —Nova Scotia, Labrador, Ellesmere Land, North, West and East Greenland, Iceland, Spitzbergen, Barents Sea, Finmark, Murman coast, Kara Sea ; 2-160 fathoms. Ellesmere Land: Cape Faraday (Ohlin); North Greenland: Murchison Sound and Cape Dudley Digges (Ohlin), Cape York (Hansen). 16. Monoculodes borealis Boeck. | Sars, l..e., 1895, p. 298, PI. 106, fig. 2. Station 49. Olriks Bay, 15-20 fathoms (1). Distribution. —England, Norway, Finmark, Kara Sea, Spitz- 150 PROCEEDINGS OF THE ACADEMY OF | Feb., bergen, East Greenland, West Greenland (northward to the Waigat) ; 3-100 fathoms. 17. Pleustes panoplus (Kroeyer). Sars, dl. c., 1895, p. 344, Pl. 121. Station 29. Olriks Bay, 7-25 fathoms (3). Distribution.—Norway, Nova Scotia, Labrador, North, West and East Greenland, Iceland, Jan Mayen, Spitzbergen, Novaja Semlja, Murman coast, Kara Sea, Point Barrow; 4-100 fathoms. North Greenland: Cape Dudley Digges (Ohlin), oe York (Hansen). 18. Paramphithoe bicuspis (Kroeyer). Sars, J. c., 1895, p. 349, Pl. 123, fig. 1. Station 4. Upernavik, 8-10 fathoms (3). Station 29. Olriks Bay, 7-25 fathoms (4). Distribution. —England, France, Kattegat, Norway, Finmark, Spitzbergen, Bear Island, Iceland, Labrador, West and North Greenland ; 3-60 fathoms. North Greenland: Cape Dudley Digges (Ohlin). 19. Acanthozone cuspidata (Lepechin). Sars, U. c., 1895, p. 370, Pl. 130. Station 45. Barden Bay, 10-40 fathoms (21). It has been suggested (Miers, Stebbing) that the species figured by Buchholz’ is different from this species. But, as Hoek points out,’ and Koelbel confirms,* the differences of Buchholz’s figure from this species are due to inaccuracies in the drawing. That the drawing in fig. 1 is incorrect, especially as regards the last. three pairs of pereiopods, is shown conclusively by the fact that Buchholz gives, in fig. 1h, a correct reproduction of the last pereiopod. Distribution. — Norway, Finmark, Labrador, Polar Islands of North America, Grinnell Land, North, West and East Greenland, Jan Mayen, Spitzbergen, Murman coast, White Sea, Kara Sea, Siberian Polar Sea (East Taimyr peninsula) ; 7-100 fathoms. Grinnell Land: Franklin Pierce Bay, Discovery Day Miele E North Greenland: Cape Dudley Digges (Ohlin). 6 Zweite deutsche Nordpolfahrt, Vol. 2, 1874, p. 362, Pl. 11. 7 Niederl. Arch. Zool. Suppl., 1881, p. 48. ® (Wsterreich. Polarstat. Jan Mayen, Vol. 3, 1886, p. 45. 1901.] NATURAL SCIENCES OF PHILADELPHIA. 151 20. Rachotropis aculeata (Lepechin). Sars, 1. c.,:1895, p. 434, Pl. 149. Station 11. Northumberland Island, 10-15 fathoms (1). Station 12. Foulke Fjord, 35 fathoms (2). Station 27. Cape Chalon, 35 fathoms (1). Station 39. Granville Bay, 30-40 fathoms (8). Station 40. Granville Bay, 20-30 fathoms (13). Station 45. Barden Bay, 10-40 fathoms (2). Station 49. Olriks Bay, 15-20 fathoms (11). Station 50. Karnah, 30-40 fathoms (4). Station 51. Robertson Bay, 35-40 fathoms (1). Distribution.—Nova Seotia, Labrador, Polar Islands of North America, Baffin Bay, Grinnell Land, North Greenland, West and East Greenland, Jan Mayen, Spitzbergen, Finmark, Novaja Semlja, White Sea, Franz Joseph Land, Point Barrow; 3-220 fathoms. Grinnell Land: Dobbin Bay, Cape Frazer, Franklin Pierce Bay, Cape Napoleon, Discovery Bay, Floeberg Beach (Miers); North Greenland: Cape Dudley Digges and Murchison Sound (Ohlin). 21. Halirages fulvocinctus (M. Sars). G. O. Sars, J. c., 1895, p. 436, Pl. 154; Pherusa tricuspis Stimpson, Proc. Acad. Phila., 1863, p. 139. Station 4. Upernavik, 8-10 fathoms (8). Station 52. Robertson Bay, 5-15 fathoms (5). Station 54. Foulke Fjord, 5 fathoms (1). Distribution. — Norway, Finmark, Nova Scotia, Labrador, Grinnell Land. North, West and East Greenland, Spitzbergen, Novaja Semlja, Murman coast, Kara Sea, Franz Joseph Land; 2-110 fathoms. — Grinnell Land: Discovery Bay (Miers); North Greenland: Littleton Island (Stimpson). 22. Pontogeneia inermis (Kroeyer). Sars, 1. c., 1895, p. 451, Pl. 159. Station 4. Upernavik, 8-10 fathoms (7). Station 36. Saunders Island, 6 fathoms (1). Station 87. Saunders Island, 5 fathoms (2). Station 54. Foulke Fjord, 5 fathoms (4). Distribution.—Norway, Labrador, East and West Eresilind (northward to Upernavik); 0-120 fathoms. ?Siberian Polar Sea (see Sars). 152 PROCEEDINGS OF THE ACADEMY OF [Feb., 23. Amphithopsis megalops (Buchholz). Paramphitoé megalops Buchholz, Zweite deutsch. Nordpolf., Vol. 2, 1874, p. 369, Pl. 12; Hansen, Malac. mar. Groenl. occ., 1887, p. 125; Amphithopsis megalops Hansen, Meddelelser om Groenland, 19, 1895, p. 129. ~ Station 29. Olriks Bay, 7-25 fathoms (11). “ Station 49. Olriks Bay, 15-20 fathoms (3). Station 54. Foulke Fjord, 5 fathoms (2). Distribution. —So far only known from East and West Green- land, 2-60 fathoms. East Greenland: Sabine Island, Germania Harbor, Shannon (Buchholz), Hecla Havn, Tasiusak (Hansen); West Greenland: from Godthaab to Upernavik (Hansen). 24. Atylus carinatus (Fabricius). Sars, J. c., 1895, p. 471, Pl. 166, fig. 1. Station 9. Saunders Island, 5-10 fathoms (1). Station 11. Northumberland Island, 10-15 fathoms (58). Station 12. Foulke Fjord, 35 fathoms (1). Station 24. Northumberland Island, 10 fathoms (1). Station 39. Granville Bay, 30-40 fathoms (1). Station 52. Robertson Bay, 5-15 fathoms (3). Distridution.—Grinnell Land, Ellesmere Land, North, West and East Greenland, Jan Mayen, Spitzbergen, Finmark, Novaja Semlja, Murman coast, Franz Joseph Land, Kara Sea, Siberian Polar Sea (East Taimyr peninsula and Tchukchee coast); 3-250 fathoms. Grinnell Land: Discovery Bay (Miers); Ellesmere Land: Cape Faraday (Ohlin); North Greenland: McCormick Bay (Ives), Murchison Sound (Ohlin), Cape York (Hansen). 25. Amathilla pinguis (Kroeyer). Gammarus pinguis Kroeyer, Dansk. Vid. Selsk. Afh., Vol. 7, 1838, p. 252, Pl. 1, fig. 5; Amathilla pinguis Buchholz, !. c., 1874, p. 353, Pl. 9, fig. 2; Boeck, Scand. and Arct. Amphip , Vol. 2, 1876, p. 411. Station 4. Upernavik, 8-10 fathoms (1). Station 9. Saunders Island, 5-10 fathoms (2). Station 17. Payer Harbor, Ellesmere Land, 16 fathoms (4). Station 49 Olriks Bay, 15-20 fathoms (1). Sars (1895, p. 490) does not think that this is a true Amathilla. Distribution. — Ellesmere Land, Grinnell Land, North, West and East Greenland, Spitzbergen, Kara Sea; 2-90 fathoms. 1901. ] NATURAL SCIENCES OF PHILADELPHIA. 153 Ellesmere Land: Cape Faraday (Ohlin); Grinnell Land: 82° 24’ N. L. (Miers); North Greenland: Cape York (Hansen). 26. Gammaracanthus loricatus (Sabine). Gammarus loricatus Sabine, in Parry’s Voy. Append., 1821, p. 231, Pl. 1, fig. 7; Gammaracanthus loricatus Bate, Catal. Amphip. Brit. Mus., 1862, p. 202, Pl. 36, fig. 2. Station 4. Payer Harbor, mouth of fresh-water stream (1). Our individual has been taken at the mouth of a small stream in perfectly fresh water. This fact is the more interesting, since we have in fresh-water lakes of Sweaen, Norway, Finland and Russia a slightly different form (var. lacustris Sars = relictus Sars, 1895, p. 494, PJ, 174). Our specimen represents the typical form. Distribution. —Kara Sea, Spitzbergen, Greenland (rare), Grin- nell Land, Ellesmere Land, Polar islands of North America, Point Barrow; 0-10 fathoms. Grinnell Land: Floeberg Beach (Miers); Ellesmere Land: Cape Faraday (Ohlin). 27. Gammarus locusta (Linne), a Sars, é. c., 1895, p. 499, Pl. 1, 176, fig. 1. Station 3. Godhavn, Disco Island, beach (34). Station 14. Payer Harbor, fresh water (24). Station 44, Barden Bay, beach (3). Station 55. Foulke Fjord, beach (22). Distribution.— Norway and southward to the Mediterranean Sea, Labrador, Ellesmere Land, Grinne!l Land, North, West and East Greenland, Iceland, Spitzbergen, Barents Sea, Franz Joseph Land, Kara Sea, Siberian Polar Sea (eastern part), Point Bar- row; 0-5 fathoms, rarely in deeper water; sometimes pelagic. Ellesmere Land: Cape Faraday (Ohlin); Grinnell Land: Floeberg Beach (Miers) ; North Greenland: Port Foulke (Stimp- son), McCormick Bay (Ives). | 28. Melita dentata (Kroeyer). Sars, J. c., 1895, p. 513, Pl. 181, fig. 1. Station 52. Robertson Bay, 5-15 fathoms (2). Distribution. — England, Kattegat, Norway, New England coast, Labrador, Polar islands of North America, West Greenland (nortkward to Disco Island), Iceland, Spitzbergen, Novaja Sem]ja, White Sea, Puget Sound (north Pacific); 2-160 fathoms. 154 PROCEEDINGS OF THE ACADEMY OF [Feb., 29. Ischyrocerus anguipes (Kroeyer). Sars, J. c., 1895, p. 588, Pl. 209. Station 29. Olriks Bay, 7-25 fathoms (1). Station 37. Saunders Island, 5 fathoms (1). Distribution. —Kattegat, Norway, Finmark, Grand Manan, West Greenland (northward to Upernavik (Hansen) and Duck Islands in Melville Bay (Ohlin)), East Greenland, Iceland, Spitz- bergen, Murman coast, White Sea, Kara Sea; 2-110 fathoms. 30. Unciola leucopis (Kroeyer). Sars, J. c., 1895, p. 620, Pl. 222 (—U. irrorata Hansen, 1. c., 1887, p. 164). Station 49. Olriks Bay, 15-20 fathoms (1). Specimens from Labrador have been recorded by Packard as U. wrorata Say, which is, according to Sars, a different species, but perhaps the Labrador form belongs to U. leucopis. Distribution. — Norway, Finmark, ? Labrador, West Greenland (northward to Disco Island), East Greenland, Spitzbergen, Barents Sea, Kara Sea; 30-120 fathoms. 31. Paradulichia typica Boeck. Sars, 1. c., 1895, p. 6®, Pl. 232, fig. 2. Station 49. Olriks Bay, 15-20 fathoms (1 &, 2 92). This species has been recorded hitherto only from Norway, where it seems to be rare. The male sex has not been observed before; our male differs not materially from the female, especially the structure of the posterior gnathopeds is essentially the same as in the female, both in shape and size. Sars describes the eyes as dark red; in our specimens they are white, but this is possibly due to the action of the alcohol. Length of our specimens (without antenne): S' 7 mm., 9 6 and 7 mm. (Sars gives 5 mm. for the adult female). Distribution. —Norway: Hardangerfjord, 30 fathoms (Boeck and Sars). 32. Hginella spinosissima (Stimpson). _Egina spinosissima ‘Stimpson, Synops. mar. Invert. Grand Manan, 1854, p. 44; Miers, Ann. Mag. Nat. Hist., ser. 4, Vol. 20. 1877; Caprella spinifera Bell, Last Arctic Voy. Belcher, Vol. 2, 1855, p. 407, Pl. 35, fig. 2; Caprella spinosissima Bate, Cat. Amph. Brit. Mus., 1862, p. 361, Pl. 57, fig. 3; gina spinifera Sars, Den Norske Nordh. Exp. Crust., 1, 1885, p. 228, Pl. 18, fig. 5; Ives, Proc. Acad. Phila., 1891, p. 481. Station 21. Murchison Sound, 25 fathoms (1). Station 26. Cape Alexander, 27 fathoms (1). So 1901. | NATURAL SCIENCES OF PHILADELPHIA. 15: Station 39. Granville Bay, 30-40 fathoms (1). Station 40. Granville Bay, 20-30 fathoms (3). Station 43. Barden Bay, 20-25 fathoms (1). Station 49. Olriks Bay, 15-20 fathoms (7). The genus Zoginella is the same as Zgina.* ZEgina echinate Boeck seems to be different from this species. Distribution. — Grand Manan, Polar islands of North America, Grinnell Land, North, West and East Greenland, Iceland, Jan Mayen, Spitzbergen, Kara Sea, Siberian Polar Sea (West and East Taimyr peninsula); 3-300 fathoms. Ginnell Land: Cape Napoleon, Dobbin Bay (Miers); North Greenland: Northumberland Island, Cape Dudley Digges (Ohlin), McCormick Bay (Ives), Cape York (Hansen). 33, Caprella linearis (Linné). Mayer, Flor. and Faun. Golf von Neapol., 6 Monogr., 1882, p. 60, figs. 17-19; Sars, I. c., 1895, p. 657, Pl. 236. Station 60. Battle Harbor, Labrador, 12-14 fathoms (18). Among our material are four ovigerous females, in which the 5-7 segments have dorsally only slight indications of tubercles; some of the other individuals are quite smooth. No adult males are present. This species differs from O. septentrionalis, (1) in the lack of tubercles on the anterior part of the body; (2) in the arm of the second pair of legs, which is longer; (3) in the reddish color (they were found in red algs). Although there are no males, I believe, we have to deal here with O. linearis. O. septentrionalis grows much larger, and my females with eggs are small, much smaller than ovigerous females of O. septentrionalis. Among the young C. septentrionalis from Godhavn (about as large as my individuals of C. linearis) are no adult females, and they have alla brownish color (found among brown alga). | Distribution. —Scandinavia, England, France, Iceland, Green- land, Grand Manan (Stimpson’s C. lobata), St. Johns, New- foundland (Ohlin). 34, Caprella septentrionalis Kroeyer. Sars, 1. c., 1895, p. 659, Pl. 237, fig. 1. Station 3. Godhavn, Disco Island, 0-1 fathom (63 jun.). Station 4. Upernavik, 8-10 fathoms (6). *Stebbing, Challenger Amphip., 1888, p. 1,248. 156 Station 9. Station 11. Station 37. PROCEEDINGS OF THE ACADEMY OF Saunders Island, 5-10 fathoms (1). Northumberland Island, 10-15 fathoms (3). Saunders Island, 5 fathoms (14). Station 52. Robertson Bay, 5-15 fathoms (1). Station 57. Sarkak, Waigat, 9 fathoms (10). Distribution. —Denmark, Norway, Finmark, Labrador, North, West and East Greenland, Jan Mayen, Spitzbergen; 2-100 fathoms North Greenland: Cape York (Hansen). [Feb., 35. Synidotea marmorata (Packard). Benedict, Proc. Acad. Phila., 1897, p. 392, fig. 2. Station 60. Battle Harbor, Labrador, 12-14 fathoms (2). Distribution. —St. Lawrence Gulf (Whiteaves), Newfoundland Bank, 36-129 fathoms (Benedict); Labrador: Kynetarbuk Bay, 7 fathoms (Packard). 36. Arcturus baffini (Sabine). A. bafini and feildeni Benedict, Proc. Biol. Soc. Washington, Vol. 12, 1898, p. 43. Station 26. Cape Alexander, 27 fathoms (62). Station 27. Station 39. Station 40. Station 45. Cape Chalon, 35 fathoms (13). Granville Bay, 30-40 fathoms (3). Granville Bay, 20-30 fathoms (several hundred). Barden Bay, 10-40 fathoms (1). | Station 49. Olriks Bay, 15-20 fathoms (109). Station 51. Robertson Bay, 35-40 fathoms (85). Station 52. Robertson Bay, 5-15 fathoms (1). The large amount of material at hand enables me to pronounce A. baffıni and feildeni varieties of one and the same species. We possess both forms, and the var. feildeni prevails for instance at Station 40, and is represented at Station 49. But, besides, there are many intermediate specimens in the different hauls, especially in Nos. 40, 49 and 51. Miers found his feildeni under the same conditions, associated with the typical form. Benedict's and Sars’ material consisted only of a few individuals of each form. Very young individuals are always without spines, and thus young individuals always belong to the var. feildeni, although their mother, to whose antenn® they cling, may be a true dafıni. In larger individuals the spines are developed in a different degree, 1901. | NATURAL SCIENCES OF PHILADELPHIA. 157 and there are a!l intermediate stages between the strongly spinous A. baffini and the almost smooth A. feildena. Sars * claims that his A. tuberosus antedates Miers’ A. feildeni, giving 1876 as the date of publication of the former. But the Arch. Math. og Naturvid., Vol. 2, p. 350, where the diagnosis of A. tuberosus is printed, bears the date 1877, not 1876. Miers’ A. feildeni was published in the Ann. Mag. Nat. Hist., Series 4, Vol. 20, p. 14, PI. 3, fig. 1, in the year 1877; but since this volume was not issued before the second half of that year, we may grant the priority of Sars’ name, although the date of 1876 is not correct. Distribution. —Fares, Norway, Iceland, Spitzbergen, East Greenland, Davis Straits, West Greenland, North Greenland, Ellesmere Land, Grinnell Land, 5-400 fathoms. North Greenland: Cape York (Hansen), MeCormick Bay (Ives), Murchison Sound (Ohlin); Ellesmere Land: Cape Faraday (Ohlin), Cape Sabine (Benedict); Grinnell Land: Cape Napo- leon, Dobbin Bay, Franklin Pierce Bay, Floeberg Beach (Miers). 37. Tole libbeyi (Ortmann). Ortmann, The Princeton University Bulletin, Vol. 11, No.3, February, 1900, pp. 39, 40. Station 26. Cape Alexander, 27 fathoms (5). Length of body 8 mm. Rostrum about as long as the head, directed obliquely upward. Head with one lateral angulation, directed forward. Eyes elliptical. Segments of pereion dorsally smooth, without any spines or tubercles. First segment later- ally with two angulations, both of them directed obliquely forward. Second and third segments with four short angulations, the ante- rior and posterior subequal, the third the smallest. Fourth seg- ment with two angulations, the anterior directed forward, the posterior smaller and directed a little backward. Fifth, sixth and seventh segments with a large anterior and a very small posterior angulation. All the angulations of these segments are compara- tively short. Pleon with two bluntly triangular angulations on either side of a bluntly triangular central portion. Uropods about as long as pleon, styliform, outer branch a little shorter than inner. Flagellum of first antenna 15-articulate ; flagellum of sec- ond antenna with more than 150 annulations. 10 Den Norske Nordh. Exp. Crust., 1, 1885, p. 109. 158 PROCEEDINGS OF THE ACADEMY OF [Feb., In “the wanting tubercles of the dorsal surface and the form of the lateral angulations, this species is related to the two species of the genus known from the North Pa- cific, and the form of the pleon recalls that of J. erostrata Rich. (Aleutian Islands). But it differs (1) in the presence of a long rostrum, (2) in the stronger develop- ment of the lateral angulations of the head, (3) in the slightly different angulations of the second and third segments of the pereion. The generic name Tole has been given to replace Janthe Bovallius nom. przoccup. (1865 Mars, 1867 Stal). (Type, J. spe- ciosa Bov. = spinosa Harg. ) The following key to the species of Tole = Janthe may serve to express the affinities of our new species: a’. —Pleon produced backward into two large angulations, between which the uropods are inserted (5). a’’.—Pleon produced into one small me- dian extension, on each side of which there are incisions for the insertion of the uropods. (Rostrum very short. ‘Two lat- eral angulations of the head. Segments of pereion each with one median, obtuse tubercle, J. bovallii (Studer) ).** East Patagonia. b’ .—Segments of pereion dorsally with spines or tubercles (c). 6'’".—Segments of pereion dorsally smooth (d). «’, —Segments of pereion dorsally each with two submedian, short. spine-like tubercles. First segment with one, second to fourth with two large angulations, fifth to seventh with one large and one (posterior) small angulation, J. spinosa (Harger).'” Nova Scotia, Baffin Bay, West Greenland. 11 Abh. Akad. Wiss., Berlin, 1883, p. 10, Pl..1, fig. 2. 12 Harger, Proc. U. S. Mus., Vol. 2, 1879, p. 158, and Rep. U. S. Fish Comm., 1880, p. 323, Pl. 2, fig. 10 (Janira spinosa); Hansen, Mal. mar. Grenl. occ., 1887, p. 191; Janthe speciosa Bovallius, Svensk. Vet. Ak. Handl., Vol. 6, No. 4, 1881, p. 4. 1901.] NATURAL SCIENCES OF PHILADELPHIA. 159 e'.—Segments of pereion dorsally with one median, spine-like tubercle. All segments with two angulations on each side, J. laciniata (Sars). West coast of Norway. d'. —Head with two lateral angulations, J. triangulata (Rich. ).** California. “i .—Head with one lateral angulation (e). "+ —Rostrum well developed, long, . . sc od. Kbban. ".—Rostrum represented only by a small median point, J. erostrata (Rich. )."* Aleutian Islands. 38. Munnopsis typica M. Sars.” ' Harger, Rep. U.S. Fish Comm. for 1878, part 6, 1880, p. 330, Pl. 2, fig. 11; Sars, Acc. Crust. Norway, Vol. 2, 1897, p. 133, Pls. 57, 58. Station 12. Foulke Fjord, 35 fathoms (2). Station 39. Granville Bay, 30-40 fathoms (18). Station 40. Granville Bay, 20-30 fathoms (2). Station 49. Olriks Bay, 15-20 fathoms (1). Distribution. —Norway, Shetland Islands, Bay of Kundy, Gulf of St. Lawrence, Baffin Bay, Grinnell Land, North, West and East Greenland, Iceland, Spitzbergen, Franz Josef Land, Novaja Semlja, Kara Sea, Siberian Polar Sea (East Taimyr); 5-500 fathoms. Grinnell Land: Cape Napoleon, Cape trazer (Miers); North Greenland: Murchison Sound (Ohlin). The Bopyride in the collection have not yet been identified. 39. Diastylis rathkei (Kroeyer). Sars, Acc. Crust. Norway, Vol. 3, 1900, p. 44, Pls. 33, 34. Station 43. Barden Bay, 20-25 fathoms (3). Distribution.— Baltic Sea, Kattegat, Norway, England, Atlantic coast of North America, Labrador, Baffin Bay, North and West Greenland, Barents Sea, Franz Josef Land, Kara Sea, Siberian - Polar Sea (mouth of Jenesei, East Taimyr, Tchukchee coast); to 400 fathoms. | North Greenland: Murchison sound (Ohlin). 40. Diastylis goodsiri (Bell). Sars, J. c., 1900, p. 54, Pl. 41. Station 18. Foulke I’jord, 15-20 fathoms (1). Distribution. —Polar islands of North America, Baffin Bay, 13 Janthe triangulata Richardson, Proc. U. S. Mus., Vol. 21, 1899, p. 857. 14 Janthe erostrata Richardson, ibid., p. 858, fig. 30. 160 PROCEEDINGS OF THE ACADEMY OF [Feb., North and West Greenland, Jan.Mayen, Spitzbergen, Barents Sea, Kara Sea, Siberian Polar Sea (East Taimyr and Tchukchee coast) ; to 80 fathoms. North Greenland: Murchison Sound (Ohlin). 41. Diastylis scorpioides (Lepechin). Sars, J. c., 1900, p. 58, Pl. 44. Station 40. Granville Bay, 20-30 fathoms (1). Station 43. Barden Bay, 20-25 fathoms (1). Station 52. Robertson Bay, 5-15 fathoms (3). Distribution. —Finmark, Lofoten Islands, White Sea, Kara Sea, Jan Mayen, West and North Greenland, West coast of Baffin Bay; to 200 fathoms. North Greenland: Murchison Sound (Ohlin). 42. Campylaspis rubicunda (Liljeborg). Sars, 7. c., 1900, p. 84, Pls. 56, 57. Station 49. Olriks Bay, 15-20 fathoms (19,1%). Distribution. —Kattegat, Norway, Atlantic coast of North America, West Greenland (Holsteinborg and Kekertak); to 70 fathoms. 43. Mysis oculata (O. Fabricius). Sars, Monogr. Mysider, Vol. 3, 1879, p. 69, Pl. 31. Station 2. Godhavn, Disco Island, 8 fathoms (1). Station 17. Payer Harbor, Ellesmere Land, 16 fathoms (3). Station 24. Northumberland Island, 10 fathoms (1). Station 86. Saunders Island, 6 fathoms (3). Station 37. saunders Island, 5 fathoms (1). Station 39. Granville Bay, 30-40 fathoms (2). Station 40. Granville Bay, 20-30 fathoms (56). Station 43. Barden Bay, 20-25 fathoms (3). Station 52. Robertson Bay, 5-15 fathoms (1). Distribution. —Labrador, Grinuell Land, North, West and East Greenland, Iceland, Jan Mayen, Spitzbergen, Finmark, Kara Sea, Siberian Polar Sea (Tchukchee coast); 2-30 fathoms. Grinnell Land: Cape Napoleon (Miers); North Greenland: Port Foulke (Stimpson), Murchison Sound and Inglefield Gulf (Ohlin). 1901.] NATURAL SCIENCES OF PHILADELPHIA. 161 44. Pandalus borealis Kroeyer. Kroeyer, Naturhist. Tidsskr., Vol. 2, 1839, p. 254; ibid. (2), Vol. 1, 1845, p. 116; Smith, Trans. Connect. Ac., Vol. 5, 1879, p. 86; Hoek, Niederl. Arch. Zool. Suppl., 1881, p. 21; Doflein, Dekap. Krebs. arkt. Meere. (Fauna Arctica, Vol. 1, part 2), 1900, p. 321. Station 59. Kudlisat, Waigat, 15-30 fathoms (8). Distribution. —Massachusetts to Nova Scotia, West Greenland (northward to Umenak), Norway, Barents Sea, White Sea, Spitz- bergen, Franz Josef Land, Bering Sea; to 260 fathoms. 45. Spirontocaris phippsi (Kroeyer). Hippolyte phippsi Smith, Trans. Conn. Ac., Vol. 5, 1879, p. 73; Han- sen, Malac. Groenl. occ., 1887, p. 43; Doflein, /. c., 1900, p. 332. Station 4. Upernavik, 8-10 fathoms (15). Station 12. Foulke Fjord, 35 fathoms (1). Station 26. Cape Alexander, 27 fathoms (2). Station 27. Cape Chalon, 35 fathoms (1). Station 29. Olriks Bay, 7-25 fathoms (3). Station 39. Granville Bay, 30-40 fathoms (5). Station 40. Granville Bay, 20-30 fathoms (16). Station 43. Barden Bay, 20-25 fathoms (1). Station 49. Olriks Bay, 15-20 fathoms (3). Station 52. Robertson Bay, 5-15 fathoms (1). Station 54. Foulke Fjord, 5 fathoms (2). Station 60. Battle Harbor, Labrador, 12-14 fathoms (1). Distribution. —Norway, Sweden, Massachusetts Bay to Labra- dor, Grinnell Land, North, West and East Greenland, Spitzber- gen, Franz Joseph Land, Siberian Polar Sea (Tchukchee coast), Point Barrow, Bering Sea, Ochotsk Sea, North Japan; 2-125 fathoms. Grinnell Land: Cape Frazer, Franklin Pierce Bay, Discovery Bay (Miers); North Greenland: Port Foulke (Stimpson), Cape Dudley Digges, Northumberland Island, Inglefield Gulf, Murchi- son Sound (Ohlin). 46. Spirontocaris spinus (Sowerby). Hippolyte sowertyi Milne-Edwards, Hist. Nat. Crust., Vol. 2, 1837, p. 380 ; H. spinus Smith, !. c., 1879, p. 68; Doflein, i. c., 1900, p. 332. Station 29. Olriks Bay, 7-25 fathoms (2). Station 39. Granville Bay, 30-40 fathoms (1). Station 40. Granville Bay, 20-30 fathoms (2). Station 49. Olriks Bay, 15-20 fathoms (1). 162 OF THE ACADEMY OF Station 50. Karnah, 30-40 fathoms (1). Station 52. Robertson Bay, 5-15 fathoms (1). Distribution.—-Scotland, Norway, Massachusetts Bay to Labra- dor, Grinnell Land, North and West Greenland, Jan Mayen, Spitzbergen, Bering Straits, Point Barrow; 2—240 fathoms. Grinnell Land: Discovery Bay (Miers); North Greenland: Northumberland Island, Inglefield Gulf, Murehison Sound (Ohlin). 47. Spirontocaris gaimardi (Milne-Edwards). Hippolyte gaimardi Milne-Edwards, Hist. Nat. Crust., Vol. 2, 1837, p- 378; Smith, !. c., 1879, p. 67; Doflein, J. c., 1900, p. 330. PROCEEDINGS [Feb., Station 4. Station 11. Station 36. Station 37. Upernavik, 8-10 fathoms (18). Northumberland Island, 10-15 fathoms (3). Saunders Isiand, 6 fathoms (4). Saunders Island, 5 fathoms (1). Station 48. Barden Bay, 20-25 fathoms (7). Station 54. Foulke Fjord, 5 fathoms (47). Distribution.— Baltic Sea, Denmark, Sweden, Norway, Seot- land, Massachusetts Bay to Labrador, Polar islands of North America, Grinnell Land, North and West Greenland, Iceland, Jan Mayen, Spitzbergen, Novaja Semlja, Kara Sea, 'Lchukchee coast, Point Barrow, Bering Sea; 2-250 fathoms. Grinnell Land: Franklin idee Bay (Miers); North ee. land: Port Foulke (Stimpson), Inglefield Gulf (Ohlin). 48. Spirontocaris grenlandica (Fabricius). Hippolyte grenlandica Smith, !. c., 1879, p. 85, Pl. 10, fig. 2; Doflein, l. c., 1900, p. 336. Station 4. Station 9. Station 12. Station 18. Station 21. Station 26. Station 27. Station 29. Station 37. Station 39. Station 40. Station 45. Station 49. Upernavik, 8-10 fathoms (11). Saunders Island, 5-10 fathoms (1). Foulke Fjord, 35 fathoms (1). Foulke Fjord, 15-20 fathoms (1). Murchison Sound, 25 fathoms (5). Cape Alexander, 27 fathoms (19). Cape Chalon, 35 fathoms (20). Olriks Bay, 7-25 fathoms (23). Saunders Island, 5 fathoms (3). Granville Bay, 30-40 fathoms (2). Granville Bay, 20-30 fathoms (24). Barden Bay, 10-40 fathoms (1). Olriks Bay, 15-20 fathoms (8). 1901. ] NATURAL SEIENCES OF PHILADELPHIA. 163 Station 50. Karnah, 30-40 fathoms (4). Station 54. Foulke Fjord, 5 fathoms (23). Distribution. — Norway, Massachusetts to Labrador, Polar islands of North America, Grinnell Land, North, West and East Green- land, Tchukchee coast, Bering Sea, Kamchatka, Puget Sound; 2-200 fathoms. Grinnell Land: Franklin Pierce Bay, Dumbell Bay (Miers); North Greenland: Cape Dudley Digges, Northumberland Island, Murchison Sound, Inglefield Gulf (Ohlin). 49. Spirontocaris polaris (Sabine). Hippolyte polaris Smith, !. ce , 1879, p. 80, Pl. 11, figs. 1-4; H. polaris and borealis Doflein, !. c., 1900, pp. 334, 335. ‚Station 4. Upernavik, 8-10 fathoms (35). Station 9. Saunders Island, 5-10 fathoms (15). Station 12. Foulke Fjord, 5 fathoms (4). Station 21. Murchison Sound, 25 fathoms (3). Station 26. Cape Alexander, 27 fathoms (10). Station 27. Cape Chalon, 35 fathoms (9). Station 29. Olriks Bay, 7-25 fathoms (51). Station 32 Foulke Fjord, 14 fathoms (1). Station 37. Saunders Island, 5 fathoms (5). Station 39. Granville Bay, 30-40 fathoms (21). Station 40. Granville Bay, 20-30 fathoms (33). Station 43. Barden Bay, 20-25 fathoms (2). Station 45. Barden Bay, 10-40 fathoms (4). Station 51. Robertson Bay, 35-40 fathoms (4). Station 54. Foulke Fjord, 5 fathoms (37). Distribution. —Sweden, Norway, Cape Cod to Labrador, Polar islands of North America, Grinnell Land, North, West and East Greenland, Jan Mayen, Spitzbergen, Bear Island, Franz Joseph Land, north of Bering Straits; 2-260 fathoms. Grinnell Land: Dobbin Bay, . Franklin Pierce Bay, Cape Napoleon, Discovery Bay (Miers); North Greenland: Littleton Island, Port Foulke (Stimpson), Cape Dudley Digges, Northum- . berland Island, Murchison Sound, Inglefield Gulf (Ohlin). 50. Crangon (Sclerocrangon) boreas (Phipps). en, Proc. Acad. Phila., 1895, p. 178; Doflein, J. c., 1900, p. Station 9. Saunders Island, 5-10 fathoms (7). Station 21. Murchison Sound, 5 fathoms (1). 164 Station 26. Station 27. Station 29. Station 39. Stalion 40. Station 45. Station 49. Station 50. Station 51. Station 52. Station 54. PROCEEDINGS OF THE ACADEMY OF [Feb., Cape Alexander, 27 fathoms (6). Cape Chalon, 35 fathoms (6). Olriks Bay, 7-25 fathoms (11). Granville Bay, 30-40 fathoms (2). Granville Bay, 20-30 fathoms (21). Barden Bay, 10-40 fathoms (3). Olriks Bay, 5-20 fathoms (10). Karnah, 30-40 fathoms (6). Robertson Bay, 35-40 fathoms (10). Robertson Bay, 5-15 fathoms (8). Foulke Fjord, 5 fathoms (2). Distribution. —Norway, Massachusetts to Labrador, Polar islands of North America, Grinnell Land, North, West and East Green- Jand, Iceland, Jan Mayen, Spitzbergen, Novaja Semlja, Franz Joseph Land, Tchukchee coast, Point Barrow, Bering Straits; 4-200 fathoms. Grinnell Land: Franklin Pierce Bay, Cape Napoleon, Discov- ery Bay (Miers); North Greenland: Littleton Island, Port Foulke (Stimpson), Cape Dudley Digges, Northumberland Island, Mur- chison Sound (Ohlin). öl. Nectocrangon lar (Owen). Ortmann, J. c., 1895, p. 181; Doflein, !. c., 1900, p. 327. Station 9. Station 11. Station 12. Station 26. Station 27. Station 39. Station 40. Station 43. Station 45. Station 50. Distribution.-—Nova Scotia, Saunders Island, 5-10 fathoms (3). Northumberland Island, 10-15 fathoms (2). Foulke Fjord, 35 fathoms (4). Cape Alexander, 27 fathoms (1). Cape Chalon, 35 fathoms (4). Granville Bay, 30-40 fathoms (5). Granville Bay, 20-30 fathoms (20). Barden Bay, 20-25 fathoms (1). Barden Bay, 10-40 fathoms (1). Karnah, 30-40 fathoms. (2). Newfoundland, Labrador, East Greenland (Hecla Havn, 70° 11’ N. L., Hansen, 1895, p. 125), West Greenland, North Greenland, Point Barrow, Bering Sea, Tehukchee coast; 4-120 fathoms. North Greenland: Inglefield Gulf (Ohlin). 1901.] NATURAL SCIENCES OF PHILADELPHIA. 165 92. Sabinea septemcarinata (Sabine). Ortmann, J. c., 1895, p. 188; Doflein, 7. c., 1900, p. 328. Station 12. Foulke Fjord, 35 fathoms (1). Station 18. Foulke Fjord, 15-20 fathoms (1). Station 39. Granville Bay, 30-40 fathoms (13). Station 40. Granville Bay, 20-30 fathoms (65). Station 43. Barden Bay, 20-25 fathoms (1). Station 49. Olriks Bay, 15-20 fathoms (18). Station 50. Karnah, 30-40 fathoms (6). Distribution. —Norway, Massachusetts Bay to Labrador, Grin- nell Land, North and West Greenland, Iceland, Spitzbergen, Novaja Semlja, Kara Sea, Siberian Polar Sea (East Taimyr peninsula and Tchukchee coast); 5-160 fathoms. Grinnell Land: Dobbin Bay, Cape Napoleon, Discovery Bay (Miers); North Greenland: Murchison Sound (Ohlin). 53. Eupagurus pubescens (Kroeyer), Smith, 7. c., 1879, p. 47; Doflein, !. c., 1900, p. 341. Station 61. Battle Harbor, Labrador, 0-1 fathom (1). Distrioution —Northeast America: New Jersey to Labrador; Greenland (west coast northward to Umenak, ca. 71° N. L.), North Europe, Spitzbergen, Murman coast, White Sea, Bering Sea, Kamchatka, Puget Sound. 54. Hyas araneus (Linné). pq, Proc. U. S. Mus., Vol. 16, 1893, p. 67; Doflein, J. c., 1900, P- 29%. Station 1. Domino Run, Labrador, 0-1 fathom (1). Station 60. Battle Harbor, Labrador, 12-14 fathoms (3). Distribution. —Northern Europe to Novaja Semlja and Spitz- bergen, Iceland; Northeast America: Cape Cod to Labrador; West Greenland (northward to Godhavn); Tehukchee coast, Ochotsk Sea; 0-100 fathoms. PYCNOGONIDA. 1. Nymphon longitarse Kroeyer. Wilson, Trans. Connect. Acad., Vol. 5, 1878, p. 19, Pl. 7, fig. 2; Wil- son, Rep. U. S. Fish Comm. for 1878, “part 6, “eso p. 489, Pl. 6, figs. 80, 31; Hoek, Challenger Pycnogon. 3, 1881, p. 20; Hoek, Niederl. Arch. Zool. Suppl., 1881, p. 15;-Pl. 1, figs. 22, 23. Station 39. Granville Bay, 30-40 fathoms (2 2). Station 40. Granville Bay, 20-30 fathoms (2 2). Station 52. Robertson Bay, 5-15 fathoms (1 <’). 166 PROCEEDINGS OF THE ACADEMY OF [ Feb., Distribution. —Massachusetts, Maine, Nova Scotia, Greenland, Norway, Novaja Semlja, Point Barrow; 2-220 fathoms. 2. Nymphon grossipes (Linné). Wilson, 7.c., 1878, p. 20, Pl. 7, fig. 1; Wilson, 1. -c., 1880, pP. 29ER 6, figs. 32-37, Pl. 7, fig. 42: Hoek, Chall., 1881, p. 20, p. 44, PJ. 3, figs. 9-12, Pl. 4, fig. 1; Hoek, Nied. Arch., 1881, jp. 12, Pl. 1, .figs. 17-21. Station 26. Cape Alexander, 27 fathoms (1 2). Station 27. Cape Chalon, 35 fathoms (1 jun.). Station 40. Granville Bay, 20-30 fathoms (2 &, 1 jun.). Station 43. Barden Bay, 20-25 fathoms (1 2). Station 49. Olriks Bay, 15-20 fathoms (2 jun.). Distribution. — North Sea, Norway, Long Island Sound to St. Lawrence Gulf, Polar islands of North America, North Greenland, East Greenland (North Shannon), Spitzbergen, Barents Sea, Novaja Semlja, Point Barrow; 0-540 fathoms. North Greenland: Northumberland Island (Ohlin). 3. Nymphon hirtipes Bell. N. hirtipes Wilson, t. c., 1878, p. 22, Pl. 5, fig. 2, Pl. 6, fig. 2: Hoek, Chall., 1881, p. 17; Hoek, Nied. ‚Arch., 1881, p. 6, Pl. 1, figs. 1-8; N. hirtum Wilson, !. c., 1880, p. 495, Pl. 7, figs. 38, 41. Station 89. Granville Bay, 30-40 fathoms (2 3, 1 2, 3 jun.). Distribution. —Massachusetts, Nova Scotia, Polar islands of North America (Norchumberland Sound), Grinnell Land, North Greenland, East Greenland, Spitzbergen, Barents Sea; 10-299 fathoms. Grinnell Land: Franklin Pierce Bay, Discovery Bay, Floeberg Beach (Miers); North Greenland: Inglefield Gulf (Ohlin). 4. Nymphon serratum G. O. Sars. Sars, Arch. Math. og Naturv., Vol. 4, 1879, p. 471; Hoek, Nied. Arch., 1881, p. 10, Pl. 1, figs. 24, 28, Pl. 2, fig. 29. Station 40. Granville Bay, 20-30 fathoms (2 JS). Distribution. — Spitzbergen Sea, 146-180 fathoms (Sars); Barents Sea, 160 fathoms (Hoek). 5. Pallene discoidea Kroeyer. Pseudopallene hispida and discoidea Wilson, l.'c., 1878,;pp. 10,12, PL 3, figs. 1, 2; Wilson, !. c., 1880, pp. 478, 479, Pl. 2, figs. 9, 10; Pallene discoidea and hispida Hoek, Chall., 1881, p. 31. Station 89. Granville Bay, 30-40 fathoms (19,1%). Station 40. Granville Bay, 20-80 fathoms (1 9). 1901.] NATURAL SCIENCES OF PHILADELPHIA. 167 The ovigerous male of Station 39 agrees in all essential points with P. hispida as figured by Wilson. The two females, however, show the chel® of the mandibles (antenns) as figured by Wilson for P. discoidea (1880, fig. 105), and the rostrum is more obtuse than in the male, which is another diagnostic character assigned to discoidea. In the shape of the end of the abdomen I do not find any difference; all three individuals have it obtuse, and not pointed and slightly bifid. In my opinion P. hispida is not different from discoidea, but represents merely the male sex. Distribution.— Maine, Grand Manan (12-55 fathoms), South Greenland, North Norway, Lapland, White Sea. “Im conclusion I add here a list of species recorded previously from the northern parts of Baffin Bay and Smith Sound, but not found by our expedition in the same latitudes: 1. Balanus erenatus Brug. Grinnell Land: Discovery Bay (Miers, Journ. Linn. Soc. Zool., Vol. 15, 1881, p. 73). 2. Balanus balanoides (L.). Port Foulke (Stimpson) ( possibly seen by the present writer at Foulke Fjord). 3. Orchomenella minuta (Kr.). North Greenland: Cape Dudley Digges, and Ellesmere Land: Cape Faraday (Ohlin). 4. Anonyz affinis Ohl. Cape Dudley Digges (Ohlin). 5. Hoplonyx cicada (Fabr.) = Anonyx gulosus Kr. Grinnell Land: Discovery Bay (Miers). 6. Ampelisca eschrichti Kr. North Greenland: Murchison Sound (Ohlin). 7. Haploops tubicola Lilj. North Greenland: Cape Dudley Digges (Ohlin). 8. Acanthostepheia malmgreni (Goes). Murchison Sound (Ohlin). | 9. Eusirus cuspidatus Kr. Grinnell Land: Franklin Pierce | Bay (Miers). | 10. Apherusa glacialis (Hans.). North Greenland: Wolstenholme Sound (Ohlin). 11. Paratylus smitti (Goes). Murchison Sound (Ohlin). 12. Amathila homari (Fabr.). North Greenland Cape Dudley Digges, Northumberland Island; Ellesmere Land: Cape Faraday (Ohlin). 13. Neohela monstrosa (Boeck). North Greenland: Murchison Sound /Ohlin). 14. Caprella monocera Sars. Cape Dudley Digges (Ohlin). 168 PROCEEDINGS OF THE ACADEMY OF [Feb., 15. Glyptonotus sabinei (Kr.) Cape York (Hansen), Cape Dudley Digges and Cape Faraday (Ohlin). 16. Diastylis spinulosa Hell. Murchison Sound (Ohlin). 17. Nymphon stroemi Kr. Grinnell Land: Cape Frazer and Floeberg Beach (Miers). | 18. Nymphon robustum Bell. Grinnell Land: Discovery Bay (Miers, Journ. Linn. Soc., Vol. 15, 1881, p. 72). E POD. CRUSTACEANS. IN THE ‘UNITED | is TATES NATIONAL MUSEUM.—THE rubs _ FAMILIES LOPHOGASTRIDE A “AND EUCOPIIDA | : 4 Dis su ee A e ” ar, F » 7 eS » Tm £ Se gr VA a x BY ARNOLD E. ORTMANN SE = eee. 7 “Of the Carnegie Museum, Pittsburg, Pennsylvania Vega Vol. XXXI, pages 23-54, with Plates I-II i + : se Washington Government Printing Office SCHIZOPOD CRUSTACEANS IN THE UNITED STATES 'NATIONAL MUSEUM.—THE FAMILIES LOPHOGASTRIDA AND EUCOPIIDA BM ARNOLD E. ORTMANN Of the Carnegie Museum, Pittsburg, Pennsylvania No. 1480. —From the Proceedings of the United States National Museum, Vol. XXXI, pages 23-54, with Plates I-II Washington Government Printing Office 1906 SCHIZOPOD CRUSTACEANS IN THE U. S. NATIONAL MUSEUM. THE FAMILIES LOPHOGASTRIDE AND EUCOPIID A. By ARNOLD E. ORTMANN, Of the Carnegie Museum, Pittsburg, Pennsylvania, INTRODUCTION. The paper submitted herewith forms the first installment of a series of articles describing the Schizopod collections in the United States National Museum. It treats of the families Lophogastride and Eucopiida, which consist almost exclusively of deep-sea forms. The material at hand, chiefly in the genus Gnathophausia, is so rich that it has been possible to prepare a complete revision of that genus, and it has been found that some characters, which were regarded hitherto as of specific value, are but differences of age-in the same species. This made it necessary to prove the changes of these characters with age, and consequently, the discussion of some of the species is some- what lengthy. _ Other families of the Schizopods will be taken up successively, and the results will be published similarly, as the time at the disposal of the writer will permit. Family LOPHOGASTRID G. O. Sars. 1. LOPHOGASTER TYPICUS M. Sars. -ORTMANN, Bull. U. S. Fish Comm. for 1903, Pt. 3, 1905, p. 967 (see for complete list of literature). —STEBBING, South African Crustacea, Pt. 2, Cape of Good Hope Dept. Agric. 1902, p. 43.—Hour and TATTERSsALL, Rep. Fisher. Ireland, Pt. 2, Append., IV, 1905, p. 141. Of this species, material was available from two regions, from which it was not hitherto known, namely, the western Atlantic (coast of United States and Gulf of Mexico), and the western Pacific (Japan). The specimens from the western Atlantic are divided into three sets: One from the coast of the Carolinas (Albatross stations Nos. 2314, 2601, 2602), consisting of together 10 males and 3 females; the second from the Gulf of Mexico (Stations Nos. 2399, 2401, 2403), PROCEEDINGS U. S. NATIONAL Museum, VOL. XXXI—No. 1480. 23 24 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. SEREI, together 9 males and 1 female; the third from Key West (ish Hawk stations Nos. 7282, 7283, 7 7286). The northern specimens, from the Carolinas, compare with the European (and South African) form in the following particulars: (1) The rostrum is longer, generally about as long as the peduncle of the antennula, but in two specimens (males) it is shorter than this peduncle, although longer than in the typical form; and in 2 females from Station No. 2602 it is slightly longer than this peduncle but dis- tinctly shorter than the antennal scale. (2) The antennal scale has on the outer margin a greater number of teeth; the normal number seems to be 6 or 7; five specimens have 6 teeth on both sides; two specimens have 6 on one side, and 7 on the other; one female has 7 teeth on both sides. Besides, there is one specimen with 6 teeth on one side, and three with 7 teeth on one side, while the other side could not be determined owing to its damaged condition. Finally, one female has 6 teeth on the right, and 5 on the left side. Thus 5 to 7 are the numbers found, 5 once, 6 fourteen times, 7 seven times. (3) In the number of lateral teeth of the telson, these specimens agree well with the European form, the usual number being 3 on each side. There are, however, a few exceptions. Four specimens have 3 teeth on one Sule but only? on the other; one specimen has 3 teeth on one side and 4 on the other (female, Station No. 2602), and one (male, Station No. 2601), has 1 spine only on each side, placed at a differ- ent level, the right one being more proximal than the left one. Those from the Mexican Gulf have the following characters: (1) The rostrum is in one case only shorter than the peduncle of the antennula; in seven specimens it is longer than this peduncle, but shorter than the antennal scale; and in one case (Station No. 2399) it is about as long as the antennal scale (in the remaining individual it is damaged). Thus the average slightly exceeds that of the northern set. (2) The antennal scale has in seven cases 6 teeth on both sides; in one case there are 6 on one, 7 on the other side; and in two cases there are 7 teeth on both sides. This agrees well with the condition found in the northern set. (3) The telson has uniformly 3 teeth on both sides, with one excep- tion, where there are 2 on the right and 3 on the left. This seems to be the normal condition in Atlantic specimens. The specimens from Key West (6 males, 2 females), collected by the U. S. Bureau of Fisheries vessel /%sh Hawk, agree very well with the Gulf form. The rostrum is as long as the peduncle of the anten- nula, except in two cases, in which it is slightly longer. The antennal scale has generally 6 teeth, but in two specimens there are 7 on the right side. The telson has 3 teeth on each side, but in two specimens there are 2 teeth on one side and 3 on the other. No. 1480, SCHIZOPOD CRUSTACEANS—ORTMANN. 25 The largest West Atlantic specimen is a male from Station No. 2401, measuring 29mm. The few females at hand are all small and measure between 16 and 18 mm. A series of fifteen specimens, 9 males and 6 females, from six stations off Honshu Island, Japan, was examined. None of them were found to be smaller than 21 mm.; the females were between 21 and 27 mm., and two of them (24 and 27 mm.) were gravid; the males being between 22 and 32 mm. They have the following characters: (1) The rostrum is comparatively long, even longer than im the West Atlantic form, which in turn exceeds the average found in the Hawaiian. There is not a single individual in which it is shorter than the peduncle of the antennula. In three (2 males and 1 female) it is about as long as this peduncle, while in all others it is distinctly longer. Generally it is shorter than the scale of the antenna, but in a few cases it is of equal length. (2) The antennal scale has generally only 3 teeth on the outer mar- gin; in one individual (male, 31 mm.) there are 2 on the right and 3 on the left side, and in another one (male, 27 mm.) the reverse is the case. Thus these specimens represent the opposite extreme of that seen in the West Atlantic form. The Hawaiian form is intermediate with 3 to 5 teeth. (3) The telson generally has 2 spines on the lateral margins on each side. Four specimens, however, constitute an exception, having 1 spine on the right side and 2 on the left. The above records show that these characters can not be regarded as of specific value. Taking the European and South African form as the type, the West Atlantic specimens agree with them in the spines of the telson, while all the Pacific specimens possess the tendency to reduce their number. The rostrum is shortest in the typical form, but in all others shows a tendency to become longer; the Hawaiian form comes close to the typical in this respect, while both the West Atlantic and the Japanese differ more distinctly. In the number of teeth of the antennal scale the typical form is intermediate (5); the West Atlantic form varies in one direction (6 to 7), while the Pacific varies in the other: the Hawaiian with 3 to 5 teeth is more closely allied to the typical form than the Japanese, which has only 2 or 3 teeth. It is very likely that intermediate localities, when found, will tend to connect these forms more closely, and it would be interesting to know particulars about these connecting links. see 26 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. Localities represented in the U. 8. National Museum. FROM U. S. BUREAU OF FISHERIES STEAMER Albatross STATIONS. 2314.—4 males. Between Charleston and Savannah, off South Carolina coast; 159 fathoms. 2399.—1 male. Gulf of Mexico; 196 fathoms. 2401.—1 male. Gulf of Mexico; 142 fathoms. 2403.—7 males, 1 female. Gulf of Mexico; 88 fathoms. 2601.—5 males. Between Cape Hatteras and Charleston, off North Carolina coast; 107 fathoms. 2602.—1 male, 2 females. Between Cape Hatteras and Charleston, off North Carolina coast; 124 fathoms. 