ae epee niece Se ocean etae SS hy aa a Ries ; oe 4 4 ha Meee wh ae Wd ier path matey 42 nes oh a Memoirs ot the aduseum ot Comparative Zodstogy = AT HARVARD COLLEGE. th. ce on REMI. «Page 205 65" ri : ¢ x ; ; ‘ * ul Tene en Ty eum, wary, 1918. apa SF z bac Memoirs of the Museum of Comparative Zodlogy = AT HARVARD COLLEGE. G le 24 1.7 Vou. XLII. Parr 2. 4 I / \- t2 > THE AMERICAN CHARACIDAE/ BY CARL H. EIGENMANN. WITH TWENTY-TWO PLATES. CAMBRIDGE, U. S. A.: Printed for tbe Museum. JANUARY, 1918. od THE AMERICAN TETRAGONOPTERINAE. 103 25. MOENKHAUSIA LEPIDURA GRACILIMA Eigenmann. Plate 101, fig. 7. Moenkhausia lepidurus gracilimus EIGENMANN, Bull. M. C. Z., 1908, 52, p. 104 (Serpa); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 438. Hasirat.— Serpa. 20983 Cotypes 21 About 39-57 mm. Serpa Thayer Anal on an average with twenty-two rays, there being one with nineteen, two with twenty, one with twenty-one, eleven with twenty-two, four with twenty-three, one each with twenty-four and twenty-five; pectoral not reaching ventrals. Depth 4 or nearly 4, the greatest depth just behind pectorals, then tapering gradually to caudal. The fontanel, in the long, slender ones with a typically colored caudal, is narrower than in the others. Lateral line 35 or 36. Color of caudal as in typical individuals of M. lepidura, but faint, with a dusky shade extending on the lower caudal lobe. Humeral spot, even in the smallest, of over twenty chromatophores, not well defined. 20717 17 47-59 mm. Villa Bella Agassiz These specimens are nearest those from Serpa. They have, on an average, twenty-two anal rays. Five have twenty-one, five twenty-two, and four twenty- three; the pectoral does not reach the ventrals. Depth 3-4; lateral line 35 or 36. Middle caudal rays and distal part of all the remaining rays as well as the upper and lower margin of the fin dusky; tip of anal lobe sometimes milk- white; humeral spot of many chromatophores, extending up from the second and third or third and fourth scales. These specimens are appreciably different from typical M. lepidura graci- lima, but gradations between them are almost perfect. 26. MoENKHAUSIA COLLETTII (Steindachner). Plate 8, fig. 1; Plate 15, fig. 4; Plate 101, fig. 3. Tetragonopterus collettii SrEINDACHNER, Flussf. Siidamer., 1882, 4, p. 33, pl. 7, fig. 3, (Obidos; Hyavary); EIGENMANN & EIGENMANN, Proc. U.S. N. M., 1891, 14, p. 53; Unrey, Ann. N. Y. aead. sci., 1895, 8, p. 81. 104 THE AMERICAN CHARACIDAE. Moenkhausia collettii E1GENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 438; Mem. Car- negie mus., 1912, 6, p. 328. HapsitTat. — Amazons and Guiana. Specimens examined. Catalogue Number of number specimens Size in mm. Locality Collector 20952 36 37-63 Jatuarana Navez 20711, 20721 20 20-59 Villa Bella Agassiz 20812 3 37-49 Tea James 20840 3 3140 ? ? 20843 41 about 34-54 Obidos Bentos 1324 C. 11804 I. 19 43-58 Wismar, Demerara River Eigenmann 1326 C. 11807 I. 5 34-39 Malali, Demerara River Shideler 1327 C. 11810 I. 136 40-61 Rockstone, Essequibo River Eigenmann 1328 C. 11806 I. 12 37-59 Gluck Island at Rockstone Eigenmann 1329 C. 11808 I. 5 41-56 Crab Falls, Essequibo River Eigenmann 1330 C. 11803 I. 19 338-46 Konawaruk, Essequibo River Eigenmann 1331 C. 11809 I. 41 35-66 Tumatumari, Potaro River Eigenmann 1332 C. 11801 I. 100+ 24-68 Erukin, tributary of Potaro Eigenmann River, below Amatuk 1333 C. 1 63 Amatuk Cataract Eigenmann 1334 C. 3 3840 Tusaca Pan, Rupununi Grant 3739 C. 111 largest 58 Braganca Haseman 3740 C. 16 45-50 Bastos Haseman 3741 C. 2 53-56 Manaos Haseman 3742 C. 5 40-56 Maciél, Rio Guaporé Haseman Head 3.7-3.8; depth 2.6 in gravid females to 3.3 in males, 3.75 in some specimens from Guiana; D. 11 (rarely 10 or 12); A. usually 33 or 341; scales 5-34-34; eye 2.5-2.75; interorbital about 3 in head. Compressed, dorsal and ventral profiles equally curved, without humps or depressions; preventral area rounded; postventral area compressed or narrowly rounded; predorsal area keeled for at least half the distance from the dorsal to the occipital process; a median series of nine or ten predorsal scales extend- ing from the dorsal to the occipital. Occipital process extending about one fifth of the distance from its base to the dorsal, bordered by two or three scales; interorbital convex in the middle, with lateral grooves; frontal fontanel narrower and about three fourths as long as the parietal; second suborbital leaving a naked area on the cheek, widest 1 Of the Amazon valley specimens one has nineteen anal rays, three have twenty, five twenty-one, six twenty-two, thirty-four, twenty-three, twenty-eight, twenty-four, eleven twenty-five, and five twenty- six. Of forty-one Guiana specimens three have twenty-one anal rays, sixteen twenty-two, sixteen twenty- three, and six twenty-four. ? Rarely 33 and 35. THE AMERICAN TETRAGONOPTERINAE. 105 below; maxillary equal to distance from tip of snout to pupil, three in the head. Usually four, sometimes five teeth in the outer row of the premaxillary, the second and third close together, the third withdrawn from the line; five teeth in the second series; maxillary with two or three minute teeth. Four large teeth in the front of the lower jaw, minute ones on the sides. Gill-rakers 7 + 10, about one third the diameter of the eye. Seales closely imbricate, with several striae; caudal lobes scaled for rather more than half their length; anal with a sheath of a single series of scales in front; lateral line but little decurrent, the rows of scales above and below it parallel with it; a well-developed axillary scale. Origin of dorsal usually nearer tip of snout than base of caudal, its height three and a half in the length, its highest ray nearly three times as high as its penultimate; caudal widely forked, the lobes longer than the height of the dorsal; anal emarginate, its highest ray reaching to base of last ray but five, its origin considerably behind the vertical from the last dorsal ray, its base about three and a half in the length; pectorals reaching ventrals, ventrals to or nearly to anal; origin of the ventrals equidistant from tip of snout and base of last anal ray. No caudal spot; a very narrow silvery band overlying a dark line; a well- defined humeral spot of numerous chromatophores above the third, fourth, and fifth scales of the lateral line; numerous chromatophores on the upper half of the cheek and opercle; a dark line of varying intensity and width along the base of the anal; scales of the back margined with dusky; scales of the median line in front of and behind the dorsal dusky, or with a dusky margin and a dusky median spot. The color varies much in intensity with different localities. Those from Jatuarana, Villa Bella, I¢a are pale, those from Obidos are dark. In life the vertical fins of the Guiana specimens at least are more or less tinged with red. Anterior anal rays of the male with recurved hooklets. Vertebrae 13 + 17. Posterior air-bladder about equal to the eye in diameter, more than twice the length of the anterior bladder, about three times as long as the eye, blunt behind and bent down to near the origin of the anal. Alimentary canal about equal to the length without the caudal. Insect eaters. There is considerable variation in shape in the Guiana specimens enumer- ated. The specimens from Rockstone are deep and thin, depth about 2.75; those from Konawaruk and the Potaro are more elongate and heavier. In the Konawaruk specimens the depth is 3.75. 106 THE AMERICAN CHARACIDAE. 27. MoENKHAUSIA COPEI (Steindachner). Plate 9, fig. 3; Plate 101, fig. 4. Tetragonopterus copei STEINDACHNER, Flussf. Siidam., 1882, 4, p. 135, pl. 6, fig. 6, (Santarem); E1rcEen- MANN & EIGENMANN, Proc. U. 8. N. M., 1891, 14, p. 53. Moenkhausia copei E1GENMANN, Rept. Princeton univ. Exped. Patagonia, 1910, 8, p. 438; Mem. Carnegie mus., 1912, 5, p. 329. Hasirat.— Santarem to Para and British Guiana. Specimens examined. Catalogue Number of number specimens Size in mm. Locality Collector 20783 30 3444 Santarem Bourget 21072 1 30 (to Para Thayer Ex- base of caudal) pedition 1321 C. 11824 I. 26 30-56 Wismar, Demerara River Eigenmann 1322 C. 11821 I. 11 33-56 Gluck Island at Rockstone Eigenmann 1323 C. 11820 I. 53 27-55 Rockstone, Essequibo River Eigenmann 1324 C. 11823 I. 42 35-45 Tusaca Pan, Rupununi Grant 3742 C. 5 40-56 Maciél, Rio Guaporé Haseman Closely allied to M. collettii; distinguished by the shorter anal. Head 3.66-4; depth 3.33-3.66; D. 11; A. 18-201; scales 5-32 to 34-3.5 (usually 33 pores in the lateral line). Eye 2.5-2.75 in the head; interorbital 3 or a little more. Slender, little elevated; dorsal and ventral profiles about equally curved, nowhere notably depressed or elevated; preventral area flattish; postventral area compressed; predorsal area obscurely keeled just in front of the dorsal, with a median series of nine scales reaching to the occipital process. Occipital process short, less than one fifth the distance from its base to the dorsal, bordered by two or three scales on the side; interorbital convex in the center, with lateral grooves; frontal frontanel much narrower and about three fourths as long as the posterior; second suborbital leaving a naked border on the cheek which is widest below; maxillary equals distance from tip of snout to pupil; frequently four teeth in the outer row of the premaxillary, of which the middle two are close together and remote from the others; five teeth in the second row; one or two maxillary teeth; four large teeth in the front of the man- dible. 1 Out of fourteen four have eighteen anal rays, nine nineteen and one twenty. THE AMERICAN TETRAGONOPTERINAE. 107 Gill-rakers one fifth to two sevenths of the diameter of the orbit, about 7 + 12. Seales closely imbricate, with few divergent striae; caudal lobes scaled for about half their length; anal with a sheath of a single row of scales in front; lateral line but little decurved, the rows of scales above and below it parallel with it; a well-developed axillary scale. Origin of dorsal about equidistant from tip of snout and base of caudal, its height three and a half in the length; caudal deeply forked, the lobes about three in the length; anal deeply emarginate, its origin behind the vertical from the last dorsal ray; pectorals and ventrals about the same length, about equal to the length of the head without the snout; ventrals not to anal, tips of pec- torals one or two scales from ventrals. No caudal spot; a very narrow silvery band overlying a narrow dark band which in some specimens becomes wider in front, sometimes expanded into a humeral spot over the fourth scale of the lateral line, continued across the upper part of the opercle and preopercle to the eye; a black line along the base of the anal, expanded into a broader spot above the base and in front of the first anal rays; middle anal rays dark; scales of the back margined with dusky, scales of the median line in front of the dorsal dark. The Rockstone specimens have the caudal rose colored in life, especially the upper lobe; those from Gluck Island have the adipose and upper caudal lobe rusty, anal lobe lemon-yellow, dorsal yellow in center, tinged with orange. Vertebrae 12 + 17. Posterior air-bladder long, banana-shaped; curved down behind to in front of the anal, its diameter but little less than that of the eye, its length at least twice that of the anterior air-bladder. Alimentary canal about equal to the length (without the caudal). 28. MorNKHAUSIA CEROS Higenmann. Plate 9, fig. 2; Plate 101, fig. 1. Moenkhausia ceros E1GENMANN, Bull. M. C. Z., 1908, 52, p. 104 (Lake Hyanuary); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 438. Hasirat.— Amazon Basin. 