3707.—1 female. Off Honshu Island, Japan; 63 to 75 fathoms. 3714.—1 male, 1 female. Off Honshu Island, Japan; 48 to 60 fathoms. 3715. —4 males, 1 female. Off Honshu Island, Japan; 68 to 65 fathoms. 3717.—1 male. Off Honshu Island, Japan; 100 to 63 fathoms. 3718.—3 males, 2 females. Off Honshu Island, Japan; 65 fathoms. 3740.—1 female. Off Honshu Island, Japan; 65 fathoms. FROM U. 8S. BUREAU OF FISHERIES STEAMER Jish Hawk STATIONS. 7232.—4 males, 2 females. Gulf Stream, off Key West; 109 fathoms. 7283.—1 male. Gulf Stream, off Key West; 127 fathoms. 7286.—1 male. Gulf Stream, off Key West; 133 fathoms. Localities previously recorded.—Norway, Shetland Islands, Ireland, Bay of Biscay, Mediterranean, Cape of Good Hope, 20-300 fathoms; off Cape St. Blaize, South Africa, 40 fathoms; Hawaiian Islands (Pailolo Channel, Molokai and Laysan Islands), at about the same depth. | | 2. LOPHOGASTER SPINOSUS, new species. Plate I, figs. 1a, 10. Type.—Cat. No. 11464, U.S.N.M. Female. U.S. Bureau of Fish- eries steamer Albatross station No. 2666, between Bahamas and Cape Fear, North Carolina. Latitude 30° 47’ 30” north; longitude 7 9° 49º west; depth, 270 fathoms. | Although built in the main according to the pattern of the typical and hitherto only known species of the genus, this species differs from the latter in several well-marked characters. (1) Rostrum greatly elongated, almost as long as the carapace in the median line. It exceeds the antennal scales, which also are greatly elongated, and it is without teeth or denticulations. It is directed forward, and is almost straight. (2) Antennal scale greatly elongated and lanceolate; its outer margin is formed by a strong rib, which extends into a long spine; the inner, lamellar part is much shorter, and reaches only to about the distal third of the spine. Outer margin of the spine with 9 spiniform ser- NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. AT rations on right side, and with 10 on the left; and, further, there is a similar serration on the inner margin, just above the upper end of the lamellar part, and opposite to the second tooth (counted from the tip) of the outer margin. (3) Lateral wings of carapace produced posteriorly into a long spine on each side, which is almost one-third as long as the carapace (exclud- ing rostrum). (4) Sixth abdominal segment with a subdorsal spine directed straight backward on posterior margin, at the base of the telson, on each side. (5) Telson slightly more elongated than in 2. typicus, and with five marginal spines on each side. The terminal spines are similar to those of L. typisus: two pairs, and between them at the posterior termina- tion a serrated crest, which, however, has only four teeth. (The tip of the telson is not very well preserved in the type, as the two outer, smaller terminal spines are broken off.) Measurements.—Total length: 39 mm.; length of rostrum (in front of eyes): 8; length of carapace along dorsal line, including rostrum: 19. GENUS GNATHOPHAUSIA Willemoes-Suhm. KEY TO THE SPECIES OF GNATHOPHAUSIA: a. Antennal scaıe small, not jointed, no strong rib terminating ina spine on outer margin; outermargin serrate. Epimera of sixth abdominal segment united ven- trally, forming together a cordiform, concave plate, incised atapex. Dorsal keel of carapace interrupted. Lower lateral keel not curving upward behind, but terminating in a spine at the postero-inferior angle. Branchiostegal lobe gen- erally with a well-developed spine (sometimes obsolete). Maxillipeds with a small exopodite. b. Both lappets of the epimera of the second to fifth abdominal segment pointed and spiniform. Antennal scale subovate, apex shortly pointed. c. Rostrum and all spines of carapace comparatively short or obsolete. . . .ingens c’. Rostrum and spines of carapace well developed and comparatively LUG oe Se ESS 2. 22.22. .2.ns m denn. calcarata (@) b’. Anterior lappet of the epimera of the first to the fifth abdominal segment small, rounded; posterior lappet pointed and spiniform. Antennal scale sublanceolate, tapering to a sharp, spiniform point. .gigas (+drepanephora?) a”. Antennal scale large, of usual-form, jointed at the extremity, outer margin formed by a strong rib terminating in a spine. Epimera of sixth abdominal segment not confluent ventrally. b. Lower lateral keel of carapace not curving up behind, but terminating in a spine on the postero-inferior angle of the carapace. Median keel of carapace interrupted, with spiniform serrations. Median line of abdominal segments with strong spines. Upper lateral keel of carapace wanting. Two epimeral spines on each side of the anterior section of sixth abdominal segment eine ds wit exopodibe = 2.1222... 0 os ad a ee et gracilis b”. Lower lateral keel of carapace curving up behind; no spine at postero-inferior “angle of carapace. Median keel of carapace not interrupted, without spini- form serrations. Median line of abdominal segments—if armed at all—only with posteriorly projecting, small spines. Upper lateral keel of carapace present, very rarely wanting. Maxillipeds without exopodite. aG. calcarata may be the young stage of G. ingens. 28 PROCEEDINGS OF THE NATIONAL MUSEUM. ‘VOL; IX c. Two epimeral spines on each side of anterior section of sixth abdominal seg- ment. Upper lateral keel of carapace present. Antennal spine obsolete. Branchiostegal lobe with a well-marked, triangular spine. Spine of outer margin of antennal scale projecting considerably beyond terminal lobe, serrated on both’margins 2222.02 2200-220 ar eta e longispina c’, One epimeral spine on each side of anterior section of sixth abdominal seg- ment. Antennal spine more or less distinct. Branchiostegal lobe without spine, generally rounded, rarely angular. Spine of outer margin of anten- nal scale not, or only slightly, projecting beyond terminal lobe. d. Upper lateral keel of carapace present. e. Abdominal segments dorsally slightly keeled, with small, posteriorly projecting spines. Epimera of fiveanteriorabdominal segments pointed posteriorly. Branchiostegal lobe rounded. J. Carapace not suddenly constricted anteriorly, and forming no shoulder. Branchiostegal lobes moderately developed ........-.........- z0ea f’. Carapace suddenly constricted anteriorly, torming a distinct shoulder in front of the anterior ends of the upper lateral keels. Branchi- ostegal lobe‘greatly expanded Cc scapularis Abdominal segments dorsally not keeled, without spines. Epimera of five anterior abdominal segments rounded posteriorly. Branchiostegal lobe slightly. anoular 2.2... Ss 3 a se eee ces te ee ee affinis e”. d’. Upper lateral keel of carapace wanting. Branchiostegal lobe rounded or angular, but without spine. Abdominal segments dorsally without keel, but posteriorly with a small, depressed, triangular projection. Epimera of five anterior abdominal segments ending in small points posteri- Orly Soe ele he wee LCR EOE ig ae lc oe re elegans 3. GNATHOPHAUSIA INGENS (Dohrn). Lophogaster ingens Dourn, Zeitschr. wiss. Zool., XX, 1870, p. 610, pl. xxx1, figs. 12-14. | Gnathophausia ingens G. O. Sars, Forh. Selsk. Christiania, 1883, No. 3; Rep. Chal- lenger, XIII, 1885, p. 30, pl. 1. I have never seen this species. It is founded upon a very old female, sexually mature, and a similar female has served as the basis for Sars's description. It is very closely allied to @. calcarata, and I strongly incline to the opinion that it will prove to be G. calcarata, representing an old female of that species, in which case it will be called G. ingens, the name calcarala becoming a synonym. (7. ingens especially agrees with G. calcarata in the following important characters: (1) General form of body, and arrangement of keels and spines of carapace. (2) Sculpture and armature of abdomen, especially as the epimera of the five anterior segments are identical in both forms. (3) Shape of antennal scale. It differs from @. calcarata in the following respects: (1) In the shorter rostrum and the inferior development of all spines of the carapace, the supraorbital spine being even wanting, the branchi- ostegal spine being obsolete. NO. 1480. SCHIZOPOD CRUSTACEA NS—ORTMANN. 29 (2) In the absence of the two pairs of oblique keels on the superior face of the carapace. (3) In the shape of the ventral epimeral plate of the sixth abdomi- nal segment, which, although closely approaching the shape seen in the largest specimens of @. calcarata, has the tips separated and bifid, the inner spine being slightly longer. The first of these characters can not be regarded as of specific value. Dohrn’s specimen measured 155 mm., Sars’s specimen 157 mm. The largest @. calcarata at hand (and ever observed) measures 115 mm., and consequently, is considerably younger than the known specimens of @. ingens. Now, as shown below, it is a general rule in this genus that all the spines of the carapace and the rostrum decrease in rela- tive size with advancing age, and thus it is easy to believe that the slight development of these spines in @. ingens is due to old age only. In fact, if we imagine that @. calcaraia grows larger and that the spines decrease proportionally, we would obtain, at about the size of 150 to 160 mm., the conditions found in @. zngens. As to the second differential character, the lack of the two oblique keels on the upper face of the carapace, this may have been over- looked by Dohrn and Sars. In fact, these two keels were overlooked by Sars in @. calcarata, at any rate, they are not mentioned in the description, although one of the figures (Plate IV, fig. 2) shows traces of them. The third character offers only a slight difference from the condi- tion seen in large specimens of @. calcarata. In the latter the tips of the epimeral plate of the sixth abdominal segment are in contact in the median line, while in @. ingens they are separated, according to Sars’s fig. 6 on Plate II. Moreover, in @. calcarata the outer spine of the bifid end of each of the tips is greatly longer than the inner, while in @. ingens the inner spine is slightly the longer. At present this last character remains the only one upon which G. ingens and @. calcarata can be separated, and it is not improbable that further material will demonstrate that one form passes into the other when we consider the changes in the sixth epimeral plate in its development from the young @. calcarata to the old. Distribution of @. ingens.—Off the west coast of Africa: “* Laos,” depth not recorded (Dohrn). Near Aru Island, Arafura Sea (New Guinea), 800 fathoms (Sars). 30 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI, 4. GNATHOPHAUSIA CALCARATA G. O. Sars. | Plate I, figs. 2a, 2b..— A Gnathophausia calcarata G. O. Sars, Forh. Selsk. Christiania, 1883, No. 5; Rep. Challenger, XIII, 1885, p. 35, pl. 1v.—ORTMANN, Bull. U. S. Fish Comm. for 1903, Pt. 3, 1905, p. 968. Gnathophausia bengalensis WooD-MAson, Ann. Nat. Hist. (6), VIII, 1891, p. 269. Specific characters. —Aside from the group characters (see q in the key), the following are to be considered as of specific value: (1) The subovate, not lanceolate, shape of the antennal scale. (2) The presence of two pairs of oblique keels on the upper surface of the carapace. (3) The shape of the epimera of the second to fifth abdominal seg- ment, both lappets of which are pointed and spiniform. (4) The bifid points of the epimera of the sixth abdominal segment, with the inner point much shorter than the outer (in old specimens only). Description.—Carapace with dorsal, upper, and lower lateral keels. Dorsal keel interrupted in the middle part. Lower lateral keel ending in a spine at the postero-inferior angle of the carapace. On upper face of carapace, between median and upper lateral keels, there are two oblique keels on each side, converging posteriorly, the anterior pair running toward the anterior end of the posterior section of the dorsal keel, but not joining it; the posterior pair running almost par- allel to the first pair, their hind ends not joining the dorsal keel. Ros- trum of various lengths, according to age, about as long as the rest of the carapace in very young specimens. In older ones, the part in front of the supraocular spines is about one-third of the length of the rest of the carapace. Supraocular spines very small, sometimes obsolete. Antennal spines small, but well developed, the most constant spines in size. Branchiostegal spines quite large and well developed in young specimens, and longer than the antennal spines. In old specimens they are not only relatively, but absolutely smaller, and become shorter than the antennal spines. Postero-dorsal spine of various lengths, according to age, but the variation is not very great; it is always well developed, but shorter than the postero-inferior spines. Spines of postero-inferior angle greatly varying in length with age; very long, almost half the length of the carapace (excluding the rostrum) in young specimens, and distinctly diverging and spreading out in a postero- lateral direction. In old specimens they are much shorter, even abso- lutely shorter, and are as short as about one-seventh of the carapace (without rostrum); they are not divergent, but directed straight back- ward. Branchiostegal, postero dorsal, and postero-inferior spines, when well developed, with more or less distinct serrations, which become indistinct with age, and even disappear entirely. No. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 31 Antennal scale small, subovate, pointed; point not produced. Outer margin serrate, serrations three to six (sometimes different on right and left sides), the distal serration at a certain distance from the tip of the scale, and the margin between this serration and the tip either straight or slightly emarginate, thus giving a more or less truncate appearance to the scale. Abdomen sculptured by a distinct transverse groove near the pos- terior margin of each of the five anterior segments; there is a similar but fainter groove near the anterior margin. The posterior groove is continued down to the epimeral lappets, and here its anterior edge is marked on an elevated ridge. This sculpture is seen clearly only in well-preserved specimens, and sometimes there are traces of a sub- dorsal longitudinal keel on each side. Also a blunt median keel is sometimes indicated. The epimera of the second to the fifth segment consist of two lappets, which are both produced and acutely pointed, the posterior being somewhat longer than the anterior. The anterior lappet of the first segment is considerably shorter than the spiniform posterior lappet, and is not produced into a spine, but bluntly pointed or even obtuse. The epimera of the sixth abdominal segment unite ventrally to form a concave, cordiform plate, which, in old individ- uals, is produced beyond the posterior margin of the sixth segment. In young individuals the right and left lappets are short and simply pointed, and separated from one another by a shallow emargination. With increasing age they become much elongated, are separated by a narrow slit, and the tips become bifid, a second point developing on the inner side, which is always much shorter than the outer point. In old individuals the inner tips are in contact in the median line and may even overlap. Variations with age.—1 had an excellent opportunity to study this species, as over 40 individuals in good condition were available, of very different sizes and ages, ranging from 42 mm. to about 115 mm. The three first-named specific characters are always present, but the fourth is observed only in older individuals. The spines of the cara- pace are very variable in their development according to age, and generally they are comparatively longer in young specimens and shorter in old ones. Sometimes, in the cases of the branchiostegal and postero-inferior spines, even the absolute length in older speci- mens is inferior to that in younger ones. This seems to be a general rule in this genus, for it was discovered by the writer in another species of the genus, @. longispina.“ Another important variation, due to age, is found in the ventral epimeral plate (see Plate I, figs. 24-2f). The smallest individual (42 mm., Station No. 3627, fig. 2a) has this plate very short; the two tips a Bull. U. S. Fish Comm. for 1903, 1905, p. 970. 32 FROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. are simply pointed and widely separated by a shallow and wide incision. With advancing age the tips of this plate are more produced (specimen of 55 mm., Station No. 2980, fig. 2h, and specimen of 68 mm., Station No. 2929, fig. 2c), a slight angulation appears on the inner side of the tips, which are not so widely separated, the incision becoming narrower and longer. Farther on the tips are gradually produced beyond the posterior margin of the segment (specimen of 81 mm., Station No. 2919, fig. 2d, and specimen of 91 mm., Station No. 4389, fig. 2º), the inner angle develops into a distinct spine, which is shorter than the tip, and the two tips approach each other closely, finally coming in contact at the level of the smaller inner point. The incision becomes long and narrow, slit-like. In the largest specimen at hand (115 mm., Station No. 3670, fig. 2,f) the two tips approach so closely to each other that the inner point of the left side overlaps that of the right. Identity of @. bengalensis with G. calcarata.—W ood-Mason gives the following differential characters for his G. bengalensis: (1) ‘‘Carapace covers the whole of the first and part of the second abdominal somite,” while in G. calcarata the carapace does not cover the trunk entirely. (2) “The antennal, branchiostegal, and postero-inferior spines appear quite smooth to the naked eye, being only obsoletely or microscopically serrated.”’ 9 (3) ‘‘Thesupraorbital spine is readily distinguishable by its shape from the rostral denticles.” (4) “The upper lateral keels are strongly roof-shaped.”’ (5) “The oblique subdorsal keels are more pronounced.”’ (6) ‘‘Antennal scale more broadly emarginate at the apex.”’ (7) “The pleural lappets of the last abdominal somite are terminated by two very unequal spines (of which the outer is longer and sharp, and the inner short and blunt), and are separated from one another posteriorly in the mid-ventral line by a long and narrow incision.”’ Length of Wood-Mason’s specimen (female with a rudimentary brood-pouch): 91 mm. Of these characters, the following may be remarked: (1) It depends entirely on the state of preservation how much of the trunk or the abdomen is covered by the carapace. In my speci- mens, there are the following limits: The minimum, when only the trunk is covered, the maximum, when the whole of the first and the anterior part of the second abdominal segment is covered. The latter vase corresponds to Wood-Mason’s species, but, as it happens, this one is found in a small individual (55 mm. Station No. 2384), which is, in all other respects, and especially in the ventral epimeral plate, a typ- ical calcarata. In many of my specimens, in which the state of pres- ervation permits, they being rather flabby, I am able at will to change the degree of covering of the abdomen, by simply pulling out or pushing in the latter. (2) The serrations are to my eyes, which are normal-sighted, always invisible, and I have to use a lens to discover them. Some- a É ão NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 39 times, chiefly in old individuals, they are actually wanting. Their presence or absence cannot constitute a specific character. (3) The supraorbital spine is sometimes distinctly visible, some- times entirely obsolete. If present, it is always marked by its position. Even when developed, it is so small that its presence or absence cannot be of specific value. (4) What Wood-Mason means by ‘‘roof-shaped” upper lateral keels, I cannot imagine. (5) The oblique dorsal keels are also found in Sars’s species; they are slightiy indicated in his fig. 2 (chiefly the posterior pair, which is most important). In poorly preserved, flabby specimens, which have undergone much rough handling, they are sometimes indistinct. They are present in all my individuals, and hence this character can not be accepted as constituting a difference between bengalensis and calcarata. (6) The degree of,emargination or truncation of the antennal scale offers variations, as is already indicated in Sars’s figures (Plate LV, figs. 2, 4,5). I have called attention to this fact in connection with the Hawaiian material”, wh’sn is further confirmed by the present material. A real emargination (z. ¢., a concave marginal line) is comparatively rare; generally there is a truncation, with the marginal line between tip and first tooth straight. (7) The description of the epimeral plate given by Wood-Mason corresponds exactly to what we see in my figs. 2a to 27, with the exception that the inner tip of each epimeral lappet is sharp, not blunt. In younger specimens, however, it zs blunt (see my figs. 20 and 2c). ‘Thus this character agrees well with the assumption that G. bengalensis is an older and larger @. calcarata. Thus of the seven characters given by Wood-Mason for @. bengalen- sis, six are not actual differences, and one, the fourth, is unintelligible. The only real difference from Sars’s description and figure is found in the epimeral plate of the sixth abdominal segment; but this organ, as shown, changes its form with age, and G. bengalensis is a rather large individual (91 mm.). Specimens from my material of the same size present an epimeral plate (see fig. 2c) closely corresponding to Wood- Mason’s description. “Sars had two specimens of this species; the large one was 98 mm., and to it belong the figures of the whole animal (slightly enlarged, Plate IV, fies. 1, 2). The carapace of the smaller one (68 mm.) is figured in his fig. 3. Sars does not say from which individual the other figures are taken, but it seems from the latter. Then hıs figure of the epimeral plate (fig. 6) belongs to this smaller individual. The same plate of an individual of the same sıze (68 mm.) is figured in my ——— “2Bull. U. S. Fish Comm. for 1903, 1905, p. 969. Proc. N. M. vol. xxxi—06——3 / 84 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXI. fig. 2c, and shows a rather more advanced stage, although it comes very eee to Sars’s figure, and differs ee from the epimeral plate of larger specimens. Sars’s figure is about intermediate between my figures 2b and 2c, representing specimens of 55 and 68 mm., respectively. Sex in @. calcarata.— It is rather hard to distinguish male and female in this genus unless full-grown individuals are at hand. Old females are readily recognized by the presence of marsupial lamelle at the bases of the thoracic legs. These lamellee ‘‘are absent in the male, but the male has, at the coxa of the last pair of legs, posteriorly and on each side, a small tuberculiform prominence, representing the outer sexual appendage.” @ In young and not quite adult females, however, the marsupial lamelle are comparatively small. In all the females of the present species, even the largest, the lamelle were not fully developed, being: short and narrow, not folding over one another in the median line, so that a ‘‘marsupial pouch” is not formed. In younger individuals these lamelle are very small, hardly distinguishable. The smallest in which I feund traces of them was 64 mm. long (Station No. 2980). In all smaller specimens there was no trace of them, and I was unable to make out whether they were young males or young females, as the male tubercle is generally not visible; in one individual only (55 mm., Station No. 2980) I thought I could see this tubercle. Upward of the size of about 65 mm. it is possible to tell the males from the females, and it is remarkable that in the material examined females were more abundant, there being only 9 males, as against 23 females. It is remarkable, further, that the largest male was only 76 mm. lons, and that all specimens above this size were females (17 of them). Sars's largest specimen of 98 mm. is said to be a male, while Wood- Mason’s specimen (91 mm.) was a female. The fact that even the largest females did not have the marsupial pouch completely developed indicates that they were not fully mature sexually. This makes 1t probable that they would have to develop further before being able to propagate, and suggests the possibility that they may attain the size of @. ingens, in which case they might assume the characters of the latter, thus making @. ingens the full- grown female of this species. Most of the specimens were from the Eastern Pacific (California region), only one young one (55 mm., Station No. 2384) being from the Gulf of Mexico. This is distinguished by a very long rostrum and very long postero-inferior spines. The rostrum, in front of the supra- ocular spines, 1s slightly longer than the rest of the carapace (exclud- ing the postero-dorsal spine), and was even longer than that, since the a cae p- 27, and Plate III, a 14 and 15. NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. oD tip is damaged. The postero- inferior spines are as eae as the distance from their base to the posterior base of the br: nor lobe (re- sembling closely Sars’s fig. 3 on Plate IV). (A specimen from Station No. 2980, also 55 mm. long, has the rostrum slightly shorter than the carapace, and the postero-inferior spines are only half as long as in the specimen from the Mexican Gulf.) For the rest, this specimen shows no differences; especially the epimeral plate agrees exactly with the specimen from Station No. 2980, shown in my fig. 2b. The cara- pace covers the anterior part of the second abdominal segment, rep- resenting the maximum among my material, but this is pr obably due to the method of preservation. lt has the appearance of having been put into strong alcohol at first, and consequently is much contracted. In slightly younger specimens from California the rostrum is rela- tively of the same length, and the postero-inferior spines at least approach the condition found in the Gulf specimen. Localities represented in the U. S. National Museum. FROM U. S. BUREAU OF FISHERIES STEAMER Albatross STATIONS. 2384.—1 young. Gulf of Mexico; 940 fathoms. 2839.—1 male, 1 female. Santa Barbara Islands, California; 414 fathoms. 2919.—1 female. Off southern California; 984 fathoms. 2923.—1 female. Off southern California; 822 fathoms. 2929.—1 male. Off southern California; 623 fathoms. 2936.—1 male, 3 females. Off southern California; 359 fathoms. 2980.—2 males, 1 female. Off southern California; 603 fathoms. 2986.—1 young. Off Lower California; 684 fathoms. 3127.—2 females. Off central California; 62 fathoms. 3348.—1 young. Off northern California; 455 fathoms. 3627.—1 young. West of Cortez and Tanner Banks; 776 fathoms. 3670.—1 female. Monterey Bay; 581 fathoms. 4333.—2 females. Off San Diego; 301 to 487 fathoms. 4334.—1 male, 1 female. Off San Diego; 514 to 541 fathoms. 4335.—1 male. Off San Diego; 500 to 530 fathoms. . 4336.—1 male, 1 female. Off San Diego; 518 to 565 fathoms. 4337.—2 males, 1 female. Off San Diego; 617 to 680 fathoms. 4339.—1 female. Off San Diego; 241 to 369 fathoms. 4351.—1 male (?) young,1 female. Off San Diego; 423 to 488 fathoms. 4353.—1 female. Off San Diego; 628 to 640 fathoms. 4354.—2 young. Off San Diego; 646 to 650 fathoms. 4379.—1 female. Off San Diego; 257 to 408 fathoms. 4380.—1 female. Off San Diego; 530 to 618 fathoms. 4381.—1 female. Off San Diego; 618 to 667 fathoms. 4382.—1 female, 1 young. Off San Diego; 642 to 666 fathoms. 4389.—1 male, 3 females. Off San Diego; 608 to 671 fathoms. 36 PROCEEDINGS OF THE NATIONAL MUSEUM. VO TER 4390. —1 female. Off Santa Catalina Islands, 1,350 to 2,182 fathoms. 4528. —1 male. Monterey Bay; 545 to 800 fathoms. Previous records.— Arafura Sea, 800 fathoms (Sars); vicinity of Talaur Island, S. of Mindanao, Philippines, 500 fathoms (Sars); Hawaiian Islands: Kaiwi Channel, and vicinity of Kauai Island, 449-881 fathoms (Ortmann); Bay of Bengal, 1748 fathoms (Wood- Mason). 5. GNATHOPHAUSIA GIGAS Willemoes-Suhm. Elate We tgs 19 os Gnathophausia gigas WILLEMOES-SUHM, Trans. Linn. Soc. London, Zool. (2), I, 1875, p. 28, pl. 1x, figs. 16, 17; pl. x, figs! 2 3. -G. O: SARs) Moraes seas Christiania, 1883, no. 4; Rep. Challenger, XIII, 1885, p. 33, pl. m1.—Orr- MANN, Bull. U. S. Fish-Comm. for 1903, Pt. 3, 1905, p. 968. This species is closely allied to G. calcarata, but differs in certain constant characters. On account of the general resemblance of both species, it is hardly necessary to give a complete description of @. gigas, and it will suffice to mention the differential characters. 1. The arrangement of the keels of the carapace is essentially the same in both species, with the exception that the posterior oblique keels of the upper face are entirely wanting in @. gigas. The anterior oblique keels are present, occupying the same position as in G. calcarata. 2. The spines of the carapace, in young specimens, are about the same as in @. calcarata, but the supraocular spine is more distinct, and as large as, or even larger than, the antennal spine. In older individuals all the spines are shorter than in @. calcarata, with the exception of the supraocular, which is always distinct. Antennal spine small, branchiostegal generally slightly larger than the latter, postero-dorsal very short. The largest are the postero-inferior spines, which approach closely those of G. calcarata, although they are shorter in the average. 3. Antennal scale of @. gzgas of slightly different shape; it is rather lanceolate, and not ovate, and the terminal point is longer and more tapering. The outer margin has four or five spiniform serrations, the anterior sharp and strong, the posterior small and sometimes obso- lete; these serrations, generally, are stronger than in @. calcarata. 4. The epimera of the five anterior abdominal segments are differ- ent in both species. While in @. calcarata both lappets of the second to fifth are strongly developed and are both spiniform, in @. gigas only the posterior lappet is produced and spiniform in all. five seg- ments, and the anterior is small and rounded (see Sars’s fig. 1 on Plate III). 5. The ventral epimeral plate of the sixth abdominal segment differs in both species in the larger individuals. In young specimens of G. NO. 1480, SCHIZOPOD CRUSTACEANS—ORTMANN. 7 gigas (see Plate II, fig. 1a, taken from a small individual, 56 mm. long, Station No. 3329), it is rather indifferent in shape, the two tips being widely separated by a very shallow incision; the two halves are not completely united in the median line. Inlarger individuals (see my fig. lb on Plate II, taken from an immature female about 90 mm. long, Sta- tion No. 2741) the tips are produced almost to the posterior margin of the segment, are more closely approached, and separated by a narrower and longer incision. This incision, however, is wider than in speci- mens of corresponding size of @. calcarata, and the tips on both sides are simple, not bifid as in @. calcarata. However, Sars in his ie. 5on Plate III draws an accessory terminal spine on the outer side of the left tip, while the right tip is entire. In our specimens I have never seen a condition like this. Our largest individual (Station No. 2860, 119 mm.) has the epimeral plate similar to that shown in our fig. 1b on Plate II, but it is slightly shorter and the outer margin is more evenly rounded, not angular, as in the latter. The characters given under 1, 3, and 4 are most important, and according to my experience always hold good. Characters 2 and 5 are not so reliable, although they may prove to be of some help. With regard to the relative length of the rostrum and the spines of the carapace, again the fact will have to be stated that they all are com- paratively longer in young specimens, as I have already pointed out. The epimeral plate of the sixth abdominal segment, although different from that of @. calcarata, is not very reliable on account of the marked changes in shape taking place during development. Our largest specimen (Station No. 2860) is 119 mm. long; and ıs a female with the marsupial pouch fully developed. Sars’s specimen was a male, 142 mm. long. Our second largest individual (Station No. 2741) is an immature female about 90 mm. long, with small, but dis- tinct marsupial lamelle, which do not form a ‘‘pouch.” All other specimens that have come under my observation are much smaller; the one from Hawaii is 50 mm., another from Sitka Sound, Alaska, (to be described elsewhere) is 55 mm. long, and the present young one from Station No. 3329 is 56 mm. long. They have no traces of marsupial lamelle, and have been regarded by me as males. But I am not quite sure as to this point. They may be young females. The two speci- mens from Station No. 3340 consist of two badly damaged carapaces with remnants of the trunk, while in both the abdomen is entirely missing. However, they undoubtedly belong to this species, since characters 1 and 3 are clearly observable. 38 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. EEE Localities represented in the U. 8. National Museum. FROM U. S. BUREAU OF FISHERIES STEAMER A/batross STATIONS. 2741.—1 female adult. Between Cape Charles and Long Island; 852 fathoms. 2860.—1 female. Between Sitka and Columbia River; 876 fathoms. 3329.—1 young. Bering Sea; 399 fathoms. 3340.—2 specimens (damaged). Between Unalaska and Kadiak; 695 fathoms. Previous records. —W est of Azores, 2,200 fathoms (Sars); Hawaiian Islands, vicinity of Kauai Island; 850-767 fathoms (Ortmann). Another locality is off Sitka Sound, Alaska, 922 fathoms. 6. GNATHOPHAUSIA DREPANEPHORA Holt and Tattersall. Gnathophausia drepanephora HoLr and TATTERSALL, Rep. Fisheries Ireland, Pt. 2, Append. No. 4, 1905, p. 113, pl. xvrrr; Ann. Nat. Hist. (7), XVI Tons pr O pit I have not seen this species, but I strongly supre that it is only the young stage of @. gigas. Holt and Tattersall create for it a separate section of the genus, uniting characters of the two main divisions; it agrees in every respect with our first division (a of the key), with the exception that the epimera of the sixth abdominal segment are said to be not united ventrally. Disregarding the latter character, @. drepanephora agrees in every particular with @. gigas, making allowance for the much less advanced age of the former (only 39 mm.); thus the spines of the carapace, chiefly the postero-dorsal and the postero-laterals are much more developed relatively. Further, in @. drepanephora, the epimera of the five anterior abdominal segments are described and figured as pos-. sessing only a posterior lappet, which is produced and spiniform while the anterior lappet is absent. This also may be due to age. As regards the epimera of the sixth abdominal segment, Holt and Tattersall describe them as not united ventrally. We have seen above, | under (@. gigas, that in young individuals (56 mm. long) these parts are not completely united in the median line, and thus it appears pos- sible that @. drepanephora represents only a stage that is younger yet than the youngest known specimen of @. gigas. Lack of material of the young of @. gigas prevents the settlement of this question finally, but Iam inclined to regard G. drepanephora as the young stage of G. gigas. G. drepanephora has been found off the western coast of Ireland, latitude 52° 27’ 06” north; longitude 15° 40’ west, in 1,770 fathoms. NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 39 7. GNATHOPHAUSIA GRACILIS Willemoes-Suhm. Gnathophausia gracilis WILLEMOES-SUHM, Trans. Linn. Soc. London (2) I, 1875, p. 33, pl. 1x, fig. 1.—G. O. Sars, Forh. Selsk. Christiania, 1883, no. 11; Rep. Challenger, XIII, 1885, p. 48, pl. vır, figs. 6-10. Gnathophausia gracilis var. brevispinis Woop-Mason and ALcock, Ann. Nat. Hist. (6), VII, 1891, p. 188. Gnathophausia brevispinis Woop-Mason and Arcock, Ann. Nat. Hist. (6), VII, 1891, p. 269.—Faxon, Mem. Mus. Comp. Zool., XVIII, 1895, p. 216, pl. 3. Gnathophausia dentata Faxon, Bull. Mus. Comp. Zool., XXIV, 1893, p. 217.0 Carapace with keels and spines of the type of the first group, but upper lateral keel entirely absent. Lower lateral keel terminating in a spine at the postero-inferior angle of the carapace. There isanother smaller spine just below this one, which is directed outward and some- times obsolete. Median keel interrupted, its posterior part with spini- form serrations. Postero-dorsal spine short. From the anterior end of the posterior part of the dorsal keel a pair of oblique keels runs forward and downward. Anterior part of dorsal keel triangularly elevated upon the gastric region, forming a prominent dentate crest, which extends forward to the rostrum. Supraocular spines small; antennal spines larger; branchiostegal spines very large. _ Antennal scale of the type of the second group, large, of usual shape, formed by a lanceolate-ovate lamella, the outer margin of which has a strong spine, which is serrated at the outer edge and pro- jects slightly beyond the terminal lobe of the lamellar part. Abdomen of the general type of the second group, but peculiar on account of the great development of dorsal spines. The first and sec- ond segments have each 2 large, triangular spines in the median line, the posterior of them at the posterior margin of the segment; the anterior spine of the first segment is generally smaller than the pos- terior. The following 3 segments (third to fifth) have each a posteri- orly projecting spine on the posterior dorsal end. The two lappets of the epimera of the first to the fifth segments are short and pointed, the posterior slightly longer than the anterior. Epimera of the sixth abdominal segment of the type of the second group, not united ventrally to form a ventral plate. There are 2 tri- angular, pointed epimeral lappets on each side of the anterior part of the sixth segment. I do not entertain the slightest doubt that @. brevispinis Wood- Mason and Alcock, is identical with G. gracilis Suhm. Faxon? admits the following differences of @. brevispinis from G. gracilis: 1. Prominent, dentate gastric crest. «The Gnathophausia figured on the colored plate opposite p. 500 in Chun, Aus den Tiefen des Weltmeeres, 1900, resembles this species, except for the spine just back of the cervical groove. bMem. Mus. Comp. Zool., XVIII, 1895, p. 218. 40 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. 2. Small size (or even absence) of the lower spine of the postero- inferior angle of the carapace. 3. Great breadth of the antennal scale. 4. Pleura of first 4 abdominal segments expanded posteriorly. 5. A transverse fold separating the 2 dorsal spines of the second abdominal segment. I have to make the following remarks as to these points: 1. According to Willemoes-Suhm, the gastric region of @. gracilas has 2 small teeth in the median line; according to Sars, who examined the same individual, it is unarmed: This difference is apparently due to the poor state of preservation of the Challenger specimen, and, as Sars’s figure is probably inaccurate in this respect, we can not depend on this character. 2. The lower spine of the postero-inferior angle of the carapace is certainly subject to variation. Faxon says that it is sometimes nearly or quite obsolete; my specimen, which agrees in most respects with G. brevispinis, has it well developed, although smaller than the upper spine and not quite so large as in Sars’s figure. Consequently this character is not reliable. In the width of the antennal scale I fail to observe any difference between Sars’s (Plate VII, fig..8) and Faxon’s (Plate J, fig. 1c) figures. In the latter, it may be slightly wider in the basal part, but this does not constitute a specific difference. As to 4 and 5 we can not compare @. brevispinis with @. gracilis, as Sars does not mention these characters. His figures, indeed, do not show the features given for @. brevispinis, but it must be borne in mind that this may be due to the poor condition of the Challenger specimen. My specimen agrees with @. brevispinis in these respects. The very peculiar association of characters found in both of these species (which are supposed to be distinct) on account of which it is necessary to place them by themselves within the genus, renders it probable, from the start, that they are identical. The above consider- ations remove any probable necessity for their separation, and hence I have no hesitation in uniting them in one species. The size of Sars’s specimen is 41 mm.; of Wood-Mason and Alcock’s 82 and 92 mm.; Faxon gives 60 mm. My specimen is about 60 mm. long, and seems to be a male, since no traces of marsupial lamelle are present.’ This species seems to attain a larger size, since the largest specimen known (92 mm.) was an ‘immature female with the last pair of incubatory lamelle only 3 mm. long” (Wood-Mason). Locality.—U. S. Bureau of Fisheries steamer Albatross station 3128—1 male. Off Central California; 627 fathoms. Previous records.—Atlantic, between Africa and Brazil, latitude 1° 22’ north, longitude 26° 36’ west, 1,500 fathoms (Sars); Bay of Bengal, 920-690 fathoms and 1,748 fathoms (Wood-Mason and No. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 41 Alcock); off Panama; 1,201 and 1, 471 fathoms (F axon); off Galapagos Islands, 551, 1,189, and 1,322 fathoms (Faxon). If the specimen figured by Chun“ is this species, we have to add: Gulf of Guinea, 4,000 meters. 8. GNATHOPHAUSIA LONGISPINA G. O. Sars. Gnathophausia longispina G. O. Sars, Forh. Selsk. Christiania, 1883 no. 10; Rep. Challenger, XIII, 1885, p. 46, pl. vir, figs. 1-5; pl. vi1r.—Ortmann, Bull. WS. Fish Comm. for 1903, Pt. 3, 1905, p. 969. This species is not represented in the present material, but I had quite a number of specimens when I worked on the Hawaiian material, and thus I am able to give a good account of it. Carapace with keels of the type of the second group: An upper lateral keel is present; the lower lateral keel curves up behind, and runs toward the postero-dorsal spine. The dorsal keel is continuous, and projects as a long postero-dorsal spine. Rostrum long. Supraocular spines well developed; antennal spine obsolete (very small or even absent); branchiostegal spine well marked and triangular. No postero- inferior spines, but posterior angles of carapace rounded off. (With the exception of the branchiostegal spine, the spines of the carapace are of the type of the second group.) Antennal scale of the type of the second group, and remarkably long; the marginal spine is greatly produced, projecting considerably beyond the terminal lobe of the lamellar part, and serrated at both the inner and outer margins. Abdomen of the ty pe of the second group, with a small posteriorly projecting dorsal spine at the hind margin of each of the five anterior segments. Epimera of the five anterior segments with the two lappets acute, the anterior short and smail, the posterior longer and spiniform; in the male, the posterior lappet of the second segment is greatly elongated, with a long spiniform tip; in the female, it does not differ essentially from those of the other segments. Epimera of sixth abdominal segment of the type of the second group, but there are two triangular, acute lappets on each side, asin @. gracilis. The chief specific characters are: The presence of a branchiostegal spine, the shape of the antennal scale, and the character of the abdominal segments. The remarkable posterior lappet of the second abdominal segment is found only in the male sex, and was males and females may be easily distinguished. As I have demonstrated with the help of Hawaiian material, the rostrum, the dorsal and branchiostegal spines, and the marginal serra- tions of the antennal scale change with age, being more strongly developed in young individuals. a Aus den Tiefen des Weltmeeres, 1900, p. 500. 49 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL, KR Size. —Sars had 5 specimens, the largest beine a male, 59 mm. long. My material from the Hawaiian Islands consisted of 40 speci- mens, the largest of which was a female, 62 mm. long, with the marsupial pouch fully developed. Since there were other females, in which at about the size of 50 mm. the marsupial lamelle were well formed, it is probable that this species does not attain the gigantic dimensions seen in others. Distribution. —Off Samboangan, Philippines, 250 fathoms (Sars). Not rare at the Hawaiian Islands (found at 15 stations), near the islands of Oahu, Molokai, and in Kaiwi Channel, 222-498 fathoms (Ortmann). 9. GNATHOPHAUSIA ZOEA Willemoes-Suhm. Plate II, fie. 2a, 20. Gnathophausia zota WILLEMOES-SUHM, Nature, VIII, (8738, p. 401, fig. 6; Trans. Linn. Soc. London (2), I, 1875, p. 32, pl. xıx, figs. 2-15; pl. x, fig. 4.—A. MıLnE-EpwaArDns, Rec. fig. Crust. nouv., I, 1883.—G. O. Sars, Rep. Chall., | XIII, 1885, p. 44, pl. vr, figs. 6-10.—Faxon, Mem. Mus. Comp. Zool, XVIII, 1895, p. 215.—CAULLERY, Ann. Univ. Lyon, fase. 2, 1896, p. 368.—ALcock and ANDERSON, Ann. Nat. Hist. (7), III, 1899, p. 3.—Horr and TATTERSALL, Rep. Fisheries Ireland, II, App. 4, 1905, p. 141.—Hansen, Bull. Mus. Monaco, KOCK 1909 oo: Gnathophausia willemoesi G. O. Sars, Forh. Selsk. Christiania, 1883, no. 6; Rep. Challenger, XIII, 1885, p. 38, pl. v, figs. 1-6.—Faxon, Mem. Mus. Comp. Zool., X VIII, 1895, p. 215, pl. E, fig. 1.—Ortmann, Bull. U. S. Fish. Comm. 10,.4903Et:23,19097P.1969. 10. GNATHOPHAUSIA ZOEA SARSI (Wood-Mason). Gnathophausia sarsi Woop-Mason, Ann. Nat. Hist. (6), VII, 1891, p. 187.—Orr- _ MANN, Bull. U.S. Fish: Comm? for 1903, Pt. 3, 1905 p-969 The following are the characters of the species: Carapace with keels and spines of the type of the second group: upper lateral keel present; lower lateral keel curved up behind; dorsal keel continuous. Rostrum, according to age, longer or shorter. Dorsal spine long in the young; shorter in the old. Supraocular and anten- nal spines well developed; branchiostegal spine absent, and branchio- stegal lobe rounded. No postero-inferior spines, but postero-inferior angle of carapace rounded off or (in the variety) rectangular, forming a narrow laminar expansion behind the marginal rim, which also curves upward. The carapace is not suddenly constrieted in the anterior part. Antennal scale of the ty pe of the second group: large, spine of outer margin projecting slightly beyond the terminal lobe of lamellar part in the young, slightly shorter than the latter in the old. Outer mar- gin of spine slightly serrated in the young, smooth in the old. Abdomen of the type of the second group: the five anterior seg- ments dorsally indistinctly keeled, and produced into small spines at -NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 43 the posterior margin. Epimera ae the five Bes segments, with the anterior lappet small, the posterior produced and acutely pointed. There is, on each segment, an indistinct subdorsal keel on each side. Epimera of sixth abdominal segment of the type of the second group, formed by only one triangular, acute lappet on each side of the ante- rior section of the segment, and not forming a ventral plate. The only difference of the variety sarsz from the typical form is found in the shape of the lamellar expansion of the postero-inferior angle of the carapace: in the typical form, this expansion is rounded off, while in the variety it is rectangular. It is possible that the latter character is only restricted to the young, and that it generally disap- pears with advancing age, but then it would disappear at different stages in different individuals, in the average, when they are about half grown (see below). The identity of G. cota and G. willemoest.—l have devoted much time to the study of the differential characters of these two species, as determined by Sars (1885), end have the following to say with ref- erence to them: In Sars’s synopsis of the species (p. 29), the length of the postero- sa spine is paramount: it is ‘‘greatly produced” in @. zoia, and ““comparatively short” in @. willemoest. ~ The differences between the species, taken from Sars’s diagnosis and description (pp. 38 and 44) are the following: 1. The length of the postero-dorsal spine just mentioned: in G. zoéa this spine reaches sometimes beyond the fourth abdominal segment, while in @. willemoesi it is only slightly longer than the first abdomi- nal segment. 2. The posterior margin of the carapace, and the margins of the postero-dorsal spine are ‘‘coarsely denticulate” in G. zoéa, and ““decidedly glabrous” in @. willemoesi. 3. The rostrum is very elongate (even exceeding the carapace with- out posterior spine), and strongly denticulate in @. zoöay it is shorter than the carapace, and provided with small, comparatively few, den- ticles in @. willemoesi. 4. The spine of the antennal scale projects somewhat beyond the terminal lobe of the lamellar part, and is slightly denticulate at the outer edge, in @. zoéa, it is a little shorter than the terminal lobe, and not denticulate, in @. willemoesi. Discussing these four points in detail: Sars seems to lay much stress upon this character. Ihave shown, however, in several of the foregoing species, that the relative length of the spines of the carapace changes withage, being generally longer in young individuals. As regards the present case, @. zoéa is founded upon specimens much younger than those of @. willemoesi. More- over, 1 have extracted embryos from the marsupial pouch of a large 44 PROCEEDINGS OF THE NATIONAL MUSEUM. VOLYXXXI. specimen (from Station No. 2723, about 105 mm. long), which undoubt- edly belongs to @. willemoesi according to Sars’s conception, and these young ones (Plate II, fig. 21) have the postero-dorsal spine well devel- oped, and comparatively much longer than any specimens ever described, extending to about the middle of the telson. Thus the length of the postero-dorsal spine depends without question on the age of the individual. 2. The denticulations or serrations of the posterior margin of the carapace, the postero-dorsal spine, the spines of anterior margin of carapace, and of the rostrum are generally in this genus more distinct in younger individuals than in older ones. I have called attention to this above (under @. calcarata). In the present case the large indi- vidual from Station No. 2723, which is surely @. willemoesi, has the - margin of the carapace not ** decidedly glabrous,” as Sars states, but there are a number of fine denticulations, less distinct than in young individuals, but easily seen. Faxon (1895) says that in @. willemoese there are denticulations along the margin of the dorsal spine. Thus this character does not hold. 3. That the relative length of the rostrum, like that of the spines of the carapace, changes with age is now well established. In the young specimens extracted from the pouch of the mother, the rostrum is decidedly longer than the carapace (Plate II, fig. 2a). If the rostrum becomes shorter with age it is not astonishing that the denticulations become less pronounced, and this is entirely in keeping with what I have shown in the second character. Thus the length of the rostrum does not possess any systematic value. 4. The fourth character needs special attention, but I think I am able to prove that it also is influenced by age. In young specimens the spine of the outer margin of the antennal scale is longer than the terminal lobe, and it is slightly serrated on the outer edge. With increasing age it becomes slightly shorter than the terminal lobe, and the serrations disappear. The following may be said in support of this view: a. The specimens representing the original @. zoéa are small or of medium size (not longer than 70 mm.), while the specimens upon which G. willemoesi was founded are very large, one measuring 136 mm., and the other being ‘‘somewhat smaller;” that is to say, they were about double the size of G. Zota. b. A large specimen (Station No. 2723) is about 105 mm. long, and has the antennal scale of @. willemoesi; another (Station No. 4306) is 88 mm. long, and has the antennal scale intermediate between @. zoéa and willemoesi; the spine is about as long as the lamellar portion on the left side and very slightly longer than the latter on the right side, and it has on the outer margin very indistinct indications of ser- rations, visible only under the microscope. The latter specimen is NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 45 also intermediate with regard to the characters 1, 2, and 3. Younger individuals among the material examined by the writer possess invari- ably the antennal scale of @. zoéa, but it must be added that the ser- rations of the outer margin are very fine. I can not see them with the naked eye, and an ordinary magnifying lens scarcely shows traces of them, but stronger instruments reveal them distinctly as sharp points for quite a distance along the margin of the spine. c. Young specimens extracted from the marsupium of a typical G. willemoesi have an antennal scale, which, in shape, is that of G. zoéa, the marginal spine being longer than'the lamellar portion. However, I could not ascertain the presence of serrations on the marein. Under the microscope, there is a kind of undulation of the margin, but no sharp, spiniform teeth. But this is not astonishing, since it is in keeping with the fact, that the serrations or denticu- lations of rostrum and postero-dorsal spine are not present in these embryonic individuals, while they are well developed in young specimens after they have left the marsupium. d. Similar changes in the length of the spine of the antennal scale, due to age, have been found in another species, @. longispina. Thus, I think, the assumption well supported, that the characters oiven for @. zoéa are only such as are due to the immaturity of the specimens, and that those assigned to @. willemoesv belong to the older stages of the same species. The name of G. zoöa has the priority over G. wellemoesi. G. sarsi.—For G. sarsi, the following differences from @. willemoesi are given by Wood-Mason“. 1. The dorsal spine reaches to the posterior end of the third abdom- inal segment. 2. “Extreme edge (of carapace) expanded at the postero-inferior angle into a conspicuous rectangular lamina, into which neither its lower lateral keel nor its raised rim enters.” 3. Upper half of the posterior margin of the carapace on each side and the lateral edges of the dorsal spine are minutely denticulated. 4. Five anterior abdominal segments with two subdorsal keels. 5. The telson is tricarinate, having a fine median carina, and “appears to be more produced at the tip than in any other De The following remarks are to be made: 1. As I have already shown, the length of the dorsal spine can be disregarded; in the present case, the length agrees well with the size of Wood-Mason’s specimen; in the typical @. zoéa, not longer than (0 mm., it reaches beyond the fourth abdominal segment or falls short of it; in G. sarsi (75 mm.) it reaches to the end of the third segment; in one of our specimens, 88 mm. long, it reaches to the middle of the third segment; in another, about 105 mm. long, to the middle of the @Ann. Nat. Hist. (6), VII, 1891, p. 187. 46 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. second; and in the type of @. willemoesi, 186 mm. long, slightly beyond the first segment. In the larva before leaving the marsupium, as has been said, it reaches to the middle of the telson, and thus the length of this spine entirely depends upon age. 2. The second is the most important character of @. sarsi, and I find it in allthe younger individuals at hand. The lower lateral keel, and also the marginal keel or rim, curve upward near the postero- inferior angle of the carapace; but the actual margin of the carapace extends behind the point, where the marginal rim begins to curve up, and runs for a short distance straight back; then it forms a right angle, extending toward the dorsal spine. Thus there is, behind the marginal rim, a “rectangular lamina” as described by Wood-Mason. Sars does not mention such astructure, neither in @. willemoesi nor in G. zoöa, he only says that the lower lateral keel curves upward before reaching the postero-inferior corner, and that the latter, in @. wille- moesi, is evenly rounded off. He does not mention the fact, that the marginal rim curves upward before reaching the posterior margin, and that there is a “lamina” behind the marginal rim. Such a lamina, however, is distinctly seen in Sars’s figures of @. willemoes? and zoéa (Plate V, fig. 1,and Plate VI, fig. 6). This is the more important, and clearly establishes the presence of this lamina in Sars’s specimens, although he did not pay much attention to this feature, he gave a fair representation of it in the figures. The lamina, however, in both cases, is not rectangular, but evenly rounded off. Looking at the specimens at hand, I find that the largest, a typical willemoesi, represents this character as described and figured by Sars, only the lamina is somewhat wider than in his figure; but it is evenly rounded off. Exactly the same condition obtains in our second largest individual, 88 mm. long. From the Hawaiian Islands 1 have mentioned two specimens of @. willemoesi, which I identified chiefly according to this character, which measure 73 and 52 mm. The largest individual observed by myself among the Hawaiian material, possessed a rectan- gular lamina, and consequently was recorded under @. sarsz. It measured 62 mm. The smallest measured 34 mm. Considering that Wood-Mason’s @. sarst was 75 mm. long, and that Sars’s specimens of G. zoéa, which have apparently a rounded lamina, were 70 mm. and less, the conclusion is reached that: all specimens hitherto observed that are over 75 mm. long, have this character developed according to the wzllemoesz type; all specimens smaller than 52 mm. have it corresponding to the sarsi type; specimens between 52 and 75 mm. may possess either a rectangular or a rounded lamina. | But it can not be said positively that this character is due only to age. It may be that the rectangular lamina becomes rounded with advancing age, and that this transition takes place at a different period in different individuals, in the average, when they are about half grown NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 47 (50 to 70 mm.). But I am not quite sure of it, and so I prefer, for the present, to regard @. sarsi as a variety of @. zoiu (= willemoes?). It should be mentioned that Faxon” thinks that @. sarsı is “a form probably not specifically distinct from @. willemoesi.” The young specimens extracted from the pouch of the old female show a distinct angle or point behind on each side of the carapace, but as the carapace is rather shapeless, being represented by a kind of a bag filled partly with oily or fatty substance (yolk), it is impossible to correlate these two small points with the infero-posterior corners of the carapace, although this correlation is very probable. 3. I have shown that the denticulation of the posterior margin of the carapace and of the dorsal spine does not constitute a specific character. 4. The subdorsal keels of the abdomen, mentioned by Wood-Mason, are present in all specimens at hand. They are formed by rather faint, blunt elevations, and I should not call them keels. They are easily overlooked, especially in poorly preserved material. 5. A third, fine median keel of the telson is distinctly seen in Sars’s illustration of the telson of @. willemoesi (Plate V, fig. 6), and is present in all specimens examined by myself. On closer examination I find that this median keel is rather a fine double keel. Wood-Mason’s sentence that the telson ‘‘appears to be more pro- luced at the tip than in any other species” is, as I have already remarked in the report on the Hawaiian Schizopods, unintelligible to me. I do not see any difference from other species in the shape of the elson. Localities represented in the U. S. National Museum. FROM U. S. BUREAU OF FISHERIES STEAMER Albatross STATIONS. GNATHOPHAUSIA ZOEA, 1723—1 female (gravid). Between Nantucket and Cape Charles, 1,685 fathoms. !306—1 male. Off San Diego, California, 207-497 fathoms. GNATHOPHAUSIA ZOEA SARSI. ,351—1 young. Between Havana and Yucatan; 426 fathoms. Previous records. Typical form, as @. zoéa: West of Azores, 1,000 fathoms (Sars); Tropical Atlantic, 1º 47’ North, 24° 23’ West, 1,850 fathoms (Sars); off Brazil, 770 fathoms (Sars); Pacific, north of Kermadec Island, 600 fathoms (Sars); off Galapagos Islands, 384 and 581 fathoms (Faxon); «Mem, Mus. Comp. Zcol., XVIII, 1895, p. 215. 48 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. Bay of Bicos ay, “800- ca 200 meters Ox Milne-Edwards and Caullery); west coast of Te eland, 382-600 fathoms (Holt and Tattersall); Azores, 1,000 meters (Hansen); near Maldive Islands, 480 fathoms (Alcock and Anderson). Typical form, as G. willemoesi: Banda Sea, 1,425 fathoms (Sars); Gulf of Panama, 1,270 fathoms (Faxon); off Acapulco, 493-664 fathoms (Faxon); Tres Marias Islands, 680 fathoms (Faxon); Hawaiian Islands, Molokai and Hawaii, 552-809 fathoms (Ortmann). G. zoéa sarsi: Bay of Bengal, 840 fathoms (Wood-Mason); Hawaiian Islands, vicinity of Kauaiand Modu Manu, 293-800 fathoms (Ortmann). THE LARVAL FORM OF GNATHOPHAUSIA ZOEA As previously mentioned, among the material is a large female of this species, representing Sars’s form @. willemoesi, which has the mar- supial pouch fully developed and filled with larva. Since larval stages of this genus have never been described, indeed, since nothing is known about the development, with the exception that on account of the presence of a marsupial pouch and in analogy to Zophogaster it is presumed that the development of the young form probably reaches a very advanced stage before it leaves the mother, it is advisable to give here a more detailed account of these young specimens. The number of the young is 21, a remarkably small number, but agreeing well with what we know about the number of the progeny of deep-sea animals. They are all uniformly developed and represent a very advanced stage, in fact, they are no longer embryos, but have left the egg completely. Probably they were about ready to leave the pouch of the mother, as all parts of the body had attained, in a general way, the condition found in the free swimming form. Within the pouch the young Gnathophausie are so arranged that they lie firmly packed together, the head of each directed toward the posterior end and the sternum of the mother, and the tail toward the anterior end of the mother, each overlapping in part the individual in front of it. That is to say, the heads are directed toward the bases, the tails toward the tips of the marsupial lamelle. The dorsal face of the larve is concave, the ventral face convex, corresponding to the curvature of the lamelle, since the back is turned toward the sternum of the mother, the ventral side toward the enveloping lamellee. In each of the young ones (see Plate II, fig. 2a) the body is distinctly divided into an anterior (thoracic) and Sone part, which forms a distinctly and completely segmented abdomen. The carapace is rep- resented by a bag-like excrescence, which is provided with distinct and long rostral and postero-dorsal spines. It is filled with the rem- nant of the yolk. Its keels are very indistinct, but there is a small point posteriorly on each side, possibly representing the postero-infe- rior corners of the carapace. The dorsal spine is long and closely NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. 49 appressed to the back of the abdomen, and reaches as far as the middle of the telson. The rostrum is very long, longer than the carapace. It is bent down and appressed toward the ventral side, and directed back- ward. Neither rostrum nor dorsal spine show any serrations. All appendages, except the eyes, are closely appressed to the ven- tral face of the body and are directed backward. In my figure they are not drawn in the natural position, but are slightly spread out and removed from the ventral side in order to show them more distinetly. The eyes are well developed and of yellowish color. All other appendages resemble more or less those of the adult form, with the general exception that the hairs and bristles are absent or less devel- oped and with the following special exceptions (compare Sars's Plate VIII): The marginal spine of the antennal scale is longer than the laminar part and has no serrations on the outer margin. The second maxilla possesses an additional joint at the end of the distal portion of the endognath (called *‘ palp” by Sars, see his fig. 7° on Plate VIII). This joint is very small, only about one-fifth as long as the preceding joint (the terminal one in the adult) and less than half as wide. (In the-adult it seems to be fused with the penultimate joint, as is indicated by the shape of this joint in Sars’s figure.) The ‘‘ pig- mented basal protuberance” (or luminous organ) is indicated in the larva. The maxilliped resembles Sars’s figure (Plate VIII, fig. 8) and also has no exopodite, as is characteristic of the second group of the genus (excepting G. gracilis), but it is more slender, the third of the five free joints being not enlarged and about half as wide as in the adult G. longispina. The gills are vestigial and less complex than in the adults. The tip of the telson has not yet assumed the shape of the adult form (see Plate II, fig. 24). It is not terminated by two strongly-curved spines forming an ‘*‘almost semilunar” projection, but is terminated by a cordiform or, rather, reniform plate, which carries on each side a larger and a smaller spine and is finely denticulate at the posterior border. ‘The marginal spines of the telson are more uniform than in the adult form, only a few smaller spines being found between the larger ones. It appears that these larva: come very near to the adult form, only the carapace remaining what might be called ‘‘embryonal” in shape. From the presence of a marsupial pouch it was to be expected that the young reach a high stage of development before being set free and dismissed from the mother’s protection. As it happens this has been fully confirmed by the present study, the young contained in the pouch of the mother having passed completely through all embry- Proc. N. M. vol. xxxi—06———4 50 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. onal stages, and through almost all larval stages; they seem to be ready to leave the marsupium, for it is clear that they need only to stretch out their appendages in order to be able to use them for free swimming. 11. GNATHOPHAUSIA SCAPULARIS, new species. Plate II, fig. 3a-3e. Type and cotype.—U. S. National Museum, 2 males, U. S. Bureau of Fisheries steamer Albatross, Station No. 2992, Revillagigedo Islands, Lower California; 460 fathoms. Cat. No. 32327. Near @. zoöa, but easily recognized by the anterior constriction of the carapace and the greatly expanded branchiostegal lobes. Shape of body rather stout. Carapace covering almost completely the first abdominal segment. Postero-dorsal spine indistinctly denticu- late toward posterior margin of carapace, rather short, projecting to about the middle of the second abdominal segment. Rostrum short, much shorter than carapace, denticulate. Supraocular spines strong. Antennal spines small, but distinct. Branchiostegal spines wanting. All keels of carapace well developed. Median keel uninterrupted. Upper lateral keels strong, curved, including a lanceolate, almost plane upper face of the carapace, widest anteriorly. Anteriorendsof upper lateral keels strongly curved downard. In front of the anterior ends of these keels the carapace is suddenly constricted and depressed, thus forming a very marked shoulder on each side. This constrietion affects greatly the course of the lower lateral keels, which suddenly begin to converge at a point just above the branchiostegal lobes. Above this point and below the anterior end of the upper lateral keel there is an almost pit-like depression, which sends a slight groove upward, toward the median keel. For the rest, the lower lateral keel is similar to that of @. zoöa, curving up behind toward the postero- dorsal spine. It projects, however, in its whole length, considerably beyond the keel of the lower margin of the carapace. Thus the whole carapace becomes rather prismatic, almost hexangular, the upper face . being flat, but interrupted by the dorsal keel, and the lower surface being wanting (between the two lower margins); compare the cross section of the carapace, Plate II, fig. 3c. Branchiostegal lobes rounded, vault-shaped, and greatly expanded, rendering the carapace at this point as wide as in the middle, in spite of the great constriction above the branchiostegal lobes. Abdomen very similar to that of @. zoéa, practically identical with it. Five auterior segments slightly keeled dorsally, with a small, posteri- orly projecting spine at the hind margin. On each side a blunt sub- dorsal keel. Epimera with the anterior lappet small and rounded or slightly angular; the posterior lappet produced into a sharp spine. No. 1480. SCHIZOPOD CRUSTACEANS: 256 IRTMANN. 31 There is a small spine at the base of the basal joint of the pleopods (as in @. zoöa). Only one epimeral spine on each side of anterior section of sixth abdominal segment. All other parts are similar to the corresponding parts of @. coca, but the antennal scale has the marginal spine considerably shorter than the terminal lobe, without serrations on the outer edge. This very remarkable species is so closely allied to @. zoöa that I should have taken the peculiar conformation of the carapace, caused by the constriction of its anterior part, for a monstrosity, were it not for the fact that two individuals are at hand. The comparatively short spine of the antennal scale possibly constitutes another specific char- acter; in specimens of @. zoéa of the same size it is longer than the terminal lobe. Both specimens are apparently males, since no traces of marsupial lamellz are visible, and the coxopodite of the last pair of thoracic legs has, posteriorly, a small tubercle, which undoubtedly represents the male orifice. Measurements of the types. —Total length of larger individual, 75mm. ; length from tip of rostrum to tip of posterior spine of carapace, 46 mm. Total length cf smaller individual, about 70 mm., but exact fig- ures can not be given, since the rostrum is broken off near the base. 12. GNATHOPHAUSIA AFFINIS G. O. Sars. Gnathophausia affins G. O. Sars, Forh. Selsk. Christiania, 1883, no. 7; Rep. Challenger, XIII, 1885, p. 41, pl. v, figs. 7-10. , I have never seen this species. It is very closely allied to @. zoéa, and differs only in the following points: 1. Supraocular and antennal spines smaller, the latter almost obso- lete. Branchiostegal lobe slightly angular, but having no spine. 2. Abdominal segments not keeled above, and possessing no dorsal projections or spines on the hind margin. 3. Posterior lappet of the epimera of the five anterior abdominal segments rounded, not spiniform. Distribution: Only one specimen, a female, of this species is known up to the present time, the one taken by the Challenger in the tropi- cal Atlantic Ocean, midway between Africa and Brazil (latitude 1° 22 north, longitude 23° 36’ west), in 1,500 fathoms. It measured 81 mm. 13. GNATHOPHAUSIA ELEGANS G. O. Sars. Gnathophausia elegans G. O. Sars, Rep. Challenger, XIII, 1885, p. 42, pl. v1, figs. 1-5. E Carapace with keels and spines of the type of the second group, but upper lateral keel absent. Lower lateral keel curving up behind and much farther distant from the marginal rim than in @. zoéa. Dorsal 52 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. MEXE keel continuous. Rostrum and dorsal spine comparatively long. Supraocular spine well developed. Antennal spine very small, almost obsolete. Branchiostegal lobe rounded or angular, but without spine. No postero-inferior spines. Marginal rim following closely the mar- gin and leaving no laminar expansion at the postero-inferior corner. Carapace not constricted in anterior part. Antennal scale of the type of the second group and very similar to that of the young @. zoéa, it is large, and the spine on the outer mar- gin is slightly longer than the laminar portion. ‘The outer edge with very minute serrations in young specimens, smooth in older ones. Abdomen of the type of the second group, at least in the young, but the five anterior segments without median keel, although with short, flattened, spiniform projections at posterior dorsal margin. In older individuals these dorsal projections are wanting. Epimera of all abdominal segments similar to those of @. zoéa. The young specimen at hand differs from Sars’s original description in the following particulars: 1. The carapace completely covers the trunk. 2. The rostrum and the postero-dorsal spine are longer. 3. Branchiostegal lobe not rounded, but angular. 4. Five anterior abdominal segments with flattened median posterior projection. 5. Spine of antennal scale finely serrated on outer margin. The first, second, and fifth characters are of no consequence, since similar variations are found in other species, and are plainly due to state of preservation or to age. Our specimen is young, 48 mm. long, while Sars’s was 56 mm. The angular (triangular) shape of the branchiostegal lobe (third character) differs markedly from what is seen in Sars’s species, and the presence of flattened spines on the posterior margins of the abdom- inal segments (fourth character) might also be of importance. Since the present specimen is only the second individual of this species ever reported, | am not prepared to say whether these two characters are of specific or varietal value, or whether they simply constitute addi- tional variations of age. Further material is necessary to decide this question. Locality.—U. S. Bureau of Fisheries steamer Albatross Station No. 3697, 1 young; off Honshu Island, Japan; 265 to 120 fathoms. — Previous record.—South of Fiji Islands, 610 fathoms (Sars). NO. 1480. SCHIZOPOD CRUSTACEANS—ORTMANN. De Family EUCOPIDZE G. O. Sars. 14. EUCOPIA AUSTRALIS Dana. Eucopia australis Dana, U. S. Expl. Exp. Crust., 1852, p. 609, pl. xt, fig. 10.— Hansen, Bull. Mus. Monaco, XLII, 1905, p. 6. The species of this genus have been largely confounded, as has been pointed out by Hansen. The following specimens all agree with #. aus- tralis Dana, as reidentified by that author. All my specimens are in poor state of preservation, but the eyes are present in all of them. The distribution of this form can not be made out satisfactorily until the older material has been reexamined. Itis known from the Antarctic Ocean (Dana, Hansen), and the present localities are of interest, since they extend the range into the northern Pacific and tropical Atlantic oceans. Localities represented in the U. S. National Museum. FROM U. S. BUREAU OF FISHERIES STEAMER A/batross STATIONS. 2751.—1 young. Lesser Antilles, latitude 16° 54 north; longitude 63° 12’ west; 687 fathoms. 3308.—6 specimens (3 female, 3 young). Bering Sea, latitude 56° 12’ north; longitude 172° 07’ west; 1,625 fathoms. 3604.—1 male. Bering Sea; latitude 54° 54’ north; longitude 168° 59’ west; 1,401 fathoms. 3696.—1 young. Off Honshu Island, Japan; 501 to 749 fathoms. 3783.—1 female. Off Kamchatka; 1,567 fathoms. 4397.—1 young. Off Santa Catalina Islands, California; 2,196 to 2,228 fathoms. 4403.—2 females, 1 young. Off San Clemente Island, California; 505 to 599 fathoms. 15. EUCOPIA UNGUICULATA Willemoes-Suhm. Eucopia unguiculata Hansen, Bull. Mus. Monaco, XLII, 1905, p. 3. A single individual, female, about 30 mm. long, belongs to this species. It is rather well preserved, and the characters pointed out by Hansen for this species are present. Locality.—The U. S. Bureau of Fisheries steamer Albatross Station No. 4383, 1 female. Off North Coronado Island, California; 287 to 395 fathoms. Found previously in the Atlantic Ocean and East Indian Archipelago (Hansen). 54 Fig. Fig. Fig. Fig. Fig. Fig. 2a 2b. 3a. =~ 3b. SC. PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXI. | EXPLANATION OF FIGURES. PLATE I. . Lophogaster spinosus, new species. Type from U. S. Bureau of Fisheries steamer Albatross Station No. 2666. View from above, 2/1. . The same. Lateral view of carapace, 2/1. snathophausia calcarata Sars. Epimeral plate of sixth abdominal segment of a specimen, 42 mm. long, from Station No. 3627, about 4/1. . The same, of a specimen, 55 mm. long, from Station No. 2980, about 4/1. . The same, of a specimen, 68 mm. long, from Station No. 2929, about 4/1. . The same, of a specimen, 81 mm. long, from Station No. 2919, about 3/1. . The same, of a specimen, 91 mm. long, from Station No. 4389, about 3/1. The same, of a specimen, 115 mm. long, from Station No. 3670, about 3/1. PLATe II. . Gnathophausia giyas Suhm. Epimeral plate of sixth abdominal segment of a specimen, 56 mm. long, from Station No. 3329, about 4/1. . The same, of a specimen, about 90 mm. long, from Station No. 2741, about 3/1. Gnathophausia zota Suhm. Larva, extracted from marsupium of mother, from Station No. 2723. Side view, about 3/1. The same, end of telson, greatly enlarged. Gnathophausia scapularis, new species. Type, from Station No. 2992. Lateral view of body, natural size. The same. Upper view of carapace. The same. Diagrammatic cross section of carapace at the level of the line A-B in fig. 3b. U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. XXXI PL. | | 2d 2b 15 SCHIZOPOD CRUSTACEANS. FOR EXPLANATION OF PLATE SEE PAGE 54. U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. XXXI PL. II UN ta 3e 1b SCHIZOPOD CRUSTACEANS. FOR EXPLANATION OF PLATE SEE PAGE 54. ee - ard an, +: Fe MR | CHIZOPOD CRUSTACEANS IN THE U.S. NATIONAL MUSEUM: SCHIZ- OPODS FROM ALASKA fos FETT ANIME BY CoGh ARNOLD E. ORTMANN — ee ee den PO Of the Carnegie Museum, Pitrsburg, Pennsylvania No. 1591.—From the Proceedings of the United States National Museum, Vol. XXXIV, pages 1-10, with Plate I Published A pril 6, 1908 Washington Government Printing Office 1908 SCHIZOPOD CRUSTACEANS IN THE U.S. NATIONAL MUSEUM: SCHIZ- OPODS FROM ALASKA BY ARNOLD E. ORTMANN Of the Carnegie Museum, Pittsburg, Pennsylvania rd No. 1591.—From the Proceedings of the United States National Museum, Vol. XXXIV, pages 1-10, with Plate I Published April 6, 1908 Washington Government Printing Office 1908 SCHIZOPOD CRUSTACEANS IN THE U. S. NATIONAL MUSEUM: SCHIZOPODS FROM ALASKA. By ArnoLD E. ORTMANN, Of the Carnegie Museum, Pittsburg, Pennsylvania. The present paper treats of a collection of Schizopods made dur- ing the investigations by the Alaska Salmon Commission in 1903. The collection, although small, contains a number of interesting forms. One of them represents a new genus the systematic position of which was ascertained with difficulty, and to which finally a posi- tion could be assigned only by altering the definition of one of the established subfamilies of the family Myside. “The paper was originally to be published by the Bureau of Fish- eries, but was turned over to the U. S. National Museum, and it forms here the second instalment of a series of publications intended to describe the Schizopods of the national collections. Order MYSIDACEA Boas. Family LOPHOGASTRID G. O. Sars. Genus GNATHOPHAUSIA Willemoes-Suhm. GNATHOPHAUSIA GIGAS Willemoes-Suhm. G. O. Sars, Rep. Voy. Challenger, XIII, 1885, p. 33, pl. 111.—ORTMANN, Bull. U. S. Fish Comm. for 1903, 1905, p. 968; Proc. U. S. Nat. Mus., XXXI, 1906, p. 36, pl. II, figs. 1a, 1b. Station No. 4267 —1 male (?), jun. — Off Sitka Sound, 922 fathoms. (Color, dark crimson). | | Previous records — Atlantic: West of Azores, 2,200 fathoms (Chal- lenger); between Cape Charles and Long Island, 852 fathoms (Albatross) ; Pacific: Hawaiian Islands, 856-767 fathoms; Bering Sea, 399 fathoms; between Unalaska and Kadiak, 695 fathoms; be- tween Sitka and Columbia River, 876 fathoms (Albatross). . @ For first paper see Proc. U. S. Nat. Mus., XXXI, 1906, pp. 23-54. PROCEEDINGS U. S. NATIONAL MUSEUM, VOL. XXXIV—No. 1591. Proc. N. M. vol. xxxiv—08——1 1 2 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. The present specimen agrees well with the one mentioned by the writer among the Hawaiian Schizopods. Its length (difficult to measure, since the specimen ıs doubled up) is about 55 mm. It differs from the typical (adult) Gnathophausia gigas in the stronger development of the branchiostegal, infero-lateral, and postero-dorsal spines; the branchiostegal spines are even stronger than in the Ha- wallan specimen. Besides, the supraocular is distinctly larger than the antennal. The outer margin of the antennal scale has five distinct teeth, while the type has only four, and the Hawaiian specimen has also four, of which the last one is very small. The rostrum is longer than in the Hawaiian individual; in the present specimen the part in front of the ocular spines is distinctly longer than the rest of the carapace, including the posterior spine, while in the one from Hawaii it is about as long as the rest of the carapace without the posterior spine. All these minor differences apparently are due to age. Family MYSIDA Dana. Subfamily LEPTOMYSINZE Norman, 1892. The division of the family Mysids into subfamilies seems quite necessary on account of the large number of genera of very varlous type contained in it. The subfamilies created by Norman “ are chiefly framed with reference to the British forms, and thus it is some- times hard to assign foreign genera and species to their proper place. According to Norman,’ the following features are characteristic for this subfamily: | Outer uropods one-jointed, their outer margin setose. Gnathopods (= second maxilipeds or second cormopods) conforming in general character of the endopodite to the maxillipeds (= first maxillipeds or first cormopods). First true legs (= third cormopods) similar to the Following in general character, and not very greatly developed and larger than the latter. Male with all pleopods greatly developed and adapted for swimming, second to fifth pair biramose, all branches multiarticulate and setose, the outer branch of fourth, and sometimes also of third modified for sexual purposes, but the modification only extending to a slight lengthening of the limb and a change in the character of the sete of the terminal joints. This diagnosis does not exactly apply to some forms, not treated by Norman, which clearly ought to be placed here, while it apparently fits others, which are more widely different in other characters. Boreomysis G. O. Sars,’ for instance, although answering fairly” well to the above diagnosis, differs at once in the presence of seven «Ann. Nat. Hist. (6), N 1892 p44 d Monogr. Mysid., III, 1879, p. 8. No. 1591. SCHIZOPODS FROM ALASKA—ORTMANN. ‘ 3 pairs of marsupial lamelle, and should be placed in a distinct subfamily. The genera Amblyops G. O. Sars“ and Pads G. O. Sars? by belong in this subfamily, but differ from all other genera in the rudimentary condition of the eyes, which are lamelliform. The male pleopods are here very uniform in shape, the first with the inner branch rudimentary, the four others with subequal branches. The telson resembles rather that of the typical Zeptomysine, being not cleft. The genera Zrythrops, Parerythrops, and Huchetomera seem to form a natural group, differing from the typical Leptomysine in the shape of the telson, which always is remarkably short, and mostly has no lateral spines. In this group the male pleopods, as in the Amblyops group, are also very uniform, the second to fifth having subequal branches. Of the other genera, Leptomysis, Mysidopsis, Mysideis, and the new genus Holmesiella described herein, again form a natural group, characterized by a peculiar development of the male pleopods, which are not so uniform as in the genera mentioned above; in the fourth pair one of the branches develops the tendency to become longer than the other, bearing at the same time a peculiar armature at the apex. The telson in all these forms is distinctly longer than in the Zrythrops group, and invariably possesses marginal spines. This group, which may be called the typical one of the Leptomysinae, since it conforms best to the original diagnosis of the subfamily, forms a transition to the subfamily Mysinae; in fact, the latter differs only in a greater accentuation of the differentiation of the male pleopods, not only the first pair, but also the second, and generally also the fifth showing distinet reductions, bearing only one ramus as in the female. Some- times this reduction even affects the third pair. The difference of the two branches of the fourth pair has become very strongly pro- nounced in the J/ysine, one branch being rudimentary, the other greatly developed. The genus Callomysis Holmes differs from all other genera in the subfamily Leptomysinae in the shape of the pleopods of both, male and female. Here, according to Holmes’ account, the pleopods of the female are rudimentary, but biramous, while they are uniramous in all other genera; and also the male pleopods are small and rudi- mentary, although all distinctly biramous; and further, differing from all other genera, here it is the third pair in the male, in which the outer ramus is elongated, much after the style in certain Mysine. @ Monogr. Mysid., II, 1872, p. 3. d Idem, I, 1870, p. 48. - € Proc. Cal. Acad. Sci. (2), IV, 1895, p. 582 4 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. If we want to include Callomysis as well as the Amblyops and Erythrops groups into this subfamily, we are to alter slightly the above diagnosis of the Leptomysine as given by Norman, and put it the following way: Subfamily : Leptomysine. Outer uropods one-jointed, their outer margin setose. Gnathopods (second cormopods) conforming in general character of the endopo- dite to the maxillipeds (first cormopods). First true legs (third cormopods) similar to the following in general character, and not very greatly developed and longer than the latter. Male with all the pleopods well developed, and adapted for swimming ,;.second to fifth pair biramose, and never resembling those of the female. Sometimes one of the branches of the fourth (rarely the third) pair modified jor sexual purposes, in being slightly lengthened and possessing pe- culiar sete on the terminal joints. The following key of the genera of Leptomysine mentioned above may be convenient for their identification. No complete revision of the subfamily is intended. KEY TO GENERA. a’. Eyes rudimentary, lamelliform. Male pleopods very uniform, the first with inner branch rudimentary, the second to fifth with two subequal branches. Amblyops Sars and Pseudomma Sars. a”. Eyes not lamelliform, more or less globular. b'. Telson short, sometimes hardly longer than wide, always much less than À twice as long as wide. Outer margin not spinous (or rarely so, in Euchetomera). Apex not cleft. Male pleopods very uniform, the second to fifth with two subequal branches. Erythrops Sars,* Parerythrops Sars,® Huchetomera Sars.¢ b’. Telson longer, generally at least twice as long as wide. Outer margin always spinous. Apex entire or cleft. Male pleopods less uniform; one branch of third or fourth pair generally longer than the other (the prolongation sometimes only caused by the presence of a terminal spine). c’. Pleopods of female rudimentary, simple. Outer or inner branch of fourth pleopods of male with tendency to become lengthened. d'. Outer margin of antennal scale setose, without distal spine. Outer branch of fourth pleopods of male with tendency to become length- ened, its terminal joints only slowly increasing. in length, if at all. e‘. Telson elongated, linguiform, apex pointed or rounded, not Cleft. Three last joints of outer branch of fourth pleopods of male with- out sete, but with three strong spines. Antennal scale very long, narrow;-pointed; == re RI are RL Leptomysis Sars.4 a Sars, Monogr. Mysid., I, 1870, p. 11; Norman, in Ann. Nat. Hist. (6), X, 1892, p. 199. d Sars, Idem, p. 40. € Sars, Rep. Voy. Challenger, XIII, 1885, p. 211. à Sars, Monogr. Mysid., III, 1879, p. 29; Norman, Ann. Nat. Hist. (6), X, 1892, p. 242. No. 1591. SCHIZOPODS FROM ALASKA—ORTMANN. 5 e. Telson more or less triangular, apex truncate or cleft. Terminal joint of outer branch of fourth pleopod of male with a single stout terminal spine. Antennal scale lanceolate or ovate. f'. Outer branch of fourth pleopod of male projecting only with the terminal spine beyond inner branch; distal joints not at all in- creasing in length. Telson triangular, apex truncate or cleft. Mysidopsis Sars.@ f. Outer branch of fourth pleopod of male distinctly projecting be- yond the inner, distal joints slowly increasing in length. Tel- son triangular, apex with a short cleft________Mysideis Sars.? d’. Outer margin of antennal scale not setose, ending in a spine near the distal end. Terminal joints of inner branch of fourth pleopod of male increasing in length, especially the last one greatly elongate, and bearing a spine at its end. Telson elongated-triangular, apex RR NOR CNC he ee a en Holmesiella, new genus. &. Pleopods of female biramous, although rudimentary. Outer branch of third pleopod of male much elongated. Outer margin of antennal scale not setose, with terminal spine. Telson subrectangular, 2-3 times as long as wide, outer margin spinous, spines remote proximally, but more close set distally; apex slightly emarginated, emargination spinous. Callomysis Holmes.