108 THE AMERICAN CHARACIDAE. Specimens examined. Catalogue Number of number specimens Size in mm. Locality Collector 20955 Type 1 50 Lake Hyanuary Navez 3725 .C. 1 52 Manaos Haseman 3726 C. 3 about 20-51 Bastos Haseman Distinguished by its caudal spot and short anal. Head 4; depth 3.25; D. 11; A. 18 or 19; seales 5-33 or 34-3. Eye 3, a little more than interorbital. Elongate, compressed; dorsal and ventral profiles gently curved, dorsal profile somewhat angulated at the origin of the dorsal, not depressed over eyes. Preventral area flattish, with a median series of scales, the lateral scales some- what angulated; predorsal area somewhat keeled, with a median series of ten scales reaching from the occipital process to the dorsal. Occipital process short, reaching about one sixth to dorsal, bordered by three scales on each side; interorbital very slightly convex; second suborbital leaving a wide naked area; maxillary not reaching end of first suborbital, equal to distance from tip of snout to pupil, two and two thirds in the head. Four teeth in the front series of the premaxillary, opposite the second and third of the inner series, the first distinetly largest; inner series of five or six graduated teeth; four large, graduated teeth on each ramus of the lower jaw and numerous small ones. Gill-rakers about 9 + 15, long and slender, one half as long as eye. Scales regularly imbricate, with four to six striae; two and a half scales between lateral line and front of anal, apparently no anal sheath; caudal lobes with scales for at least half their length; lateral line slightly decurved, the rows of scales above and below it parallel with it; a well-developed axillary scale. Origin of dorsal about equidistant from tip of snout and base of caudal, the ventrals a little nearer tip of snout; highest dorsal ray not quite four in the length; anal emarginate, its origin but little more remote from the tip of the snout than the end of the dorsal, anal basis a little more than one fourth of the length; the adipose fin opposite the end of the anal. Ventrals reaching anal; pectorals to ventrals. The middle of the first fully developed anal ray of the male provided with a large retrorse hook on each side. A faint, ill-defined, silvery band, above which is a gray line; middle caudal rays jet black, the color spreading out over the base of the fin. Scales and fins minutely punctate; sides brassy iridescent. Humeral spot very faint or absent. THE AMERICAN TETRAGONOPTERINAE. 109 29. MoENKHAUSIA COTINHO Eigenmann. Plate 9, fig. 1; Plate 101, fig. 2. Moenkhausia cotinho E1cENMANN, Bull. M. C. Z., 1908, 52, p. 104 (Para); Rept. Princeton univ. exped. Patagonia, 1910, 3, 434; Mem. Carnegie mus., 1912, 5, p. 327. Hasirat.— Amazon Basin; Guiana. Specimens examined. Catalogue Number of number specimens Size in mm. Locality Collector 21013 Cotypes 2 46-54 ? Justa (to base of caudal) 21070 Cotypes 3 67-71 Para Thayer Ex- pedition 3729 C. 3 53-55 Villa Bella Haseman 3730 C. 2 52-55 Manaos Haseman By Ge 1 52 Maciél, Rio Guaporé Haseman 3728 C. 1 54 San Joaquin Haseman 3747 C. 1 48 Santarem Haseman ISIPAGe wakes 35 34-55 Wismar, Demerara River Eigenmann 1313 C. 11814 I. 33 42-60 Malali, Demerara River Shideler 1314 C. 11818 I. 22 52-62 Tukeit, Potaro River Eigenmann 1315 C. 1 64 Cangaruma, Potaro River Eigenmann 1316 C. 11815 I. 6 45-51 Mud flats below Wismar Eigenmann 1317 C. 11812 I. 27 44-66 Tumatumari, Potaro River Eigenmann 1318 C. 11819 I. 17 43-59 Crab Falls, Essequibo River Eigenmann 1319 C. 11816 I. 7 41-57 Christianburg Canal Eigenmann 1320 C. 11817 I. 2 35-57 Rockstone, Essequibo River Eigenmann Distinguished by its slender form combined with the broad basal caudal bar. Head 3.7-4; depth 2.8-3.3; D. 11; A. 19-21. Scales 5-31 to 33-3.5. Eye 2.71-8. Interorbital slightly greater or less than eye. Elongate, not strongly compressed or elevate; dorsal and ventral profiles equally curved, without notable depressions or elevations. Preventral area rounded or flat, with a median series of scales, bordered by scales not at all or but little angulated; postventral area compressed, with a median series of large, angulated scales; predorsal area rounded with a median series of nine scales from the dorsal to the occipital process. Occipital process short, reaching one sixth the distance to dorsal, bordered by two or three scales on each side. Interorbital slightly convex; second sub- orbital greatly arched, leaving a very narrow naked area; maxillary two and 110 THE AMERICAN CHARACIDAE. two thirds to three in the head; three or four teeth in the outer series of the premaxillary, five teeth in the second series; two teeth in the maxillary. Lower jaw with four large teeth followed by a much smaller recurved tooth and a number of minute teeth. Gill-rakers 7 + 9, very short, the longest about one fifth the diameter of the eye. Seales very regularly imbricate, of comparatively uniform size, each with about five diverging striae, and with the surface minutely marked as in M. oligolepis. Caudal lobes sealed for at least half their length; scales above anal not decreased in size, at most four (34) scales between origin of anal and lateral line; anal with a basal sheath of a single series of scales in front, none posteriorly. A well-developed axillary scale. Dorsal a little nearer base of middle caudal rays than tip of snout, highest dorsal ray three and a half or four in the length; ventrals nearer tip of snout than the dorsal, equidistant from tip of snout and base of lower caudal rays; origin of anal equidistant from tip of snout and the second or third scale behind the dorsal; ventrals scarcely or not reaching anal; pectorals to near ventrals. Anal emarginate. Brassy, fins dusky. A very large and very conspicuous vertically oval black spot occupying all the base of the caudal (to near the tip of the middle rays), bordered behind, especially on the third, fourth, and fifth rays from the middle, by milk-white.’ The three cotypes from Para are much paler, the caudal spot while covering the same area is very faint except that part not covered by the caudal scales. In all the specimens from the Amazon Basin the lateral line is complete. It is also complete in one hundred specimens from Wismar, Malali, Tukeit, and Cangaruma. The first two of these localities are on the Demerara River, the second two on the Potaro River of British Guiana. Out of six specimens from below Wismar one has the line interrupted. In at least four out of six specimens from Christianburg, but one mile from Wismar, the lateral line is either interrupted or incomplete. In the Rockstone specimens it is incomplete. In the Crab Falls specimen the lateral line is developed on from ten to seventeen scales. In five specimens from Konawaruk the lateral line is incomplete. Out of the twenty-seven specimens from Tumatumari the lateral line is ‘ In living specimens from British Guiana this spot is surrounded by rusty. complete on both sides of two specimens, two have it complete on one side and interrupted on the other. side and the rest in so far as the specimens are fit for examination it is incomplete. THE AMERICAN TETRAGONOPTERINAE. interrupted on the other. In a number of specimens it is incomplete on one In five it is interrupted on both sides. Lateral line of Moenkhausia cotinho from Tumatumari. Seales with pores in italics. Left Right 1, 30 30 2, 30 31 SG 2 Pip eal een bg 31 Awe 23 +4-+ 4 By Qe ae ee te eG, 20 eee 1 pe bes 6, 16+4+2411 2+9+3 Tie alee Set itt 20+10+2 8, 8B+1+24+5 26 +1243 Gig 83 ser ete tre hig 145 Fa eta esi as a) 10, 21411 a1+1+2+8 hieieee ee 12) 23 + 10 1D, Gh) deo) See 18 + 14 13, 16 + 16 16 + 16 (Ap 17 RIS SU Say 15, Dyas 124+2+24+15 iGo ighe tl Ser eeae 13 + 19 Wp, peo by ee aly 1, FRETS 13 + 20 19, 71 +20 12+ 18 A eritical examination of the details given above shows a regular gradation from the completed lateral line of Moenkhausia at the top of the list to the incomplete line of Hemigrammus at the bottom. In specimens numbered 3 and 4 in which the line is complete on one side several pores failed of development, not at the end of the line but at some dis- tance from the end. In number 5 the line reaches the caudal on both sides but some pores are missing on both sides. In number 9 we find the same but the missing pores occur four scales further forward. In 6, 7, and 8 the line does not reach the caudal on one side and in all the rest it fails to reach the caudal on both sides. It becomes progressively shorter. Numbers 11, 12, 14, and 15 show that the shortening may take place by the dropping, not of the last pore but of some pores in advance of it. In this series we see a regular progression without notable breaks from the condition which is considered to characterize one genus to the condition charac- 112 THE AMERICAN CHARACIDAE. terizing another genus. This series should be compared with the series of M. sanctae filomenae. To complete the record I add the conditions in the specimens from Kona- waruk, Crab Falls, and Christianburg. Konawaruk is a short distance up the Essequibo from the mouth of the Potaro River, Crab Falls is a still shorter distance below the mouth of the Potaro and Tumatumari a few miles above the mouth of the Potaro at its first cataract. Lateral line of Moenkhausia cotinho. A. Crab Falls B. Konawaruk Left Right Left Right 17+ 16 16+ 17 14+17 12+ 19 16+ 15 10+ ? 18+17+3 12+ 21 16+17 12 + 20 138+ 19 18+ 19 15+ 18 14+ 19 12 + 20 11 + 20 15+ 18 13+ 19 11+ 20 10 + 22 14+ 18 138+ 18 14+ 19 16+ 16 14+17 13 + 16 13+ 19 12 + 20 C. Christianburg 12+ 20 13+ 18 Left Right 12 + 20 12+ 21 16+10+3 10 + 21 12 + 20 11+ 21 11+ 21 9+ 23 12 + 20 ? ? +21 ? + 22 10 + 22 11+ 21 9+ 24 9 + 23 I have arranged the series from Crab Falls in regard to the pores in the line on the left sides. There is a regular gradation with an approximate but not complete correlation on the two sides of the body. 5 SES i>. | SH ae eo Peal tater oqurz0o0 x ese so100 % |99°S-E8'¢ tedoo *"")G2"E-9°6 11779][09 2 L 8 9L 9 ae (eee ee BUNIIORIs aise! |Pevetre!|(aletes | ferate Sot) ffs |(ar etn fapmtn} fate) ate) mtv | eae) ntansffavayr|l ese] |fsel| el>eel| sexe -fe¥ pane) |inehellhe ene Ital avoxe | ax=ae} Nal anor eas eed ehoael| cas be Fe lUBUTOse yy ero] \arend SoA aaa lon lease P| esse ese tal| ‘aretsal a gd ows [lace l ayes all Bestel easel [Pager lPeterl lees eT suai faxstsl tovets e aBor seater eoeeet| eyes [Psbeee ieee 97 P| UNAS A) fe = Se ae o's-& snanpiday woaiet| bebstal (Pecetesltoceee | eats al| events +e eIpautzayut clz vote peePeefeeefee eel ee legz snanozyp1p Loc fecefee |e epee efee fee fee e[ee fee efec dee fee e[ee Spr Gel (sinter lao lek slyly] x feo pecdeet pede voles -loze-egz aeysoo ei | aes | eee ee Pel lsae sere Ss aS Ol od eco eer lated Broel ac.ollee velo fecs| yg [eeefeee[ecefersfenefens velo) pezez wayaprys Dera (lites wecfeeefere fen fee fen sfee sper e|ee efor efeccfecstenetee tee Peed ye [gg] gg forfeccfesctesefes ede fes Pests sls: 2K eX xX me! SKK Ne) coal i st oD Sl iD) = Ame “nN i¢) NO 4 i=) i) co) i] 5 8) a Corel te) i xX G HEME CAL? ph tear etlg |e fechectc bch oz FE | €e| Ze] Te] O8| 62] 8Z| 42] 9] Gz] Fz] Ez] ca|| SE] Ze] 9E| Ge| FE] ee] Ze] Te] 08] 62] 8z| 22] 9%] Gz] FZ) a] ce] 12] 0] 6) ST] ded SaTVOG “SAVY TVNY “OUT [DLAIDT ay) Ur sajvog pun shiny joupy fo aqv 7, 114 THE AMERICAN CHARACIDAE. 4. Knopus, gen. nov. xvd, a trifle, d50us, tooth. Typr.— Bryconamericus breviceps Eigenmann. This genus differs from Moenkhausia as Bryconamericus differs from Astyanax. Second suborbital expanded, in contact with the preopercle below; four teeth in the second row of the premaxillary; caudal scaled at its base; lateral line but little decurved. Haxpitrat.— Tapajos, Tocantins, and Paraguay Rivers; Merida, Venezuela. Key to the Species. a. Depth 3.5-4.24. b. Dentary with a series of four large teeth, the series continued on the side by graduate teeth. Head 4.25; depth 3.75-4.25; eye 2.75 in head, equals interorbital; maxillary with 2 or 3 teeth; D. 10; A. 18-21, usually 19; scales 5-35 to 38-3; caudal entirely hyaline. 1. heteresthes (Kigenmann). bb. Dentary with eight graduate teeth. Head 4; depth 4; eye 3.25 in head; 1.25 in interorbital; maxillary with 3 teeth; D. 10; A. 16; scales 14-33-2.............. 2. meridae Kigenmann. bb. Dentary with 3 or 3.5 large teeth followed by abruptly smaller teeth on the side; head 4; depth 3.5-3.75; eye 2.5-2.66, equals the interorbital; maxillary with 1-5 (usually 3) teeth; D. 10, A. 22-24; scales 5-39-3.5 or 4; middle caudal rays dark. 3. moenkhausii (Eigenmann & Kennedy). aa. Depth 3 or less than 3 in the length; dentary with four large graduated teeth and a few smaller, similar ones on the side. c. Head 4.5-4.66; depth 2.66-3; D. 10 or 11; A. 20-23; scales 5.5 or 6-38 to 41-4; eye 3-3.5; maxillary teeth 2 or 3. Caudal with numerous small scales. 