‘ Genus HOLMESIELLA Ortmann, new genus.d Diagnosis—A genus of Mysidae, belonging to the subfamily Lep- tomysinae. Body of the usual form. Eyes large. Third joint of peduncle of antennule in the male with a strong conical process on the lower side of the distal extremity. Legs slightly setose, with the propodite triarticulate, dactylopodite short, with a long, curved, termi- nal spine. Marsupial pouch of female consisting of three pairs of leaflets, the anterior small. Pleopods of female all rudimentary, short and simple. Pleopods of the male all biramous, but in the first pair the inner branch is short and simple; in the second, third, and fifth pair both branches are well developed, of about the same length, and mul- tiarticulate; in the fourth pair it is the inner branch that is much elongated, about twice as long as the outer. The terminal joints in- crease ın length, and especially the last one is much elongated, almost three times as long as the penultimate, and carries at the distal ex- tremity a long and strong spine. The three last joints do not possess any sete. Telson elongated, triangular, apex truncated, margins spinulose. Uropods narrow; otolithe well developed. @ Sars, Monogr. Mysid., II, 1872, p. 12; Norman, Ann. Nat. Hist. (6), X, 1892, p. 163. b Sars, Idem, III, 1879, p: 1. € Holmes, Proc. California Acad. Sci. (2), IV, 1895, p. 582. @ Named in honor of Prof. S. J. Holmes, in recognition of his work on Pacific Crustaceans. 6 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. The chief character of this genus is furnished by the development of the fourth pair of pleopods of the male (Plate [figo Ad Here it is the inner ramus (1. e., the one that carries a ibe file proc- ess at the base) which is eloneated beyond the outer one, while in all other genera with a tendency to increase the length of a branch of this appendage, it is always the outer branch that surpasses the inner. In shape, this elongated inner branch resembles to a degree that of the outer branch of Mysidopsis and Mysideis, being somewhat an exag- geration of the structure found in these two genera. In the form of the antennal scale (Plate I, fig. 2) Holmesiella differs from all related genera (Leptomysis, Mysidopsis, Mysideis), and rather recalls Callomysis, or the genera of the Hrythrops group. The shape of the telson does not differ much from the types known among the typical group of the Leptomysine. In all other respects, it possesses nothing that varies considerably from the characters as- signed to the subfamily Leptomysine. Type of the genus.—Holmesiella anomala. HOLMESIELLA ANOMALA Ortmann, new species. Plate I, figs. 1-18. Station No. 4192.12 young (male and female) (cotypes) —Gult of Georgia, off Nanaimo, Vancouver Island, 89-97 fathoms. Station No. 4251.—5 an adults mes — Stephens Passage, south of Juneau, 198 fathoms. Station No. 4257 —1 male adult, re One No. 31494, U.S.N.M.— Vicinity of Funter Bay, Lynn Canal (north of Juneau), 350 fathoms (estimated). Station No. 4264—2 female adults, cotypes Cat. No. 31492, U.S.N.M.—Off Freshwater Bay, Chatham Strait, south of Juneau, 293-282 fathoms. Description of adult male.—Total length of largest specimen (type, from Station No. 4257), 37 mm. Body slender, but strong. Cara- pace with the frontal part projecting, not pointed, but broadly rounded. Zyes comparatively large, cornea globular, dark brown. Antennulew (Plate I, fig. 1).—Projecting beyond the eyes with the terminal joint of the peduncle; first joint subeylindrical, second joint very short, terminal joint swollen, thicker than the two preceding ones, about as long as thick, with the usual conical process at the distal end on the under side. Antenne (Plate I, fig. 2).—With the peduncle shorter than that of the antennule. Antennal scale large, projecting far beyond the peduncle of the antennule, lanceolate, margins almost parallel in the middle part; outer margin almost straight, without setae, terminating in a strong spine a short distance from the tip. Tip and inner margin setose. No. 1591. SCHIZOPODS FROM ALASKA—ORTMANN. 7 True legs (Plate I, fig. 8) slender, sparsely setose. Propodite three-jointed ; dactylopodite short, with a long curved terminal spine. Abdomen long and slender. Abdominal appendages greatly dif- ferentiated, but all biramous. First pair of pleopods (Plate I, fig. 9) with outer branch well developed and multiarticulate; inner branch short, about half as long as outer, uniarticulate, with a blunt process near base. Second and third pair (Plate I, fig. 10) with both branches nearly alike and multiarticulate, the inner one hardly longer than the outer, bearing a blunt process at the base. Fourth pair of pleopods (Plate I, fig. 11) with outer branches similar to that of the first, second, and third pair, but inner branch (bearing a blunt process at base) much elongated, about twice as long as outer. This is due chiefly to the lengthening of the three distal joints, of which the first two increase only slightly, while the last one is consid- erably longer than these two together. All three terminal joints are destitute of sete, but the last one bears at its end a long and stout spine. The fifth pair of pleopods is similar to the second and third. In young males the pleopods,are not so strongly developed; in the second, third, and fifth the inner branch is distinctly longer than the outer (two or three joints projecting beyond the tip of the outer), and the inner branch of the fourth is not so greatly elongated, although the remarkable increase in length of the distal joints is distinctly indicated. Uropods (Plate I, fig. 13) well developed, with well developed otolithe ; both branches longer than the telson, but the outer one much longer than the inner. Margins setose, inner margin of the inner branch with a row of seven spines near the otolithe, of which the distal one is remote from the rest. Telson (Plate I, fig. 13) elongate-triangular; margins straight, with 16-18 spines along the greater distal part of the margins; the spines increase slowly toward the end, the last one on each side being twice as long as the one preceding it. Between the two long spines forming the outer corners of the telson the apex is truncated and car- ries 4 spines, the two outer ones short and stout, the inner ones very long and setiform. The largest female represented in the collection (Station No. 4264) measures 40 mm. The conical process of the antennule is lacking in the female. The marsupium consists of three pairs of leaflets, of which the first pair is quite small. The pleopods (Plate I, fig. 12) are all uniform, being simple and of the usual shape in the | family, increasing slightly in length from the first to the last. 8 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. Subfamily MY SINZE Norman. Diagnosis —(Outer uropods one-jointed, their outer margin setose. Gnathopods (2. Cormopods) conforming in general character of endopodite to the maxillipeds (1. Cormopods). First true legs (3. Cormopods) similar to the following in general character. Male with first, second, and fifth (exception, Zemimysis) pleopods as in female; the third consists of a basal joint and two branches, rarely it is also simple; the fourth consists of a basal joint and two branches, the inner minute, the outer styliform and generally of great length. Genera—Hemimysis Sars; Diamysis: Czerniavsky; Neomysis Czerniavsky; Macropsis Sars; Mysis Latreille; Schistomysis Nor- man; Macromysis A. White. Genus NEOMYSIS Czerniavsky 1882.2 Diagnosis (according to Norman).—Antennal scale subulate, very long and narrow, six to ten times as long as broad (running out into | an acute, spine-like termination), eilfäted on both margins. Labrum acutely pointed in front. Legs with multiarticulate tarsus (propo- dite), posterior pairs more strongly built than the anterior, and with more articulations in tarsus. Telson subtriangular, elongated, apex entire, pointed, margins spined (the spines subequal, no smaller spines alternating with larger °). In the male the third as well as the first, second, and fifth pleopods are simple, and resemble the same organs in female; fourth pleopod with a short peduncle, not much longer than broad, inner branch as usual in Mysine, outer branch _ consisting of only two articulations, the first very long, the second rather short; from its end spring two subequal, spiniform, ciliated filaments of no great length. Type.—M ysis vulgaris J. V. Thompson. NEOMYSIS KADIAKENSIS Ortmann, new species. Station No. 4272.1 male, 2 females.—Afognak Bay, Afognak Island, Kadiak Group, 17 to 12 fathoms. Body slender ; total length of largest individual (female), 21 mm. Frontal margin shghtly produced, bluntly triangular (correspond- ing closely to that of N. vulgaris, as figured by Sars.?) Eyes, anten- nule, and antenne similar to those of N. vulgaris, but antennal scale more slender, 13-14 times as long as wide (9-10 times as long as “ Norman, Ann. Nat. Hist. (6), X, 1892, p. 147. db Norman, Idem, p. 261. ° This sentence is to be dropped on account of Neomysis americana (Smith). à Monogr. Mysid., III, 1879, pl. xxxIv, fig. 1. NO. 1591. SCHIZOPODS FROM ALASKA—ORTMANN. 9 wide in N. vulgaris). Propodites of legs with 9 to 12 joints, 1. e., the third cormopod (first true leg) has 9 joints, the fourth and fifth have 11 joints, the sixth, seventh, and eighth have 12 joints; for the rest, the true legs resemble those of N. vulgaris. Telson elongate- triangular, about three times as long as broad at the base, margins with 20 to 23 spines, occupying a little more than the distal two- thirds of the margin, the proximal part being unarmed. These spines are rather uniform in size, increasing slightly and uniformly toward the tip, being very crowded near the tip, while near the prox- imal part of the margin they are slightly more distant from each other. Spines at the corners of the narrowly truncated apex resem- bling the adjacent marginal spines; between them are two small spines. Uropods as in N. vulgaris. Pleopods of male resembling closely those of N. vulgaris, but the distal joint of outer branch of the fourth is about half as long as the proximal, and a little longer than the terminal filaments. Type. —Cat. No. 31493, U.S.N.M. This species is closely allied to Meomysis vulgaris (Thompson) of North Europe,’ but differs in the more slender antennal scale, the number of joints of the propodites of the true legs, the relative length of the two joints of the outer branch of the fourth pleopods of the male, and in the shape and armature of the telson. N. vulgaris attains a length of 17 mm. Neomysis americana (Smith) from the northeastern coast of North America, is distinguished by the evenly rounded rostrum the antennal scale, which resembles that of N. vulgaris, the fourth pair of pleopods of the male, in which the first joint of the outer ramus is 4 to 5 times as long as the second, while the latter is little more than half as long as the terminal filaments, and by the telson, which resembles in shape that of N. vulgaris, and has unequal mar- ginal spines, with several smaller ones in the intervals of the larger. Size, 14 mm. Another species belonging to this genus is Veomysis rayi (Mur- doch), from Point Barrow, Alaska,° but this species is much larger (up to 65 mm.), the rostral projection is quadrangular with rounded corners, the propodites of the true legs have 8 to 9 joints. The telson resembles that of V. vulgaris, but the account of it given by Murdoch is not full enough to make an exact comparison. “Sars. Monogr. Mysid., III, 1879, p. 80, pl. xxxiv; Norman, Ann. Nat. Hist. (6), X, 1892, p. 261. dRep. U. S. Fish Comm., I, 1873, p. 552, and Trans. Conn. Acad., V, 1879, p. 106. ° Proc. U. S. Nat. Mus., VII, 1884, p. 519, and Rep. Pol. Exp. Point Barrow, 1885, p. 14 plea, fig. 3. 10 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. Neomysis awatchensis (Brandt), from Avacha Bay, Kamchatka, is rather incompletely known. It is said to be of an entirely black color, and to resemble N. vulgaris, with the exception of a shorter antennal scale and a “ truncated and four spined telson.” This lat- ter character, however, does not seem to differ from N. vulgaris. EXPLANATION OF PLATE I. (All figures are considerably enlarged. ) Holmesiella anomala, new genus and new species. a je} . Antennula of young male from Station No. 4192. . Antenna of adult female. . Mandible of adult female. First maxilla of adult female. . Second maxilla of adult female. First cormopod (first maxilliped) of adult female. . Second cormopod (second maxilliped) of adult female. . Fourth cormopod (second true leg) of adult female. . First pleopod of adult male. . Third pleopod of adult male. . Fourth pleopod of adult male. . Fourth pleopod of adult female. . Telson and uropods of adult female. DOPADOMA A SL ea et be pa vo “Brandt, Krebse, in Middendorf's Sibirische Reise, II, Pt. 1, 1851, p. 126. U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. XXXIV PL. I PARTS OF HOLMESIELLA ANOMALA FROM ALASKA. FOR EXPLANATION OF PLATE SEE PAGE 10. A NIAN DIV ND ITS INFLUENCE THE FRESHWATER FAUNA. . — KREIS ee ye Reprinted from N Vol. LII, No. 210, May-August, 1913. u PRENSA Dy e RR a THE ALLEGHENIAN DIVIDE, AND ITS INFLUENCE UPON THE PRESHWATER FAUNA. (Pirates XII-XIV.) ARNOLD E. ORTMANN, Ph.D, Sc.D. (Read April 18, 1913.) CONTENTS: PAGE TETE Ca be AR PR E RE O PRN RR RR 287 manter 1: Statement of Distributional Facts in Najades .............. 290 Chapter 2: Systematic Affinities of the Najades of the Interior Basin and NASE oc ee oe ea 323 Chapter 3: Distributional Facts in other Freshwater Animals .......... 326 Chapter 4: Summary of Distributional Facts which call for an Explana- a RP SE RR Sr 338 Chapter 5: Physiographical Facts. History of the Allegheny Mountain MEET Nr PER java secante ose: É via. DU nid PL > 341 EE manter 6: Explanation of Distributional Facts..........scescssenso sono 350 DERA O TAS O SIOIS yale a «ois. 0. 5 o's 2010 enden ein vee seine 381 INTRODUCTION. It is a well-known fact, noticed already by Rafinesque, in 1820 (Monogr. Coqu. Biv. et Fluv.), that the Appalachian Mountain sys- tem forms, for many freshwater animals, a sharp faunistic division line, which separates a fauna known as that of the Interior Basin from that of the Atlantic Slope (Mississippian and Atlantic Region PROC. AMER. PHIL. SOC., LII. 2IO A, PRINTED JULY II, I9I3. Reprinted from Proceedings American Philosothical Society, Vol. lit., 1913. 288 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, of Simpson, 1893, p. 354, and Ig00a, p. 505, pl. 18). But it should be noted, from the beginning, that this holds good only for certain groups of animals, while in others no such differentiation is observed. While this appears to be correct in a general way, investigations on the details of the relations of the two faunas on the eastern and the western side of the Alleghenies are very few. In fact, there are none whatever that have treated this question from a broader view- point. The most elementary requirement, the study of the actual dis- tributional facts of freshwater animals, had been greatly neglected. From most of the more important rivers (Susquehanna, Potomac, Allegheny, Monongahela, Kanawha) hardly any observations were at hand, which would have permitted any definite opinion as to the general character of their faunas, and in the region of the head- waters of these, our previous knowledge was a blank. For this reason, the present writer had first of all to undertake the task of obtaining reliable and complete data with regard to the fauna of the various streams running off the Alleghenian divide. In the course of these studies it became evident that the most im- portant group of freshwater life is formed by the Najades or Fresh- water Mussels. They offer two advantages: first they are very rich in species, the natural affınities of which are now rather clear; and second, they are forms which apparently possess no exceptional means of dispersal, that is to say, they are, as a rule, unable to cross from one drainage system into another over land (either actively or passively). This opinion of mine agrees with that held by Simpson (1900b), but is in sharp contrast to that expressed by Johnson (1905), who believes that “shells” or “mollusks” in general, and also especially Najades, have frequently been dispersed by birds, etc. Such cases may happen among the Najades, but they cannot be con- sidered as the normal way, and Johnson’s view rests upon very inadequate ideas about Najad-distribution, and chiefly the instances of apparent discontinuous distribution of species, which would favor the assumption of transport, are, without exception, founded upon defective facts. (It should be remembered that the chief means of dispersal of the Najades consists of transport in the larval state by fishes, on which the larva are attached ; but this precludes the possi- bility of transport over land.) 20) 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 289 Thus the present paper treats in the first line of the Najades. But there are other groups, which are important, yet they will be interesting only in so far as they confirm the results obtained from the Najades. These are certain freshwater Gastropods, and the crayfish-genus Cambarus. However, in the Gastropods we are handicapped by an insufficient knowledge of their mutual natural affınities; and in the Crayfishes the number of forms, which are to be considered, is rather small, so that it would be difficult to obtain general results from them alone. In the present paper, the writer is going to pay attention only to that part of the Alleghenian divide which lies between the New York-Pennsylvania state line and the northern line of Tennessee (see Plate XII.). In the north we have a rather natural boundary: from about the New York state line northward the Glacial area begins, offering geological and physiographical features which are of rather recent age, and have created special conditions, which should be investigated separately. In the south, in the region of the headwaters of the Tennessee drainage, the conditions form the con- tinuation of those farther north, but become here so complex that they deserve special study, to which additional, and much more ex- tended investigations are necessary, involving the “ Tennessee- ' Coosa problem.?! I have considered the upper Tennessee only so *This is the problem in which Johnson (1905) is especially interested. The old idea is (see chiefly Hayes, 1899) that the headwaters of the Tennessee once continued in the direction of the Coosa (Appalachian River), and that the present course of the Tennessee is due to a deflection in consequence of stream capture. Johnson believes (and also White, 1904) that the present course of the Tennessee is original, and I consider his physiographical evi- dence as perfectly sound and satisfactory. But since the Najades (and other freshwater groups) have been used to demonstrate the correctness of the assumption of the existence of the Appalachian River (see: Simpson, Igoob, p. 133, Adams, 1901, p. 846, and Ortmann, 1905, p. 130), we must take cogni- zance of this line of evidence, and dispose of it in some way. Johnson did this by dismissing it as not convincing, as not apt to demonstrate stream capture. However, as I have said, he is wrong in this, and I believe that the distribution of the Najades does indicate stream capture in this region, but in the opposite direction: the original fauna belonged to the old Tennessee (similar to the present in its course), and certain southern tributaries of it have been captured by the Coosa-Alabama system. This idea is already im- plied in Simpson’s (Igoob, p. 135) sentence: “it is probable that nearly all the 290 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, far as to ascertain the great contrast which exists between it and the river systems to the north of it. Thus my investigations cover, on the western side of the Alleghenies, the drainages of the Allegheny and Monongahela rivers (upper Ohio), of the Kanawha River, and ‚in part only of the Big Sandy, Licking and Tennessee rivers (Clinch and Holston). On the eastern side, the systems of the Delaware, Susquehanna, Potomac, and of the upper James and Roanoke are included. It is believed that the faunistic facts with regard to these rivers are reasonably complete and that my collections in them have fur- nished the knowledge, not only of what is present in them, but also of what is absent; under circumstances, this latter fact may even be more valuable than positive records. CHAPTER I. STATEMENT OF DISTRIBUTIONAL Facts IN NAJADES. The nomenclature of the Najades is that introduced by myself - in some recent publications (chiefly Ortmann, I912a, pp. 222) ff.). The lists give the number of distinguishable forms, no matter whether they are species or varieties. Unless otherwise stated, all information is founded upon the writer’s personal experience, and the specimens from the various localities are preserved in the col- lections of the Carnegie Museum in Pittsburgh. The great mass of new distributional facts secured by the writer makes it imperative to give them in full. For this reason, the present chapter is somewhat lengthy and contains much that is uninteresting reading for those which are not specialists. But this is unavoidable. A. WESTERN SIDE OF ALLEGHENIES. Il. THE Upper Onto FAUNA IN GENERAL. First I give a complete list of species (or forms) found in the upper Ohio drainage, above Smith Ferry, Beaver Co., Pa., in the Unionid& of the Alabama River system have been derived from the Tennes- see,” and White (1904, p. 38) directly says that the upper course of the orig- inal Walden Gorge River (tributary to Tennessee) has been captured by Con- asauga River (tributary to Oostanaula and Coosa Rivers). 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 291 Ohio, Allegheny, Monongahela Rivers, and their tributaries, exclud- ing those found only in the Beaver or French Creek systems (Gla- cial Drift streams) .? List No. 1. . Fusconaia subrotunda (Lea) . Fusconaia undata trigona (Lea) . Fusconaia undata rubiginosa (Lea) . Crenodonta plicata undulata (Barn.) . Quadrula pustulosa (Lea) . Quadrula lachrymosa (Lea) . Quadrula tuberculata (Barn.) . Quadrula metanevra (Raf.) . Quadrula cylindrica (Say) . Rotundaria tuberculata (Raf.) . Plethobasus cooperianus (Lea) 12. Plethobasus cyphus (Raf.) . Pleurobema obliquum (Lamarck) . Pleurobema obliquum pyramidatum (Lea) . Pleurobema obliquum coccineum (Conr.) . Pleurobema clava (Lam.) . Elliptio crassidens (Lam.) . Elliptio dilatatus (Raf.) . Symphynota compressa Lea. . Symphynota costata (Raf.) . Hemilastena ambigua (Say) . Anodonta grandis Say . Alasmidonta marginata (Say) 24. Strophitus edentulus (Say) 25. Ptychobranchus phaseolus (Hildr.) 26. Obliquaria reflexa Raf. 27. Cyprogenia irrorata (Lea) HH He OW ON aU EO AH DENN DEE fe) NO po NT ON UT OS D W *? Forms peculiar to Beaver or French Creek (or both) are: Fusconaia subrotunda kirtlandiana (Lea), Symphynota complanata (Barnes), Anodonta imbecillis Say, Anodontoides ferussacianus (Lea), Carunculina parva (Barnes). : Symphynota compressa Lea probably also falls in this category, but is also found in the uppermost Allegheny. 292 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, 28. Obovaria retusa (Lam.) 29. Obovaria circulus (Lea) 30. Obovaria circulus lens (Lea) 31. Obovaria ellipsis (Lea) 32. Nephronaias ligamentina (Lam.) 33. Amygdalonaias elegans (Lea) 34. Amygdalonaas donaciformis (Lea) 35. Plagiola depressa (Raf.) 36. Paraptera gracilis (Barn.) 37. Proptera alata (Say) 38. Eurynia fabalis (Lea) 39. Eurynia iris (Lea) 40. Eurynia recta (Lam.) 41. Lampsilis luteola (Lam.) 42. Lampsilis ovata (Say) 43. Lampsilis ovata ventricosa (Barn.) 44. Lampsilis multiradiata (Lea) 45. Lampsilis orbiculata (Hildr.) 46. Truncilla triquetra (Raf.) 47. Truncilla perplexa rangiana (Lea) It should be noted, that, of these, six forms (nos. 6, II, 28, 31, 33, 34) have been found exclusively in the Ohio below Pittsburgh, while nine forms (nos. 3, 15, 16, 19, 25, 30, 38, 39, 47) have not been found there, but only above Pittsburgh, but they are found else- where in the Ohio drainage, so that they are not restricted to this region. No. 21 has been found only once, in the headwaters of the Monongahela, in West Fork River, in Lewis Co., W. Va. Thus there are 37 forms in the Ohio below Pittsburgh. II. LowER ALLEGHENY AND MONONGAHELA RIVERS. There are, in the Allegheny River above Pittsburgh and below Franklin, Venango Co., Pa., the following Najades. ILAGE INO. 2: 1. Fusconaia subrotunda (Lea) 2. Fusconaia undata rubiginosa (Lea) 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 293 3. Crenodonta plicata undulata (Barn.) 4. Quadrula pustulosa (Lea) 5. Quadrula tuberculata ( Barn.) 6. Quadrula metanevra (Raf.) 7. Quadrula cylindrica (Say) 8. Rotundaria tuberculata (Raf.) 9. Plethobasus cyphyus ( Raf.) o. Pleurobema obliquum (Lam.) 11. Pleurobema obliquum pyramidatum (Lea) 12. Pleurobema obliquum coccineum (Conr.) 13. Pleurobema clava (Lam.) 14. Elliptio crassidens (Lam.) 15. Elliptio dilatatus (Raf.) 16. Symphynota costata (Raf.) 17. Alasmidonta marginata (Say) 18. Strophitus edentulus (Say) 19. Cyprogenia irrorata (Lea) 20. Obovaria circulus lens (Lea) 21. Nephronaias ligamentina (Lam.) 22. Plagiola depressa (Raf.) 23. Paraptera gracilis (Barn.) 24. Proptera.alata (Say) 25. Eurynia recta (Lam.) 26. Lampsilis luteola (Lam.) 27. Lampsilis ovata (Say) 28. Lampsilis ovata ventricosa (Barn.) 29. Lampsilis multiradiata (Lea) 30. Lampsilis orbiculata (Hildr.) 31. Truncilla triquetra (Raf.) 32. Truncilla perplexa rangiana (Lea) Aside from the six species found only below Pittsburgh, the fol- lowing nine of list no. I are missing here: nos. 2, 19, 21, 22, 25, 26, 29, 38, 39. A very similar fauna goes up the Monongahela River. Unfor- tunately, this fauna is now destroyed, and our knowledge of it rests upon a collection in the Carnegie Museum made before 1897 by 294 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, G. A. Ehrmann in the vicinity of Charleroi, Washington Co., Pa. (and a few scattered additional records secured by others). The following is the list of these. hast No. 3: . Fusconaia subrotunda (Lea) . Fusconaia undata trigona (Lea) . Fusconaia undata rubiginosa (Lea) . Quadrula pustulosa (Lea) . Quadrula tuberculata (Barn.) . Quadrula metanevra (Raf.) . Quadrula cylindrica (Say) . Plethobasus cyphyus (Raf.) . Pleurobema obliquum (Lam.) . Pleurobema obliquum pyramidatum (Lea) . Elliptio crassidens (Lam.) 12. Elliptio dilatatus (Raf.) . Symphynota costata (Raf.) . Anodonta grandis Say . Strophitus edentulus (Say) . Ptychobranchus phaseolus (Hildr.) . Obliquaria reflexa Raf. . Cyprogenia irrorata (Lea) . Obovaria circulus (Lea) . Obovaria circulus lens (Lea) . Nephronaias ligamentina (Lam.) . Plagiola depressa (Raf.) . Paraptera gracilis (Barn.) 24. Proptera alata (Say) 25. Eurynia recta (Lam.) 26. Lampsilis luteola (Lam.) 27. Lampsilis ovata ventricosa (Barn.) 28. Lampsilis orbiculata (Hildr.) O No) CON en im INS E AV dE [o & | ota E Ow [RR o + We) EI SU or, on D DB Ww N o NHN HO The following species have not been found here, but were prob- ably present in this region, since they exist both below and above: 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 295 20. Crenodonta plicata undulata (Barn.) 30. Rotundaria tuberculata (Raf.) 31. Alasmidonta marginata (Say) 32. Lampsilis multiradiata (Lea) 33. Truncilla triquetra (Raf.) Comparing these two lists (nos. 2 and 3), we see that they are practically identical: 23 forms are in either list, to which probably five others should be added, which should be expected in this part of the Monongahela. Thus there would be 28 forms common to these rivers. Even those species, which are peculiar to only one of these rivers, might exist or might have existed in the other. In a general way, those species found in the Monongahela, and not in the Allegheny, are preeminently big-river-forms (for instance Fusc. undata trigona, Obliquaria reflexa, Obovaria circulus), while, vice versa, those of the Allegheny are small-river-forms (Pleurobema obliquum coc- cineum, Pleurobema clava, Truncilla perplexa rangiana). This is in keeping with the general character of these rivers; the Monon- gahela is, although not appreciably larger, more quiet and steady, with finer bottom (gravel, sand), while the Allegheny is rather rough, with coarser gravel and rocks. One thing is very evident: that the Ohio fauna extends into both rivers above Pittsburgh, but somewhat depauperated, decreasing from 37 to about 30 Najad-forms. Ill. THE UPPER ALLEGHENY AND ITS TRIBUTARIES. Going up the Allegheny River, we meet first a section, which is utterly polluted (from northern Armstrong Co., to Oil City, Ve- nango Co.). But above Oil City the river is in good condition, up to Warren Co., and the New York state line. In this stretch (Ve- nango, Forest, and Warren Cos.), the following Najades have been collected by the writer: List No. 4. 1. Crenodonta plicata undulata ( Barn.) 2. Rotundaria tuberculata (Raf.) 296 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, 3. Pleurobema obliquum coccineum (Conr.) 4. Pleurobema clava (Lam.) 5. Elliptio dilatatus (Raf.) 6. Symphynota costata (Raf.) 7. Alasmidonta marginata (Say) 8. Strophitus edentulus (Say) 9. Ptychobranchus phaseolus (Hildr.) 10. Nephronaias ligamentina (Lam.) II. Eurynia fabalis (Lea) 12. Eurynia recta (Lam.) 13. Lampsilis ovata (Say) 14. Lampsilis ovata ventricosa (Barn.) 15. Lampsilis multiradiata (Lea) 16. Truncilla perplexa rangiana (Lea) To these should be added, as found in tributaries of the Alle- gheny in Warren Co.: 17. Symphynota compressa Lea 18. Anodonta grandis Say 19. Lampsilis luteola (Lam.) Compared with the lower Allegheny (list no. 2), the number of species has been reduced by more than a third, but for those which have disappeared a few others have turned up, namely, nos. 9, II, 17 and 18. Of these, Symphynota compressa (no. 17) is a peculiar form restricted to the tributaries of the upper Allegheny (and also in French Creek and Beaver River drainage, see above, p. 291, foot- note 2). The others are species which generally prefer small streams and avoid larger rivers. Above Warren Co., Pa., the Allegheny River flows in New York state, and we have only a few records from this section (Marshall, 1895). But then we reach Pennsylvania again in McKean Co. Here I secured a number of species in the Allegheny River, and received others from Dennis Dally, and P. E. Nordgren made a col- lection in Potato Creek. Here is the list of these. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 297 List No. 5. (Those marked * are from the Allegheny, those marked + from Potato Creek.) *1. Pleurobema obliquum coccineum (Conr.) *+2, Elliptio dilatatus (Raf.) 13. Symphynota compressa Lea *ta. Symphynota costata (Raf.) *5. Alasmidonta marginata (Say) 76. Strophitus edentulus (Say) *17. Lampsilis luteola (Lam.) *8. Lampsilis ovata ventricosa (Barn.) The number of forms again has been greatly reduced in com- parison with list no.4. All species found here are also found farther below, and thus this fauna is simply depauperated. I collected also in the uppermost Allegheny above Coudersport, Potter Co., but here this is a mere run, and has no Najades. (Im- mediately below Coudersport it is polluted.) We come now to the eastern tributaries of the Allegheny River, running down from the divide in a general east-west direction. They are (from north to south): Clarion River, Red Bank River, Mahoning Creek, Crooked Creek, and Kiskiminetas River. The first two are entirely polluted, and no shells are known from them. The same is true for Mahoning Creek, from Punxsutawney down. But in northern Indiana Co. there is a tributary of the latter, Little Mahoning Creek, where I collected the following shells: List No. 6. . Pleurobema obliquum coccineum (Conr.) . Elliptio dilatatus (Raf.) . Symphynota costata (Raf.) . Alasmidonta marginata (Say) . Strophitus edentulus (Say) . Ptychobranchus phaseolus (Hildr.) . Lampsilis luteola (Lam.) . Lampsilis ovata ventricosa (Barn.) ON OM BW HD H 298 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, The similarity of this fauna to that of the uppermost Allegheny is evident. Eight forms are in either list, seven of which are found in both. Crooked Creek has its fauna fully preserved. I collected in both the lower and upper part. In the lower part, in Armstrong Co., near its confluence with the Allegheny, the following are found. Wisi Nowa. . Fusconaia undata rubiginosa (Lea) . Crenodonta plicata undulata (Barn.) . Pleurobema obliquum coccineum (Conr.) . Elliptio dilatatus (Raf.) Symphynota costata (Raf.) . Anodonta grandis Say . Alasmidonta marginata (Say) . Strophitus edentulus (Say) 9. Obovaria circulus lens (Lea) 10. Nephronaias ligamentina (Lam.) 11. Eurynia fabalis (Lea) 12. Euryma wis (Lea) 13. Euryma recta (Lam.) 14. Lampsilis luteola (Lam.) 15. Lampsilis ovata ventricosa (Barn.) 16. Lampsilis multiradiata (Lea) 17. Truncilla triquetra Raf. ON AWM BW lim This is a depauperated lower Allegheny fauna, with the addition of a few species (nos. 6, 11, 12) which are characteristic for smaller streams. In the upper part of Crooked Creek, in Indiana Co., there are: List No. qb. . Fusconaia undata rubiginosa (Lea) . Symphynota costata (Raf.) . Anodonta grandis Say . Strophitus edentulus (Sav) Kho NH 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 299 5. Obovaria circulus lens (Lea) 6. Lampsilis luteola (Lam.) This part of the creek is a very small stream. Of the six species found here, three are also in the uppermost Allegheny and in Little Mahoning, while three (nos. I, 3, 5) are absent in them. Anodonta grandis is a small-creek-form elsewhere, but Fusconaia undata ru- biginosa and Obovaria circulus lens are peculiar to this creek, and although they are also small-creek-forms, they are not known to advance so far up toward the divide in other rivers. Of course, we should bear in mind that other tributaries of the Allegheny in this section, the fauna of which has been destroyed, might have con- tained these species. The full and typical Kiskiminetas-Conemaugh fauna is irrepa- rably lost to us on account of pollution of the waters. However, a few remnants have been preserved. Nothing is known from the Kiskiminetas proper. In the Conemaugh River at New Florence, Westmoreland Co., I found the dead shells of the following forms: . Pleurobema obliquum coccineum (Conr.) . Pleurobema clava (Lam.) . Elliptio dilatatus (Raf.) . Ptychobranchus phaseolus (Hildr.) . Nephronaias ligamentina (Lam.) . Eurynia recta (Lam.) . Lampsilis ovata ventricosa (Barn.) . Lampsilis multiradiata (Lea) CONST GS Gr RS Ne These are all found in the Allegheny above Oil City, but it is hardly probable that this list contains more than half of the species originally present in the Conemaugh. | From small tributaries in Westmoreland and Indiana Cos., I was able to secure four species: Elliptio dilatatus (Raf.)—Yellow Creek, Indiana Co. Symphynota costata (Raf.)—Two Lick Creek, Indiana Co. Anodonta grandis Say—Beaver Run, Westmoreland Co. Strophitus edentulus (Say)—Yellow Creek and Blacklegs Creek, Indiana Co., and Beaver Run, Westmoreland Co. 300 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, Also this fauna is fragmentary, since these streams are partially polluted. But there are two tributaries of the Kiskiminetas system, in the mountains, between Chestnut Ridge, Laurel Hill Ridge, and Allegheny Front, which have furnished what appears as complete faunas. Loyalhanna River, near Ligonier, Westmoreland Co., contains: List No. 6 . Pleurobema obliquum coccineum (Conr.) . Pleurobema clava (Lam.) . Elliptio dilatatus (Raf.) . Symphynota costata (Raf.) . Alasmidonta marginata (Say) . Strophitus edentulus (Say) . Piychobranchus phaseolus (Hildr.) . Lampsilis ovata ventricosa (Barn.) 9. Lampsilis multiradiata (Lea) ON OU BW ND HH Also Anodonta grandis Say should be mentioned, but this has been found only in ponds cut off from the river. Of Nephronaias ligamentina (Lam.) a single individual has been found many years ago, but recent investigations have failed to bring it to light again. Seven of these species have occurred in the other lists of the tributaries of the Allegheny, while two are new (nos. 2 and 9). In Quemahoning Creek, in Somerset Co., I collected: List No. 9. . Elliptio dilatatus (Raf.) . Symphynota costata (Raf.) . Alasmidonta marginata (Say) . Strophitus edentulus (Say) . Ptychobranchus phaseolus (Hildr.) . Lampsilis ovata ventricosa (Barn.) 7. Lampsilis multiradiata (Lea) Onntnr BR XD HH All these are also found in the Loyalhanna, but two of the latter (nos. 1 and 2) are lacking. The streams belonging to the Allegheny, discussed so far, form 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 301 a unit, as will become evident by comparison with the next group (upper Monongahela drainage). This is the most easterly advanced part of the Allegheny drainage. For this reason it will be advan- tageous to give the full list of all species which advance here farthest toward the Alleghenian divide. Combined Lists: 6, 7b, 8, 9. . Fusconaia undata rubiginosa (Lea) . Pleurobema obliquum coccineum (Conr.) . Pleurobema clava (Lam.) . Elliptio dilatatus (Raf.) . Symphynota compressa Lea . Symphynota costata (Raf.) . Anodonta grandis Say . Alasmidonta marginata (Say) . Strophitus edentulus (Say) . Ptychobranchus phaseolus (Hildr.) . Obovaria circulus lens (Lea) 12. Lampsilis luteola (Lam. ) . Lampsilis ovata ventricosa (Barn.) 14. Lampsilis multiradiata (Lea) H OO ON AU BW MH + Le - OW This is a comparatively rich fauna. Although not all of these I4 species are found in every one of these streams, the average number is about 7 or 8. Some of the species (Symphynota costata, Strophitus edentulus) are found in all of these creeks, and five spe- cies are in most of them (Pleurobema obliquum coccineum, Ellip- tio dilatatus, Alasmidonta marginata, Ptychobranchus phaseolus, Lampsilis ovata ventricosa). Looking over the Allegheny River fauna, we see that the Ohio fauna, well and richly represented in the Ohio below Pittsburgh by 37 forms, depauperates in the Allegheny. Although a few species are added toward the headwaters, the general tendency is that one species after the other disappears in the upstream direction. But one feature of this should be emphasized: the decrease in the number of forms is gradual, no sudden deterioration of the fauna being 302 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, observed at any point. In the uppermost headwaters there is yet a comparatively rich fauna of together 14 species. We shall see that in other parts of the western drainage this con- dition is not found, and our rather detailed account of the Allegheny fauna has been given with the chief purpose of bringing out the above fact. IV. MONONGAHELA RIVER AND TRIBUTARIES. We have seen above (list no. 3) that the Monongahela just above Pittsburgh had surely 28 species, but possibly 33. Farther up no Najades are known and the fauna is destroyed, for the water is everywhere badly polluted. But above Clarksburg, Harrison Co., W. Va., conditions are good again in West Fork River. This is a Plateau stream, not rough, but rather sluggish, and the proper en- vironment for shell-life seems to be present. The Carnegie Museum possesses material collected by the writer at Lynch Mines, Harrison Co., at Lightburn and Weston, Lewis Co., and some additional forms collected by J. P. Graham at West Milford, Harrison Co., W. Va. This gives us a good, and, as I believe, a rather complete idea of this fauna. In the following list those forms found at the uppermost point in this river (Weston) are marked with a *. (None is peculiar to this locality.) | List No. 10. I. Fusconaia subrotunda (Lea) *2. Crenodonta plicata undulata ( Barn.) 3. Quadrula tuberculata ( Barn.) 4. Quadrula metanevra wardi (Lea) 5. Quadrula cylindrica (Say) 6. Rotundaria tuberculata (Raf.) *7, Pleurobema obliquum coccineum (Conr.) *8. Pleurobema clava (Lam.) *g, Elliptio dilatatus (Raf.) *10. Symphynota costata (Raf.) 11. Hemilastena ambigua (Say) 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 303 *12, Anodonta grandis Say *13. Alasmidonta marginata (Say) *14. Strophitus edentulus (Say) 15. Ptychobranchus phaseolus (Hildr.) *16. Obovaria circulus lens (Lea) *17. Eurynia fabalis (Lea) *18. Eurynia tris (Lea) *19. Lampsilis luteola (Lam.) *20. Lampsilis ovata ventricosa (Barn.) *21. Lampsilis multiradiata (Lea) 22. Truncilla triquetra Rat. 23. Truncilla perplexa rangiana (Lea) This is a fauna very similar to that farther below, but somewhat depauperated. It is remarkable that this fauna goes far up, and that there are yet 14 species at the uppermost locality (Weston), where the river is merely a creek. Also here the rule holds good, that the typical Ohio fauna decreases in richness in an upstream direction, and that this decrease is gradual, not sudden. In sharp contrast to this are the eastern tributaries of the Monon- gahela, which come down from the mountains. The first of them is the Youghiogheny River. The fauna of the lower parts of this river is entirely lost on account of pollution. Between Connelsville and Confluence, Fayette Co., Pa., the river runs through a canyon, is very rough, forming falls (largest at Ohiopyle). Above Con- fluence it is less rapid, and flows in a broad valley, offering condi- tions favorable to Najades; but only a single species is found here: Strophitus edentulus (Say). The next of the mountain streams is Cheat River. Also this river runs through a long canyon, and above this canyon there are no Najades in it.” But below the canyon the fauna is rich. In the following list, the species marked * are found also at Mont Chateau, ®] collected above Parsons, Tucker Co., W. Va., in Shavers Fork. Below - Parsons the river is badly polluted, and also Dry Fork is polluted through Blackwater River. I have been told that there used to be some shells in the Cheat, below Parsons, but we have no means of ascertaining what species they were. PROC. AMER. PHIL. SOC., LII, 210 B. PRINTED JULY II, IQI3. 304 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, W. Va., immediately below the canyon, the others are from Cheat Haven in Pennsylvania, about eight miles farther below. JERSE INO. SUIT 1. Fusconaia subrotunda (Lea) 2. Crenodonta plicata undulata ( Barn.) 3. Quadrula pustulosa (Lea) 4. Rotundaria tuberculata (Raf.) 5. Pleurobema clava (Lam.) *6. Elliptio dilatatus (Raf.) *7, Symphynota costata (Raf.) *8. Alasmidonta marginata (Say) *g. Strophitus edentulus (Say) *10. Ptychobranchus phaseolus (Hildr.) II. Nephronaias ligamentina (Lam.) 12. Euryma iris (Lea) *13. Eurynia recta (Lam.) *14. Lampsilis ovata ventricosa (Barn. ) *15. Lampsilis multiradiata (Lea) The eight species found near Mont Chateau are not in the main channel of the river, but in small side branches, which are more or less protected. In the main channel the bottom consists of large boulders and rocks, not firmly packed, but loose and easily movable, chiefly at flood stage. Moving and shifting bottom prevents perma- nent settlement of Najades. At Cheat Haven conditions are more favorable, and here we have a rich fauna, agreeing well with that of the lower Monongahela, but of course somewhat depauperated corresponding to the smaller size of the river. Tygart Valley River, which joins West Fork River at Fairmont, to form the Monongahela, has the same character as the Cheat. There is a more slowly running upper part, above Elkins, Randolph Co., W. Va., a rather long canyon, down to Graiton, and a less rough portion below this. In the canyon a tributary flows into it, Buckhannon River, which again is running more slowly in its upper part. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 305 In the lower Tygart, the fauna has been destroyed by pollution. The upper part, above Elkins, contains only two species: Symphynota costata (Raf.) Strophitus edentulus (Say) The upper part of the Buckhannon drainage has one species: Strophitus edentulus (Say) I found this not in the river itself, which is dammed and has slack water, but in a small tributary, French Creek, at Hampton, Upshur Co., W. Va. Thus, in these mountain streams tributary to the upper Monon- gahela, we meet with conditions entirely different from those in the upper Allegheny and its tributaries: the rich Ohio fauna, only slightly depauperated, goes up to a certain point, up to the lower end of a canyon, which represents an extremely rough part of these rivers. This is best observed in the case of the Cheat (list no. II), while in the others pollution has destroyed the original conditions. But we may easily imagine what these were when we look at the fauna of the plateau stream, West Fork River (see list 10). At the lower end of the canyon the fauna suddenly stops, and above the canyon, in the high valleys, where the rivers are more quiet, very few species, one or two, are found, if such are present at all. It should be noted that one species, Strophitus edentulus, is found in all three rivers, which have shells, but that Symphynota costata is only in the Tygart. Thus the canyon apparently forms here a natural barrier. V. FAUNA OF THE KANAWHA RIVER. Farther to the south we have the Kanawha drainage in West Virginia. The fauna of the Kanawha itself is unknown, for this river is much polluted, and has been transformed into a series of pools by dams, conditions unfavorable for Najad-life. However, there are two tributaries in the plateau-region, which contain shells. The first is Elk River. Here I collected repeatedly and was able to secure the following species. Those marked * are from the uppermost station, at Sutton, Braxton Co., W. Va. 306 ORTMANN—THE ALLEGHENIAN DIVIDE. Ürst Nor 12: . Fusconaia subrotunda leucogona Ort. . Fusconara undata trigona (Lea) . Crenodonta plicata undulata (Barn.) . Quadrula pustulosa (Lea) . Quadrula tuberculata (Barn.) . Rotundaria tuberculata (Raf.) . Pleurobema clava (Lam.) . Elliptio crassidens (Lam.) . Elhptio dilatatus (Raf.) . Symphynota costata (Raf.) . Alasmidonta marginata (Say) . Strophitus edentulus (Say) . Ptychobranchus phaseolus (Hildr.) . Obovaria circulus (Lea) . Nephronaias ligamentina (Lam.) . Proptera alata (Say) . Eurynia fabalis (Lea) . Eurynia iris (Lea) . Eurynia recta (Lam.) . Lampsilis ovata (Say) . Lampsilis ovata ventricosa (Barn.) . Lampsilis multiradiata (Lea) [April 18, This fauna is of typical upper Ohio character (compare lists 2 and 3). With one exception (Fusconaia subrotunda leucogona) every form is also found in western Pennsylvania, and this one is only the local representative of Fusconaia subrotunda. Yet this fauna has a somewhat peculiar “facies” in so far as it contains several forms, which elsewhere prefer larger rivers (Fusconaia undata trigona, Elliptio crassidens, Obovaria circulus, Proptera alata). In addition I collected some shells in Coal River, at Sproul, Kanawha Co., W. Va. To 2. Fusconaia undata rubiginosa (Lea) Crenodonta plicata undulata (Barn.) 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 307 3. Strophitus edentulus (Say) 4. Obovaria circulus lens (Lea) 5. Lampsilis luteola (Lam.) 6. Lampsilis multiradiata (Lea) And the Carnegie Museum possesses, from Little Coal River, from the Hartman collection: 7. Quadrula pustulosa (Lea) 8. Quadrula metanevra wardi (Lea) 9. Pleurobema obliquum coccineum (Conr.) This would add 5 forms (nos. I, 4, 5, 8, 9), so that 27 forms are known from the lower Kanawha drainage, which are practically all typical upper Ohio forms. Going up the Kanawha, we find that this river, as New River, comes through a canyon out of the mountains. This canyon is ex- tremely rough, containing several falls (Kanawha falls at lower end of canyon, and New Richmond falls, eight miles below Hinton. Good photographs of New River scenery have been published by Campbell and Mendenhall, 1896). In the region of Hinton, Sum- mers Co., W. Va., the river is somewhat less rough. Here I col- lected, at the confluence of New River and Greenbrier River, the following species: East No. 73. 1. Ouadrula tuberculata (Barn.) 2. Rotundaria tuberculata (Raf.) 3. Elliptio dilatatus (Raf.) 4. Symphynota tappaniana (Lea) To these, probably, Alasmidonta marginata (Say) should be added, for it is found farther up in the New River drainage, and thus we would have five species here, four of which are found in the lower Kanawha drainage, while one (Symphynota tappaniana) is entirely new, and found nowhere else in the whole upper Ohio drainage. In fact, this is a species known hitherto only from the Atlantic watershed. Farther up I collected in the Greenbrier River at Ronceverte, Greenbrier Co., W. Va.; in New River at Pearisburg, Giles Co., Va.; 308 ORTMANN—THE ALLEGHENIAN DIVIDE. LApril 18, and in Reed Creek, Wytheville, Wythe Co., Va. Three species only are present here: JERSE INO, inal, 1. Elliptio dilatatus (Raf.) 2. Symphynota tappamana (Lea) 3. Alasmidonta marginata (Say) At Pearisburg I did not find no. 3, but at the other localities all three were present. In addition, Elliptio dilatatus has been reported by Call (85, p. 30) from Bluestone River (tributary to New River, emptying into it just above Hinton).* These conditions correspond closely to what we have observed in the case of the mountain streams tributary to the Monongahela. There is a rough part in the river in the shape of a canyon. Below the canyon the fauna is rich, above it is extremely poor. In the present case two species (Quadrula tuberculata and Rotundaria tuberculata) have gone up through the lower part of the canyon, but they were unable to go farther, and the uppermost parts of the New River system, where conditions undoubtedly are favorable for Najades, contain only three species, two of which belong to the Ohio fauna, while the third is a complete stranger. With the ex- ception of this case, which will be further discussed below, the whole Kanawha fauna, including that of New River, is undistin- guishable from the general upper Ohio fauna. But it should be noted that the species found in the headwaters of the Kanawha are different from those found in the headwaters of the mountain tribu- taries of the Monongahela. VI. Bic SANDY AND LICKING RIVERS. South of the headwaters of New River, in the Greater Allegheny Valley, we strike the headwaters of the Tennessee drainage, Holston, * Bluestone River is now badly polluted. I have seen it in its upper part, at Rock, Mercer Co., W. Va. Call (ibid., p. 55) already gives Rotundaria tuberculata (as Unio verrucosus Barn.) from New River, Virginia: but according to my investigations, this is only in the New River in West Virginia (at Hinton). Call also says Bluestone River, Virginia, but only the extreme headwaters are in Virginia, the rest in West Virginia. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 309 Clinch and Powell Rivers. However, to the west of these, on the Allegheny Plateau, there are other rivers, tributary to the Ohio, the fauna of which was hitherto entirely unknown. Since a quite dif- ferent fauna turns up in the Tennessee, it would be surely interest- ing to know something about these intermediate western rivers, and for this reason I made several trips into this region, and was able to collect the following data, first for the Levisa Fork of Big Sandy River, at Prestonsburg, Floyd Co., Ky. . Fusconaia subrotunda (Lea) . Crenodonta plicata undulata (Barn.) . Quadrula pustulosa (Lea) . Quadrula tuberculata (Barn.) : Elliptio crassidens (Lam.) Symphynota costata (Raf.) Obovaria circulus lens (Lea) . Nephronaias ligamentina (Lam.) . Amygdalonaias elegans (Lea) . Proptera alata (Say) . Eurynia recta (Lam.) O ON AM BPW ND H om rat (O) 12. Lampsilis ovata ventricosa (Barn.) In the Licking River, at Farmer, Rowan Co., Ky., I found: . Crenodonta plicata undulata (Barn.) . Quadrula pustulosa (Lea) . Quadrula tuberculata (Barn.) Pleurobema obliquum coccineum (Conr.) . Elliptio dilatatus (Raf.) Symphynota costata (Raf.) Anodonta grandis Say . Strophitus edentulus (Say) . Ptychobranchus phaseolus (Hildr.) . Obovaria circulus lens (Lea) . Nephronaias ligamentina (Lam.) . Proptera alata (Say) . Lampsilis luteola (Lam.) . Lampsilis ovata ventricosa (Barn.) on Aw ROM He He A He Ron HO 310 ORTMANN—THE ALLEGHENIAN DIVIDE. Ne In a tributary of the Licking, Fleming Creek at Pleasant Valley, Nicholas Co., Ky., I found, aside from Anodonta grandis and Lamp- silis luteola: 15. Anodontoides ferussacianus (Lea) Although these two lists give by no means the complete faunas of these rivers, they show clearly that they are practically identical with the upper Ohio drainage in West Virginia and western Penn- sylvania. All these species have occurred in our previous lists, with one exception, the very last one, Anodontoides ferussacianus. This is a western and northern species. Of the characteristic Tennessee (and Cumberland) drainage fauna not a trace is seen in these rivers. It is unknown at present whether there is a point in the upper parts of these rivers, where the fauna stops suddenly in an upstream direction. My chief object in introducing here the faunas of these rivers is to show that they cannot be separated from the general Ohio fauna. VII. FAUNA OF UPPER TENNESSEE RIVER. We come now to the Tennessee River. It is well known that this system contains an extremely rich fauna, with a large number of peculiar types. It is not my object to go into detail here, and I only want to bring out the contrast of this fauna to that of the upper Ohio in general, and especially to that of upper New River. With this in view, I collected (September, 1912) in the uppermost parts of Holston and Clinch Rivers in Virginia. Of course, my collec- tions are by no means complete, as is clearly shown by a comparison with the list published for Holston River by Lewis (’71), which, however, needs revision. But what I have found is sufficient for the present purpose. List No. 16. Middle and North Fork Holston, in Smyth Co. (Those marked * only in Middle Fork.) 1. Fusconaia sp.? 2. Pleurobema (possibly 2 species) 3. Pleurobema fassinans (Lea) 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. sll 4. Symphynota costata (Raf.) 5. Alasmidonta minor (Lea) 6. Alasmidonta fabula (Lea) 7. Alasmidonta marginata (Say) 8. Strophitus edentulus (Say) 9. Ptychobranchus subtentus (Say) 10. Nephronaias perdir (Lea) *11. Nephronaias copei (Lea) 12. Medionidus conradicus (Lea) 13. Eurynia nebulosa (Conr.) *14. Eurynia dispansa (Lea) 15. Eurynia vanuremensis (Lea) 16. Lampsilis ovata ventricosa ( Barn.) 17. Lampsilis multiradiata (Lea) Clinch, in Tazewell Co. . Fusconaia bursa-pastoris (Wright) . Fusconaia sp.? . Quadrula cylindrica strigillata (Wright) . Pleurobema (probably 2 species) . Elliptio dilatatus (Raf.) . Symphynota holstonia (Lea) . Symphynota costata (Raf.) . Alasmidonta minor (Lea) . Alasmidonta marginata (Say) . Strophitus edentulus (Say) . Ptychobranchus subtentus (Say) . Medionidus conradicus (Lea) . Eurynia perpurpurea (Lea) 14. Eurynia nebulosa (Conr.) 15. Eurynia planicostata (Lea) 16. Lampsilis ovata ventricosa (Barn.) 17. Lampsilis multiradiata (Lea) 18. Truncilla haysiana (Lea) 19. Truncilla capsaeformis (Lea) O QN AW BW NN HH ID) H oS) These are altogether about 26 species, of which only 6 have occurred in our previous lists (Elliptio dilatatus, Symphynota cos- 312 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, tata, Alasmidonta marginata, Strophitus edentulus, Lampsilis ovata ventricosa, Lampsilis multiradiata). All others (about 20) are not found in the upper Ohio drainage; some have representative forms there (Fusconaia bursa-pastoris, Quadrula cylindrica strigillata, Euryma nebulosa, Truncilla capsaeformis) ; but others are types, which are not at all represented there (Pleurobema fassinans, Alas- midonta minor and fabula, the genus Medionidus, Eurynia perpur- purea and vanuremensis, Truncilla haysiana are the most important ones). It should be noted especially that the New River species, Elliptio dilatatus and Alasmidonta marginata, which are found in the Ten- nessee drainage, are not represented by identical forms. Elliptio dilatatus of upper New River is a dwarf race, while the Clinch type is large and normal. The Clinch and Holston type of Alasmidonta marginata is peculiar by its extremely bright color markings. The contrast between these rivers is thus clearly established, and becomes even more striking, when we consider the fact that in gen- eral physiographic characters these rivers are very similar to each other, and further, that the Holston and Clinch, where I collected in them, are much smaller, mere creeks, compared, for instance, with New River at Pearisburg. SUMMARY OF FACTS CONCERNING THE WESTERN FAUNA. To express it in a few words, the chief features of the western fauna are: a umform fauna goes from Licking River up through the whole upper Ohio drainage into the headwaters of the Allegheny, but in the mountain streams tributary to the Monongahela and Kanawha a sudden depauperation is observed and farther above very few species are present. The fauna of the upper Tennessee is related to the Ohio fauna, but has many peculiar elements. As a whole, the Ohio fauna is to be regarded as a somewhat depau- perated Tennessee fauna; this is not so evident from the lists given above, but is a well-known fact, for which we do not need to furnish here particular proof. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 313 By ALLAN BIC SIDE: Besides the writer’s own investigations, the following publica- tions have been used for compilation of the faunistic lists: For Delaware, Susquehanna, and Potomac rivers: Gabb, 1861; Hartman and Michener, 1874; Pilsbry, 1894; Schick, 1895 ; Caffrey, FOUL. For James River: Conrad, 1846. Since the Atlantic side does not form a single drainage system, but consists of a number of rivers running independently to the sea, we must discuss these rivers separately. Dap, PAUNA COF THE DELAWARE: RIVER. This is the most northern system in the region discussed here. The following Najades are known to exist here: List: Nor 87. . Margaritana margaritifera (des) . Elliptio complanatus (Dillw.) . Elliptio fisherianus (Lea) Symphynota tappaniana (Lea) . Anodonta cataracta Say . Anodonta implicata Say Alasmidonta heterodon (Lea) . Alasmidonta undulata (Say) . Alasmidonta varıcosa (Lam.) . Strophitus undulatus (Say) . Strophitus edentulus (Say) 12. Eurynia nasuta (Say) 13. Lampsilis radiata (Gmel.) 14. Lampsilis carıosa (Say) 15. Lampsilis ochracea (Say) 0 ON an PWD H [e eS = O It is to be remarked that no. 3, no. 10 and no. 15 are found ex- clusively in the tidewater region of the lower Delaware and Schuyl-. kill, and that no. 3 is at the best extremely rare (only once reported), and that no. 10 is altogether a doubtful form. No. 1 is very local (uppermost Schuylkill). 314 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, All the others go up beyond tidewaters, and are found in the Delaware River or its tributaries on the Piedmont Plateau. The Allegheny Valley and its eastern boundary being obscured in this region, it practically is connected with the Piedmont Plateau. The Delaware River proper extends soon into the Glacial area, but there are tributaries outside of it west (northwest) of the Blue Mountain (Kittatinny Mountain), belonging to Lehigh River. The Lehigh itself is polluted; but I have collected in this region the following species (Princess Cr. and Meniolagomeka Cr., at Kunkletown and Smith Gap, Monroe Co.; Mahoning Cr., Leheighton, Carbon Co.; and Lizard Cr., Mantz, Schuylkill Co.). . Elliptio complanatus (Dillw.) . Anodonta cataracta Say . Alasmidonta heterodon (Lea) . Alasmidonta undulata (Say) . Alasmidonta varıcosa (Lam.) . Strophitus edentulus (Say) Om BW MH Possibly the list is not quite complete (Symphynota tappaniana might be here). But I never found all of these species associated at a single locality, and it should be stated right here that it is a general rule that on the Atlantic side certain species are of rather erratic distribution, being sometimes missing at certain localities for no apparent reasons, while at others they may be abundant. With the exception of Margaritana margaritifera, probably all of the Delaware River species (14) were once found in the lower part of Schuylkill River. Although the fauna of this river has been studied for nearly one hundred years, reliable information about the details of the distribution of the shells are not at hand. At the present time this river is so polluted that the fauna is extinct, only in the Schuylkill canal is a rather rich remnant of at least 8 species (nos. 2,4,5,748, 11, 12, 13.01 listo. 27) use canon an idea of how far the species advanced upstream and shall never know this. In the headwaters of the Little Schuylkill River, in Schuylkill Co., northwest of Blue Mountain, a very peculiar species turns up, 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 315 Margaritana margaritifera, and still exists there, and I have col- lected it repeatedly in 1909 and 1910. But it has become very rare, and is restricted to some small, clear, and cold mountain runs, in which no other Najades are found. This species stands by itself, and, as we shall see below, needs special discussion. II. THE FAUNA OF THE SUSQUEHANNA RIVER. The following is a list of the species, positively known to occur in the Susquehanna drainage :® IES BINDS nor . Elliptio complanatus (Dillw.) . Symphynota tappamana (Lea) . Anodonta cataracia Say . Alasmidonta undulata (Say) . Alasmidonta marginata susquehannae Ortm. . Alasmidonta varicosa (Lam.) . Strophitus edentulus (Say) . Lampsilis radiata (Gmel.) 9. Lampsilis cariosa (Say) COON OM BW NH H The lower Susquehanna, in Maryland, is unknown. Possibly, the lowland and tidewater species, Elliptio fisherianus and Lamp- silis ochracea, might be found there. And further, Alasmidonta heterodon has not been taken in the Susquehanna drainage, although it is present to the north and south of it. Even adding these three species, the fauna of the Susquehanna falls short of that of the Delaware by three species; four seem to be absent (Margaritana margaritifera, Anodonta implicata, Strophitus undulatus, Euryma nasuta), while Alasmidonta marginata susquehannae is added. The first two species surely reach their southern boundary in the Dela- ware drainage, while the doubtful Strophitus undulatus seems to be * Anodontoides ferussacianus (Lea) has been reported from the head- waters of the Susquehanna in New York state. It is not found in Pennsyl- vania, and the New York record should be confirmed; but even when correct, this may be neglected, for this species surely does not belong to the original fauna of this system, but is a postglacial immigrant. 316 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, local, and Eurynia nasuta has been reported farther south on the Coastal Plain (as far as North Carolina by Simpson; from James River by Conrad, ’36; from the lower Potomac by Dewey, '56; and Marshall, '95). But these localities should be confirmed, since this species has been frequently confounded with Elliptio productus and fisherianus. According to Rhoads ('04), it is also in Sussex and Kent Cos., in Delaware. The Susquehanna drainage extends not only into the Allegheny Valley and into the mountains, but clear through the mountains, and encroaches upon the Allegheny plateau. All of the species men- tioned above go up into this region, but two of them have only a limited distribution, and seem to be restricted to the larger rivers. These are Lampsilis radiata and L. cariosa. Both of them go in the North Branch to the New York state line. In the Juniata is only L. cariosa (up to Huntingdon, Huntingdon Co.), and in the West Branch both go up at least to Williamsport, Lycoming Co. In the real headwaters there are only seven species, and they are not always associated at a particular locality (generally there are only from three to six together). One locality is of special interest: this is Cush Cushion Creek, in Greene Twp., Indiana Co. This is the most western point to which the Susquehanna fauna advances, and the following species areiherer 1. Elliptio complanatus (Dillw.) 2. Symphynota tappamiana (Lea) 3. Alasmidonta varıcosa (Lam.) 4. Strophitus edentulus (Say) Not very far from here, in Chest Creek, Patton, Cambria Co., I found: 1. Elliptio complanatus (Dillw.) 2. Symphynota tappaniana (Lea) 3. Alasmidonta undulata (Say) 4. Strophitus edentulus (Say) Also Anodonta cataracta Say has been found in this region, in Beaver Dam Creek, Flinton, Cambria Co. Thus there would be six 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 317 species in this uppermost part of the drainage of West Branch. Alasmidonta marginata susquehannae has not been found here. The seven species of the upper Susquehanna drainage are the same as those of the Delaware, with the exceptions that in the former Margaritana and Alasmidonta heterodon are missing, while in their place Symphynota tappaniana and Alasmidonta marginata susquehannae turn up. Thus there are five species common to both drainages. Further investigations may change this slightly. But this seems to be assured, that although similar faunas exist in both rivers, the Susquehanna falls short by several species of the Delaware, and that the lack is made good only in part by the presence of a local form, Alasmidonta marginata susquehannae. III. THE FAUNA OF THE PoToMAC RIVER. The following species are positively known to exist in the Potomac drainage: List No. To. . Elliptio complanatus (Dillw.) . Elliptio productus (Conr.) Symphynota tappamana (Lea) . Anodonta cataracta Say . Alasmidonta undulata (Say) Alasmidonta varicosa (Lam.) Strophitus edentulus (Say) . Lampsilis radiata (Gmel.) . Lampsilis ovata cohongoronta Ortm. . Lampsilis cariosa (Say) 11. Lampsilis ochracea (Say) 0 ON ANAWD H H (O) In addition, there might be, in the lower Potomac, Elliptio fish- erianus (Lea) and Eurynia nasuta (Say) ; these have been frequently confounded, but forms like them are positively known to occur in the Potomac at Washington. Possibly both of them are there. Further, there might be, in the tributaries on the Piedmont Plateau, Alasmidonta heterodon (Lea), which is found both to the north and south of the Potomac drainage. 318 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, No. 9, Lampsilis ovata cohongoronta, should be disregarded, and dropped from the list of the original fauna of the Potomac, for it probably is a modern introduction from the west (Ortmann, Igı2b). Thus, including the doubtful forms, there would be 13 species belonging to the Potomac drainage. This is two less than in the Delaware; while three of the latter are missing here (Margaritana margaritifera, Anodonta implicata, Strophitus undulatus), one other is added, Elliptio productus. This latter case is important, because we positively know that this species is a southern form, which reaches its most northern range in the Potomac. Aside from Elliptio fisherianus and Eurynia nasuta, which, when present, are found only in the lower Potomac, three others, Lamp- silis radiata, cariosa, and ochracea, are restricted to the lower parts of the drainage, below the gap in the Blue Ridge at Harper’s Ferry. Above and to the west of this point, that is to say, in the Allegheny Valley and the Allegheny Mountains; only the following species are present (of course, disregarding the introduced no. 9): . Elliptio complanatus (Dillw.) . Elliptio productus (Conr.) Symphynota iappaniana (Lea) Anodonta cataracta Say . Alasmidonta undulata (Say) . Alasmidonta varicosa (Lam.) 7. Strophitus edentulus (Say) NRO NA Also here, seven species ascend into the headwaters, and among them there are again the same five (Elliptio complanatus, Anodonta cataracta, Alasmidonta undulata, Alasmidonta varicosa, Strophitus edentulus) which we have seen to be common to the headwaters of the Delaware and Susquehanna. An additional one, Symphynota tappaniana, is also found in the Susquehanna, while Elliptio pro- ductus is a new element in this fauna. I do not think it necessary to give further particulars. But again it should be noted, that the distribution of these species is rather erratic, and that they generally are not all found associated. Elliptio productus has not been found yet in the region of the Alle- 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 319 gheny Valley (Antietam and Conodoguinet creeks in Maryland and Pennsylvania, Shenandoah River in the Virginias), but it is rather frequent in the Potomac and its tributaries in West Virginia, Mary- land and Pennsylvania in the region of the Allegheny Mountains. IV. THE FAUNA OF RAPPAHANNOCK RIVER. The Rappahannock is a Piedmont Plateau stream, and is entirely east of the Blue Ridge. I collected near the headwaters about Rem- ington, Fauquier Co., and Culpepper and Rapidan, Culpepper Co., Va. The following is the list: List No. 20. . Elliptio complanatus (Dillw.) . Elliptio productus (Conr.) Elliptio lanceolatus (Lea) Symphynota tappaniana (Lea) . Alasmidonta heterodon (Lea) . Alasmidonta undulata (Say) 7. Strophitus edentulus (Say) Nu Ro DD 4 I give this list only for comparison; probably it is not quite com- plete. The interesting points are, that Alasmidonta heterodon turns up here again, and that there is here a new, southern form, which does not go farther north (Elliptio lanceolatus). V. THE FAUNA OF THE UPPER JAMES RIVER. I did not do any collecting in James River east of Blue Ridge, and although a few records are at hand from the lower James, it is impossible to give a complete list. West of Blue Ridge, the fauna of North River (called Calf Pasture River in its upper part) has been studied many years ago by Conrad (1846). I place his list by the side of the forms collected by myself in this region: List No ar. Conrad's list: Species collected by myself: Unio subplanus Conr. —1. Lexingtonia subplana (Conr.) Umio purpureus Say —2. Elliptio complanatus (Dillw.) PROC. AMER. PHIL, SOC., LIT. 2IO C, PRINTED JULY II, IQI3. 320 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, Unio lanceolatus Lea, probably ==3. Elliptio productus (Conr.) 4. Symphynota tappaniana (Lea) Unio collinus Conr. =. Alasmidonta collina (Conr.) Alasmodon undulata Say —6. Alasmidonta undulata (Say) 7. Strophitus edentulus (Say) Unio constrictus Conr. —8. Euryma constricta (Conr.) Alasmodon marginata Say Anodon cataracta Say Anodon marginata? Say I did not find U. lanceolatus, but in its place Ell. productus is very abundant, so that, I believe, Conrad confused these two species. Anodonta marginata is given by him as doubtful, and we may rest assured that this (northern) species is not found here. But it is quite possible that Alasmodon marginata (now Alasmidonta vari- cosa) and Anodonta cataracta are here, and I do not hesitate to add these to my list. My list has two species, not mentioned by Conrad. Thus we would have ten species in the upper James drainage. The five species common to the headwaters of the more northern Atlantic streams are again here, there is one species (Symphynota tappan- iana) known from upper Susquehanna and Potomac, one species (Ell. productus), known from upper Potomac, and three species, which turn up here for the first time: Lexingtonia subplana Alasmidonta collina Euryma constricta These additional elements are undoubtedly more southern types, which reach here their most northern station. VI. THE FAUNA OF THE UPPER ROANOKE RIVER. Only the uppermost Roanoke is known to me. It drains a rela- tively small portion of the Allegheny Valley, chiefly in Roanoke and Montgomery Cos., Va., and has the following, poor fauna: 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 321 Bist Nos 22: 1. Elliptio complanatus (Dillw.) 2. Strophitus edentulus (Say) 3. Eurynia constricta (Conr.) These species are all found in the upper James, and one of them (no. 3) clearly shows the affinity with that system. This is undoubt- edly a depauperated fauna, corresponding to the small size of the streams. Possibly the record is not complete. Below Roanoke, the river is polluted, but east of the Blue Ridge there are surely addi- tional species in this system. SUMMARY OF FACTS CONCERNING THE EASTERN FAUNA. Full list of all species known to exist on the Atlantic slope (in the region investigated) : Lost INO, 2. . Margaritana margaritifera (L.) . Lexingtonia subplana (Conr.) . Elliptio complanatus (Dillw.) . Elliptio fisherianus (Lea) . Elliptio productus (Conr.) . Elliptio lanceolatus (Lea) Symphynota tappaniana (Lea) . Anodonta cataracta Say . Anodonta implicata Say 10. Alasmidonta collina (Conr.) 11. Alasmidonta heterodon (Lea) 12. Alasmidonta undulata (Say) 13. Alasmidonta marginata susquehannae (Ortm.) 14. Alasmidonta varicosa (Lam.) 15. Strophitus undulatus (Say) 16. Strophitus edentulus (Say) 17. Eurynia constricta (Conr.) 18. Eurynia nasuta (Say) 19. Lampsilis radiata (Gmel.) 20. Lampsilis cariosa (Say) 21. Lampsilis ochracea (Say) O ON Au mwN H 322 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, Lampsilis ovata cohongoronta Ortm. has been dropped as not indigenous on the Atlantic slope. The following facts are observed: I. Probably seven species of these have a rather general distri- bution. In five of them this is perfectly clear (nos. 3, 8, 12, 14, 16), but probably also nos. 7 and 11 fall under these; they only may have been overlooked in certain regions. 2. There are six forms, which apparently have a more northern range, disappearing toward the south, nos. I, 9, 18, 19, 20, 21. The last four have the peculiarity in common that toward the south they become more or less restricted to the coastal plain. 3. On the other hand, there are six forms, which have their center more toward the south and disappear toward the north. Isso ars dns MOS. 2,2, 5, ©, WO, amel 17, 4. Of the two remaining forms, no. 13 is a local form of the Susquehanna drainage, while no. 15 is altogether doubtful, but may be a local (tidewater) form of no. 16. Compared with the western fauna of 47 species (list no. 1), the Atlantic fauna is decidedly poor (less than half the number of spe- cies). But in the Ohio we notice a general and marked decrease of species in the headwaters, so that there are only fourteen species in the headwaters of the Allegheny River. In the eastern drainage systems, there is also a slight decrease toward the headwater, but this is much less in proportion, and in the mountain region we have yet thirteen species (nos. 1, 2,3) 5, 746, 1o, 11.72, 19,121 vos a8 Thus we may say, that, disregarding a few species restricted to the lowlands and the larger rivers, the fauna of the Atlantic streams remains, in each river system, rather uniform up to the headwaters, decreasing hardly in the number of species. Further, in the region of the headwaters of the Monongahela and Kanawha, the conditions are actually reversed. Here only very few species (not more than three) are found in the western streams, while the eastern streams (Potomac, James) have decidedly more, the James, for instance, at least eight, possibly ten. Thus the At- lantic fauna is here richer than the western. But the Tennessee fauna (list no. 16) again holds its own, and the Atlantic fauna falls by far short of it. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 323 CHAPTER: 2. SYSTEMATIC AFFINITIES OF THE NAJADES OF THE INTERIOR BASIN AND OF THE ATLANTIC SLOPE. In order to understand the mutual relations of the western and eastern faunas, which, as we have seen, are at present rather sharply distinguished, it is necessary to consider the systematic affinities of the forms belonging to either. Up to a comparatively recent time the natural system of the Najades was extremely obscure. However, the great synopsis of Simpson (I900@) has paved the way for a proper understanding of the relationship of our Najades, and the more recent papers of the present writer (chiefly 1912a) have furnished what is believed to be the natural system, expressing, as far as possible, the genetic affinities within this group. Using this system as a guide, the following remarks are to be made: E The general fauna of the upper Ohio drainage (list no. I, p. 291) contains no less than seventeen genera, which are not found on the Atlantic side, namely: Fusconaia Hemilastena Amygdalonaias Crenodonta Ptychobranchus Plagiola Quadrula Obliquaria Paraptera Rotundaria Cyprogema Proptera Plethobasus Obovaria Truncilla Pieurobema Nephronaias | This is entirely sufficient to show the tremendous difference be- tween the two faunas, and demonstrates clearly that the Allegheny Mountains formed an important barrier to the eastward distribution of the bulk of the western fauna. No further discussion of this is required. II. The fauna of the headwaters of the Allegheny River (com- bined lists 6, 7, 8, 9, p. 301) contains five species (out of fourteen) which are typically western and belong to genera just mentioned: 324 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, Fusconaa undata rubiginosa Pleurobema obliquum coccineum Pleurobema clava Ptychobranchus phaseolus Obovaria circulus lens Another one, Symphynota costata, should be added, since, although the genus is found in the east, the subgenera are different (Lasmigona and Symphynota). This shows that although a number of the typical western genera have gone way up into the headwaters, they have not been able to cross the divide. III. On the Atlantic side (see list no. 23) we have two genera (Margaritana and Lexingtonia), which are not found in the interior basin. Margaritana has, indeed, a related form (Cumberlandia monodonta (Say) ) in the Tennessee and Ohio drainage, but there is probably no direct genetic connection between them, and the his- tory of Margaritana, as will be seen below, is a case by itself. IV. Lexingtoma is possibly related to and descended from cer- tain interior basin forms (such as Fusconaia and Pleurobema), but the relationship is remote, and for all practical purposes we may class it with the cases to be mentioned presently. These are the following forms (of list no. 23): nos. 3, 4, 5, 6 (the four species of Elliptio), and nos. 10, 11, 12 (Alasmidonta collina, heterodon, un- dulata). All these are forms of the respective genera, which have no closely allied or representative forms on the western side, although the genera are represented there. Attention should be called to the fact that Lexringtonia, three species of Elliptio (fisherianus, productus, lanceolatus) and Alasmi- donta collina undoubtedly belong to the southern element in the At- lantic fauna, and that their distribution northward is limited. How- ever, it is also probable that Elliptio complanatus, Alasmidonta heterodon and undulata belong to the same class. The first and third are undoubtedly southern in their affinities, and allied species are frequent upon the southern portion of the Atlantic slope (in the Carolinas and Georgia). This is not so clear in the case of Alasmidonta heterodon. Here it has the appearance, as if the dis- 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 325 tribution might be more northern, but this may be due to defective knowledge of the facts. V. Another group of Atlantic species has closely allied species in the interior basin. No. 17 of the list, Eurynia (Micromya) con- stricta, has a representative form in the upper Tennessee drainage (Eurynia (Micromya) vanuxemensis). Six others (nos. 8, 9, 14, 19, 20, 21) have closely related, indeed representative forms, in the upper Ohio drainage. ‘The relation is as follows: no. 8 and 9, Anodonta cataracta and implicata, represent the western Anodonta grandis. no. 14, Alasmidonta varicosa, represents the western Alasmi- donta marginata. no. 19, Lampsilis radiata, represents the western Lampsilis luteola. no. 20 and 21, Lampsilis cariosa and ochracea, represent the western Lampsilis ovata ventricosa (and its allied forms). It should be noted that just these Atlantic forms are preémi- nently those which have a more northern range upon the Atlantic side. VI. Finally, there are four species on the Atlantic side, which are specifically identical with western forms. Particulars are as follows: no. 13, Alasmidonta marginata susquehannae, is a local form of the Susquehanna drainage, closely resembling the widely dis- tributed western Alasmidonta marginata. no. 7, Symphynota tappaniana, is represented on either side by an absolutely identical form. But here the distribution is rather general on the eastern side and local on the western (New River). -no. 16, Strophitus edentulus, is absolutely identical on either side, and also widely distributed, east as well as west. But it should be noted that it is apparently absent in New River. no. 18, Eurynia nasuta. Here we see that the identical species is on the Atlantic side and in Lake Erie basin, but not in the upper Ohio drainage. We see at once that these cases apparently are not subject to the same laws, and further below they shall be treated each by itself. There remains yet one of the Atlantic forms, no. 15, Strophitus 326 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, undulatus. We must dismiss this for the present, for we do not know much about its taxonomic standing and its distribution. This may be nothing but a local form of Strophitus edentulus, and then it would have to the latter the same relation as Lampsilis ochracea has to L. cariosa (the former is the tidewater form of the latter). As a whole, the Atlantic fauna should be regarded as an offshoot of the fauna of the interior basin, with the exception of Margaritana margaritifera. It does not possess any very strongly marked types of its own, but all may be traced back to western types. How- ever, there are different elements on the Atlantic slope, which ap- parently reached their present range by different ways, and probably at different times. The greatest independence is shown among those which are found in the southern section of the Atlantic slope, and there is an indication of the development of a secondary center of dispersal in this region, producing a few characteristic types, more remote in their affinities from the forms of the interior basin. The other forms are generally more or less closely connected with western species, in fact, clearly are representative forms of them. CHAPTER 3. DISTRIBUTIONAL FACTS IN OTHER FRESHWATER ANIMALS. Before we advance further in our attempt to study the mutual relations of the eastern and western freshwater faunas, it is well to compare a few other groups with the Najades, in order to ascertain - whether there are parallel cases to those described above. 12 SEHNEREDZZ For the identification of my material I am indebted to V. Sterki. Although I have collected a great many Spherude from the streams of Pennsylvania, West Virginia, and Virginia, my collections are by no means complete. Nevertheless, as far as they go, they serve to confirm the well-known fact, that with regard to these small shells, the Alleghenian divide does not form an important faunistic bound- ary. Thus the Spheriide distinctly differ from the Najades, and undoubtedly must have been subject to other laws. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 327 It is not necessary to give a detailed account of the single species; it suffices to enumerate those species which I have before me from both sides of the mountains: Spherium sulcatum (Lam.) Spherium solidulum (Pr.) Spherium stamineum (Conr.) Spherium striatinum (Lam. ) Musculium transversum (Say) Musculium truncatum (Linsl.) Pisidium virginicum (Gmel.) Pisidium compressum Pr. Of course, these examples will become more numerous when more exhausting studies have been made. Altogether, we may safely assume that it is a general rule among this group, that the distribution is not influenced by the Alleghenian divide. As we have seen above, this condition is extremely rare among the Najades. In the present case, the distribution of the Spherude seems to have been formed under the influence of one great general factor, which probably is the faculty of these shells to cross over divides, presumably by being transported. It is very pertinent to bring this out here most emphatically, because, as we have seen, this factor has had very little or no effect among the Najades, as is shown by the entirely different character of their distribution. ie GASEROPODA, FAMILY = PEEUROGERIDZE . The identifications have been kindly furnished by A. A. Hinkley. I have a rather satisfactory material of this family, although the records are not as complete and exhausting as in the Najades. The whole character of the distribution of these freshwater snails is like that of the Najades, and, consequently, it is indicated that no exceptional means of dispersal (transport) have played a part. The range of the species follows rather closely the river systems, and the effect of the Alleghenian divide as a barrier 1s quite evident. Two facts, however, are to be regretted, first, that in the region 328 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, investigated the number of species is not very great, and second, that the natural affinities within this family are yet entirely obscure. Nevertheless, some interesting points are easily observed, as will be seen from the following account. A. THE UPPER OHIO DRAINAGE in western Pennsylvania and West Virginia has the following species: 1. Pleurocera canaliculatum (Say) 2. Pleurocera altipetum Anth. 3. Goniobasis livescens (Mke.) (incl. var. depygis (Say) ) 4. Goniobasis translucens Anth. 5. Anculosa dilatata (Conr.) It is to be remarked that the two Pleuroceras are restricted to the larger rivers; no. I is in the Ohio proper at and below Pittsburgh, and has also been found as far up as the lower Youghiogheny in Allegheny Co., Pa.; while no. 2 is in the middle Allegheny up to Venango and Warren Cos. No Pleuroceras have ever been found in any of the smaller streams. Goniobasis livescens is in the Beaver drainage, and in that of French Creek of the Allegheny (also in Lake Erie), and it appears as if this species should be classed with those Najades which have been mentioned (on p. 29I, footnote 2) to be peculiar to those drainages. The Goniobasis-species of the Allegheny River, begin- ning in the Ohio River below Pittsburgh, and going up through Armstrong, Venango, Forest to Warren Co., is, according to Hink- ley, G. translucens, and this species is also abundant in the drainages of Beaver River and French Creek. Except in the lower Youghiogheny, where (many years ago) Pleurocera canaliculatum has been found, no species of Pleurocera or Goniobasis are known from the whole Monongahela drainage. I have no doubt that some existed once at least in the lower Monon- gahela, but the pollution of the waters apparently has exterminated them, and no records have been preserved. The upper Yough- iogheny, where the water is clear, is entirely without Pleuroceride, and this is positively established, for a search has been made for them. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 329 This is a fact which should be emphasized, for in the head- waters of the Monongahela, Anculosa dilatata turns up. This is found in the lower part of the Cheat at Cheat Haven, Fayette Co., Pa., and goes up through the canyon into the headwaters (Shavers Bork, Parsons, Tucker Co. W. Va.); it is also in Tygart Valley River, at Elkins, Randolph Co., W. Va., and even in the plateau stream, West Fork River, at Lynch Mines, Harrison Co., W. Va. No Anculosas are found in the rest of the upper Ohio drainage in western Pennsylvania. Farther south in West Virginia our knowledge probably is frag- mentary. In the Kanawha drainage, no Pleuroceride are known to me, except Pleurocera validum Anth. in Elk River; and New River and Greenbrier rivers, at least from Hinton upward, contain Ancu- losa dilatata (Conr.). The latter is exceedingly abundant in this region. In the Big Sandy, at Prestonsburg, Floyd Co., Ky., I collected Pleurocera unciale Hald., a species which is also found in Clinch River. Licking River at Farmer, Rowan Co., Ky., has Pleurocera cylindraceum Lea. It appears that there is a certain correlation in the distribution of the Pleuroceride and the Najades of the upper Ohio drainage, at least as far as it concerns the genera Pleurocera and Gomobasis. It is well known that the greatest variety of forms is found in the lower Ohio and its tributaries, and it is suggested that this fauna has migrated upstream, and that there is a general decrease in the num- ber of species in an upstream direction. But the different tributaries of the upper Ohio seem to have received or have developed different species. In addition, most of the species do not go very far into the headwaters, and the smaller streams generally do not contain Pleuro- cerid@, or only rarely so.º One very remarkable fact is to be noted. In the headwaters of the Monongahela, excluding the Youghiogheny, and also in the headwaters of the Kanawha (New and Greenbrier rivers), Anculosa ° This, however, is different in the Beaver drainage, where species of Goniobasis are found in small creeks. But the characteristic species, G. lives- cens, probably did not come up the Ohio, but came “across country” from the West. 330 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, is the only genus found, and it is represented in all these streams by one and the same species, A. dilatata. This genus is not found any- where else in the whole upper Ohio drainage in West Virginia and Pennsylvania, but it is represented on the Atlantic side by a closely allied and widely distributed species. It is perfectly clear that this case does not submit to the same laws which governed the Najad fauna and the other Pleuroceride of this region. Further particu- lars will be given below. As regards the upper Tennessee fauna (Clinch and Holston rivers), we have here again a rich development of Pleuroceride, as is well known. I do not think that my collections represent this fauna fully, but I have collected the following species: Io fluvialis (Say) (Holston and Clinch) Pleurocera estabrooki (Lea) (Holston) Pleurocera knoxense (Lea) (Holston) eee Pleurocera unciale Hald. (Clinch, also, as we have seen, in Big Sandy.) 