4. breviceps (Higenmann). ce. Head 4.25; depth3 +; D.10; A. 20; scales 4.5-36-3.5, eye 3; interorbital 2.8; maxil- lary with three broad teeth; caudal with large scales on the basal third. 5. victoriae (Steindachner). ccc. Head 3.75; depth 3; D. 10; A. 20; scales 642-4.5; eye 3; maxillary with three teeth. 6. chapadae (Fowler). cece. Head 3.5; depth 3; D. 10; A. 27; scales 5-38-4; interorbital 2.2 in the head; maxil- lary. without tooth is.)0s kisi. s cess ees ea eke reise si aeremyene 7. jacunda (Fowler). ececc. Head 4; depth 2}; D.9; A. 28; scales 6-39-4; interorbital 2.4 in the head; maxillary without, teeths a. o > sects ot unrcematety cote cael ae cerns 8. smithi (Fowler). 1. Knopus HETERESTHES (EHigenmann). Plate 10, fig. 4. Bryconamericus heteresthes EIGENMANN, Bull. M. C. Z., 1908, 52, p. 105 (Tapajos); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 434. Hapitat.— Tapajos. Forty specimens, 20862 Cotypes 27-51 mm. Tapajos Dexter, James, Talisman THE AMERICAN TETRAGONOPTERINAE. 115 This is the most slender of the species of the genus. Head 4.25; depth 3.75-4.24; D. 10 (counting everything). A. most often 19', scales 5-35 to 38-37; eye 2.75 in the head, equal to the interorbital. Slender, elongated, very little compressed, the width being about half the depth; head blunt, the dorsal and ventral profiles equally arched, without depres- sions or humps; preventral area rounded; postventral area compressed, very narrowly rounded; predorsal area rounded, without trace of a keel, with a median series of 9-11 scales between the dorsal and occipital process. Occipital process very short, about one eighth of the distance from its base to the dorsal, bordered by two scales on the sides; frontal fontanel less than one third as long as the parietal; interorbital flattish; second suborbital covering the entire cheek, leaving no naked portion; mouth small, the lower jaw included; maxillary short, equal to snout, three and three fourths in head; lower jaw equals diameter of eye. Four or five (rarely six) teeth in the front row of the premaxillary, the second tooth withdrawn from the line of the others, or the first pushed forward; four teeth in the inner series; maxillary with two or three teeth; mandible with four large teeth in front continued on the sides in a series of graduated teeth, the fifth tooth not notably smaller than the fourth tooth. Gill-rakers about 5 + 9, very small, the longest one fifth of the diameter of the eye. Seales deeply imbricate, without striae; anal sheath composed of a single series of small scales; caudal lobes scaled for at least one third of their length, the scales caducous. A well-developed axillary scale; lateral line very little decurved, the series of scales above and below it parallel with it. Origin of dorsal equidistant from tip of snout and caudal; the highest ray one fifth of the length; adipose fin behind the vertical from the last anal ray; caudal lobes equal to the depth; anal origin behind the vertical from the last dorsal ray. Origin of ventrals equidistant from tip of snout and second scale in front of the dorsal or tip of last anal ray. Ventrals not reaching anal, the pectorals not reaching the ventrals. Highly iridescent, silvery; a silvery lateral band two thirds as wide as eye, from humeral spot to caudal; a vertical humeral spot crossing the third and part of the fourth scale of the lateral line; a few pigment-cells on upper part of opercle and preopercle. Fins all hyaline, without chromatophores. 1In eleven of the largest, three have eighteen, five nineteen, two twenty, and one has twenty-one rays. 2 Of ten one has 5.5 seales above the lateral line, and one has 3.5 below it; one has thirty-five, two thirty-six, four thirty-seven, and one thirty-eight pores in the lateral line. 116 THE AMERICAN CHARACIDAE. Anterior anal rays of males with numerous recurved hooklets. Vertebrae 13 + 20; occipital process not extending back to the vertical from the posterior face of the skull. Posterior air-bladder continued to the anal, its diameter two thirds that of the eye; its length one and a half times that of the anterior section; ali- mentary canal little longer than the entire fish. 2. KNopUS MERIDAE Higenmann. Knodus meridae EIGENMANN, Ann. mag. nat. hist., 1910, ser. 8, 7, p. 216 (Merida). One specimen, 53 mm. Merida, Venezuela British Museum P. M. Briceno Head 4; depth 4; D. 10; A. 16; scales 4-33-2. Eye 3.25 in the head, about .8 in snout; 1.25 in the interorbital. Basal half of caudal scaled. Slender; dorsal and ventral profiles scarcely arched. Snout short, blunt; second suborbital covering the entire cheek, without a naked angle below its anterior corner; maxillary two in snout and eye; occipital process about one eighth the distance of its base from the dorsal. Five teeth in the outer row of the premaxillary, the second retreated from the line of the rest; four teeth in the inner series of the premaxillary; maxil- lary with three broad multicuspid teeth; mandible with eight graduated teeth. Two scales between the lateral line and anal; each scale of the sides with numerous diverging striae. Large scales on the base of the anal, scales on the base of the caudal lobes also large. First dorsal a little nearer to the snout than to the base of the middle caudal rays, the highest ray a little more than five in the length; upper caudal lobe nearly five in the length, the lower slightly shorter; anal scarcely emarginate; ventrals reaching to anal, pectorals not quite to ventrals. A broad silvery band, tapering on the caudal peduncle, continued to the end of the middle caudal rays. No humeral or caudal spots. THE AMERICAN TETRAGONOPTERINAE. 117 3. KNoDUS MOENKHAUSII (Eigenmann and Kennedy). Plate 10, fig. 3. Poecilurichthys moenkhausti E1iGeENMANN & Krnnepy, Proc. Acad. nat. sci. Phil., 1903, p. 522 (Arroyo Trementina). Bryconamericus moenkhausii E1GENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 434. Hasirat.— Paraguay; Upper Amazon. Specimens examined. Catalogue Number of number specimens Length in mm. Locality Collector 10001 I. 1 Near Arroyo 10002 I. W | 29-43 Trementina, Anisits 10003 I. } Paraguay 20760 8! 40-45 Tabatinga Bourget Head usually 4 (rarely 4.3); depth 3.5-3.75; D. 10, counting everything; A. 22-24; scales 5-39-3.5 or 4, rarely 38 scales in the lateral line; eye 2.52.66, equal to interorbital. Slender, little compressed, the width about 2 in the depth; dorsal and ventral profiles equally curved, without elevations or depressions; preventral area rounded, postventral compressed; predorsal area narrowly rounded, without a keel, with a median series of (about 12) scales between the occipital process and the dorsal. Occipital process about as broad as long, its length equals one eighth of the distance from its base to the dorsal, bordered on the side by one or two scales; interorbital flattish; frontal fontanel as wide as, and half as long as, the parietal; second suborbital covering the entire cheek to the lower opercular limb; maxillary slender, its anterior margin not conspicuously arched, its length not 1 These eight have the following characters: Eye in) Mandible in Teeth of Teeth of the length the length the pre- the D. A. Seales Head Depth of head of head maxillary maxillary 10 22 5-38-? 4 3.5 2.66 3.54 4&4 5 10 24 ? 4.3 3.75 4&4 3 10 22 5-39-? 4 3.5 2.5 3+ 4&4 3 10 22 5-39-3.5 4. 3.75 2.5 3+ 4&4 3 10 24 5-38-4 4.2 3.5 2.5 3+ 5&4 1 10 22 5-39-3.5 4 3.6 2.6 3+ 4&4 4 10 24 5-39-3.5 4 3.7 2.5 3+ 5&4 1 10 23 ? 4 3.5 2.6 3 4&4 3 118 THE AMERICAN CHARACIDAE. much greater than the length of the snout, three and a half in the head; lower jaw two and three fourths in the head; uniformly four teeth in the inner series of the premaxillary, six of the specimens from Tabatinga with four, two with five in the outer series, the second and sometimes the third removed from the line of the first and fourth; lower jaw with only three or three and a half large teeth in front and several small ones on the sides; two of the maxillaries of the left side of specimens from Tabatinga with one, four with three, one with four and one with five teeth. Gill-rakers about 6 + 9, very minute, the longest about one seventh of the diameter of the eye. Seales closely imbricate, with four to six diverging striae; a well-devel- oped anal sheath of about two rows of scales; caudal lobes scaled for about one third their length, the scales caducous; lateral line slightly decurved, parallel with the row of scales below it. Origin of dorsal equidistant from tip of snout and base of caudal, or slightly nearer the latter; origin of the ventrals nearer the tip of the snout by a space equal to or greater than the diameter of the eye, equidistant from tip of snout and base of last anal ray; highest dorsal ray one fifth of the length; anal emargi- nate, its origin equidistant from tip of snout and second third of dorsal; ven- trals scarcely reaching to anal, pectorals usually not quite to origin of ventrals. An ill-defined silvery lateral band or if dissolved a band of scattered chroma- tophores from the eye to the base of the caudal, the cells sometimes concen- trated to form a vertical, humeral spot crossing the lateral line. Vertebrae 13 + 23. In the types of K. moenkhausii the caudal sheath of scales apparently is not as well developed as in the specimens from Tabatinga. The lateral color-band is less well developed. I am not able to make out other differences with the material at hand. 4. Kwnopus BREvicEps (Kigenmann). Plate 10, fig. 2. Bryconamericus breviceps EIGENMANN, Bull. M. C. Z., 1908, 62, p. 105 (Goyaz); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 434. Hasirat.— Amazon Basin. THE AMERICAN TETRAGONOPTERINAE. 119 Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 20692 Cotypes 24 about 65-87 Goyaz Honorio 3748 C. 19 21-62 Villa Bella Haseman 3749 C. 45-48 Aleoboca Haseman 3750 C. 44 Rio Mamoré Haseman Distinguished by its short head, small fins. Head 4.5-4.66!; depth in males and spent females about 3, in females with eggs 2.66-2.8; D. 10-11; A. 20-23. Scales 5; or 6-38 to 41-4 above ventrals or anal. Eye 3 (rarely more, to 3.5); interorbital equals eye. Elongate, rather heavy; dorsal profile slightly depressed at the nape; ventral profile more strongly arched than the dorsal; preventral area rounded, postventral area more narrowly rounded; predorsal area rounded, with a median series of about twelve scales from the dorsal to within one scale of the occipital crest. Occipital process very short, not reaching one ninth the distance from its base to the dorsal, bordered by two scales on the side; frontal fontanel very short; suborbital covering the entire cheek; snout pointed, maxillary not much longer than snout, three and three tenths in head; mandible two and a half in head. Four or five teeth in the front row of the premaxillary, the first further forward than the rest, the second and fourth, or second and third, sometimes withdrawn from the line; only four in the second row; two or three teeth on the maxillary; lower jaw with four graduated teeth and a few small similar ones on the side. Gill-rakers very short, one fourth the diameter of the eye, 6 + 10. Seales regularly imbricate, thin, adherent, with about six feeble striae; anal sheath of a single row of scales; caudal lobes, with minute scales for about 1 Ten specimens selected at random, have the following spent 10 20 6-414 D. A Scales Depth Eye 2 with eggs 10= (93) 21 5.5-38-4 2.66 3 Shes oe ae 10 21 6-414 2.66 3.3 Ott nes 11 = (103 21 6-39-4 2.8 3.2 Ops oS 10 22 5-40-4 2.15 3 eas as 10 20 5.5-39-4 .66 3 fol 10 23 5.5-36-4 .86 3.5 g all 3 fou 3 ©) 3 ros 3 120 THE AMERICAN CHARACIDAE. half their length; a well-developed axillary scale; lateral line but feebly decurved, the rows of scales above it and below it parallel with it. Origin of dorsal about equidistant from tip of snout and base of caudal; ventrals a little nearer snout, equidistant from tip of snout and end of anal, not nearly reaching anal in the types, to the anal in the rest; highest dorsal ray four or five in the length; origin of anal under the dorsal or behind the last dorsal ray; pectoral not reaching the ventrals. A plumbeous lateral band on the row of scales above the lateral line, lost in front of the dorsal, becoming dusky behind and continued to the end of the middle caudal rays as a faint band; an inconspicuous vertical humeral spot just above the third and fourth scales of the lateral line, sometimes crossing these. Dorsal and anal dusky. Vertebrae 14 + 22. Air-bladder in a gravid female small, ending bluntly behind, not curved down, but ending at the beginning of the posterior wall of the abdominal cavity; posterior part a little more than one and a half times as long as the anterior section, its diameter not equal to that of the small eye. Alimentary canal very little longer than the body; pyloric coeca very large, about seven. Stomach contained insect larvae. 