5. Goniobasis simplex (Say) (Holston and Clinch) 6. Anculosa gibbosa Lea (Holston and Clinch) To is.a type entirely peculiar to this region. Except Pl. unciale, which is also in the Big Sandy, the others have no striking relation- ship to any of the species mentioned above from the upper Ohio. The Anculosa may have a somewhat closer genetic relationship with the Anculosas farther north, in New River, etc., but morphologically they are distinctly separated. Thus it is clear that the Plewrocerid-fauna of ie upper Ten-. nessee undoubtedly corresponds to the Najad-fauna of this region, and probably has had a similar history. B. PLEUROCERIDA OF THE ATLANTIC SIDE. The genus Pleurocera is entirely missing on the Atlantic side. Goniobasis is represented by two species:” G. virginica (Gmel.) and * Additional species are found from North Carolina southward. G. nick- liniana Lea has been reported (Tryon, ’66, p. 31) from Bath Co., Va. (orig- inal locality: near Hot Springs, drainage of Jackson River). This species is unknown to me. I collected in Jackson River at Covington, Alleghany Co., 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 331 G. symmetrica Hald. The former is common all over the Delaware, Susquehanna, Potomac and James river drainages, and has been found practically everywhere, possibly with the excéption of the smallest streams in the headwaters. This species has no closely allied or representative form in the upper Ohio drainage, but if Tryon’s arrangement of the species (1866, p. 39 f.) is natural, re- lated forms are found in Tennessee and Alabama. It is unknown how far this species ranges southward, but according to our present knowledge, it seems that it belongs rather to that group of fresh- water forms, which point in their affinities to a center lying on the southern Atlantic slope. Specimens of a Goniobasis collected by myself in Mason Creek, Salem, and Tinker Creek, Roanoke, Roanoke Co., Va. (Roanoke drainage) have been identified by Hinkley as G. symmetrica, a species reported (Tryon, ’66, p. 30) from West Virginia, East Tennessee, South Carolina, North Georgia, and Alabama. But there is much uncertainty about this, and West Virginia seems to be more than doubtful. One fact, however, is sure: this species is not found north of the Roanoke on the Atlantic side. Thus also this appears as a southern type, and should be classed with the same group as G. virginica. In addition there is a species of Anculosa on the Atlantic side: A. carinata (Brug.). This is absent in the Delaware drainage, but extremely abundant in the systems of the Susquehanna, Potomac, James, and Roanoke, and goes far up in the mountain streams. This species is very closely allied to A. dilatata of New River and the headwaters of the Monongahela, and undoubtedly stands in closest genetic relationship to it. In fact, these two species are so intimately allied on the one hand and are so polymorphous on the other, that it is extremely hard to distinguish them. It has been mentioned that they also have an allied but more sharply distin- guished species in the upper Tennessee (A. gibbosa). There is no doubt that we have to class this case with those of the very closely allied or identical species of Najades on either side less than twenty miles from Hot Springs, but only Anculosa carinata was there, in various forms, some of which resemble very much Lea’s figure of G. nicklimana. 332 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, of the divide. ‘The present case most resembles that of Symphynota tappaniana, where we have a species found both in New River and on the Atlanticside. Therange of the latter is not entirely identical, for it is not found in the Monongahela drainage, and goes, on the Atlantic side, farther north, while A. carinata only reaches the Sus- quehanna in which it goes up to New York state. Ill. FAMILY: VIVIPARIDZE: GENUS: CAMPELOMA RAE: Also in this group we lack a modern revision of the species, and there is much uncertainty with regard to the geographical distribu- tion. What I have collected in Pennsylvania, West Virginia and Virginia apparently falls under three described species: Campeloma decisum (Say), C. rufum (Hald.), and C. ponderosum (Say), and with the first one I unite as undistinguishable, what has been called C. integrum (Say). At any rate, I am not able to distinguish the common form of the upper Ohio drainage in western Pennsylvania and West Virginia from the common form of the Atlantic side (from Delaware to James). The identical form is also in Clinch River. C. decisum seems to prefer the larger rivers, but it is not absent in the headwaters, and I have it from the mountain region on either side of the divide (Shaver’s Fork, upper Tygart system, Greenbrier, uppermost tributaries of Allegheny, and many places in the head- waters of the Potomac and James). Consequently, this would be again a case where an identical species is found on either side of the divide, and where this divide does not form a barrier to the dis- tribution. Of the other two species, C. rufum is known to me only from northwestern Pennsylvania, in the Allegheny and its tributaries (French Creek) and in the Beaver and Little Beaver drainage. This looks very much as if it belonged to those forms, which invaded Pennsylvania from the west, coming “across country.” (After all, this may be only a local form of C. decisum, with which it is often found associated. ) I found C. ponderosum only in Elk Creek, West Virginia, and farther down in the Ohio (Portsmouth, Scioto Co., Ohio). Here it 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 338 is the only Campeloma present, and it should be emphasized that in the upper Kanawha drainage, in Greenbrier River, not this species, but C. decisum is found. C.rufum and ponderosum have no representatives on the Atlantic side, and clearly belong to the fauna of the upper Ohio River, although they probably belong to different parts of it. IV. DECAPOD CRUSTACEANS: THE CRAYFISHES OF THE GENUS CAMBARUS. The conditions presented by the distribution of the crayfishes have been discussed by the writer with regard to the state of Penn- sylvania (Ortmann, 1906). These studies have been continued to- ward the south, and most of the facts given here for Virginia and West Virginia are new and add considerably to our previous knowl- edge. Of course, a certain ecological group is to be disregarded here, the burrowing crayfishes, for they do not live in open water, rivers or creeks, and do not depend in their distribution on drainage systems (Cambarus carolinus Er.,C.monongalensis Ortm.,C.diogenes Gir.). A. The following river and creek forms are found on the WEST- ERN SIDE of the mountains. Cambarus obscurus Hag. This species belongs to the upper Ohio system, from Moundsville, W. Va., in the Ohio, and from Fishing and Fish Creek upward. But it should be noted that subsequent investigations have shown that it goes a little farther down in the Ohio proper, for it is in the river at St. Mary’s, Pleasants Co., W. Va. In the Allegheny River this species goes up to the headwaters (Coudersport, Potter Co., Pa.), and also in the tributaries (Red Bank, Mahoning, Crooked), except in the Kiskiminetas-Conemaugh, where it goes only to the mouth of the canyon at Blairsville, while it goes up into the upper Loyalhanna in Westmoreland Co. Thus the Conemaugh resembles the conditions seen in the more southern mountain tributaries of the Monongahela. In the latter this species goes only to the lower end of the canyons, and is not found in the upper parts (Youghiogheny, Cheat, Tygart), while in the plateau stream, West Fork River, it is found nearly to the sources (Weston, Lewis Co., W. Va.). 394 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, Cambarus propinquus sanborni Fax. As has been shown in my previous paper, this species takes the place of C. obscurus as the river-species below the lower boundary of the range of the latter. In the Ohio proper, C. propinquus sanborm has been found at Parkersburg, Wood Co., and at Ravenswood, Jackson Co., W. Va. It is also present in the'tributaries of the Ohio in this region. An additional locality in the drainage of Middle Island Creek is McKim Creek, Union Mills, Pleasants Co, W. Va. It is in the Little Kanawha drainage in North Fork Hughes River, Cornwallis, Ritchie Corsandmitıe Little Kanawha River, Burnsville, Braxton Co., W. Va.® From the Kanawha drainage I have it from Elk River, Clay, Clay Co., and I collected it also in Mud River, Milton, Cabell Co., which is in the Guyandot drainage. Although I did not get it in the Big Sandy, it is surely there, for its type locality (according to Faxon) is Smoky Greek, Carter) Co, Ky. (1 could not locates tars creek, but a place called Smoky Valley is in western Carter Co., and is in the Tygart Creek drainage; Little Sandy and Tygart Creek fall into the Ohio below the mouth of the Big Sandy.) Beyond this, this species disappears, and its place is taken by the next, but I have ascertained this only in Rowan and Fleming Coss Kg Cambarus rusticus Gir. This is the river-species of Licking River, which flows into the Ohio below Cincinnati. The old record for this species, Cincinnati, would thus be confirmed. I found this species in Licking River proper at Farmer, Rowan Co., and in the tributaries, Triplet Creek, Morehead, Rowan Co., and Fleming Creek, Pleasant Valley, Nicholas Co., Ky. | Cambarus spinosus Bund. This is the representative species of C. rusticus in the upper Tennessee drainage, and I found it in Clinch River at Richland and Raven, Tazewell Co., Va. From this center of distribution it has crossed over into the Gulf and Atlantic drain- ages in Georgia and South Carolina, but this does not concern us here. In a general way, these river crayfishes show the same geograph- ical features as the bulk of the Ohio River shell fauna. The species * These two localities are interesting, for they approach closely localities in the West Fork River, at Lynch Mines, Harrison Co., and Weston, Lewis Co., where C. obscurus is found. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 335 of the propinquus group (obscurus and propinquus sanborni) have the same peculiarity as the Najades, in going up, in the rivers, only to the falls line in the mountain streams of West Virginia and south- ern Pennsylvania, while in the upper Allegheny they go up nearly to the sources. The fact that in the Kiskiminetas-Conemaugh they do not follow the Najades into Somerset Co., and that thus this river “resembles the southern ones; and that then again the upper Loyal- hanna conforms with the northern streams, is not very astonishing, for the Kiskiminetas system, being geographically intermediate, should also be expected to form faunistically a transition. These crayfishes, however, differ from the Najades, in present- ing a uniformity of the upper Ohio fauna only in so far as they are systematically closely allied, belonging all into the same natural group. But specifically they are quite sharply distinct, and thus indicate, in their distribution, three faunistically different sections: the upper Ohio is characterized by C. obscurus, farther down C. pro- pinquus sanborni takes its place, and finally, beginning with Licking River, C. rusticus turns up, and this species has a representative also in the upper Tennessee, C. spinosus. These conditions are important for the history of the crayfish fauna of the Ohio basin, and suggest, as I believe, that the Najad and the crayfish population of this system was not entirely subject to the same laws. Cambarus barton (Fabr.). This is not a river species, but a species of the small and smallest creeks, going up to the very springs. It is found everywhere on the western side of the mountains, for instance, Blackwater River and Shaver’s Fork, small runs tributary to Buckhannon River, upper New River drainage (Reed Creek), and small runs tributary to Clinch River. It is also on the Atlantic side (see below). Cambarus longulus Gir. Is found, on the western side, only in the upper Kanawha drainage, Greenbrier and New Rivers, and also in the upper Tennessee drainage, Holston and Clinch. It is also on the Atlantic side (see below). PROC. AMER. PHIL. SOC,, LII. 210 D, PRINTED JULY II, 1913. 336 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, B. CRAYFISHES OF THE ATLANTIC SIDE. Cambarus blandingi (Harl.). This species has not been treated in my report on the Pennsylvanian crayfishes, but I have discovered subsequently that it is present in great numbers in the ditches of the Delaware meadows at League Island, Philadelphia. Its distribution is from New Jersey to Georgia, and in a slightly different form (var. acutus Gir.) it extends westward over the Gulf plain to Texas, and northward into the interior basin. The existence of related species chiefly upon the Gulf plain (Ortmann, 1905, p. 105) indicates that the center of this species is in the southeastern United States, and there is no question that it reached our section (from Virginia northward) by migration coming from the south. Thus it clearly belongs into the same group to which those Najades belong, for which we have located the center of dispersal in the southern parts of the Atlantic slope. Cambarus limosus (Raf.) A species confined primarily to the lowlands and Piedmont region from New Jersey to Virginia, but which has gone up, in the Susquehanna and Potomac, into the moun- tains, possibly only secondarily. The facts of the distribution have been compiled in my former paper (1906, pp. 425 ff.), and the con- clusion was reached (p. 432) that this is a form belonging to the northern section of the Atlantic slope, and that its connection with the western forms allied to it is around the northern end of the Appalachians. Thus it clearly falls into the same category with certain Najades mentioned above. | Cambarus obscurus Hag. This western species exists in the upper Potomac drainage. I have previously (1906) considered this as an accidental introduction, and more recently (1912), pp. 51-54) I have parallelized this case with that of Lampsilis ventricosa cohon- goronta, as due to artificial transplantation. Thus this is not an original feature of the Potomac drainage, and should be disregarded. Cambarus acuminatus Fax. A species, known hitherto from the Atlantic drainage only in North and South Carolina, and also re- ported from French Broad River in North Carolina, tributary to the Tennessee. On the Atlantic side, however, this species extends farther north, and I have found it in Mason Creek, at Salem, and 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 337 in Tinker Creek, at Roanoke, Roanoke Co., Va. (Roanoke drainage), and in Mountain Run, Culpepper, Culpepper Co., Va. (Rappahan- nock drainage). Although differing from C. blandingi in not be- longing to the coastal plain, but rather to the Piedmont plateau, or even the mountains, the direction of its distribution apparently was the same, from south to north, and thus it clearly belongs to the southern element of the Atlantic fauna. In the fact that the same species is also found in the Tennessee drainage, it resembles to a degree the case of Eurynia constricta and vanuremensis among the Najades. But this may be disregarded for the present, for it does not concern the region under discussion. Cambarus bartom (Fabr.). All over the Atlantic side, also south of Pennsylvania, and I collected it myself, for instance, at Charlottes- ville, Albemarle Co., Va., and additional records are to be found in my former list of localities (1906, pp. 382-384). Here we have a species of wide and general distribution both on the western and eastern side of the mountains, going up into the very headwaters within the mountains. Thus it is clear that the divide has not acted as a barrier in this case, which I have explained by the exceptional means of dispersal possessed by this species in consequence of its ecological habits. This species is able to cross divides. Cambarus longulus Gir. We have seen that this is in the upper Tennessee and the upper Kanawha, on the western side. On the eastern side it is a common form in the upper James drainage (Jack- son and North Rivers). It also has been reported from the upper- most Shenandoah drainage, South River at Waynesboro, Augusta Co. Va. This distribution clearly resembles that of Symphynota tappani- ana among the Najades, and that of the genus Anculosa among the Pleuroceride, and there is no question that similar factors have con- tributed to bring this about, although in each of these cases certain peculiarities are observed. We shall devote more time to this far- ther below. 338 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, CHAPTER 4. SUMMARY OF DISTRIBUTIONAL FACTS WHICH CALL FOR AN EXPLA- TION. The above is the faunistic material which I have been able to col- lect. Comparing the facts observed in the different groups of fresh- water animals discussed, several classes have been brought to our attention repeatedly, and they may be condensed under the following generalized heads. I. WESTERN SIDE. 1. The Allegheman divide actually forms a sharp faunistic bound- ary for a great number of freshwater creatures. This is most evi- dent for the forms of the interior basin, which go up to a greater or lesser distance in the upper Ohio drainage, but do not cross the divide. To these belongs the bulk of the Najad-fauna; the genus Pleurocera and the western species of Gomobasis, among the Pleu- rocerid@, at least one species of Campeloma (C. ponderosum) ; and the group of Cambarus rusticus and propinquus of the crayfishes (which are closely allied). In a general way the interior basin fauna appears as a unit, a number of species, chiefly Najades, being found uniformly in all parts of the Ohio drainage, from the upper Tennessee region to the upper Allegheny River. 2. Nevertheless there are indications of a differentiation into sev- eral subdivisions, which may be described as follows: (a) The most sharply differentiated part is the upper Tennessee region, and to this belongs probably the whole Cumberland-Ten- nessee drainage. This is clearly seen in the Najades, in the Pleuro- cerid@, and in the existence of a peculiar species of crayfish, Cam- barus spinosus, belonging to the rusticus group. (b) Another part comprises the main fauna of the Ohio, chiefly of the middle and upper parts, and its tributaries. This fauna shows preéminently the uniformity mentioned above, and goes from Lick- ing and Big Sandy rivers in Kentucky to the upper Allegheny, in- cluding the Kanawha and Monongahela. In the Allegheny this fauna goes to the headwaters. But in the Kanawha and Monon- 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 359 gahela it goes only up to a point at the lower end of the canyon of the mountain tributaries. This latter feature is expressed in the Najades, and also in the genera Pleurocera and Goniobasis in the Pleuroceride. Also the crayfishes of the propinquus-group (Cam- barus propinquus sanborni and C. obscurus) show it distinctly. (c) A third part is the region of the headwaters of the mountain streams, tributary to Kanawha (New and Greenbrier) and Monon- gahela (Buckhannon, Tygart, Cheat, Youghiogheny). This fauna is chiefly characterized by-negative features, by the absence of the typical forms of the upper Ohio (2b). But it also has some positive characters; for instance, the presence of Symphynota tappaniana in the upper Kanawha; of Anculosa dilatata in the upper Kanawha, Tygart, and Cheat; and of Cambarus longulus in the upper Kan- awha. Of the various streams belonging to this region, each has some features of its own, and the elements have various relations to each other. It is very important to notice that most of the forms found in these streams are represented, on the Atlantic side, by identical or very closely allied forms (Symphynota tappaniana, Strophitus edentulus, Anculosa dilatata, Cambarus longulus). Other elements of this fauna belong to the general Ohio fauna (Symphy- nota costata, Elliptio dilatatus, Alasmidonta marginata), and just these have no closely allied forms on the Atlantic side (Alasmidonta varicosa is indeed allied to A. marginata, but as we shall see, it is not closely connected with the New River form). It further should be noted that the New River shows relations to the upper Tennessee in Cambarus longulus, and possibly also in Anculosa. Further, the upper Kiskiminetas-Conemaugh drainage in Pennsylvania shows an intermediate condition between the more southern mountain streams and the more northern tributaries of the Allegheny; with regard to the Najades it conforms to the latter, with regard to the crayfishes to the former (excepting again the Loyalhanna ). EASTERN SIDE: 1. The fauna of the Atlantic slope shows little evidence that it. ever was an important, independent center of radiation. All forms belonging to it have more or less close relations to forms of the 340 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, interior basin (except Margaritana). A certain uniformity of this fauna is also expressed in two ways: (a) By the uniform and wide distribution of certain species, indicating the possibility of intermigration between the various river systems; (b) by the fact that the fauna of each river, disregarding a few lowland species, goes up, in its bulk, into the mountains and ap- proaches closely the headwaters without appreciable depauperation. 2. There is a differentiation of elements within the Atlantic fauna, indicating different origin. (a) A southern element pointing to a secondary center of radia- tion in the southern parts of the Atlantic slope is distinguishable. This center itself, however, lies chiefly outside of the region dis- cussed here. Forms like Leringtonia, like those of the Elliptio complanatus and fisherianus-group, Alasmidonta collina, heterodon, and undulata, Eurynia constricta, among the Najades, Goniobasis virginica and symmetrica among the Pleuroceride, Cambarus bland- ingt and acuminatus, among the crayfishes, belong here. These forms exhibit morphologically the greatest independence, and are possibly the oldest element in the Atlantic fauna. In some cases it is hard or impossible to connect them with types of the interior basin by more than general relationship.’ (b) In the northern section of the Atlantic slope exists a group of forms, which are more closely related to species of the interior basin and often must be regarded as their direct representatives. These are the Najades enumerated under group V. (p. 325), and the crayfish, Cambarus limosus. They all have their main range in the north, and toward the south they disappear sooner or later, and have no representatives in the south. Very often their southward range becomes restricted to the coastal plain. (c) Further, there is a third group among the Atlantic forms. These are either conspecific with western forms or extremely closely allied. These are the Najades mentioned under VI. (p. 325), the °It might be mentioned here, that these forms probably will be intimately connected with the Tennessee-Coosa problem, and their number will be greatly added to, when the fauna of the Carolinas and of Georgia is taken into con- sideration. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE 341 Spherude, the Anculosa dilatata-carinata group of the Pleuroceride, Campeloma decisum, and the crayfishes, Cambarus bartoni and longulus (I disregard, for the present, C. spinosus and C. acumi- natus, as probably belonging to the Tennessee-Coosa problem, at any rate to a region lying to the south of the one which interests us here). These forms generally go way up into the mountains, and prac- tically meet there with the western range of the respective forms, so that the distribution seems almost continuous across the mountains, and suggests crossing of the divide. There is great variety in the details of distribution of these forms, and two main groups may be distinguished: those with a more universal range on either side of the mountains, and those with a more restricted range on one or on both sides. The above is a sketch of the chief distributional features, and we see that it is possible to group a number of cases under the same heads, which means to say that very likely similar causes have acted to bring about similar distribution. But before we begin the task to investigate the laws which governed these different types of dis- tribution, it is necessary to recall to our mind certain fundamental facts with regard to the physiography of the Alleghenies. CHAPTER 5. PHYSIOGRAPHICAL Facts. History OF THE ALLEGHENY MOUN- TAIN REGION. The origin and the development of the Appalachian or Alle- ghenian mountain system is rather well worked out (see McGee, 1888, Davis, 1889, Davis, 1891, Willis, 1896, Hayes, 1896, Davis, 1907), and we may assume that its general features are established. We do not need to go much into detail here, but certain phases in the mountain forming process should be brought out, which will be important for our present purpose. 342 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, A. FORMATION OF MOUNTAINS BY UPHEAVAL AND EROSION. Lateral pression in a general direction from northwest to south- east, in Permian and Postpermian times, formed the ancient and original Alleghenian system, which consisted of a number of more or less parallel folds (anticlines and synclines) running in a north- east-southwest direction. ‘These folds were pressed up against an old block of Archaic rocks lying to the east of them, the Old Appa- lachian belt of Davis (1907), now Piedmont plateau. They were piled up highest in the eastern part, close to the old Archaic rocks, but also in the southern parts the elevation was originally higher than in the northern, and in this section not only folds, but also faults, were formed. As soon as this mountain system began to develop, erosion set in. The original drainage features conformed to the original structure; the highest elevation being well to the east, the divide was situated here, close to the old Archaic land, and the old rivers had to follow the structure of the mountains, running first between the parallel ridges in consequent, synclinal valleys, and finding their outlets at certain points in a westerly (northwesterly) direction, toward the interior basin. On the other side, toward the Atlantic Ocean, there were shorter streams, originating also on the highest elevation, run- ning east and southeast, and reaching the sea after having traversed the belt of Archaic rocks. The longitudinal streams on the western side of the divide began to carve out their valleys. But in addition, on top of the anticlines, anticlinal valleys began to develop, running parallel to the synclinal valleys, and very soon an important differentiation in the power of erosion of these streams became evident, which is due to the geo- logical structure and succession of rocks of the mountains. The beds which compose them are all archaic and palaeozoic; but while the uppermost (Carboniferous) consist largely of hard sandstones, in the lower beds (Devonian and older) softer shales and limestones prevail. While the oldest rivers were running uniformly over sand- stones, the anticlinal rivers, and chiefly those running on the highest elevations, had the best chance to cut first through the sandstones and reach the softer beds below. After this, these streams working 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 343 in a less resistant material, had the advantage, and thus the anticlinal valleys were more deeply excavated than the synclinal valleys. This process advanced farthest in the eastern section of the mountains, so that what was once the highest elevation became finally a deeply excavated valley. This general process was repeatedly interrupted by the fact that the whole region was reduced to base level. One of these periods of base level conditions is most important to us, that of Cretaceous times, when most of the mountain region was a peneplain, little ele- vated above the sea, but with certain hills (monadnocks) standing above this level. In Postcretaceous times a reelevation took place, and the rivers began their work again, according to the same laws, but with complications due to the base-level period. During the latter, they had acquired courses across the strike of the mountains, and these were inherited by the later rivers, and often they were compelled to cut across hard rocks, thus forming so-called water gaps, which have no apparent connection with the original geological structure. The difference in the erosion has produced a physiographical differentiation within the whole system. In the western parts, where the Pre-Carboniferous soft rocks have not been reached, either synclinal valleys are present, or the drainage system is independent on the structure, irregular or dendritic. This section has been base- leveled rather completely in the past, and thus it is of the character of a plateau, and has been called the Alleghenian Plateau. The eastern parts, which were originally much higher, have been much cut into by the anticlinal streams, which have carved out broad lime- stone valleys, with high ridges of harder rock between them, so that this region has a more mountainous character, and is known as the Allegheny Mountains proper. Within these mountains, farthest to to the east, where there was once the highest elevation, an exception- ally broad valley has been excavated, called the Great Allegheny Valley. Thus we have, going from west to east across the mountains (see Plate XII.): (1) The Allegheny Plateau; (2) the Allegheny Moun- tains, with numerous ridges and valleys, the most eastern valley being 344 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, the Great Allegheny Valley, then follows, east of the mountains, a much older section of the country; (3) the Piedmont Plateau, a pene- plain, the remnant of the Old Appalachian land; and finally toward the ocean comes an additional physiographic division, (4) the Coastal Plain, lying between the Piedmont Plateau and the sea, of various width, which consists of marine deposits of much younger geological age (Cretaceous and Tertiary) (see McGee, 1888, Powell, 1896, Davis, 1907). | In the southern Appalachians this division is somewhat modified. The boundary between 2 and 3 is more developed (Blue Ridge) and is called the Appalachian Mountains, while no. 2 has more of a valley character and is called Appalachian Valley. No. ı is called Cumberland Plateau (see Hayes, Soo IPI, i), The boundary between the Coastal Plain and the Piedmont Pla- teau is well marked by an escarpment forming a falls line for the streams traversing the Piedmont Plateau. The Allegheny Moun- tams, and chiefly the Allegheny Valley, are marked off from the Piedmont Plateau by the flank of an anticline, consisting largely of archaic rocks, known in Virginia as Blue Ridge, and continued into Pennsylvania as South Mountain. But farther north this ridge be- comes obscure, and Piedmont Plateau and Allegheny Valley are more or less indistinct. In southern Virginia the Blue Ridge widens out and becomes a more important member of the system, finally reaching in North Carolina the highest elevation (see above). The Great Allegheny Valley is very distinct northwards, in Pennsylvania, Maryland and northern Virginia, forming a broad and flat limestone valley, and is sharply differentiated from the more western moun- tains and valleys. Farther south it merges more or less with the mountain region, which consists of several broad and flat limestone valleys, separated by longitudinal ridges formed by monoclinal harder rocks. The boundary between the Allegheny Mountains and the Alle- gheny Plateau is well marked in Pennsylvania and Maryland by the western flank of an anticline, known as Allegheny Front. Farther south this may be traced to a certain distance,!º but then, in West 0 Willis, 1896, p. 186 (also Abbe, 1809, p. 70), use the name Allegheny Front much farther South, for the escarpment west of Bluestone River: this 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 345 Virginia, the mountain-type of erosion encroaches upon the plateau, and, for instance, the valley of the upper Tygart and Greenbrier valley are largely anticlinal valleys of the mountain-type (see Fon- taine, 1876, p. 9), so that the eastern edge of the Allegheny Plateau is pushed back westward. In the region between James and New River and beyond (toward the southwest), conditions become more complex by the development of faults, and here the eastern edge of the plateau (Cumberland Plateau) is formed by a tremendous fault, which brings the Carboniferous down to about the same level with the Cambrian. (See maps and profiles in Rogers, 1884; also geo- logical map by Willis, 1912; as to the faulting, see Lesley, 1865; Stevenson, 1887; Powell, 1896, p. 79.) B. STREAM CAPTURE. There is yet another factor which contributed to make the struc- ture of the Alleghenies more complex. We have seen that the orig- inal divide of the waters probably was well to the east, not far from the old Piedmont land. It is clear that from this divide the way to sea-level (the Atlantic Ocean) was short and direct, while westward it was long and devious. This produced a much steeper grade of the eastern streams, and consequently the eroding power of the latter must have been much greater than that of the western streams. The eastern rivers had thus the first chance to saw through the divides westward. This resulted in the general law that the Atlantic streams have the tendency to cut into and to encroach upon the region which originally drained westward. This general law is not without exceptions, but such are rare. Also the Atlantic streams have been subject to stream capture be- tween themselves; Campbell (1896, p. 675) points out the unsym- metrical development of their basins, with the divides shifting toward the southwest; the Susquehanna developed at the expense of the Potomac, the Potomac at the expense of the James, the James at that of the Roanoke. Similar conditions probably existed on the western side. | is correct only in so far as this escarpment represents the eastern boundary of the Allegheny Plateau, but it does not correspond to the same structural line as the Allegheny Front in Pennsylvania. 346 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, This stream piracy or capture must have gone on all through the history of the mountains; but the evidence for the older cases is largely lost on account of the base level conditions prevailing at vari- ous times. Only more recent (Postcretaceous) cases are more or less clear. But in a general way the present rivers indicate that stream capture has been most effective in the northern parts of the Alle- ghenies, and, toward the south, the various rivers show this phe- nomenon in a lesser degree. (Davis, 1889; Hayes and Campbell, 1894, p. 192; also Campbell, 1896.) In addition, these processes were modified by a tilting of the reelevated peneplain in opposite directions in the north and south (Powell, 1896, p. 79). C. PRESENT CONDITION OF DRAINAGE. (See Plate XII.) At the present time we have only in the southern Appalachians the remnants of the primitive condition of the drainage, streams running toward the west, with their sources near or in the Biue Ridge, well to the east. This is the case in the Tennessee and New River region. New River is a good example of this, and we may safely regard this river as representing most nearly the original drainage features (Davis, 1907,90. 73227 Where 1s) nor anolaer nem in the whole Appalachian region that so well preserves its ancient Conase A Following the Allegheny Mountains and the Allegheny Valley northward, we meet streams draining more and more in an easterly direction, first the Roanoke, then, in succession, the James, Potomac and Susquehanna, and it is interesting to notice that the first one “ Davis means here by “ancient” preéminently the Pretertiary time. But probably the present New River is not the oldest line of discharge out of this region. Using the same methods as used by Davis (1889) for the construction of the old Anthracite River in Pennsylvania, we would obtain an old river running West in the depression between two elevations (monad- nocks), along which now runs the Chesapeake and Ohio Railroad (between Covington and Hinton, see Pl. XII. and profile, Pl. XIV., fig. 2). Probably the fault on the western side of Peters Mountain also played a part in defining this oldest line of discharge. The present New River would then be a later (but probably also Pretertiary) feature, and would have about the same re- lation to the old river, as the present Susquehanna has to the old Anthracite River, after its reversion. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 347 occupies only the valley, and very little of the mountains, while every succeeding one cuts farther back into the mountains (Campbell, 1896, p. 675). In the region of the uppermost Roanoke there is a good instance of more recent stream piracy. The headwaters of the North Fork are running first in a southwesterly direction in a valley, which is clearly continued toward New River; but just north of Christians- burg this fork makes a sharp bend, cuts through Paris Mountain, and flows then eastward and northeastward. It is clear that the Roanoke has captured here a former tributary of New River (see ‘Campbell, 1896, p. 674, and our map, Pl. XII., and profile pl. XIV, 2er iN). James River has cut much farther into the Allegheny Mountains. It is doubtful whether the original streams in this region belonged to New River. According to Hayes and Campbell (1894, p. 110) no important shifting of divides has taken place in this region during the Tertiary cycle, although, as we have seen, Campbell (1896) assumes stream piracy between James and Roanoke. This region is extremely complex in structure and has little been investigated. Coming to the Potomac drainage, we observe that this river has cut clear across the mountains, and has reached, in northeastern West Virginia and in western Maryland, the western boundary of the Allegheny Plateau, Allegheny Front, and at one point has even cut through this and encroached upon the Allegheny Plateau, draining now a longitudinal synclinal valley. (See our map, Pl. XII., and profile pl. SURV, fig. 2.) As tothe former drainage in this region very little is known. But according to Campbell (see above) the Potomac has robbed, in the region of the mountains, James River, and in one case, in the Shenandoah Valley, we have instances of more recent stream piracy during the Tertiary cycle. The Shenandoah is a rather recent stream, which has captured in succession several older streams, running originally independently through Blue Ridge east- ward (see Davis, 1891, p. 576, and Abbe, 1889, p. 68). The Susquehanna in Pennsylvania has progressed farthest in the capture of western streams. It has not only cut clear across the mountains, but also has invaded a large section of the plateau, which 348 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, originally drained to the westward (see Plate XII.) The primitive drainage features of this region have been worked out by Davis (1889), and according to him this whole region was once drained by the ancient Anthracite River, running in a northwesterly direc- tion through what is now the anthracite basin, its sources being situated well to the east, in the Kittatinny highland. The upper part of this river was first reversed, so that it discharged southeast- ward (direction of present Schuylkill), and then the Susquehanna encroached upon this system, becoming finally the master stream in Central Pennsylvania during Jura-Cretaceous times. The final step in the development of this drainage was the capturing of the plateau drainage, but also this falls largely into Pretertiary times. That the Susquehanna encroached also southwestward upon the drainage of the Potomac has been mentioned above, and this probably is the chief change of this system which belongs to the Tertiary time. D. History OF THE WESTERN DRAINAGE. At the present time all western streams are finally united into one great system, that of the Ohio, which finally runs into the Mis- sisssippi and the Gulf of Mexico. In the past this was different, and we know now that the present system is of comparatively young age, that the Ohio is a recent stream, and that the former drainage features of this region were entirely different. According to the investigations of a number of writers (for instance, Foshay, 1890; White, 1896; Leverett, 1902; Tight, 1903), there was no Preglacial Ohio River, but in its place there was a system of northward flowing streams. In the region under consideration two of them are well established: the Old Monongahela in western Pennsylvania and northern West Virgina, and the Old Kanawha in West Virginia (the Big Sandy belonging to the latter). How the conditions were farther down is somewhat doubtful, but there might have been a third river of the same general character (Licking-Miami, or Cin- cinnati River, see below). The advancing ice of the Glacial period shut off the outlet of these rivers, dammed them up, converted them into lakes, and finally the waters were forced to seek another outlet, and the general slope 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 349 of the country and the direction of the edge of the ice made them find this outlet in a southwesterly direction, thus connecting the old Preglacial systems by a new river, which was the beginning of the present Ohio. The Ohio thus was formed during Glacial times. The northward flowing Preglacial rivers were connected by a master stream called Erigan River, running in a direction about par- allel with the direction of the present St. Lawrence. There is some dispute as to the direction of this old river (northeast or southwest), but the evidence preponderates which assigns to it a northeasterly flow. The present writer has shown also (1906, p. 429) that cer- tain facts in the distribution of crayfıshes point to this conclusion, that is to say, that this drainage finally was eastward into the At- lantic Ocean. This question will be discussed farther below. E. MUTUAL CONNECTION OF THE ATLANTIC STREAMS. The present Atlantic streams, Delaware, Susquehanna, Potomac, James, Roanoke, are quite independent from each other, and dis- charge separately into the sea, so that no direct intercommunication of their waters seems possible. However, we have seen that their headwaters interlock closely, and that it is probable that in the past stream capture has taken place between them in the region of the Allegheny Mountains (see above the quotation from Campbell, 1896, p. 675). In their course across the Piedmont Plateau these streams are at present generally well separated, but farther to the east, where they enter the region of the Coastal Plain, they reach a physiograph- ical section of a character which permits frequent interchange of the waters. In addition, we know that the Coastal Plain extended, at certain times, farther seaward, and that the present Delaware and Chesapeake Bays and also the estuaries of the other Atlantic streams represent drowned river valleys, so that probably in the past this interchange of the waters took place on a larger scale (see LeConte, 1891; Powell, 1806, p. 73; Spencer, 1903, Davis, 1907, p. 717). Thus the Atlantic streams were not always isolated from each other, and in the past, as well as in the present, an intercommunica- tion of their waters was possible, chiefly on the Coastal Plain, which, of course, also must have permitted an exchange of the faunas. The importance of this will be understood below. 