5. KNopbus VICTORIAE (Steindachner). Plate 16, fig. 3. Tetragonopterus victoriae SreinDACHNER, Anz. K. akad. wiss. Wien, 1907, 44, p. 83 (Victoria on the Parnahyba). One specimen, 3751 C. 53 mm. Lagoa Parnagua, Jan. 17, 1908 Haseman Head 4.25; depth 3+; D. 10; A. 20 (-22); scales 4.5-36 (to 38)-3.5; Eye 2.25-3; interorbital 2.8 in the head. Elongate, not greatly compressed, the ventral profile a little more arched than the dorsal; preventral and predorsal areas rounded, the latter with twelve scales; occipital process very short, about one seventh of the distance between its base and the dorsal, bordered by two scales; interorbital rounded, a constric- tion between the fontanels. Cheeks entirely covered, maxillary shorter than eye; premaxillary with five teeth in the outer series of which the second and fourth are entirely withdrawn from the rest; four teeth in the inner series of the premaxillary; dentary with three large teeth, similar but much smaller ones on the side. THE AMERICAN TETRAGONOPTERINAE. 121 Dorsal rounded, its highest ray shorter than the head, its origin equl- distant from snout and middle caudal rays. Caudal lobes longer than the head; origin of anal behind the vertical from the last dorsal ray; ventrals not reaching anal, their origin nearer base of last anal ray than snout: pec- torals not reaching ventrals. Scales very regular, with two or three striae; caudal with a few scales on the base of the lobes, extending further on the lower lobe than on the upper. Anal with a sheath of a single series of scales. Maxillary scale small. Highly iridescent, a silvery lateral band; tip of dorsal hyaline, an oblique dusky streak through its middle. A dark spot on the base of the middle caudal rays, continued faintly to the tip of the middle rays and then obliquely across the lobes. A very faint humeral spot. It is more than probable that the single specimen at hand is the K. vic- toriae described by Steindachner. His specimens have the silvery band bor- dered by dark above. A cherry-red spot at base of each caudal lobe in life. 6. KNODUS CHAPADAE (Fowler). Plate 10, fig. 1. Astyanax chapadae Fow Er, Proc. Acad. nat. sci. Phil., 1907, p. 350, fig. 33 (Santa Anna da Chapada). Bryconamericus chapadae ErGENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 434. 21829 Paratype. Acad. Nat. Sci. Phil. 44 mm. to base of caudal. Santa Anna da Chapada, Matto Grosso, headwaters of the Paraguay. Known only from the types. Very closely related to K. breviceps, but with much longer head. Like K. breviceps except in the characters noted below. Head about 3.75; depth about 3; D. 10; A. 20; scales 6—42-4.5; eye 3, equals interorbital. Elongate, without prominent elevations or depressions in the profiles, the median series of scales in front of the dorsal not quite complete, replaced by the overlapping scales of the two sides from the occipital process to about the fourth seale behind the occipital process. Maxillary equals snout, three and a half in head; mandible two and four tenths. Five teeth (three on one side) in the front row of the premaxillary, the second is withdrawn from the line, three several pointed teeth on the maxil- lary; mandible with four large teeth and several small ones on the side. 122 THE AMERICAN CHARACIDAE. Base of caudal scaled; ventrals rather nearer tip of last anal ray than to snout. Dusky, a very faint humeral spot; middle caudal rays black; anal and a band from the middle of the anterior dorsal rays to the tips of the last six rays with numerous chromatophores. 7. Kwnopus JAcuNDA (Fowler). Bryconamericus jacunda Fow er, Proc. Acad. nat. sci. Phil., 1913, p. 555, fig. 17 (Madeira River, about 200 miles east of W. Long. 62° 20’, Brazil). This species is known from the type 31 mm. long in the collections of the Philadelphia Academy of Natural Sciences. The following description is con- densed from Fowler. Head 3.5; depth 3; D. 10; A. 26; scales 5-38-4; 12 predorsal scales; snout 4 in the head, eye 2.8, interorbital 2.2, maxillary 2.75, depth of caudal peduncle 2.5. Five large, broad teeth in the inner series of the premaxillary. No maxil- lary teeth. Suborbital completely covering cheeks. No interpolated rows of scales; anal with a basal series of scales along its whole length. Origin of dorsal equidistant from caudal and front of eye; ventrals extend- ing past origin of anal, pectorals beyond base of ventrals. A vertical humeral spot crosses the third to fifth scales of the lateral line; a faint lateral streak. This is evidently a young specimen and may belong to Moenkhausia. 8. Knopus smrtrur (Fowler). Bryconamericus smithi Fowuer, Proc. Acad. nat. sci. Phil., 1913, p. 557, fig. 18 (Tributary of the Madeira River near Porto Velho, Brazil). This species is known from six specimens 24—35 mm. long, in the collec- tions of the Philadelphia Academy of Natural Sciences. The description is condensed from that of Fowler. Head 3.66-4; depth 2.87-3.2; D. 9-10; A. 27-30; scales 6-36 to 39-4; 12-14 predorsal scales; snout 3.12—3.8 in the head, eye 2.2-2.75, interorbital 2.42.8, maxillary 2—2.8, depth of caudal peduncle 2.25. Six five-pointed teeth in the premaxillary. No maxillary teeth. Su THE AMERICAN TETRAGONOPTERINAE. 123 orbital completely covering cheeks. No interpolated rows of teeth; anal with a basal series of scales along its whole length. Origin of dorsal midway between snout and base of caudal; ventrals reach- ing anal, pectoral extending beyond base of ventrals. A vertical humeral spot over fourth and fifth scales of the lateral line. “Closely related to the preceding species, though apparently differs in the smaller head and deeper body” Fowler. 5. Marxrana Higenmann. For Edward Laurens Mark. Markiana Etcenmann, Smithsonian misc. coll. quart., 1903, 45, p. 145. Tyrr.— Tetragonopterus nigripinnis Perugia. Related to Moenkhausia and Gymnocorymbus, from which it differs in the squamation and the abbreviated caudal; the scales are crenate, very regularly arranged, becoming gradually smaller below the lateral line, the series extending about halfway up on the anal. Compressed, deep, with a regularly arched ventral outline, the dorsal regu- larity being interrupted at the nape, the profile concave over the eyes. Head short, broad; an occipital fontanel continued as a groove on the occipital crest, a frontal fontanel extending forward to middle of eye; mouth small, the small maxillary nearly vertical, scarcely reaching the eye, slightly slipping under the preorbital; cheeks covered by the suborbitals. No maxillary teeth; outer row of premaxillary with triangular cutting edge, scarcely notched; inner teeth very heavy, with a few points arranged in a crescent; three anterior teeth of the mandible heavy, the fourth much smaller. Gill-membranes free from isthmus, slightly united to each other; gill-rakers setiform, about twelve on the lower arch; dorsal over origin of anal; margin of anal convex; adipose well developed; lateral line nearly straight, near the middle of the body. Nares together; tongue fleshy, adnate. Hasrtat.— Guiana and La Plata. Key to the Species. a. A dark caudal spot; pectorals dark, extending much beyond origin of ventrals; depth 2.33; head Dida OWA TA4 A BCAlER i —OS—1, 60 LO! arc spsievslsceislere vie ov cldleievs ee stelow epee e 1. nigripinnis (Perugia). aa. No caudal spot; uniformly silvery; A. 40; scales 7.5-41-7 to the ventral..2. geayi (Pellegrin). 124 THE AMERICAN CHARACIDAE. 1. MARKIANA NIGRIPINNIS (Perugia). Plate 13, fig. 3-5. Tetragonopterus nigripinnis Peructa, Ann. Mus. civ. storia nat. Genova, 1891, ser. 2a, 10, p. 643 (Rio de la Plata); 1897, ser. 2a, 18, p. 25 (Reyes; Rio Beni); ErgenMANN, Proc. U.S. N. M., 1893, 16, p. 53; Unrey, Ann. N. Y. acad. sci., 1895, 8, p. 263, 273. Markiana nigripinnis E1GeENMANN, Smithsonian misc. coll. quart., 1903, 45, p. 145; Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 438. Astyanax nigripinnis EIGENMANN & Oct», Proc. U.S. N. M., 1907, 33, p. 30 (Paraguay). Tetragonopterus anomalus STEINDACHNER, Anz. K. akad. wiss. Wien, 1891, p. 173; Ichthyol. beitr., 1891, 15, p. 27; Sitzungsb. K. akad. wiss. Wien, 1891, 100, p. 173, 369, pl. 3 (Rio Parana); ErGenmMann, Proc. U. S. N. M., 1893, 16, p. 53. Hasitat.— La Plata Basin. 2. MArKIANA GBAyt (Pellegrin). Tetragonopterus (Markiana) geayi PELLEGRIN, Bull. Mus. hist. nat., 1908, 14, p. 347 (Apuré). Markiana geayi E1GENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 438. Known from a single specimen 104 mm. long, in the Jardin des Plantes. 6. GymNocoryMBus Eigenmann. yuurds, naked; xépuvufos, summit. Gymnocorymbus EIGENMANN, Bull. M. C. Z., 1908, 62, p. 94. Typre.— Gymnocorymbus thayeri Eigenmann. Very deep, compressed, Tetragonopterini form; anal long, its margin nearly straight, its origin behind the origin of the dorsal; mouth moderate, the maxil- lary reaching below eye; first and second suborbital leaving a moderate naked area all around its lower margin; scales all cyeloid; lateral line complete, caudal and anal largely scaled; maxillary with one or two teeth; premaxillary with an outer series of tricuspid teeth and an inner series of many pointed teeth. Hasrrar.— Amazons and Paraguay. Key to the Species. a. Scales in lateral line 33-36; parietal fontanel arched over at base of occipital process; anal sheath of three or four series of scales; anal margin straight; anal and area above it not notably dark. 1. thayeri Figenmann. aa. Scales in lateral line 30-35; parietal fontanel not arehed over; anal sheath of five or six series of scales; anal margin rounded; anal and area above it dark.......... 2. ternetzi (Boulenger). THE AMERICAN TETRAGONOPTERINAE. 125 1. GyYMNOCORYMBUS THAYERI Eigenmann. Plate 11, fig. 2. Gymnocorymbus thayert E1GENMANN, Bull. M. C. Z., 1908, 62, p. 93 (Tabatinga to Gurupa); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 437. HapitatT.— Amazon. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 19242 type 1 40 Tabatinga Bourget 20706 2 54 Teffé Agassiz 19272, 20973 4 30-56 Cudajas Thayer & Bourget 20804 1 70 Manacapuru James 20807 9 50-77 20998, 21065 20 40-50 Silva, Lake Saraca Thayer 20984 29 38-57 Serpa Thayer 20710, 20720 4 50-62 Villa Bella Agassiz 20789 22 44-58 Santarem Bourget 21007 8 45-55 José Fernandez Cotinho 20724 2 65-72 Gurupa Agassiz 21001 7 44-54 Jose Fernandez Cotinho Head 3.5 on an average; depth 1.7 on an average, ranging from 2.1 to 1.4; D. 11; A. 34-41', most frequently 38 or 39; scales 7 to 8-33 to 36-8 to ventrals; eye 2.25-3, 2.65 on an average; interorbital slightly less than the eye in the young, slightly more than the eye in the adult. Very deep and very much compressed; the ventral profile much more arched than the dorsal, its deepest point at the origin of the anal; dorsal profile depressed over the eyes, humped in front of the dorsal; preventral area narrowly rounded in cross-section, postventral area more narrowly compressed; predorsal area narrowly rounded. Occipital process one third or somewhat less the distance from its base to the dorsal; occipital fontanel continued to the tip of the occipital process as a groove, parietal portion sometimes partly arched over and demarked from the occipital groove; frontal fontanel about half the length of the occipitai, its anterior end over the anterior margin of pupil; the profile beginning to 1 Of sixteen counted one has thirty-four anal rays, two thirty-five, one thirty-six, one thirty-seven, four thirty-eight, five thirty-nine, one forty and one forty-one. 2 Of twelve counted four have thirty-three anal rays, one thirty-four, five thirty-five and two thirty- six. 126 THE AMERICAN CHARACIDAE. rise at the bridge between the fontanels at an angle of about 45° from the line joining tip of snout and middle of caudal. Interorbital convex, snout very short, mouth very oblique; second suborbital leaving a moderate naked area around its entire free margin; maxillary equals snout and eye in front of pupil; normally four teeth in the front row of the premaxillary, the third slightly removed from the line of the rest; five teeth in the inner series; maxillary with one broad or two narrow teeth; mandible with four or five large, graduate teeth and several smaller ones on the side. Gill-rakers about 10 + 15, slender, the longest nearly half the length of the eye. Seales cycloid, regularly imbricate, mid-preventral series very small; occipital process bordered by about five scales on each side; caudal lobes sealed to near their tips; scales of the sides continued without break into the anal sheath, which is composed of three or four series of scales in front and reaches up one third of the anal base. Scales everywhere cycloid, with several (five to seven on a scale above the middle of the lateral line) diverging striae; an axillary scale. Lateral line very little decurved, parallel with the row of scales just below it. Origin of dorsal equidistant from tip of snout and base of upper caudal rays; its margin very oblique, the highest ray three in the length; adipose well devel- oped, its origin about over the sixth anal ray from the last; origin of anal equi- distant from tip of snout, and the third scale behind the dorsal, in the young, with the middle of the dorsal in the adult; margin of anal nearly straight; ventrals very small, equidistant from tip of snout and base of one of the last few anal rays, a little nearer to the tip of the snout than the dorsal or equi- distant with the latter, not quite reaching anal in the adult; pectorals long, their bases elevated, their tips reaching the third scale above and third or fifth behind the origin of the ventrals. Color similar to that of Tetragonopterus argenteus, a dark humeral bar followed by a lighter area and this again by a bar less well marked than the first; the first humeral bar is most intense above the third, fourth, and fifth scales of the lateral line, is vertical and extends in some cases to just behind the axil of the pectoral; the second bar extends across the ninth, tenth, and eleventh scales of the lateral line from in front of the dorsal; the area between the bars just above the lateral line is bright silvery. Lower sides brassy; fins hyaline to uniform dusky. Males with hooklets on the anal. THE AMERICAN TETRAGONOPTERINAE. 127 Vertebrae 11 +19. Six ray-bearing interhaemals in front of the first fully developed haemal spine, five between it and the second. Second air-bladder more or less boot-shaped, the “toe” and “leg” of the same length, the toe sharply bent down, its tip reaching about halfway between the spinal column and anal, its greatest diameter half the length of the head; anterior air-bladder equal to the length of the “leg” of the posterior. Alimentary canal about equal to the length without the caudal. 2. GYMNOCORYMBUS TERNETZI (Boulenger). Plate 11, fig. 1. Tetragonopterus ternetzi BOULENGER, Proce. Zool. soc. Lond., 1895, p. 528; Trans. Zool. soc. Lond., 1896, 14, p. 35, pl. 8, fig. 2 (Descalvados; Matto Grosso); Boll. Mus. univ. Torino, 1900, 15, no. 370, p. 2 (Urucum). Gymnocorymbus ternetzi EIGENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 137. Hasirat.— Paraguay and Guaporé Basins. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 11435 I. Cotype 1 39 to base Descalvados Ternetz ot caudal) 3294 C. 4 39-53 Arequa, Paraguay Haseman 3295 C. 12 38-54 Jauru, Paraguay Basin Haseman 3296 C. 1 Bi San Joaquin, Guaporé Haseman Basin Very close to G. thayert. Head 3.25; depth 1.8; D. 11 or 12; A. 40-42; scales 8-30 to 35-8; eye 2.5 mm.; interorbital 2.5. Parietal portion of the posterior fontanel not demarked from the groove on the occipital process; a single maxillary tooth. Gill-rakers 9 + 14. Anal sheath of five or six rows of scales covering half of the anal. About ten striae on a scale above the middle of the lateral line. Origin of dorsal equidistant from tip of snout and end of adipose fin or nearer caudal than snout; origin of anal and base of fourth dorsal ray equi- distant from tip of snout; margin of anal rounded; origin of ventrals and fourth scale in front of dorsal equidistant from tip of snout, reaching anal. The vertical bars more uniform in color throughout their height than in G. thayeri, separated by a wider interspace, the second bar largely behind origin of dorsal; anal and area above it, with the caudal peduncle dark; dorsal, dark. 128 THE AMERICAN CHARACIDAE. 7. TuHayertia Eigenmann. In memory of Nathaniel Thayer. Thayeria EIGENMANN, Bull. M. C. Z., 1908, 62, p. 94. Typr.— Thayeria obliqua Eigenmann. Small, elongate Tetragonopterids reaching a length of near 80 mm., dis- tinguished from all others by the unequally lobed caudal. It is otherwise near Hemigrammus and Creatochanes. Caudal scaled, lateral line incomplete. Hasirat.— Amazon Basin. THAYERIA OBLIQUA Eigenmann. AX el VND Plate 3, fig. 5, Plate 80, fig. 1, 2, 4, 6. Thayeria obliquus EIGENMANN, Bull. M. C. Z., 1908, 52, p. 94 (Obidos); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 437. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 20841 Cotype 25 47-76 Obidos Bentos 3712 C. 5 47-62 Bastos Haseman TE } 4 52-62 Maciél, Rio Guaporé Haseman 3711 C. ? Head about equal to the depth, 2.6 (in young)-3 in the length; D.10.5— 11; A. usually 16 or 17, rarely 15 or 181; scales 5-11 + 18-3; eye in the smallest equals twice the length of the snout, 2.4 in head, slightly greater than the interorbital; in the adult 2.9 in head, equal to the interorbital. Little compressed, elongate, but little deeper than the head at the occi- put; profile gently and evenly convex to the tip of the occipital process. Preventral and postventral areas rounded. Predorsal area rounded, with a median series of scales. Occipital process short, its length about six in the distance from its base to the dorsal, bordered by three scales; nares close together, separated by a flap only; frontal fontanel about half as long as the parietal, triangular, the anterior angle sometimes rounded, above the anterior margin of the pupil; ‘In a count I found one with fifteen anal rays, five with sixteen, six with seventeen, and two with eighteen. THE AMERICAN TETRAGONOPTERINAE. 129 parietal fontanel somewhat wider than the frontal, extending as a groove to the tip of the short occipital process; surface of bridge between the fontanels below the surface of the skull; interorbital slightly convex; cheeks nearly covered, the naked area between the second suborbital and the preopercle only about one fifth the width of the third preorbital; a notch between the first suborbital and preorbital, the maxillary slipping under the preorbital but not under the first suborbital; premaxillary-maxillary border angulated, the maxillary reaching but little beyond anterior border of eye. Mouth and dentition as in Tetragonopterus; the lower jaw with four heavy teeth on each side, abruptly followed on the side by minute teeth; pre- maxillary with three or four teeth on the front series, one of which frequently drops out of line; five graduated, multicuspid incisors in the inner series; the tips of the cusps very unequal in height, arranged in a nearly straight line. Maxillary without teeth. Gill-membranes free from the isthmus, gill-rakers 7 + 15, slender, about one half as long as the filaments. Seales with the margin slightly crenate, the exposed part of the scale with numerous slightly diverging striae; lateral line reaching to above ventrals; anal with a sheath; caudal partly sealed, ventrals with a slender axillary scale; lateral line scarcely decurved. Fins with exception of caudal all small; the origin of the dorsal in the middle of the body, very little behind the ventrals; adipose fin over end of the small, emarginate anal. Pectoral about equal to head less opercle, not reaching to ventrals; ventrals a little nearer tip of snout than dorsal, slightly shorter than pectoral, not reaching anal; anus nearer ventrals than anal; anal emarginate, its highest (first and second divided) rays reaching at least to base of the last, sometimes to the tip of the last rays; last ray not reaching more than halfway to caudal; dorsal small, its height equals length of head less half the opercle; caudal large, forked at the middle, the lower lobe much the longer, equals distance from tip of snout to middle of pectoral. Brassy; anterior anal lobe usually dusky; male with a black band from upper angle of gill-opening to base of middle caudal rays, then obliquely along the upper part of the lower caudal lobe; female with a similar band on the caudal: the band on the sides extending obliquely upward to the first row of seales below the origin of the dorsal which is the second row above the dark stripe of the male. Posterior part of air-bladder about twice as long as the anterior, scarcely 130 THE AMERICAN CHARACIDAE. reaching to above anal; alimentary canal about equal to the entire length of the fish; seven pyloric coeca. Intestine contains debris of minute insects and plant fibers. Vertebrae 13 + 15. 8. Pristetua Eigenmann. mpiorns = a saw, i.e.the fully dentate maxillary. Pristella EIGENMANN, Bull. M. C. Z., 1908, 52, p. 99. Typr.— Holopristes riddlei Meek. This genus differs from Hemigrammus much as Hemibrycon differs from Astyanax. Lateral line incomplete, caudal scaled for at least one third of its length; maxillary with teeth along nearly the entire anterior edge; gill-rakers long, setiform; gill-membranes free from each other and from the isthmus. Hapirat.— Coasts of Guiana and Orinoco. Key to the Species. a, Depth 2.3-2.75; A. 20-24; dorsal, anal, and very frequently ventral, each with a conspicuous black Spots) MO; CAUGKL POL, Le ae « o.25- ical eaeisy tn shared Be one etetele aks oe eeteaiea tiers if riddlei (Meek). aa. Depth 3.5; A. 16-18; caudal with a spot on the base of its middle rays, other fins all plain. 2. aubynei Eigenmann. 1. PRISTELLA RIDDLEI (Meek). Plate 13, fig. 2. Holopristes riddlei Murx, Proc. U. 8. N. M., 1907, 33, p. 11 (Los Castillas). Pristella riddlei E1GENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 437; Mem. Carnegie, mus., 1912, 5, p. 330, pl. 45, fig. 3. Hapirar.— Guiana and Venezuela. Specimens examined. Number of Size Catalogue number specimens in mm. Locality 10896 Type 1 about 29 Los Castillas — Paratypes ! 4 29-31 Los Castillas 1317 C. 11798 I. 56 12-29 Wismar, Demerara River 1308 C. 11800 I. 8 37-47 Georgetown Trenches 1309 C. 11796 I. 233 26-45 Botanic Garden, Georgetown 1310 C. 11799 I. 5 Christiansburg Canal 1311 C. 11797 I. 3 Kumaka ' Collection of Field Museum, Chicago. Collector Riddle Riddle Eigenmann Eigenmann Shideler Eigenmann Eigenamnn THE AMERICAN TETRAGONOPTERINAE. 131 Head 3.75-4; depth about 2.3-2.75; D. 11; A. 20-24; scales 5-32-3, 6-8 with pores; eye 2.64; snout 4.12; interorbital about 2.5 in the head. Short, deep, especially in the female, not greatly compressed; ventral profile more regularly, and in the female more strongly arched than the dorsal profile; profile of head nearly straight, rising at the occipital process. Pre- ventral area broadly, the postventral more narrowly rounded; predorsal area keeled, with nine or ten scales. Occipital process about one fifth of the distance from its base to the origin of the dorsal, bordered on the side by about three scales; head convex, the fontanels broadest at the base of the occipital process, tapering regularly to the tip of the process and to a point over the anterior margin of the eye; frontal fontanel about as long as the parietal without the groove; second suborbital covering the entire cheek or leaving a very narrow naked area at its middle, a wider one at its anterior and posterior ends; mouth very oblique, the pre- maxillary with a very short antero-posterior extent, the maxillary regularly convex in front, broader than the preorbital, about 3 teeth in the front row of the premaxillary, about 8 in the second. Those of the outer series incisors with parallel margins, with a prominent broad central lobe and two receding shoulders, the teeth becoming conical toward the sides; the posterior series pointed incisors, or three pointed incisors with the middle point much the longer. Maxillary with a few large teeth near its upper angle and minute conical teeth scattered along nearly the entire margin; lower jaw with a single series of teeth, imper- fectly tricuspid, the points broad, not unlike those of the upper jaw, graduated, the lateral teeth minute, conical; snout and maxillary two and a fourth in head. Gill-rakers 8 + 12, a little over half the length of the eye. Seales cycloid, very regularly imbricate, with numerous striae parallel with their convex margin and few divergent striae; anal sheath of a single series of scales along the base of the anterior rays; caudal scaled for about one third of its length. Origin of dorsal and ventrals about equidistant from snout; pectorals reaching ventrals, ventrals to anal; anal emarginate. A humeral spot over the third and fourth scales of the lateral line; no caudal spot; dorsal, anal, and ventrals each with a conspicuous, jet-black spot; dorsal spot not extending upon the last ray, and leaving base and tips of rays hyaline; anal spot covering the third and fourth fifths (from the base) of the rays forming the anterior lobe; ventral spot leaving the outer and inner rays and bases and tips of all the rays hyaline. Very brilliant in life, 132 THE AMERICAN CHARACIDAE. translucent, the caudal bright red, upper parts tinged with red, basal part of dorsal and anal lobe below the black spots bright yellow, the distal parts milk-white. 2. PRISTELLA AUBYNEI Eigenmann. Plate 13, fig. 1. Pristella aubynei ErceENMANN, Ann. Carnegie mus., 1909, 6, p. 24 (Lama Stop-Off); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 437; Mem. Carnegie mus., 1912, 5, p. 330, pl. 45, fig. 4. Hasitrat.— Lamaha Basin, British Guiana. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 1042 C. Type 1 50 Lama Stop-Off Eigenmann 1043 C. 11735 I. 203 20-50 Lama Stop-Off Eigenmann 1044 C. 11736 I. 50 28-46 Cane Grove Corner Eigenmann 1045 C. 11737 I. 21 35-49 Maduni Stop-Off Eigenmann This species is very abundant in the canal from Cane Grove Corner to Maduni Creek Stop-Off, British Guiana. This species is placed in the genus with P. riddlei because in the technical characters they agree. There is every probability that they are not immedi- ately descended from the same ancestor. Head 3.75; depth 3.5; D. 10; A. 16-18; scales 6-31 to 33-3 rarely 4; 7 to 9 pores in the lateral line; eye 2.33; interorbital 3. Elongate, heavy forward; ventral profile curved more than the dorsal, which is nearly straight to the dorsal, not depressed over the eye; preventral area broad, rounded, postventral area keeled; predorsal area narrowly rounded. Occipital process triangular, very short, equal to one sixth of the distance from its base to the dorsal. Fontanel widest at the base of the occipital process, anterior fontanel slightly shorter than the posterior, triangular, its anterior pointed end a little in advance of the middle of the eye. Second suborbital leaving a wide naked area below, a narrower one behind. Mouth oblique; maxillary slender, its anterior margin nearly straight; two and three fourths in the head; five teeth in the front series of the premaxillary of which the middle one is withdrawn from the line of the rest. Inner series of teeth large, multi- cuspid, graduate. Maxillary with numerous similar teeth; lower jaw with four or five graduate, multicuspid teeth in front and minute ones on the side. Gil-rakers about 6 + 11. THE AMERICAN TETRAGONOPTERINAE. 133 Seales thin, not conspicuously regularly imbricate; each scale with several nearly parallel horizontal striae; anal sheath composed of a single row of scales along the front of the fin; caudal lobes scaled for about one eighth of their length. Origin of ventrals a little nearer tip of last anal ray than snout, slightly in advance of the dorsal; penultimate dorsal ray more than half the length of the longest which is three and three fourths in the length. Anal emarginate, ventrals reaching anal; pectorals not to ventrals. In life, base of upper caudal lobe red, base of lower caudal lobe yellow, some yellow on under side of caudal peduncle and in front of anal. A circular spot about as large as eye on base of middle caudal rays. A dark line in front of dorsal, a series of spots behind it. A well-defined humeral spot on and over the second and third scales of the lateral line. HemiIGRAMMUS GILL AND HypHEssSOBRYCON DurRBIN.! Compressed, rarely subeylindrical. Greatest depth on or near the vertical from the first dorsal ray. Postventral region narrow. Maxillary not slipping under the preorbitals. Lower jaw included, when the mouth is closed, but usually projecting beyond the snout when the mouth is open. Premaxillary teeth in two rows, the outer row more or less incomplete. All teeth conical or flat or fan-shaped, with 3-7 cusps, usually graduated from the enlarged median cusp. Seales eycloid, regularly imbricate, striae few and variable in number. No interpolated scales or rows of scales. Anal sheath short, of a single, usu- ally incomplete series of small scales. Lateral line somewhat decurved to nearly straight, the series of scales just below it parallel to it. Pores developed on the first three to eighteen scales. The genus Hemigrammus was placed in the synonymy of Astyanax (Tetra- gonopterus) by Ulrey because Liitken had shown that in some supposed speci- mens of 7’. fasciatus the lateral line is complete, in others not. Two other species, 7. theringii and T. oerstedvi are given by Ulrey as possessing these inter- mediate characters. But in the description of 7. oerstedii it is specifically stated that the lateral line is complete, not interrupted. Also all the speci- mens of 7’. iheringii so far secured have a complete lateral line. This left 7. 1 The account of these genera has been worked up from my original manuscript by Mrs. Marion Durbin Ellis (Miss Marion Lee Durbin). She has devoted so much labor and care to these genera that she alone should be credited with the authorship. 134 THE AMERICAN CHARACIDAE. fasciatus as an intermediate species. lLiitken separated the species with an incomplete lateral line as a variety, T. interrupta. Upon reéxamining Liitken’s specimens Eigenmann pronounces 7’. fasciatus and T. interrupta as being unques- tionably distinct, differing in several characters besides the completeness or incompleteness of the lateral line. During the examination of the very large series of specimens enumerated in the present work I found a complete lateral line in several species. Thus, among one hundred and two specimens of Hemigrammus levis from Lago do Maximo one had a complete lateral line. In over one hundred from other places the lateral line is incomplete. Of nineteen hundred and seventy-seven specimens of Hyphessobrycon gracilis from Brazil four have the lateral line complete. Of five specimens of H. inconstans two have the lateral line complete. Of nearly fifteen hundred specimens of H. liitkeni four have the lateral line complete and several others have it interrupted. Of one hundred and five specimens of H. inconstans from Quibdo, eighteen have a complete lateral line, eleven have it complete on one side and not on the other, and seventy-six have it incomplete on both sides. Hyphessobryeon is separated from Hemigrammus by the single charac- ter, the scaled or naked condition of the caudal. Three out of the present fifty-four species of the two genera seem to be intermediate in regard to this character.’ Thus, Hemigrammus elegans has but few scales on the caudal and is put with Hemigrammus because it lacks the enlarged scale at the base of each caudal lobe which is characteristic of Hyphessobrycon. 4H. analis usually has only four or five scales on the caudal, but like H. elegans it lacks the enlarged basal scales and is placed with Hemigrammus. Jd. stictus usually has the basal scale and is, therefore, put with Hyphessobrycon, although it sometimes has a number of small scales actually on the base of the caudal lobes. A question as to the validity of the species of these genera has been raised on the ground that these small fishes are immature, the young of other species. Accordingly dissections were made wherever sufficient specimens were at hand. One or more specimens were dissected of each of thirty-two species, and ovaries with large, in several cases apparently ripe, eggs were found in so many species that there is no room to doubt that, in most cases at least, we are dealing with mature specimens. The following table contains the result of the dissections in detail: THE AMERICAN TETRAGONOPTERINAE. 135 Species Hemigrammus ulreyi coeruleus unilineatus marginatus erythrozonus levis hyanuary brevis rodwayl ocellifer microstomus cylindricus analis cupreus Hyphessobrycon callistus serpae copelandi bentosi rosaceus panamensis gracilis taurocephalus parvellus minimus eos santae anasitsi liitkeni reticulatus duragenys stictus bifasciatus Number dissected 2 eer ae a ae Ll el el el LO CO No —_ mee bo Result of the dissection eggs present, but small x “~~ well developed “ “ “ “ ripe, large and yellow ripe, « “ «“ large, ovary broken up not large large and ripe well developed white and scattered in body cavity, comparatively few present but not large male specimens. eggs large and evidently ripe eggs large and evidently ripe specimen poorly preserved inside “ “ “ “ “ “ “ “ “ eggs large and evidently about ripe specimen a male eggs fairly well developed eggs large, well developed “ “ “ no eggs, sex uncertain eggs large and very evidently ripe no eggs eggs large, evidently ripe eggs of unequal size, some large and full of yellow oil eggs unequally developed, some quite large and ripe no eggs eggs large, evidently ripe eggs large, evidently ripe It seems quite certain that these genera are of polyphyletic origin, that several sections have been and are arising independently from Astyanax and Moenkhausia and probably other genera. rather than entities. These genera are conveniences 9. Hermicrammus Gill. juc = half, yeauun = a line. Hemigrammus Gru, Ann. Lyc. nat. hist. N. Y., 1858, 6, p. 420. Typr.— Poecilurichthys (Hemigrammus) unilineatus Gill. 136 THE AMERICAN CHARACIDAE. Minute or small; premaxillary teeth in two rows; the maxillary teeth wanting or reduced in number and restricted to the upper part of its free margin; scales in the lateral line 29-36; lateral line incomplete. Caudal scaled. Hasirat.— Orinoco, Essequibo south to Paraguay, Rio das Velhas, and Rio Grande do Sul. Key to the Species. a. Dorsal with a well-defined black spot. b. Anal unmarked, a black line along its base. Dorsal black, with a wide white stripe from the tip of the first rays to the base of the last. Humeral spot horizontally elongate, continued as a black line to the caudal. Second suborbital leaving a wide naked margin behind and below. Maxillary with two or three conical or tricuspid teeth. D. 11, A. 23 to 25; scales 5 or 6-30 to DOT OO stasis cline «is Mislote Ae eee ced Eee Se oe aes ne STS ee eee 1. ulreyi (Boulenger). bb. Anal with black on the rays. ce. An iridescent blue line one scale wide extending from the base of the pectoral to the scale above the last anal ray; a wide light lateral stripe from the upper part of the eye to above the middle of the base of the caudal, interrupted or not by the vertically elongate humeral spot. Ventrals and anal lobe with a submarginal dark band. Second suborbital leaving a narrow naked margin. Maxillary with four or five, sometimes two or three, tricuspid teeth. D. 11; A. 20'to 22:\ scales'5-3) or 82-8/5.........2.sacrsee-ocoun 2. coeruleus Durbin. cc. Anal with an intense black bar from a little in front of the base of the first ray to the tips of the fourth and fifth rays. Humeral spot vertically elongate, often faint and sometimes lacking. Second suborbital leaving a narrow naked area below. Six small, tricuspid and conical teeth in the maxillary. D. 11, A. 23 to 27; scales 5-32 to 34-3 to 4.5. 