390 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, CHAPTER 6. EXPLANATION OF DISTRIBUTIONAL FACTS. We are now ready to study the faunistic facts with regard to their genesis, and shall take them up according to the classification given above (Chapter 4, pp. 338-341). Ae Ij it, The fact that the eastern and western faunas are sharply distinct, and that the Allegheny system actually forms a sharp faunistic bar- rier of the freshwater faunas, does not need any comment, for moun- tain ranges generally are most apt to act as divides between rivers and their faunas unless the elements of these faunas have excep- tional means of dispersal (by transport). The very fact that the western forms generally have not crossed the divide, nor have the eastern forms, indicates that among three of the groups discussed here ( Najades, Pleurocerid&, Crayfishes) no such exceptional means of dispersal have acted to any considerable degree. However, as we shall see farther on, there are some exceptions. One point, however, deserves special mention. ‘There have been periods of general base-leveling, the last important one belonging to the Cretaceous time. It is very likely that at this time the barrier was not so well marked, and that a more general interchange of the faunas was possible. If any cases in the present distribution are to be traced back to this time, there are very few of them, and the majority of the cases, chiefly of the Najades, does not show any evidence of this. This means to say that probably the bulk of the Najad-fauna of the Appalachian River systems is not older than the Cretaceous time, probably largely Postcretaceous. This is an important conclusion in view of the fact that we know from fossil remains that Najades existed in North America in Jurassic time and possibly even earlier. But it should be noted that these fossils are known practically exclusively from the western parts of the continent. This, however, cannot be followed up any farther, since it would lead us too far away from our present purpose. While thus the western fauna could not cross the Alleghenian 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 391 barrier, we further have noticed the fact that it forms distinctly a unit from the upper Allegheny River at least to Licking River in Kentucky. It is hardly necessary to discuss this, since the present conditions sufficiently explain this uniformity; all these rivers, run- ning westward, are united into one master stream, the Ohio. Also the system of the Tennessee, which has much in common with the Ohio, finally unites with this river. However, when we come to study the origin of this fauna and to consider the fact that the Ohio drainage in its present form is a modern feature of our hydrography, we have to ask the question, what the old conditions were? There is hardly any doubt that the uniform Najad-fauna of the upper Ohio basin is, in its origin, connected with the origin of the Ohio River, that is to say, that it is not older than the Glacial time, probably largely Postglacial. The fact brought out above, that from the upper Allegheny downstream this fauna becomes richer, and that the number of species increases steadily farther down (from 47 in Pennsylvania to about 60 or more in the vicinity of Cincinnati), makes it certain that the center of dispersal of this fauna was in the region of the lower Ohio, probably also including the Tennessee system, and that this fauna migrated upstream in Glacial and Post- glacial times as soon as the present Ohio was formed, depauperating gradually in the direction toward the headwaters. sem (a The fauna of the upper Tennessee is very strongly marked. Nevertheless it shows distinct affinities to the Ohio fauna. We have studied only a very small part of it, and it is well known that farther down in the Tennessee and also in the Cumberland River drainage, this fauna becomes still richer. Without a closer and more exhausting study of this fauna it is impossible to express any definite ideas as to the origin of it. Thus we have to dismiss this topic here and it is sufficient to say that prob- ably this fauna represents the common ancient stock, and the great center of radiation, not only of the interior basin fauna, but also of that of the Atlantic slope and the Gulf region. That the Ohic PROC. AMER, PHIL. SOC., LII. 210 E, PRINTED JULY II, 1913. 352 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, River fauna probably is a branch of this fauna has been indicated, and the migration was in this case from the lower Ohio upstream. The question remains whether the upper Ohio received also elements from the upper Tennessee by another route, and this question is sug- gested by the fact that the headwaters of Clinch and Holston rivers on the one side and those of Big Sandy and New River approach each other very closely and frequently interlock in the mountains. It is known (see Campbell, 1896, p. 670) that the headwaters of the Big Sandy are preparing to capture the headwaters of Clinch River in Tazewell Co., Va., in a region where the latter river has a rich and characteristic fauna. The Big Sandy tributaries have already reached the valley limestone and may have already deflected some of the smaller tributaries of the Clinch. In the Najad-fauna of the Big Sandy (see p. 309) there is no evidence for this. But the fact that a species of Pleurocera, Pl. unciale, is common to the Clinch and the Big Sandy, possibly supports this assumption. There is also little evidence for a communication between the upper Tennessee and New River except the existence of the Pleu- rocerid-genus Anculosa in both systems and the presence of an identical species of crayfish, Cambarus longulus. The two species of Najades, which are common to both systems, Elliptio dilatatus and Alasmidonta marginata, are without convincing value, since they are found all over the interior basin, and of Elliptio dilatatus there is surely quite a different, dwarfed race in the New River, while the Clinch contains the normal form. In view of the tremendous con- trast between the upper Tennessee and the New River faunas, it is not very likely that there was any extended migration at any time across this divide, or that there was any important shifting of this divide. This is in accord with the general history of these streams. According to Campbell (1894, p. 110), the divide between New and Holston rivers is a narrow col characteristic for a long-maintained divide, and Hayes (1896, p. 330) says that the headwaters of the Tennessee, running generally over softer rocks, had a tendency to encroach northeastward upon the upper Kanawha system, but that this tendency was counterbalanced by the fact that New River also cut its own channel deeply into the (harder) rocks of its own trans- 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 398 verse valley. If there was any stream piracy in the past it would have been the Tennessee, which had the advantage over the New River, so that the latter could not receive anything from the former. This seems to be supported by the general character of the fauna. The two cases mentioned above (Anculosa and Cambarus longulus) will be taken up again further below. rer yu (bs The main fauna of the Ohio reaches, as we have seen, in the Kanawha and the mountain tributaries of the Monongahela only up to the lower end of the falls-line, marked by a canyon. It is clear that here the upward migration of the Ohio fauna is checked by the physiographical character of these streams. The upper Allegheny and its tributaries are Plateau streams, originating upon the Alle- gheny Plateau at elevations of about 2,000 feet (see pl. XIII, fig. 1), and the West Fork River of the Monongahela falls into the same class (see pl. XIII, fig. 2), and in these streams the fauna goes way up: But in the case of the tributaries of the Monongahela, Youghiogheny, Cheat, Tygart, and also in New River (including Greenbrier) of the Kanawha system, the sources are in mountains of 3,000 to over 4,000 feet elevation. These rivers have a very steep grade, and in a certain region they all run through a more or less well developed canyon. The lower end of this canyon forms the upper boundary of the Ohio River fauna in the Youghiogheny at Connelsville, Pa., in the Cheat at Mont Chateau, W. Va., in the Tygart at Grafton, W. Va., in the New River at Kanawha Falls, W. Va.’ (Compare our ersales, PI XII, fig. 2, and Pl. XIV. fig. 1.) We have to regard it as an ecological fact among the Najades (and some other freshwater Mollusks, for instance, the genus Pleu- rocera), as well as in the river-crayfishes (Ortmann, 1906, p. 412), that they do not like rough water and unstable, shifting bottom. The canyons of the falls-line of these rivers are, next to their upper- 2 Of course, exceptional cases, where single species have found a way up and through the canyon, may be disregarded. Such are the cases of Quad- rula tuberculata and Rotundaria tuberculata in the New River at Hinton, and probably also of Symphynota costata in the Tygart at Elkins. 394 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, most headwaters, the roughest parts of them, characterized by firm bedrock bottom covered with loose stones and boulders, often shift- ing, chiefly during flood stages. Such conditions are entirely unfa- vorable to crayfishes and Najades (the latter generally demanding sand and gravel, which is firmly packed), and thus we have here an ecological barrier to the upstream migration of the Ohio fauna, which is absent, for instance, in the upper Allegheny. The fact that this fauna is here checked by a modern physio- graphical feature confirms the assumption that the upstream migra- tion of it falls in a rather recent (Glacial and Postglacial) time. Excepting these mountain streams just discussed, the uniform Postglacial upper Ohio fauna comprises all the headwaters of the Ohio (Allegheny and Monongahela), and further all the tributaries in West Virginia; also the fauna of the Big Sandy belongs-undoubt- edly here, and we know that this river once was closely connected with the Old Kanawha River (Tight, 1903), and that its history was similar to that of the other rivers, which are ancestral to the upper Ohio system. ‘This is somewhat different in the case of Licking River in Kentucky. Leverett (1902, p. 109) unites this river with the Preglacial lower Ohio (and with the Kentucky, Cumberland and Tennessee rivers). If this is correct, we should expect in this river the Tennessee-Cumberland fauna; but there is no trace of it here,® and the Licking fauna is entirely of the same character as that of the rest of the upper Ohio, as far as it concerns the Najades. Of Pleuroceride a new species turns up here, but this material is too unsatisfactory. But on the other hand a peculiar crayfısh is found in the Licking, Cambarus rusticus, which distinctly points to the west. But since also Monongahela and Kanawha are characterized by different (although closely allied) species of crayfıshes, Licking River also in this particular falls in line with these other streams. The physiographical evidence with regard to the history of Lick- “See p. 309. The fauna is not completely known, but according to my collections, only one species turns up, which is absent in other parts of the upper Ohio drainage discussed here: Anodontoides ferussacianus. All the rest is typically upper Ohioan. It also should be noted, that one species, Lampsilis luteola, is present here, which is absent in the Cumberland-Tennes- see fauna. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. | 399 ing River is yet obscure. As we have seen, Leverett unites it with the Preglacial lower Ohio. But the fauna of the river, especially of the Najades, strongly points to the fact that Licking River has a similar history to that of the Kanawha and Monongahela, that is to say, that it was in Preglacial times a northward flowing stream, which might have belonged to the old Erigan River (see above, p. 349), and that it had no connection with the lower Ohio and Ten- nessee-Cumberland. And indeed this is the assumption made by Tight (1903, see map, pl. 1), who gives to the Licking and Kentucky rivers (under the name of Cincinnati River) a northward flow in Preglacial times. Thus, in this case, zoögeographical evidence is in favor of Tight's assumption, and this is an interesting instance, where zoögeography contributes to the solution of a physiographical question.!* We have repeatedly emphasized, that the upper Ohio fauna is a unit, and rather uniform all over the terrritory it occupies, with the only qualification, that it slowly depauperates in an upstream direc- tion. This is true, in the first line, of the Najades, but it may be correct also for certain Pleuroceride, at least such forms which follow mainly the large rivers (certain species of Pleurocera, as for instance, Pl. canaliculatum). But in other groups, some minor dif- ferences within the upper Ohio fauna are noticed. Some evidence of this is seen in the Pleuroceridae of the smaller rivers, the Alle- sheny, Monongahela, Kanawha, Big Sandy and Licking, each of which has different species of Pleurocera and Goniobasıs (provided such are present at all). But these conditions require further study, chiefly with regard to the affinities of these forms. But it is inter- esting to note, that it seems that the conditions known to exist among the crayfishes are duplicated here. In the case of the crayfishes, I have pointed out (1906), Er there are two different species in the upper Ohio drainage, and that “= This should be studied farther, chiefly with regard to the additional question regarding Kentucky River: If Tight's and our view is correct, Ken- tucky River should conform in its fauna to that of Licking River and the upper Ohio in general; if it belongs, however, to the lower Ohio, it should. contain elements of the Cumberlandian fauna. Unfortunately the Kentucky fauna is practically unknown. 356 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, their distribution undoubtedly is correlated with the old Preglacial drainage systems. Cambarus obscurus belongs to the old Monon- gahela River, while C. propinguus sanborni indicates, in its present distribution, the old Kanawha River. This theory has been fully confirmed by my subsequent investigations, which have shown that C. obscurus actually is the river-species of the Monongahela in West Virginia, up to the headwaters of the Plateau stream West Fork River, while to the south of this, in the little Kanawha, Big Kana- wha, Guyandot, and in the corresponding part of the Ohio proper, C. propinquus sanborm is found. This latter form probably is also in the Big Sandy, and a few smaller streams to the west of this in Kentucky, all belonging to the Old Kanawha of Preglacial times. The additional information was obtained that in Licking River another species is found, C. rusticus. This means, that this river had a more isolated position from the others in Preglacial times, although belonging probably also to the old Erigan drainage. While thus the Najad fauna of the upper Ohio follows in its distribution the modern features of this river, and while we are to conclude, for this reason, that it is largely Postglacial, the crayfish fauna indicates Preglacial conditions. And further, it seems that, among the Pleuroceride, we have both elements represented, but, unfortunately, the natural affinities of this group are yet too obscure to permit any final conclusions. lane Es (ey. In the headwaters region of the mountain streams tributary to the Monongahela and Kanawha, above the canyon, there is generally a section, where these rivers are less rough, and run more quietly in elevated, often broad valleys (compare profiles, Pl. XIIT., fig. 2, pl. XIV., fig. 1). As has been said, the fauna of these parts is chiefly characterized by the absence of the common upper Ohio types. Nevertheless we have a small number of forms here, which are more or less characteristic. These forms are not uniformly present in all these rivers, and their distribution may be tabulated as follows: 1. Monongahela drainage— 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 391 a. Youghiogheny: Strophitus edentulus. b. Cheat: Anculosa dilatata. E: Tygart: Symphynota costata, Strophitus edentulus, Anculosa dilatata. 2. Kanawha drainage— a. Greenbrier: Elliptio dilatatus, Symphynota tappaniana, Alas- midonta marginata, Anculosa dilatata, Cambarus longulus. b. New River: The same as in Greenbrier, and in addition (at Hinton only) : Quadrula tuberculata and Rotundaria tuber- culata. Two classes may be distinguished among these: those which have no relations on the eastern side, and those which are represented there by identical or very closely related forms. The former are: Symphynota costata of the Tygart, and Ouadrula tuberculata, Ro- tundaria tuberculata, Elliptio dilatatus, and Alasmidonta marginata of the upper Kanawha. These are species rather generally distrib- uted in the upper Ohio region, and they probably belong to this fauna, representing forms, which for certain special reasons, pos- sibly by mere chance, were able to ascend somewhat higher in the mountain streams than the bulk of the Ohio fauna. The other forms, Symphynota tappaniana, Strophitus edentulus, and the crayfish Cambarus longulus, are represented on either side of the divide by the identical species, while in the case of Anculosa two extremely closely allied species, A. dilatata and carinata, are found west and east of the divide. These latter facts are very interesting, and touch upon the ques- tion, whether and how it was possible that certain forms of fresh- water life were able to cross the divide. For the present, we shall only indicate this problem, but we shall take it up again, when we come to speak of the Atlantic forms, which are more or less nearly related to western ones (see below, under fact II., 2, c). It also should be pointed out, that an additional interesting ques- tion is involved here. We have seen, that the general Najad-fauna of the Ohio, which goes up to the lower end of the canyons, is of Postglacial age. This fact suggests, that also the falls line of the canyons is comparatively recent, and that it marks a last rejuvena- 358 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, tion of these streams in consequence of a reelevation of the coun- try. According to Foshay (1890, p. 400) and others, this rejuvena- tion is of Postglacial age. Thus we might expect to find in these upper parts of the mountam streams, the remnants of the fauna which existed in these rivers in Preglacial (Tertiary) times. I have no doubt, that at least some of these are Tertiary elements, and pos- sibly just those which are found on either side of the mountains might belong to them. However, this fauna is too fragmentary, to be sure about this, and it is quite evident, that also in Tertiary times not the whole of the fauna of these rivers went up to near the headwaters. ‘Thus we have to wait till additional evidence with regard to the Tertiary fauna of the headwaters of the Erigan sys- tem is forthcoming. PACT Ai pr ad It has been seen, that there is a certain amount of uniformity in the Atlantic fauna, in spite of the fact that the Atlantic river sys- tems are quite isolated from each other. In fact, most of the At- lantic species are not restricted to a single drainage, but are found im) several, often practically im all or them. "This means) thassıhere is or there was the possibility of an intercommunication of the faunas of these rivers, and the question arises, how this was brought about. All these rivers, after having traversed the Piedmont Plateau; “run for a greater or lesser distance through the Coastal Plain. This plain is little elevated above sea-level, and consequently the rivers are sluggish here; there is considerable deposition of material in this region, and a great tendency toward a change in the river channels: the rivers are practically at base-level. It is a general rule, that in a country approaching base-level, the intercommunication of neigh- boring rivers is greatly facilitated (see Adams, 1901, p. 842), and that consequently a wide distribution of the fauna is favored. ® The best evidence would be fossil forms from the high river terraces. Such do exist, but the remnants are too poorly preserved, to be of any value. It should also be noticed, that there is a number of species in the upper Ohio drainage, which distinctly avoid the larger rivers: also these might be elements of the old Tertiary fauna. It is interesting, that several species of the present fauna of the mountain streams fall into this class, namely: Symphynota costata, Alasmidonta marginata, Strophitus edentulus. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 359 There is no question that this is one of the factors, which has largely brought about the more or less universal distribution of the species of the Atlantic slope, and has permitted their spreading from one river system into others, notwithstanding the contrary opinion of Johnson (1905), who does not believe that “river captures” are to be assumed in this region, but that passive transportation accounts for the universal distribution of certain Najades over the Atlantic slope. Indeed, it is not river capture in the strict sense, which caused the present conditions, but what Adams (J. c.) calls “ removal of barriers” in a country approaching base-level. This is also prac- tically the opinion of Simpson (1893, p. 354, footnote 2), when he” says, that shells may migrate from river to river “across overflowed regions near the sea, in times of floods.’ (We always must bear in mind that the migration was by the help of fish, which carried the larva.) This lowland zone reaches all the way up the coast to New York state. But we know, that’ at certain times it extended even farther north, when the continent stood at a higher elevation, and when the coastal plain was wider than at present. We must also consider, that at other times the coast was more submerged than now, and that then also the Piedmont Plateau was more or less at base-level, offering the same conditions favorable to a migration of the fauna. Moreover, we have seen, that there was stream-capture in the region of the mountains, and that the northern rivers had a tend- ency to encroach upon the southern. This should have caused a migration of southern forms northward in the mountain region, but not of northern forms southward. There is indeed evidence of it in the fact, that forms with a northern center of dispersal (those falling under II., 2, b) availed themselves, in their southern disper- sal, of the coastal route, for instance, Lampsilis radıata, carıosa, ochracea and Cambarus limosus, for they become more and more re- stricted to the lowlands in the southern parts of their range. On the other hand, those forms, which have a more general distribution, also in the mountain region, are chiefly southern in their origin, as for instance: Elliptio complanatus, Alasmidonta undulata, Gonio- basis virginica, and these may have availed themselves, in their 360 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, northward dispersal, also of stream piracy in the mountains. In a few cases, the latter probably was the prime factor in the dispersal, chiefly in the case of Anculosa carinata. Thus there is no difficulty in admitting the possibility of the dis- persal of the Atlantic fauna over more or less of the whole region. The facts in the distribution of the Najades, as well as in the Pleu- roceride, and in the crayfishes support this assumption. But the other fact, that certain forms of the Atlantic slope did not reach a universal distribution, and were apparently obstructed in their dispersal at certain points, needs further discussion. This is a more difficult problem, but, as far as possible, it will be taken up below. Erer JUL, a (o) Aside from certain species (Najades: Elliptio fisherianus, Ano- donta cataracta and implicata, Eurynia nasuta, Lampsilis radiata, carıosa, ochracea, and the crayfish Cambarus blandingi), which are more or less typically species of the lowlands or the great rivers, the fauna of the Atlantic streams is rather uniform, in each sys- tem, from the Piedmont Plateau upward into the mountains, to near the sources. (See list no. 23 of Najades, and also Goniobasis vir- ginica, Anculosa carinata, Cambarus limosus.) That is to say, the | fauna does not deteriorate, or very little so, in an upstream direc- tion. This differs strikingly from the conditions on the western side, where a gradual decrease of the number of species toward the sources is the rule, or where we even observe a sudden disap- pearance of species at certain points in the mountain streams. The explanation of this fact is found, as I believe, in a general physiographical character of the Atlantic streams, which is best ex- pressed by their profile (see our profiles on Pl. XIII., and Pl. XIV,, fig. 1). We see that the profiles of the Atlantic streams are more nearly normal (Abbe, 1899, p. 61, fig 3; of course we must dis- regard the falls line at the eastern edge of the Piedmont Plateau). This profile indicates comparative stability, with the slope steepest at the headwaters, decreasing rapidly just below headwaters, and then gently farther down. ‘These streams are more mature than those of the western side. On the eastern side, new cycles of ero- 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 361 sion, of rejuvenation, indicated by falls or rapids beginning some- where in the lower parts, have had time to work back to the head- waters (the cycle being completed), while on the western side these cycles, at least some of them, are not quite finished, and are indi- cated by falls and rapids lying at various distances below the head- Meances (see profiles, Pl. XIII., fig. 2, PL XIV., fig. 1). It does not require any further discussion to see that this dif- ference of the eastern and western streams is finally to be referred to the different general slope of the rivers, the former being short and more direct in their course to the sea, and thus working faster. The consequence is, that the aquatic life of the lower sections of the Atlantic streams finds congenial conditions up to near the head- waters, since the conditions are more nearly uniform all along the stream. Only close to the headwaters, there is a rather sudden change, and here the fauna deteriorates also quite suddenly. Pence 11.5282): We have seen that a differentiation of elements within the At- lantic fauna is indicated, and that first of all, a southern element is Clearly distinguishable. A number of Najades belong here, the snail Goniobasis virginica, and two crayfishes, Cambarus blandingi and acuminatus (see p. 340). In all these forms it is evident that they have their center of radiation somewhere in the southern section of the Atlantic slope (Carolinas, Georgia), whence they migrated northward (see Simp- son, 18965, p. 337). But we notice that the different forms have advanced northward to different points. Some of them spread all over the Atlantic slope, northward even beyond the section dis- cussed here; so, for instance, Elliptio complanatus, Alasmidonta undulata (possibly also Alasmidonta heterodon), which go to New England; Goniobasis virginica has reached the state of New York, and Cambarus blandingi (restricted to the lowlands) has reached middle New Jersey. Others do not go so far. Elliptio fisherianus, a lowland form, goes northward to the lower Delaware; Elliptio productus to the Potomac; Elliptio lanceolatus and Cambarus acuminatus to the 362 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, Rappahannock; Leringtonia subplana, Alasmidonta collina, Eurynia constricta to the James; and Goniobasis symmetrica to the Roanoke. This peculiar fact, that the southern elements in the Atlantic fauna have advanced to different distances northward, is hard to explain. The general tendency to migrate northward is understood by what has been said under II., 1, a, but the question remains, why certain forms have been unable to go as far as others. In part, I believe, this may be explained by the ecological prefer- ences of the single species, and a comparison of a few of them will show what I mean. Elliptio complanatus is ubiquitous, and is able to live under a great variety of environmental conditions. It consequently had the best chance to spread north, and actually has the widest range of all. Elliptio fisherianus is a typical lowland species, and it has used the easy way over the coastal plain, and has succeeded in going farther north than the two allied species, E. pro- ductus and lanceolatus, which, as far as I can judge, are rather up- land species, which could not avail themselves so much of the op- portunities offered by the lowlands; they very likely depended more on stream capture within the mountains, which naturally was a slower and more difficult way of dispersal. Probably this holds good also in the cases of Cambarus blandingi and C. acuminatus,; the former is a lowland species and has reached farther north than the latter, which seems to be an upland species. This, however, is only a suggestion. Our knowledge of the actual distribution, and also of the ecological habits of these forms is not satisfactory enough to draw positive conclusions. It is also possible, that the special history of these forms, chiefly with regard to their geological age, plays a part in this, and it might be that the oldest forms had the best chance to obtain the widest range. This might be correct in the case of Elliptio complanatus, while a rather recent type, Eurynia constricta, has stopped rather far south. But this surely is no general explanation, as is seen in the case of Leringtonia subplana, a primitive type, which did not go farther north than Eurynia constricta. This question should be taken up in connection with a more detailed study of the origin and the distribution of the southern At- 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 363 lantic element, and this is a problem correlated with the Tennessee- Coosa problem, and the connection of the Tennessee fauna with the southern and southeastern drainage systems of the Appalachians. It can be solved only after much more extended investigations in the Gulf and Atlantic streams from Alabama to the Carolinas. | This much is sure, that the existence of this southern element in the Atlantic fauna is well established. Simpson (1893, p. 355) already has indicated it clearly, and that it probably is connected with the fauna of the interior basin around the southern extremity of the Appalachians (see also Ortmann, 1905, p. 124). This center forms part of Adams’ (1902 and 1905) great southeastern center, but is probably a rather sharply separated, and rather old subdivision of it. It had, with regard to aquatic life, a northward route of dis- persal, not only in Postglacial, but also in Preglacial times, on the Atlantic slope. This route has been admitted by Adams (1905) for land-forms, but has not been mentioned (J. c., p. 63) for aquatic forms. | DAC re ie UU Another element of the Atlantic fauna seems to have its center in the north (from Pennsylvania and New Jersey northward). The following Najades belong here: Anodonta cataracta, Anodonta im- plicata, Alasmidonta varicosa, Lampsilis radiata, Lampsilis cariosa, Lampsilis ochracea,'* and the crayfish: Cambarus limosus. All these forms have in common, that they are most abundant north- ward, and advance southward either not at-all (Anodonta impli- cata), or chiefly on the coastal plain. Only Alasmidonta varicosa seems to be more universal in its distribution on the Atlantic side. Lampsilis ochracea is a form of the lowlands (estuaries). Lamp- silis radiata and cariosa, and apparently also Anodonta cataracta have a rather wide distribution in Pennsylvania, but southward they seem to occupy only a narrow belt on the coastal plain. The same is true of Cambarus limosus. However, our knowledge of the dis- | tribution of these forms in the lowlands of Virginia, and southward, is rather unsatisfactory, but the fact is undeniable that, while these “© Margaritana margaritifera and Eurynia nasuta resemble these to a de- gree, but, as we shall see below, are peculiar in other respects. 364 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, latter three forms are found in Pennsylvania way up into the moun- tain region in the Susquehanna, they are missing west of Blue Ridge in the Potomac,” James, and Roanoke. This fact, that the southward range of some of these forms falls largely within the coastal plain, where there were special advantages for migration, is corroborative evidence for their northern origin: they were first and originally present in the northern section of the Atlantic slope, where they had, in consequence of the longer time elapsed, a better chance to spread upstream. I have treated of the origin of the distribution of a member of this northern fauna, Cambarus limosus, in a former publication (Ortmann, 1906, p. 428ff.). I have pointed out, that this species is well marked, but possesses allied forms in the interior basin, and I have not the slightest doubt that the Najades enumerated above fall under the same head, and that the origin of their distribution is to be explained in a similar way. Also these Najades are well defined species, but possess allied representatives in the interior basin (see above p. 325). According to the theory advanced for Cambarus limosus, these Najades came around the northern end of the Appalachians, in Preglacial times, by way of the Erigan River, which flew in the gen- eral direction of the present St. Lawrence. This river received the ancestral forms of these species from the interior basin (more es- pecially from the lower Ohio and Tennessee drainage) in some way, which is at present not fully understood. But there is no serious obstacle to the assumption of this possibility on account of the prob- able numerous changes of the drainage in these parts. Having once reached the Atlantic coastal plain at the mouth of the Erigan River (region of St. Lawrence Gulf and New Foundland), there was no barrier to their farther dispersal southward, chiefly since the coastal plain, as we know, extended at certain times further sea- ward. This dispersal was first along the coast, but several of these forms migrated thence upstream in the various rivers of the Atlan- tic side. TC. limosus is found here and there in the upper Potomac, but it prob- ably reached these parts only recently by the aid of the Chesapeake-Ohio Canal. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 365 The southward migration was unequal, but the causes of this are not very clear, but might be compared with the similar phenom- enon in the case of the southern elements. When the Glacial period set in, the ice coming from the north separated the eastern range of these forms from that on the west- ern side. Habitudinal segregation was thus effected, and this in- duced differentiation into species. The final consequence is, that the Atlantic forms developed into well marked species, which have a rather young age (Glacial), and still are closely allied to correspond- ing forms in the interior basin. In Postglacial times, after the ice had disappeared, a reaction, a northward migration set in, and these species reoccupied a good deal of the territory lost in Glacial times. In this advance they were accompanied by certain southern types, which also invaded the glaciated area (Elliptio complanatus, Alas- midonta undulata). Thus the origin and the history of this part of the Atlantic fauna appears rather clear. The most interesting fact is, that the case of Cambarus limosus has a number of parallel cases among the Na- jades. This element in the Atlantic Najad-fauna, however, has been recognized already by Simpson (18965, p. 337), who also explains its origin by migration around the northern end of the Appalachians. Considering the two elements together, the northern and the southern, and the fact that the species belonging to them migrated to various extents south or north, we obtain a satisfactory explana- tion of the fact, mentioned above (p. 315, 318), that the Susquehanna, and also the Potomac, fall short, in the number of species, of the rivers both to the north (Delaware) and south (James). Certain forms of the northern fauna have not gone south beyond the Del- aware, and certain southern forms have not gone north beyond the James, and this leaves a balance against the intermediate systems of the Susquehanna and Potomac. In the Susquehanna, this short- coming has been in part supplemented by an indigenous form (Alas- midonta marginata susquehanne), and in the Potomac by a southern form (Elliptio productus). This peculiar condition is a point which very strongly speaks for our assumption of two distributional cen- ters in the Atlantic fauna, a northern and a southern. 366 ORTMANN—THE ALLEGHENIAN DIVIDE. | [April 18, usem JUL culo) There is a third group of forms among the Atlantic fauna, which have for a common character the fact that they are conspecific or extremely closely allied to western forms, and which show in their distribution certain peculiar, but not quite uniform conditions. We have seen (under I., 2, c, p. 339, 357) that the corresponding western forms are in part characteristic for the mountain streams tributary to the Monongahela and Kanawha, so that there is the appearance, as if certain species had crossed the divide of the Allegheny Moun- tains. It remains to be investigated, whether such a crossing of the divide should be admitted, and what the means were, by which this was accomplished. Certain cases, however, should be dismissed*® from the beginning, namely first of all those, where passive migration by transport is probable or possible. The Sphaerude belong here, and also Campe- loma decisum. Here the whole character of the distribution is such, that it does not appear to follow drainage systems at all, but goes across country, suggesting exceptional means of dispersal, such as transportation by birds etc. In other cases, active migration across divides is possible and probable: this concerns chiefly, as I have pointed out in a previous paper (Ortmann, 1906, p. 448), the crayfish Cambarus bartoni. This species, as well as the Spherudide and Campeloma decisum, has a rather universal distribution east and west of the divide. And further, I shall disregard here Cambarus spinosus and acuminatus, as belonging to the southern Appalachians, as far as it concerns the distribution on both sides of the divide, and also Euryma constricta and vanuremensis fall into the same class. Thus there remain the following forms to be discussed here. 1. Strophitus edentulus. 2. Alasmidonta marginata and marg. susquehannae. 3. Symphynota tappamana. “Two very recent cases, Cambarus obscurus and Lampsilis ventricosa (cohongoronta), in the upper Potomac must be entirely disregarded, for here artificial, although accidental and unintentional, transplantation has been effected by human agency (see Ortmann, 1912)). 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 367 4. Anculosa dilatata and carinata. 5. Cambarus longulus. The peculiarities of distribution in each of these cases have been shortly characterized above (p. 357) for the western side of the mountains, and it will be remembered that none of them are fully alike in all particulars, although resembling each other to a degree. This is also so on the eastern side. Thus it is best to take them up one by one. Strophitus edentulus. This species has a rather general distribution, but it is peculiar in so far as it is one of the two species of Najades which alone are found in the mountain-tributaries of the Monongahela (Youghio- gheny and Tygart), while it is missing in the upper Kanawha region.” This forbids it to place this species simply with those which (like the Spherudé and Campeloma decisum) have a uni- versal distribution east and west of the divide. Indeed, the gen- eral distribution of Strophitus, for instance in Pennsylvania, might suggest that this form has exceptional means of dispersal, and ’ might be transported from one drainage into another.” But its absence in the New River system speaks against this, for we cannot imagine that any means (birds for instance), which would have been able to carry this species across divides, should have carefully avoided the New River system. Strophitus edentulus is a form eminently characteristic for small streams, and is rare or missing in large rivers. In the upper Alle- “ This negative statement might be doubted. But at the four localities, where I collected Najades (Ronceverte in Greenbrier River; Hinton and Pearisburg in New River; Wytheville in Reed Creek), shells were abundant, and in every case J hunted for this species, examining carefully also dead shells lying around; but no trace of Strophitus was discovered. *In order to bring out all facts, which possibly might have a bearing upon this question, it should be mentioned, that Lefevre and Curtis (Science, 33, I9II, p. 863, and Bull. Bur. Fish., 30 (for 1910). 1912, p. 171) have recently discovered a remarkable circumstance in the life-history of this species, dif- ferent from all other known Najades: the larvae (glochidia) of Strophitus undergo their metamorphosis without a parasitic stage on fishes. For the present, however, I could not tell how this could favor passive transport of the young shell. But the fact should be kept in mind. PROC. AMER. PHIL. SOC., LII. 210 F, PRINTED JULY II, I913. 368 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, gheny drainage it goes way up into the headwaters:” it is in the upper Youghiogheny and in the upper Tygart and Buckhannon rivers. Thus it closely approaches the divide in the whole northern section of the upper Ohio drainage. On the eastern side, it is also found close up to the divide in the Susquehanna, Potomac, James, and Roanoke drainages.”” The eastern and western ranges are consequently in rather close contact along the northern part of the Alleghenian divide, from the uppermost Allegheny River to the region of the headwaters of the Monongahela, Potomac and James. But the close approach is most marked in central Pennsylvania, in Cambria, Indiana, and Westmoreland counties. Here this species is common in all small streams running east and west from the divide, and, for instance, the locality in Cush-Cushion Creek, be- longing to the Susquehanna, is not more than twenty or twenty-five miles from the nearest localities in the Allegheny drainage (Creek- side, Homer, Goodville). This is just in the region where the Susquehanna drainage has largely encroached upon the drainage of the Allegheny River, and where stream capture has taken place. Although Davis (1889, p. 248) believes that this was accomplished chiefly in Pretertiary times, there is no objection to the assumption that to a lesser degree this process continued in the headwaters also during the Tertiary, in fact, that it is going on at present. If this is admitted, there is no difh- culty in imagining that with the waters part of the fauna of the western streams was taken over into the eastern drainage, and since Strophitus inhabits these smaller western streams, it might thus have crossed the divide, in this region, by the help of stream capture. * Potato Cr. Smethport, McKean Co.; Little Mahoning Cr., Goodville, Indiana Co.; Crooked Cr., Creekside, Indiana Co.; Yellow Cr. Homer, In- diana Co.; Blacklegs Cr., Saltsburg, Indiana Co.; Beaver Run, Delmont, Westmoreland Co.; Loyalhanna Riv., Ligonier, Westmoreland Co.; Quema- honing Cr., Stanton's Mill, Somerset Co.; all in Pa. ” For instance: in the system of the Susquehanna: Cush-Cushion Cr., Greene Twp., Indiana Co.; Chest Cr., Patton, Cambria Co.; Swartz Run, Ash- ville, Cambria Co.; Beaver Dam Cr., Flinton, Cambria Co.; Raystown Branch Juniata Riv., Everett and Mt. Dallas, Bedford Co.; all in Pa.; South Branch Potomac Riv., Romney, Hampshire Co, W. Va.; James drainage: Calf Pasture Riv., Goshen, Rockbridge Co. Va.; Roanoke drainage: Mason Cr., Salem, Roanoke Co., Va. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 369 Of course, this presupposes that the original home of this form was in the interior drainage basin. But I hardly think that this could have been otherwise, on account of the tremenduous range of Strophitus edentulus in the west, and we have seen that the Atlantic slope probably never has been an important center of de- velopment. Strophitus differs from all the other elements of the Atlantic fauna (discussed so far) by the fact that the identical species is found on either side of the mountains. Thus it is improb- able that it had a similar history to that of the other forms (the northern and southern elements) of the Atlantic fauna, and we are forced to assume a special explanation of its distribution. I think, that the evidence introduced above favors the theory, that it actually crossed the divide by the help of stream capture, or in other words, by the shifting of the divide, and that this probably took place in the region of the headwaters of the West Branch Susquehanna. It might have happened elsewhere; it might have happened repeatedly: but the region indicated is the most likely. After having once (or repeatedly) crossed, this species spread over the Atlantic slope, both north and south, and occupies now the whole of it, from Virginia to New England (exact data from Virginia southward are lacking). This of course, was accomplished by the same means as in the other members of the Atlantic fauna, and it is not astonishing since this species is not only upon the Piedmont Plateau, but also on the Coastal Plain.” Further details cannot be given, and chiefly it is impossible to fix the geological time when Strophitus crossed the mountains. As has been said, possibly this happened repeatedly, presumably in the Tertiary, and may have happened even later.2* More information as to its southern range may furnish additional evidence, and con- firm the view that the crossing of the divide was effected in the northern section of the Alleghenies, and not in the south. At pres- “T found it in Delaware River, Penns Manor, Bucks Co., Pa. Its dis- tribution upon the Coastal Plain is yet incompletely known, but it seems to - be represented there at least by a local (or ecological?) form, Strophitus un- dulatus. * At present, this species has a continuous range from West to East in the state of New York, and this, of course, belongs to the Postglacial time. 370 ORTMANN-THE ALLEGHENIAN DIVIDE. [April 18, ent, the absence of it in the New River system is the most important fact which speaks for the assumption made above. Alasmidonta marginata and Alasmidonta marginata susquehanne. The typical western Alasmidonta marginata has a wide distribu- tion in the interior basin, and in the Allegheny Mountains it goes up into the headwaters of the Holston, Clinch, into New River, and into the uppermost Allegheny River, but it is not found in the head- waters of the mountain-tributaries of the Monongahela (although it is immediately below the canyon in the Cheat). In the upper Allegheny, it goes, like Strophitus, into very small streams,”° and it is in general a species characteristic for smaller streams, avoiding large rivers. On the Atlantic side, it is represented by two forms. The one is Alasmidonta varicosa, a closely allied, but nevertheless sharply distinct species, which has been discussed above (p. 363 f.) together with those forms constituting the northern element in the Atlantic fauna, which migrated, in Preglacial times, around the northern end of the Appalachian chain. But there is a second representative on the Atlantic side, which has been hitherto overlooked, and which I have called Alasmidonta marginata susquehanne, which stands much closer to the western form, in fact, is very hard to distinguish from it. This form is re- stricted to the Susquehanna drainage in Pennsylvania and New York, and it is found frequently associated with A. varicosa, but is always perfectly distinct from it. | It seems, according to the material at hand, that Alasmidonta marginata susquehanne has its metropolis in the Juniata River and the part of the Susquehanna in central Pennsylvania, which is below the junction of the west and north branches. It has not been found in the west branch and its tributaries (although Al. varicosa is there), but we should consider that the fauna of this branch is poorly known, and that it has been largely destroyed by pollution from mine waters. ” Allegheny River, Larabee, McKean Co.; Little Mahoning Creek, Good- ville, Indiana Co.; Loyalhanna River, Ligonier, Westmoreland Co.; Quema- honing Creek, Stanton’s Mill, Somerset Co.; all in Pa. 1913. | ORTMANN--THE ALLEGHENIAN DIVIDE. 371 In the localization of its eastern range, this form differs from Strophitus. But just this fact points to a connection across the divide with the western range of Al. marginata. This comes up, on the western side, close to the divide, and although the corresponding form is not known from the West Branch Susquehanna, the dis- tribution on the eastern side suggests that it must have crossed the divide in this general region, presumably in consequence of stream capture. This is the more probable, since the western race of Al. marginata found in the headwaters of the Allegheny in Indiana, Westmoreland, and Somerset Cos., in Pa., approaches the Susque- hanna-form much more closely than the typical marginata, as found, for instance, in the Beaver drainage. This leads us to consider this as a parallel case to that of Stroph- itus edentulus. Alasmidonta marginata crossed the divide by similar means and in about the same region as Strophitus; but there is the difference that it did not spread beyond the Susquehanna drainage, This may be explained by the assumption that this crossing, in the case of Alasmidonta, falls into a later time. Of course, this explanation is only tentative, but according to our present knowledge, it is the only possible one. The fact of the restriction of Al. marginata susquehanne to the Susquehanna drain- age is of the greatest weight for our argument, since we cannot imagine that this form reached its present area by any other way. Symphynota tappanıana. Up to shortly ago, this species was known only from the Atlantic slope, where it has a wide distribution from New England to Vir- ginia (allied species are in North and South Carolina). On account of its relation to the western S. compressa, it appeared to fall into the group which has been designated as the northern element in the Atlantic fauna (indeed, Simpson, 18965, places it there). But after I discovered that this species is also found in the western drainage, but only in the upper Kanawha system (Greenbrier and New rivers), where it is extremely abundant, in fact the prevailing form of Najad-life, the history of it must be different. | Its general distribution in the east, and its localization in the west, might suggest that we have here a case like that of Alasmi- 372 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, donta marginata, but reversed, and that the original range was on the east side, and that the upper Kanawha received it from the east, probably by stream capture, since transport over land is not very likely on account of the improbability that birds (or other crea- tures) carried this species only into the Kanawha, and refused to do so into other western streams.?º But as we have seen above, it is not probable that the upper Kanawha has captured any streams of the eastern drainage, but rather the reverse is true (above, p. 346f.). The present course of New River represents most nearly the ancient drainage features, while the eastern streams (Roanoke, James and possibly also Po- tomac) have captured sections of the old New River and Greenbrier system. New River runs within the mountains on a distinctly higher level than most of the other streams which have cut much more deeply into the Cretaceous base-level, and thus had a better chance to capture parts of New River, than vice versa (see Pl. XIV., Der a). This induces us to assume that Symphynota tappaniana origi- nally was a local form of the New River drainage, developed prob- ably out of the western S. compressa as an ecological mountain- form. In this case it is strange that the range of S. compressa does not come very near to that of S. tappanıana, but this may be due to a subsequent restriction of the range of S. compressa.”* ” There is, however, one fact in favor of this assumption. S. tappaniana is one of the few cases of hermaphroditism known in Najades. If we grant, that in rare cases, specimens have been transported, we must admit the pos- sibility that a new stream might have become stocked with this species, by the transplantation of a single individual. But then again, we do not know, whether self-fertilization occurs here. I mention this here, to bring out all possible arguments. ” The nearest place known to me for S. compressa, is Little Kanawha River, where it is very rare, and also this locality is isolated. Forms like S. compressa and tappaniana seem to be absent in the upper Tennessee drainage, but in the latter is Symphynota holstonia (which is not an Alasmi- donta), and a very doubtful, incompletely known species, S. quadrata (Lea), which has a certain external resemblance to S. tappaniana, but may be any- thing. S. holstonia is surely not closely related to S. tappaniana, for it has no lateral hinge-teeth. It remains to be seen, whether there are any related forms in the upper Tennessee, which, when present, might suggest, that New River received its species from the Tennessee. 1913.] ORTMANN-- THE ALLEGHENIAN DIVIDE. 373 After S. tappaniana had reached the James drainage (it has not been found in the Roanoke, but only the headwaters of this are known), it had a chance to spread on the Atlantic side and to attain its present wide range, exactly as the majority of the Atlantic forms, favored by the same causes. It always remains a small-creek-form, but just in these small creeks the best opportunities were given to cross from one system into the other. Anculosa dilatata and carınata. Anculosa carinata is the Atlantic form and is known to me from the Roanoke to the Susquehanna, where it goes up into New York state. In this restriction (not being found in the Delaware and be- yond) it is different from Strophitus and Symphynota tappaniana, which go to New England. West of the divide we have Anculosa dilatata, first of all in the same region where Symphynota tappaniana is found (Greenbrier and New rivers) ; but in addition it is also in the upper Monongahela drainage, in Tygart and Cheat rivers; in the latter it goes down below the canyon, as far as Cheat Haven, Fayette Co., Pa., and further it is found in West Fork River. Re- markably enough, it is absolutely absent in the upper Youghiogheny, although the conditions appear favorable for it. With exception of these localities in the Monongahela drainage, the distribution fairly well agrees with that of Symphynota tap- paniana, and we won’t make a mistake if we advance the same expla- nation for it: stream capture on the part of certain Atlantic streams (Roanoke and James), which robbed the water and the fauna of certain parts of the old New River drainage. Thus only the pres- ence of this form in the Tygart and Cheat needs explanation; into West Fork River it undoubtedly got from the Tygart. | The headwaters of these rivers interlock in a very complex way in Pocahontas and Randolph Cos., W. Va. (see Pl. XII.), and there is no objection on general principles to assume that there has been intercommunication of these rivers by stream capture. But condi- tions are rather obscure in this region and have been so little inves- tigated from a physiographical standpoint that it is practically im- possible to draw any positive conclusions as to the history of the development of the headwaters of these systems. 374 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, But it is highly interesting to notice that the distribution of Ancu- losa dilatata in the Greenbrier on one side, and in the Tygart and Cheat on the other, points to stream capture in this region, and the theory is suggested that the Monongahela drainage encroached upon and robbed the Greenbrier drainage. The opposite way is not pos- sible on account of the limitation of this form northward, and this also speaks against the possibility of passive transport. If this as- sumption is correct, it also explains the fact that the Youghiogheny, which also heads in the same general region, did not receive this species. The upper Youghiogheny flows in a high synclinal valley, is more nearly an old consequent river than, for instance, the upper Cheat, which has cut down way below the level of the upper Yough- iogheny. ‘Thus it is impossible that the latter ever robbed the Cheat, capturing its fauna; rather the opposite has happened, and probably is happening now. The Atlantic form, Anculosa carinata, after having reached the Roanoke and James, and after having become established on the eastern side, had the same tendency to spread as the rest of the Atlantic forms. But it did not go so far as many others, reaching only the Susquehanna drainage. In this case northward migration probably was due to the crossing over divides (by stream capture) in the mountain region. Anculosa is a shell characteristic for rough water in mountain streams and goes possibly farther up than any other of the forms discussed here. In the lowlands, it has never been found, and it is also less frequent in the Piedmont section of the streams, although present there. Thus its migration very likely took place chiefly within the mountains, and I think that its limited range northward is due to this fact. The genus Anculosa is represented in the uppermost Tennessee drainage by the species Anculosa gibbosa, which is to a certain degree related to the dilatata-carinata-group. In fact, the Tennessee drainage is the only other region where relations of this are found. This makes it clear that New River must have received its Anculosa- stock from the upper Tennessee. It is hard to say how this was accomplished. We have seen (p. 352 f.) that stream capture was rare in this region; at any rate, if there was any, it was rather in the ad dá 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 375 opposite direction. Nevertheless, there might have been cases where in the headwater region smaller streams have been deflected from the Holston or Clinch to the New River, and since Anculosa is an abundant small-creek-type, it might thus have managed to get across. But in this case also transportation is to be considered as a possible means, since many of the headwaters originate in the same longi- tudinal valleys, and come very close to each other without sharp barriers between them. But the fact that the species in the two systems are sharply distinct speaks against this, for if transport had been possible once, it should have been possible repeatedly, which would have prevented specific isolation. Cambarus longulus. The distribution of this species again agrees, in a general way, with that of Symphynota tappaniana and of Anculosa, but is rather more restricted on either side. It is extremely common in the whole Greenbrier and New River drainages. It is also found in the upper Tennessee. On the eastern side it is common in the James drainage, but has not been found in the Roanoke, and besides, it has been reported from the uppermost Shenandoah (Waynesboro, Augusta Co., Va.). Farther north, chiefly in the rest of the Potomac drainage, it is positively absent, and also on the west side it does not go into the upper Monongahela system (as Anculosa does). Its presence in New River and Tennessee in forms which are spe- cifically identical shows a closer connection of these two faunas than in any of the previous cases. We have seen that in Cambarus bartom, a closely allied species, general distribution is very likely due to active or passive migration across divides. This might be true also here. But Cambarus longulus differs from C. bartoni in its ecological habits, inhabiting preferably larger mountain streams, and not the smallest headwaters or even springs, as C. bartomi does. For all practical purposes we may compare C. longulus with Ancu- losa, and whatever the means were which permitted Anculosa to get from the Tennessee into the New River, might have worked as well in the case of this crayfish. Having reached the New and Green- 376 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, brier, it did not go beyond this drainage on the western side and did not reach upper Tygart and Cheat as Anculosa did. The rea- sons for this as well as for the fact that it did not become specifically distinct in New River are unknown for the present, but probably they are to be found in a difference of the time of migration from that of Anculosa. From New River, C. longulus got into James River by the same means as Symphynota tappamiana and Anculosa, 1. e., by stream capture. It did not get out of this drainage except at one place, in the uppermost Shenandoah. This is probably to be connected with the stream piracy committed by the Shenandoah all along its present valley (see above, p. 347). Just at Waynesboro there is a wind gap in the Blue Ridge, Rockfish Gap, which undoubtedly once served as an outlet for a tributary of the James River (Rockfish Creek or Mechum River), which was beheaded by the Shenandoah exactly as was Beaverdam Creek at Snickers Gap (Davis, 1891, p. 576). The question remains, why C. longulus did not spread over the rest of the Shenandoah and Potomac drainage. This may be due to ecological causes. The species may not find farther down in the Shenandoah a congenial environment. Where I found C. longulus the water was always rough and full of rocks, and the lower Shen- andoah, although by no means a sluggish river, has considerable quiet stretches. I also found this species generally at elevations higher than the Shenandoah in the average. This would correspond to a degree to the conditions seen in C. bartom, which is also a spe- cies avoiding larger streams and quiet water. | Taking these last three cases together, Symphynota tappaniana, Anculosa, and Cambarus longulus, it is seen that, although they differ in particulars, they fall under one general head, and that very likely similar causes were working to effect their distribution. Dis- regarding Strophitus and Alasmidonta, which probably crossed the divide farther north, they are the only cases where freshwater forms seem to have crossed the Allegheny divide in its central parts, prob- ably by the help of stream capture. The total number of such cases is very small compared with the numerous cases which follow the general rule, that the Allegheny 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 377 Mountains have formed and are forming a sharp barrier between the western and eastern fauna. But this is exactly what was to be expected, for the distribution of freshwater animals is primarily governed by the conformation of the drainage systems and their boundaries, provided there are no exceptional means of dispersal which permit a transport or migration over land. SPECIAL CASES. So far we have attempted to explain those cases which submitted to a classification such as has been given above (Chapter 4, pp. 338-341). But perusing the end of Chapter 2 (pp. 324, 325), we see that not all forms have been treated and that there are among the Najades at least three others which show special features. These are: Margaritana margaritifera, Eurynia constricta, Euryma nasuta. We may pass over Eurynia constricta with a few words. This species belongs undoubtedly to the southern element in the Atlantic fauna, and has been treated with it above. The peculiarity in this case is that it has an extremely closely allied species in the head- waters of the Holston (and elsewhere in the Tennessee drainage). It might be possible that here we have evidence of a direct crossing from the Holston into the Atlantic drainage. But as far as we know, the two species do not come in close contact with each other in the region investigated, and if there is any contact it is some- where else, probably in the southern Appalachians, and this case thus would belong to the Tennessee-Coosa problem. It should be added that probably also two crayfishes fall into the same class, Cambarus acuminatus and C. spinosus. The other two cases must be treated separately, each forming a class by itself. Margaritana margaritifera. In our region this species is found exclusively in the upper Schuylkill drainage in Pennsylvania (Schuylkill Co.). This is the only locality known outside (to the south) of the terminal Moraine. Farther to the northeast, within the Glacial area, in New York and New England, and all the way to New Foundland, this species is rather abundant. In addition, it is found (in a somewhat different 318 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, form) in northwestern North America and in absolutely the same form in Iceland and parts of Europe and Asia. The distributional facts have been summarized by Walker (1910), and as to the origin of the distribution he draws the conclusion (/. c., p. 139) that the presence of this species in northeastern North America is best ex- plained by the assumption that it immigrated, probably in late Tertiary times, from Europe by a land-bridge over Iceland and Greenland. I accept this fully. Also the idea of Walker, that the Glacial epoch restricted the range of this species, must be accepted. In fact, we are to regard the present station in Pennsylvania as the last remnant of the Glacial refugium of this species, just in front of the terminal Moraine. Here it survived and the present distribution is largely a Postglacial re-occupation of lost territory,?* and in this it fully agrees with the other Atlantic forms, chiefly the northern ele- ment. It differs, however, from the latter in its ecological prefer- ences : Margaritana is a form of cold water and is averse to limestone. Thus it is evident that Margaritana is a stranger among the other Najades of the Atlantic side, in fact, it is an element of the North American fauna which stands by itself and has been subject to en- tirely different laws in its distribution. It is true, there is a shell in the interior basin which is allied to it, but only remotely so, be- longing to another genus: Cumberlandia monodonta (Say). Another one is Margaritana hembeli (Conrad) from southern Alabama and Louisiana.” Both of these do not seem to have any direct genetic connection with M. margaritifera and are probably relics of a former more general distribution of this most primitive and archaic group of Najades, undoubtedly reaching back in their history far beyond the other Najades and far into Mesozoic times. Eurynia nasuta. On the Atlantic side this species is found from the Delaware > Tt is doubtful, whether all of the present range was regained from this Pennsylvanian stock; it is quite possible, that there were other refugia, sit- uated on the former seaward extension of the present coast. The Pennsyl- vanian refugium is the only one, which has been positively ascertained. ” The so called Margaritana decumbens (Lea) of Alabama is an ex- tremely doubtful form in every respect (see Walker, 7. c., p. 128). 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 379 River estuary northward, and goes probably a little farther south on the Coastal Plain into Virginia. In this distribution it would agree very well with the northern stock of the Atlantic fauna. But it differs from the members belonging to this in that it has no repre- sentative species in the upper Ohio basin. However, it is found on the western side of the Alleghenies and is widely distributed in the lake drainage, chiefly in Lake Erie and the state of Michigan, and it is absolutely the same form that is found there. The fact is that these ranges are not disconnected, but appear to be rather continuous across the state of New York and the known localities follow in a general way the line of the present Erie canal from Buffalo to the Hudson River at Albany. This region lies outside the scope of the present paper, but it should be mentioned here that there are other western species of Najades which follow the same line of dispersal eastward from the St. Lawrence drainage to Hudson River. It is very likely that Eurynia nasuta belongs to this group, and it prob- ably is the one of them which has reached in modern times the widest dispersal upon the Atlantic side. Its western origin is con- firmed by the fact that the only species allied to it, Eurynia sub- rostrata (Say), is western and is found in the central and western parts of the interior basin in large, quiet rivers, ponds and lakes, avoiding rough water and strong current. For this reason, prob- ably, it is not found in the upper Ohio drainage. This species has crossed somewhere in the region from northern Illinois to northern Ohio into the lake drainage, developed there into the species nasuta, which then spread eastward, following the quiet waters of the lakes and those of the canal till it reached the estuary of the Hudson. Thence it had no difficulty to spread farther over the Coastal Plain and reached across New Jersey?” the lower Delaware, and even be- yond. Also on the Atlantic side it preserves its preference for lakes, estuaries, canals, etc., that is to say, for quiet water. We thus are to regard Eurynia nasuta as a quite recent immi- grant in the Atlantic drainage, belonging surely to the Postglacial time, and this immigration might have been completed even by the “ It is present, for instance, in the Delaware-Raritan canal at Princeton, Mo 380 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, help of the modern, artificial canals. But, of course, it is difficult to decide positively whether canals have played a necessary part in this dispersal. This question should be investigated in connection with the other western forms, which have taken the route of the Erie canal; but this is not our present object. The above studies would be more complete if the conclusions were supported by paleontological evidence; if we had fossil rem- nants of Najades or other aquatic creatures which would give us an idea as to the faunas of the two watersheds in the past, chiefly during Tertiary times. It is very much to be regretted that prac- tically nothing is known in this line. There is indeed a famous locality, Fish House, Camden Co., New Jersey, opposite Philadelphia, which has yielded fossil Najades, probably belonging to the Glacial time. These shells have been de- scribed and discussed by Lea and chiefly by Whitfield (Mon. U. S. Geol. Surv., 9, 1885), and their geological age has been ascertained by Woolman (Ann. Rep. Geol. Sury. N. J. (for 1896), 1807 201 ff.), Pilsbry (Pr. Ac. Philad., 1896, p. 567) and Simpson U. S. Mus., 1895, p. 338). But for the present time these fossils are absolutely useless, because western affinities have been main- tained for these species, which surely do not exist. The species have been identified mainly from casts, and Lea as well as Whitfield have indicated, by the names given to them, their supposed affinities to western species. I have taken the trouble of making plaster casts of the inside of specimens of the living species with which they have been correlated, and practically in all cases it became evident at a glance that there was no similarity at all. But this should be the subject of a special paper. It suffices here to make the statement, first, that the number of species described from this deposit (about a dozen) should be reduced to not more than three or four, and second, that there is not a single one which has distinct and unmistakable affinities to any typical western species. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 381 SUMMARY OF CONCLUSIONS. 1. I think that the present studies have demonstrated the funda- mental fact, that certain freshwater animals are apt to furnish im- portant evidence for past conditions of drainage by their present distribution, while others are not. The most important of the former are the Najades. There are many cases (not only in our region) where indentical or closely allied species are found in dif- ferent drainage systems which have at present no direct water con- nection. Such cases are generally restricted to limited, well-defined regions. In our region we have seen that such cases exist in the mountains in the section which has the upper New River for its center; but similar instances are known in Pennsylvania, in the headwaters of the Susquehanna. This localisation is the most important evidence against the assumption that passive transport over land has played a part in these cases: if this was possible at all, or if it was a factor to be considered, evidence for this should be general. But just where we might expect that transport should have worked by all means, there is no evidence whatever for it. This is most especially true in the case of the divide between the upper Tennessee drainage and that of New River. If Najades should be able to cross divides by being transported, it should have happened just here. Also the gen- eral condition of the eastern and western fauna, its dissimilarity, shows that Najades were not transported across the mountains. Very likely the freshwater snails of the family Pleuroceride submit to the same general law as the Najades and are important for the study of the old drainage features. But they should be further studied, chiefly with regard to their actual distribution, their sys- tematics and relationships. Finally, some crayfishes of the genus Cambarus are extremely valuable in this respect, but unfortunately their number is not great. 2. The Allegheny system forms an old and very well-marked boundary between aquatic animals inhabiting the interior basin and the Atlantic slope. This barrier may have been rendered insignifi- 382 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, cant at certain times in the past. ' But beginning with the Post- cretaceous elevation of the country and the subsequent rejuvenation of all drainage systems, this barrier has been emphasized again and persists to the present time. 3. The uniformity of the fauna of the upper Ohio basin is a character acquired in Postglacial times, and it has been shown that not only Big Sandy River, but also Licking River, and possibly also Kentucky River, belong to the upper Ohio basin, and not to the Cumberland-Tennessee drainage. In this case sodgeographical evi- dence contributes to the solution of a question which has not been fully settled by physiographical methods. 4. On the western side we have remnants of am older (Pre- glacial) faunistic differentiation. The most important division is the Tennessee-Cumberland fauna, of which, however, only a small part has been considered in the present paper, and which deserves more detailed study. Other remnants of what might be Preglacial faunas are possibly seen in the headwaters of the Monongahela and Kanawha rivers. But in these cases the physiographical develop- ment of these parts must be studied more closely before we can arrive at a final conclusion, 5. The Atlantic fauna is a distinct fauna and the creation of two faunal provinces, Mississippian and Atlantic (Simpson, 1900, p. 505), is fully justified. Nevertheless, the Atlantic fauna is a sec- ondary one, derived originally from that of the interior basin, and its chief character consists in the absence of a great number of types of the interior basin. 6. Within the Atlantic fauna we have to distinguish two maim elements, a northern and a southern. ‘The northern came from the interior basin around the northern end of the Alleghenies ; the south- ern came around the southern end. The former belongs to the Pre- glacial time, but is not very old, while in the latter there are some rather ancient elements, going back possibly to the earlier Tertiary, or even beyond. The southern element probably is closely connected with the Tennessee-Coosa problem. 7. Along the Atlantic slope we have a dispersal line directed both north and south, which has been clearly recognized, for land-forms, 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 383 by Adams (1902 and 1905). But this route was available also for aquatic forms of life and lies probably mainly upon the Coastal Plain, where barriers are largely removed by base-leveling. To a smaller degree stream piracy in the uplands may have played a part in the dispersal of the Atlantic forms. 8. In the mountains we know a few cases which indicate crossing of the divide, but compared with the mass of the fauna, these cases are very insignificant. However, they are zoögraphically of the greatest interest in so far as they indicate probable cases of stream capture. In order to properly understand these cases, the physiog- raphy of the region involved should be studied more closely. 9. In addition, we have on the Atlantic side a few cases of ab- normal distribution for which special explanations have been ad- vanced. One of them concerns a form, Margaritana margaritifera, which differs in the origin of its distribution entirely from all North American Najades,’' and which is a stranger in our fauna. The other case, Eurynia nasuta, possibly is due to Postglacial migration from the St. Lawrence basin to the Atlantic slope, and may be in part quite recent. 10. Further investigations should be made primarily in the region of the southern Atlantic slope and in the southern Appalachians, and should be connected with the study of the Tennessee-Coosa problem from the zoögeographical side. In this region there are extremely interesting conditions, which, however, are very unsatisfactorily known, and have led Johnson (1905) to the erroneous assumption that the evidence taken from the Najades is unreliable with regard to the reconstruction of the old drainage systems. In addition, other freshwater groups should be studied. In the present paper the Najades have furnished the chief evidence, but it has been shown that also certain Gastropods and the Crayfishes are or might be valuable; but there are surely other groups, chiefly the Fishes. 3 ** At present, only a land snail, Helix hortensis Muell., falls under the same head. PROC. AMER. PHIL. SOC. LII. 210 G, PRINTED JULY 14, I913. 384 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, BIBMIOGRAREN: Abbe, C., Jr. 1899. A General Report on the Physiography of Maryland. In: Clark, W. B. Maryland Weather Service, I, 1899, pp. 41-216. Abbe, C., Jr. 1902. The Physiography of Garrett County. In: Clark, W. B. Maryland Geological Survey. Garrett Co., 1902, pp. 27-54. Adams, C. C. 1901. Baseleveling and its Faunal Significance, with Illustrations from the Southeastern United States. Americ. Natural. 35, 1901, pp. 839- 852. Adams, C. C. 1902. Southeastern United States as a Center of Geographical Distribution of Flora and Fauna. Biol. Bull., 3, 1902, pp. 115-131. Adams, C. C. 1905. The Postglacial Dispersal of the North American Biota. Biol. Bull., 9, 1905, pp. 53-71. Bolster, R. H. 1907. In: Parker, H. N., Willis, B. Bolster, R. H., Ashe, W. W., and Marsh, M. C. The Potomac River Basin. U. S. Geol. Surv.— Wat. Suppl. ea, IRADSP mo, 1102, 1007 Caffrey, G. W. ıgıı. The Molluscan Fauna of Northampton ey Pennsylvania. Nautilus, 25, IQII, pp. 26-29. Call, R. E. 1885. A Geographic Catalogue of the Unionide of the Mississippi EA Bull. Des Moines Acad. Sci., I, 1885, pp. 9-57. Campbell, M. R. 1896. Drainage Modifications and their Interpretation. Journ. Geol., 4, 1896, pp. 567-581, 657-678. Campbell, M. R., and Mendenhall, W. C. 1896. Geologic Section along New and Kanawha Rivers in West Virginia. 17th Ann. Rep. U. S. Geol. Surv. (for 1895-96), part 2, 1806, pp. 479-511. Conrad, T. A. 1835-38. Monography of the Family Unonide. 1835-1838. Conrad, T. A. 1846. Notices of Freshwater Shells, etc., of Rockbridge County, Virginia. Americ. Journ. Sci. (2), I, 1846, pp. 405-407. Davis, W. M. 1899. The Rivers and Valleys of Pennsylvania. Nation. Geogr. Magaz., I, 1889, pp. 183-253. Davis, W. M. 1891. The Geological Dates of Origin of Certain Topographic Forms on the Atlantic Slope of the United States. Bull. Geol. Soc. Amer., 2, 1891, pp. 545-584. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 385 Davis, W. M. | 1907. The United States of America. Regional Geography. In: Chapter 39 of: Mill, H. R. The International Geography, 1907, pp. 715-735. Dewey, C. 1856. List of Najades found in Western New York. oth Ann. Rep. Reg. Univ. N. Y., 1856, Dp. 32-38. Fontaine, see: Maury and Fontaine. Foshay, P. M. 1890. Preglacial Drainage and Recent Geological History of Western Pennsylvania. Amer. Journ. Sci. (3), 40, 1890, pp. 397-403. Gabb, A. F. 1861. List of Mollusks Inhabiting the Neighborhood of Philadelphia. Pr. Acad. Philad., 1861, pp. 306-310. Hartman, W. D., and Michener, E. 4 1874. Conchologia Cestrica. 1874. Hayes, C. W. 1896. The Southern Appalachians. The Physiography of the United States. Nat. Geogr. Soc., 1896, pp. 305-336. Hayes, C. W. 1899. Physiography of the Chattanooga District in Tennessee, Georgia, and Alabama. 19th Ann. Rep. U. S. Geol. Surv. (1897-98), part 2, 1899, pp. I-58. Hayes, C. W., and Campbell, M. R. ' 1894. Geomorphology of the Southern Appalachians. Nation. Geogr. Magaz., 6, 1894, pp. 63-126. Hoyt, J. C., and Anderson, R. H. 1905. Hydrography of the Susquehanna River Drainage System. U. .S. Geol. Surv.— Wat. Suppl. & Irrig. Paper no. 109, 1905. Johnson, D. W. 1905. The Distribution of Freshwater Faunas as an Evidence of Drainage Modifications. Science, 21, April 14, 1905, pp. 588-592. Le Conte, J. 1891. Tertiary and Post-Tertiary Changes of the Atlantic and Pacific Coasts. Bull. Geol. Soc. Amer., 2, I891, pp. 223-328. Lesley, J. 1865. Coal Formation of Southern Virginia. Pr. Amer. Philos. Soc., 9, 1865, pp. 30-38. Leverett, F. 1902. Glacial Formations and Drainage Features of the Erie and Ohio Basins. Monogr. U. S. Geol. Surv., 41, 1902, pp. 1-781. Lewis, J. 1871. On the Shells of the Holston River. Amer. Journ. Conchol., 6, 1871, pp. 216-210. Marshall, W. B. 1895. Geographical Distribution of the New York Unionide. 48th Rep. N. Y. State Mus., 1895, pp. 47-99. 386 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, Maury, M. F., and Fontaine, W. M. 1876. Resources of West Virginia. State Board of Centennial Managers, 1876. McGee, W J 1888. Three Formations of the Middle Atlantic Slope. Amer. Journ. Sci. (3), 35, 1888, pp. 120-143. Ortmann, A. E. 1905. The Mutual Affinities of the Species of the Genus Cambarus, and their Dispersal over the United States. Pr. Amer. Philos. Soc., 44, 1905, pp. 92-136. Ortmann, A. E. 1906. The Crawfishes of the State of Pennsylvania. Mem. Carnegie Mus., 2, 1906, pp. 343-524. Ortmann, A. E. 1912a. Notes upon the Families and Genera of the Najades. Ann. Carne- gie Mus., 8, 1912, pp. 222-365. Ortmann, A. E. 1912b. Lampsilis ventricosa in the Upper Potomac Drainage. Nautilus, 26, 1912, pp. 51-54. Pilsbry,: He A. 1894. Critical List of Mollusks Collected in the Potomac Valley. Pr. Acad. Philad., 1894, pp. II-30. Powell, J. W. 1896. Physiographic Regions of the United States. The Physiography of the United States. Nation. Geogr. Soc., 1896, pp. 65-100. Rhoads, S. N. 1904. A Glimpse at the Shell Fauna of Delaware. Nautilus, 18, 1904, pp. 63-67. Rogers, W. B. 1884. A Reprint of Annual Reports and other Papers on the Geology of the Virginias. New York, 1884. Schick, M. . 1895. Mollusk Fauna of Philadelphia and Environs. Nautilus, 8, 1895, pp. 133-140. Simpson, C. T. 1893. On the Relationship and Distribution of the North American Union- ide, with Notes on the West Coast Species. Amer. Natural., 27, 1893, Pp. 353-358. | Simpson, C. T. 1896a. On the Mississippi Valley Unionida found in the St. Lawrence and Atlantic Drainage Areas. Amer. Natural., 30, 1896, pp. 379-384. Simpson, C. T. 1896b. The Classification and Geographical Distribution of the Pearly Freshwater Mussels. Pr. U. S. Mus., 18, 1896, pp. 295-343. Simpson, C. T. 19004. Synopsis of the Najades or Pearly Freshwater Mussels. Pr. U.S. Mus., 22, 1900, pp. 501-1044. 1913.] ORTMANN--THE ALLEGHENIAN DIVIDE. 387 Simpson, C. T. ıgoob. On the Evidence of the Unionide Regarding the Former Courses of the Tennessee and other Southern Rivers. Science, 12, July 27, 1900, pp. 133-136. Spencer, J. W. 1903. Submarine Valleys off the American Coast and in the North At- lantic. Bull. Geol. Soc. Amer., 14, 1903, pp. 207-226. Stevenson, J. J. 1887. A geological Reconnaissance of Bland, Giles, Wythe, and Portion of Pulaski and Montgomery Counties of Virginia. Pr. Amer. Philos. Soc., 24, 1887, pp. 61-108. Tryon, G. W., Jr. 1865-66. Monograph of the Family Strepomatide. Amer. Journ. Conchol., I, 1865, pp. 299-341; 2, 1866, pp. 14-52, 115-133. U. S. Geological Survey. Topographical Atlas Sheets (as far as published). Walker, B. ıgıo. Distribution of Margaritana margaritifera in North America. Pr. Malacol. Soc. London, 9, 1910, pp. 126-143. White, C. H. 1904. The Appalachian River versus a Tertiary Trans-Appalachian River in Eastern Tennessee. Journ. Geology, I2, I904, pp. 34-39. White, I. C. 1896. Origin of the High Terrace Deposits of the Monongahela River. Amer. Geologist, 18, 1896, 368-379. Willis, B. 1896. The Northern Appalachians. The Physiography of the United States. Nation. Geogr. Soc., 1896, pp. 169-202. Willis, B. 1912. Index to the Stratigraphy of North America, Accompanied by a Geological Map of North America. U. S. Geol. Surv. Prof. Pap., Ze 1912, CARNEGIE MUSEUM, PITTSBURGH, PA,, April 18, 1913. 388 ORTMANN--THE ALLEGHENIAN DIVIDE. [April 18, EXPLANATION OF PLATE XII. MAP oF THE ALLEGHENY SYSTEM OF VIRGINIA, WEST VIRGINIA, MARYLAND AND PENNSYLVANIA. The chief Physiographical Divisions are: AP: Allegheny Plateau; AM: Allegheny Mountains; AV: Allegheny valley; PP: Piedmont Plateau; CP: Coastal Plain. They are marked off by heavy dotted lines. From the upper Clinch River to Covington, on Jackson River, runs another dotted line, which indicates the chief fault of this region, discussed in chapter 5, p. 345. The line of heavy dashes represents the divide between the Interior Basin drainage in the West, and that of the Atlantic Slope (including the St. Lawrence) in the East and North. The following abbreviations for rivers and creeks have been used: Upper Ohio and Allegheny drainage: All = Allegheny River. Cr = Crooked Creek. Bv= Beaver River. Fr=French Creek. Clar = Clarion River. Kis = Kiskiminetas River. Con = Conemaugh River. Loy = Loyalhanna River. Mah== Mahoning Creek. Po = Potato Creek. Qu = Quemahoning Creek. RB = Red Bank Creek. ‘Monongahela drainage: a Bl = Blackwater River. ; SF == Shavers Fork. Bu = Buckhannon River. Tyg = Tygart Valley River. DF = Dry Fork. WF == West Fork River. Tributaries of Ohio in West Virginia and Kentucky: F=Fish Creek. L. Fk=-Levisa Fork of Big Sandy River. Fg = Fishing Creek. L. Kan= Little Kanawha River. Hg — Hughes River. M. I.=Middle Island Creek. Delaware drainage: Leh= Lehigh River. Liz = Lizard Creek. P= Princess Creek. Susquehanna drainage: C. C. = Cush Cushion Creek. N.B.=North Branch of Susque- hanna. Ch= Chest Creek. Si= Sinnemahoning Creek. Cl= Clearfield Creek. Sw = Swatara Creek. Coned = Conedoguinet Creek. Tı= Tioga Creek. Conew = Conewago Creek. W. B. = West Branch of Susque- hanna. 1913.] ORTMANN—THE ALLEGHENIAN DIVIDE. 389 Potomac drainage: An = Antietam Creek. S. B. = South Branch Potomac River. Con = Conococheague Creek. To = Tonoloway Creek. N. B. = North Branch Potomac W=Wills Creek. River. James drainage: N =North River (headwaters called: Calf Pasture River). RF=Rockfish Creek. Riv = Rivanna River. Roanoke drainage: N. F. = North Fork Roanoke River. Holston drainage: Holston = North Fork Holston S. F. = South Fork Holston River. River. M. F. = Middle Fork Holston River. EXPLANATION OF PLATE XII. PROFILES OF RIVERS. Fic. 1: Profile up from Pittsburgh, Pa., along Allegheny River, Mahon- ing and Little Mahoning Creeks to Divide, and thence down along Cush Cushion Creek, West Branch Susquehanna, and Susquehanna River to Havre de Grace, Md. (sea level). Between Curvensville and Keating the river has not been accurately sur- veyed. Compiled from: U. S. Geol. Surv. Atlas Sheets, and Hoyt and Ander- son, 1905, pl. 28 and 20. Fic. 2. Profile from a little above McKeesport, Pa., up the Mononga- hela and its tributaries (Youghiogheny, Cheat and Shavers Fork, Tygart Valley River, West Fork River) to the Divide, and thence down the South and North Branch and the Potomac River, to Washington, D. C. The sources of Shavers Fork and South Branch Potomac are about twenty miles apart. On account of the exaggerated vertical scale, the head- waters of all rivers appear much longer than they actually are. Compiled from: U. S. Geol. Surv. Atlas Sheets, and Bolster, 1907, pl. 5 and 6. 390 ORTMANN—THE ALLEGHENIAN DIVIDE. [April 18, EXPLANATION OF PLATE XIvo PROFILES OF RIVERS AND MOUNTAINS. Fic. 1. Profile from Charleston, W. Va., up the Kanawha, New and Greenbrier Rivers, to the Divide, and thence down the Jackson and North Rivers to Lynchburg, Va., on James River. Also the profile of the upper Roanoke is given and its location with reference to New River, and the old abandoned valley connecting the two. The upper parts of New River are only roughly sketched. The sources of Greenbrier and Jackson Rivers are about fifteen miles apart. Compiled from U. S. Geol. Surv. Atlas Sheets. Fic. 2. Profile along the crest of the Allegheny Front, and the ranges farther south (Peters and East River Mountains), which form its continua- tion. The rivers and creeks at the eastern foot of the mountains are indicated by dotted lines. In the region of the B. & O. Tunnel exact data are missing. The two sections of the profile are connected at r—y. The range behind Dans Mountain is Savage and Backbone Mountain. Compiled from U. S. Geol. Surv. Atlas Sheets. Explanation of abbreviations: Streams: Cl= South Fork Clinch River. N. Br. = North Branch Potomac. ' St= Stony Creek. Ray=Raystown Branch Juniata Riv. Du=Dunlap Creek. Dun = Dunning Creek. N. FR. S. Br. Pot. = North Fork ot Fra. Jum == Frankstown Branch South Branch Potomac. Juniata River. W. G. = Water Gaps (of New River, flowing West, and of Potomac, flowing Past): Towns: Tunnels: Cov = Covington, Va. C. & O.=Chesapeake and Ohio RR: Pet = Petersburg, W. Va. B. & O.=Baltimore and Ohio R. R. Cumb = Cumberland, Md. P. R. R.= Pennsylvania R. R. Holl = Hollidaysburg, Pa. It is believed that the depression in the region of the C. & O. Tunnel is a remnant of the Cretaceous Peneplain. PLATEEXII2 No. 210 PROCEEDINGS AM. PHiLOS. Soc, VOL. LII. N ppodirmonygee®*” SW feel “PIN “CAM “BA jo WALSAS ANAYHOATIV ef Me Ud) = ’ 1 N a = 4 h 'ê AS ‘ E ‘ ae!) I / | Me 7 e die a = My My di 4 No 4 3, \ i N Piz N a N = 1 4 + N eu x ail A ‘ R A i In) 1 ' Bin i a A F 4 % Br / quo A RA U 4 i + É nas 1 I > ss | ” I . E N All ro » n . ‘ r iy, =, r 1 Ú Na É = ») + . ö ‘ Ay E a RA a x 5 . (a ey Ok di 0 x iy x PA à f DAS : i N } + A + 1 a M E ta an | NM =f { \ 0 in A ' i o Bel 7 na 4 { i eo =D ee UR Fe As! 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