3. unilineatus (Gill). ccc. Black on the dorsal restricted to the first three rays, usually not intense. An oblique blackish line from the base of the third to the tip of the seventh anal rays; tips of the second and third rays white. No humeral spot. Second suborbital without naked margins. Maxil- lary with three, 5-pointed teeth. D.11; A. 23 or 24; scales 5-30 to 33-4.5. 4. elegans (Steindachner). aa. Dorsal without well-defined black markings (see also elegans). d. No humeral or caudal spot. e. A wide lateral streak from the middle of the caudal to the head and another narrower streak from above the anterior anal rays to the mandible without black chromatophores; the sides and back everywhere else dusky. Anal lobe and distal half of dorsal lobe dusky. Second suborbital about one half as wide as the eye; without naked margins. Maxillary 1.33 in the eye, with two to four, 3- to 5-pointed teeth. D. 11; A. 20 to 22; scales 5=31 to 189-3 t08325s hens tusoee eet ee eee oe 5. erythrozonus Durbin. ee. Lateral stripe leaden, caudal lobes crossed by a broad, black marginal or submarginal band. Maxillary slender, about equal to the eye. D. 11; A. 20 to 24; scales 5-29 to SEO VON a enn wayne ae Ntity AL eye: Ger Ee 6. marginatus Ellis. dd. No humeral spot, caudal spot usually developed, (see also marginatus). f. Maxillary without teeth. g. Premaxillary teeth tricuspid or conical. Maxillary much shorter than the eye. D. 11; A. 17 to 19; scales 3.5-30 to 32-2.5 to 3.............. 7. nanus (Liitken). gg. Premaxillary teeth 5- to 7- and 9-pointed. Maxillary equal to the eye. D. 11; A.'17it0720;/scales'5=30) to $48.5 8.-cees,c eon ee eee ene 8. levis Durbin. ff. Maxillary with teeth. h. An unpigmented area between the caudal spot and the lateral stripe; caudal spot not continued forward on the caudal peduncle. Premaxillary teeth with 5 to 7 cusps. Second suborbital two thirds the eye in width. Depth 3.2. Maxil- lary with one 7-pointed tooth. D.11; A. 24; scales 4-32-4. 9. microplerus Meek. hh. Caudal spot continued forward on the caudal peduncle; more or less continuous with the lateral stripe. THE AMERICAN TETRAGONOPTERINAE. 137 i. Asilvery area on the upper half of the caudal peduncle. Anal lobe dusky, lateral stripe and caudal spot very evidently continuous. j. Depth 3.6 to 3.8. Second suborbital about half the eye in width, leaving a naked margin behind and below. Maxillary with one or two narrow 4- pointed teeth. D.11; A. 14 or 15; scales 5-32 or 33-3. 10. hyanuary Durbin. jj. Depth 3. Second suborbital about three fourths the eye in width, in contact with the preopercle. Maxillary with three, 3-5 pointed teeth. D. 11, ING CRY ECAC Gas Py} (roles =s are Og BU SIoe aoe mnO Hoon es 11. matei Kigenmann. ai. No silvery area on caudal peduncle; caudal spot and lateral stripe only dimly connected. Second suborbital in contact with the preopercle. k. Caudal peduncle slender, its depth 1.5 in the distance from the base of the middle caudal rays to the base of the last anal ray. Caudal spot not as wide as the caudal peduncle, on the middle caudal ray and not con- tinued forward to the vertical from the adipose. Head 4; depth 2.7 to 38. Maxillary with two to four, conical or tricuspid teeth. D. 11, A. 22-24; scales 5-32 to 34-2 to 3.5........ 12. rodwayi Durbin. kk. Caudal peduncle deep, its depth equal to the distance from the base of the middle caudal rays to the base of the last anal ray. Caudal spot on the caudal peduncle, extending backward to the tips of the middle caudal rays, and forward to a vertical from one of the last five anal rays. Head 3.5; depth 2.6. Maxillary with two or three 3- to 5-pointed teeth. D. 11; A. 20 to 22; scales 5-29 to 33-3 or 4........... 13. brevis Ellis. kkk. Caudal spot intense, continued backwards along the middle caudal rays and along the edge of each caudal lobe. Anal falcate. Head 3.4. Maxillary with two 5-pointed teeth. D.11; A. 16-19; scales probably ALOV GSO MOO Om eres ecyesere evel cle siaisiciete auteresscoue 14. tridens Kigenmann. ddd. Humeral and caudal spots both developed. l. Dorsal equidistant from base of middle caudal rays and tip of snout, or nearer the caudal. m. Origin of the dorsal equidistant from front of eye and caudal. Origin of the anal on the vertical from the last dorsal ray. Second sub- orbital leaving very narrow naked margins below and behind. Humeral spot distinct, vertically elongate, surrounded by a bright area, often with a second elongated spot behind the bright area. An iridescent spot on the upper half of the caudal peduncle. Caudal spot often continued along the edge of each caudal lobe. Maxillary with two or three, conical or tricuspid teeth. Depth 2.5; D.11; A. 22 to 26; scales 5-30 to 33-3 to 3.5. 15. ocellifer (Steindachner). mm. Origin of dorsal half the length of the head nearer the caudal than the snout. Origin of the anal on the vertical from the first or second dorsal rays. No bright area around the vertically elongate humeral spot. Second suborbital in contact with the preopercle. Maxillary with one tricuspid tooth. D.11; A. 22; scales 5-30-3. 16. bowlengeri Eigenmann. mmm. Origin of dorsal slightly nearer middle caudal rays than tip of snout. Origin of anal on the vertical from the first to third scale behind the dorsal. Caudal spot wider than long, not continued backwards on the caudal peduncle. Humeral spot small. Maxillary with two, 4- or 5-pointed teeth. Second suborbital leaving narrow naked margins below and behind. D. 11; A. 15-17; scales OOO ate orl oe ome cna Riche arse gai eateries 17. iota Durbin. mmmm. Origin of dorsal equidistant from snout and base of middle caudal rays; origin of anal under dorsal; caudal spot not continued on the caudal; maxillary with four or five 6-pointed teeth; third suborbital in contact with the preopercle behind. D. 11; A. 24-25; lateral line 38-35............ 18. barrigonae Kigenmann. ll. Origin of dorsal nearer snout than base of middle caudal rays. Humeral 138 THE AMERICAN CHARACIDAE. spot small and indistinct. Maxillary with two or three small conical or tricuspid teeth. Depth 3; D. 11; A. 20-23; scales 5-30 to 34-3 to BO cc xeusatere tee sea nete.c ee eben 19. schmardae (Steindachner). dddd. Wumeral spot present; no caudal spot, (humeral spot sometimes faint or lacking). n. Anal rays 19-26. o. Compressed, humeral spot often very faint. p. Middle teeth of the inner row of the premaxillary 5- to 7-pointed; outer caudal rays unmarked. Frontal fontanel almost equal to the parietal. q. Depth 2.75. Humeral spot very faint, horizontally elongate. Second suborbital sometimes in contact with the pre- opercle below. Maxillary three fourths of the eye, with two or three small conical or tricuspid teeth. D. 11; A. 23 to 26; scales 5-33 to 34-3.5...20. lunatus Durbin. qq. Depth 2.8-3.5. Humeral spot faint sometimes vertically elongate. Second suborbital leaving narrow naked mar- gins behind and below. Mouth very small. Maxillary little more than one half the eye, with two or three 4- to 7-pointed teeth. D.11; A. 19 to 22; scales 5-31 to 34-3. 21. microstomus Durbin. qqq. Depth 3.75. Humeral spot faint or diffuse, roundish. Second suborbital leaving narrow naked margins behind and below. Mouth moderately large. Maxillary equal to eye. First seven anal rays dusky. D. 11; A. 19-22; scales 5-30 to 33-3. Caudal not deeply sealed, 3 to 5 scales on each lobe.-......:......- 22. orthus Durbin. pp. The inner row of the premaxillary with five to seven narrow 3- pointed teeth. Sides of caudal lobes often edged with a narrow dusky line. Humeral spot faint, vertically elongate, behind the upper margin of the eye. Eye 2.9 in the head. Frontal fontanel small, one half the length of the parietal. Second suborbital leaving narrow naked margins behind and below. Maxillary with three to five conical or tricuspid teeth. D. 11; A. 20-22; scales 5 to 7-30 to 33-3 or 3.25. 23. cupreus Durbin. oo. Subcylindrical, eye a little longer than broad, 2.25 in the head, snout comparatively long, 3.25 in the head. Maxillary nearly straight, with three to six tricuspid or conical teeth. Humeral spot small and intense. D.11; A. 17—20; scales 5-30 to 34-3. 24. cylindricus Durbin. nn. Anal rays 12 to 14. Depth 3.2 to 3.5. Humeral spot diffuse. A wide silvery lateral stripe. Each dorsal scale marked with an intense dark spot. Second suborbital leaving considerable naked margins behind and below. Maxillary with two or three 6- to 7- pointed teeth. D. 11; A. 12-14; scales 5-30 to 32-3. 25. analis Durbin. 1. HeMIGRAMMUS ULREYI (Boulenger). Plate 17, fig. 1; Plate 78, fig. 9, 10. Tetragonopterus ulreyi BOULENGER, Proc. Zool. soc. Lond., 1895, p. 529; Trans. Zool. soc. Lond., 1896, 14, p. 35, pl. 8, fig. 3 (Descalvados); Boll. Mus. univ. Torino, 1900, 16, no. 370, p. 3 (Urucum); EIGENMANN, Ann. Carnegie mus., 1907, 4, p. 126 (Corumba). Hemigrammus ulyreyi EIGENMANN & OGLE, Proc. U. S. N. M., 1907, 33, p. 13; EraenmMann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 435; Exuis, Ann. Carnegie mus., 1911, 8, p. 162 (Petas, Bolivia; Caceres; Jauru; Rio Santa Rita). Hasirat.— Paraguay Basin. THE AMERICAN TETRAGONOPTERINAE. 139 Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 11434 I. Cotype 1 33 Matto Grosso 10162 I. 1 37 Corumba Anisits 3048 C. 1 39 Near Petas, Bolivia Haseman 3049 C. + 38-41 Caceres Haseman 3050 C. 16 35-44 Jauru Haseman 3051 C. 4 38-43 Rio Santa Rita Haseman Head 3.25 to 3.5, depth 2.5 to 2.75; D. 10; A. 23-25; scales 5 or 6-30 to 33-3.5; eye 2 to 2.5 in the head, interorbital 3. Compressed depth of head at the base of the occipital process 1.5 in the greatest depth. Preventral region flat, with sometimes a complete series of 11 seales. Predorsal region rounded having a regular median series of 9 scales. Occipital process 4 in the distance between its base and the dorsal, bor- dered by three scales. Interorbital almost flat. Frontal fontanel triangular, narrower than and nine tenths as long as the parietals without the occipital groove. Second suborbital bordered behind and below by a naked margin, one half to one third of its own width. Mouth moderately large. Maxillary shorter than the eye, a little less than 3 in the head. Mandible heavy, equal to the eye. Premaxillary with five or six, 4- and 3-pointed teeth in the inner row, and three or four tricuspid ones in the outer row. Maxillary with two or three conical or tricuspid teeth. Dentary with a graduated series of four large, 3- to 5-pointed teeth, and a series of eight to twelve minute, conical ones on the side. Gill-rakers 7 + 13. Anal sheath short, consisting of 2 or 3 scales and covering the bases of the first four or five rays. Lateral line with pores on eight to ten scales. Origin of the dorsal equidistant from the snout and caudal, penultimate ray 2.5 in the longest, which is about one fourth of the length. Origin of the anal on the vertical from the last dorsal ray. Anal faleate. Ventrals on the vertical from the third scale in front of the dorsal. Ventrals just reaching the anal; pectorals just reaching the ventrals. Dorsal with a triangular black spot having the first ray for its base and the base of the fourth ray for its apex, the fin from the second to the eighth ray margined with black; the last two rays with scattered chromatophores. Humeral spot narrow, horizontally elongate, and enlarged posteriorly not quite connected with the black lateral stripe. No caudal spot. Somewhat silvery 140 THE AMERICAN CHARACIDAE. below the lateral stripe and on the cheeks. Anal and caudal dusky, a black stripe along the base of anal. 11434 I. U. from Matto Grosso, British Museum have all of these mark- ings intense black, while in 10162 I. U. from Corumba they are exceedingly faint. 2. HeEMIGRAMMUS COERULEUS Durbin. Plate 17, fig. 2. Hemigrammus coeruleus Durxrn, Bull. M. C. Z., 1908, 62, p. 99 (Manacapuru); ErcenmMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Exits, Ann. Carnegie mus., 1911, 8, p. 162 (Manaos). Hasirat.— Amazon. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 20801 Type 1 46 Manacapuru James 20801 Paratypes 102 42-52 Manacapuru James 3052 C. 3 49-58 Manaos Haseman Head 3.5; depth 2.75; D.11; A. 20-22; scales 5-31 to 32; eye 2.5 to 2.7 in the head; interorbital equal to the eye. Compressed; depth of head at the base of the occipital process 1.5 in the greatest depth. Preventral region slightly rounded, median series of scales somewhat irregular, a broad scale occupying the whole space between the bases of the ventrals. Predorsal region broadly rounded with a complete median series of nine scales. Occipital process one eighth of the distance from its base to the dorsal, bordered by one and one half or two scales. Interorbital very slightly convex. Frontal fontanel triangular just half as long as the parietal without the occi- pital groove. Second suborbital leaving a narrow naked area behind and a slightly wider one below. Maxillary very slightly longer than the eye. Mandi- ble two in the head. Snout short, mouth large. Premaxillary with five, 5- pointed teeth in the inner row; and four or five less frequently two, conical or tricuspid teeth in the outer row. Maxillary with four or five sometimes two or three, tricuspid teeth. Dentary with four large teeth, a smaller one, and four or five minute conical ones on the sides. Gill-rakers 8 + 10. Caudal sealed halfway to the tips of the longest rays. Anal sheath con- sisting of about five scales and covering the base of the first ten rays. Lateral line with pores on the seven or eight scales. THE AMERICAN TETRAGONOPTERINAE. 141 Origin of the dorsal the length of the eye farther from the snout than from the base of the caudal. The penultimate ray slightly more than half the length of the longest, which is about four and a half in the length. Caudal equal to the length of the head. Origin of anal on the vertical from the last dorsal ray or a little behind it. Anal broad, emarginate, the longest rays reaching the base of the last ray. Base of ventrals on the vertical from the second scale in front of the dorsal. Ventrals barely reaching the anal. Pectorals just reach- ing the ventrals. Distal two thirds to three fourths of dorsal black or blackish, the color more intense in males; a submarginal bar on the anal lobe, and the proximal half of the ventrals, black, the rest of the anal rays often tipped with black. No caudal spot. Humeral spot vertically elongate, a bright area in front and behind it. A wide light lateral stripe from the upper part of the eye to above the middle of the base of the caudal, paralleled below by a less distinct, brown stripe. A bright iridescent blue streak from the pectoral to the scale above the last anal ray. The scales of the sides below the lateral stripe, except those bearing the blue stripe, with a greenish iridescence. Scales of the back and sides above the lateral stripe deeply outlined with dusky. => 3. HEMIGRAMMUS UNILINEATUS (Gill). Plate 21, fig. 5; Plate 78, fig. 8. Poecilurichthys Hemigrammus unilineatus Grut, Ann. Lye. nat. hist. N. Y., 1858, 6, p. 420 (Trinidad) ; GUnTuHER, Cat. fishes Brit. mus., 1864, 5, p. 317. Tetragonopterus unilineatus EIGENMANN & EIGENMANN, Proc. U. 8. N. M., 1891, 14, p. 54; Urey, Ann. N. Y. acad. sci., 1895, 8, p. 285, (Para, Brazil); Gi~Bert, Proc. Wash. acad. sci., 1900, 2, p- 163 (Pernambuco). Tetragonopterus (Hemigrammus) unilineatus Rucan, Proc. Zool. soc. London, 1906, p. 384 (Trinidad). Hemigrammus unilineatus EIGENMANN and Oct, Proce. U. 8. N. M., 1907, 33, p. 12 (Trinidad); Ercen- MANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Mem. Carnegie mus., 1912, 5, p- 332; pl. 48, fig. 1; Exurs, Ann. Carnegie mus., 1911, 8, p. 162 (Braganga; Maciél, Rio Guaporé). Hasirat.— Trinidad, Guianas, and Amazons. Specimens examined. Number of | Length Catalogue number specimens in mm. Locality Collector 5779 I. 5 28-38 Para, Brazil Hartt 10801 I. 1 40 Los Castillas, Venezuela Riddle 1440 C., 11898 I. 110 35-48 Creek in Moro Passage Shideler 1441 C., 11899 I. 22 3141 Creek in Barima River Shideler 1442 C., 11900 I, 86 23-48 Aruka River Shideler 142 THE AMERICAN CHARACIDAE. Number of Length Catalogue number specimens in mm. Locality Collector 1443 C., 11901 T. 7 32-52 Isoro Mud Creek Shideler 1444 C., 11902 I. 26 26-53 Mud flats in Demerara River Eigenmann below Wismar 1445 C. ] 37 Georgetown Trenches Eigenmann 1446 C., 11903 I. q 4147 Wismar Eigenmann 1447 C., 11904 I. 5 35-47 Cumaka, Demerara River Eigenmann 3043 C. 24 27-48 Bragan¢a Haseman 3044 C. 9 31-38 Maciél, Rio Guaporé Haseman Head 3.75; depth 2.2-3; D. 11; A. 23 to 27; scales 5-32 to 34-3 to 4.5; eye 2.25 to 2.5 in the head; interorbital narrower than the eye, 3 in the head. Compressed, deepest at the vertical of the first dorsal ray; depth of head at base of occipital process three fifths in the greatest depth. Preventral regions rounded, without complete series of median scales. Predorsal region rounded without a regular series of median scales. Occipital process 6 in the distance from its base to the dorsal, bordered by 2.5 to 3 scales. Interorbital almost flat. Frontal fontanel very narrowly triangular, two thirds the length of the parietal without the occipital groove. Second suborbital leaving a narrow naked margin below it. Mouth moderately large; maxillary equal to the eye; mandible a little longer, half the length of the head. Premaxillary with two to four conical or tricuspid teeth in the outer row and five or six, tricuspid teeth in the inner row. Maxillary with six small conical and tricuspid teeth. Dentary with a graduated series of five, 3- to 5-pointed teeth and a series of twelve or more minute conical ones on the sides. Gill-rakers 6 + 10. Basal third of caudal scaled. Anal sheath rudimentary or wanting. Lat- eral line with pores on 5 to 8 scales. Origin of the dorsal equidistant from the snout and caudal, its penultimate ray one third of the longest which is 3.25 in the length. Origin of the anal on the vertical from the first scale behind the dorsal. Anal deeply emarginate. Ventrals on the vertical from the first scale in front of the dorsal. Ventrals overlapping the anal a distance equal to half the length of the eye. Pectorals overlapping ventrals the same distance. Dorsal black except the tips of the anterior 5 or 6 rays. An oblique black line on the anal from the base of the first to the tips of the fourth and fifth rays. Humeral spot vertically elongate, often faint and sometimes lacking. No caudal spot. Lateral stripe narrow. Scales of the back outlined with dusky. THE AMERICAN TETRAGONOPTERINAE. 143 4. HEMIGRAMMUS ELEGANS (Steindachner). Plate 17, fig. 3. Tetragonopterus elegans STEINDACHNER, Flussf. Siidam., 1882, 4, p. 36, pl. 7, fig. 4 (Obidos); E1raeNMANN & E1cenmann, Proc. U.S. N. M., 1891, 14, p. 285; Unrey, Ann. N. Y. acad. sci., 1895, 8, p. 285. Hemigrammus elegans EIGENMANN & OL», Proc. U.S. N. M., 1907, 33, p. 12; Ercenmann, Rept. Prince- ton univ. exped. Patagonia, 1910, 3, p. 436. Hasitrat.— Amazon. Specimens examined. Number of Catalogue number — specimens Size in mm. Locality Collector 20734 4 27-30 Santarem Bourget 20869 1 35 Tapajos Dexter, James, & Talisman 20840 ! Lh te 28 Obidos James Head 3.5-3.67; depth 2.67-3; D.11; A. 23 or 24; scales 5-30 to 33-4.5; eye 2.25-25; interorbital 3. Compressed; depth of head at base of occipital process 1.75 in the great- est depth. Preventral region rounded; no regular series of median scales. Predorsal region rounded, with a regular median series of 9 scales. Occipital process one fourth of the distance from its base to the dorsal, bordered by three scales, interorbital almost flat; frontal fontanel almost equal to the parietals without occipital groove. Second suborbital leaving a narrow naked area behind and below. Mouth large. Maxillary barely as long as the eye, mandible equal to the eye. Snout very blunt, equal to half the length of the eye. Premaxillary with an outer series of three 5-pointed teeth, and an inner series of five teeth, the center one of which has five cusps, the next three to six cusps each and the end one seven. The maxillary with three, 5-pointed teeth broader than those of the outer premaxillary series. Dentary with five, 3- to 5-pointed teeth followed by a few conical ones on the sides. Gill-rakers about 7 + 10. Caudal only partially scaled. Anal sheath of six scales covering the bases of the first seven rays. Lateral line with pores on from seven to eleven scales, not decurved. Origin of dorsal a very little nearer snout than caudal. Penultimate ray three in the longest which is 2.75 in the length. Caudal probably equal to 1 In part. 144 THE AMERICAN CHARACIDAE. the head. Origin of the anal on the vertical from the eighth or ninth dorsal ray. Ventrals on a vertical from the first or second scale in front of the dorsal. Ventrals reaching just to the anal. Pectorals reaching to the ventrals. The distal three fourths of the first, second, and third, and distal one fourth of the fourth dorsal rays pigmented. An oblique blackish line passing over the basal fifth of the third, the entire fourth and fifth, and the tips of the sixth and seventh anal rays. The first and distal half of the second and third anal rays, with intervening membrane, with a milk-white elongate spot. A very slender dark gray lateral stripe from the caudal peduncle to the vertical from the dorsal. A few chromatophores, much scattered and very faint, occur in the humeral region. The one 35 mm. specimen from Tapajos differed from the rest in the anal marking. In it the oblique line was lacking, giving place to a semicircular dark spot including the tips of the sixth, seventh, and eighth rays. 5. H®rMIGRAMMUS ERYTHROZONUS Durbin. Plate 21, fig. 4. Hemigrammus erythrozonus DurBin, Ann. Carnegie mus., 1909, 6, p. 56 (Erukin); Ercenmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Mem. Carnegie mus., 1912, 5, p. 333, pl. 48, fig. 2. Hasirat.— British Guiana. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 1448 C. Type 1 32 Erukin Eigenmann ees Soe t 32 21-33 Erukin Eigenmann Head 3.75; depth 3.33 to 3.75; D.11; A. 20-22; scales 5-31 to 34-3 to 3.5; eye 2.5 in the head, snout 1.5 in the eye. Interorbital less than eye, about 2.75 in head. Compressed; depth of head at base of the occipital process 1.5 in the greatest depth. Preventral region rounded, without complete, regular series of median scales. Predorsal region rounded, median series of scales incom- plete, always more or less irregular near the head. Occipital process from one sixth to one seventh of the distance from its base to the dorsal; bordered by 3 scales. Interorbital convex. Frontal fontanel much narrower than parietal, triangular, two thirds of the parietal THE AMERICAN TETRAGONOPTERINAE. 145 without the occipital groove. Second suborbital leaving a narrow naked margin behind and below. Snout short; mouth moderately large. Maxil- lary 1.33 in the eye. Mandible equal to the eye, 2.5 in head, much weaker than the upper jaw. Width of naked area of the cheek 4 in the eye. Pre- maxillary with five 3- to 5-pointed teeth in the inner row, and two or three narrow tricuspid teeth in the outer row. Maxillary with two to four, 3- to 5-pointed teeth. Dentary with four or five, 5- to 7-pointed teeth in a graduated series, followed by seven or eight minute tricuspid and conical teeth on the sides. Gill-rakers 8 + 6. Anal sheath short, of three scales covering the bases of the first five anal rays. Caudal scaled over the basal one fourth. Lateral line with pores on six to nine scales. Origin of dorsal equidistant from the snout and caudal, penultimate ray one third the longest which is 3.67 in the length. Origin of the anal on the vertical from the last dorsal ray. Anal deeply emarginate, longest ray 1.25 in the length of the base. Caudal equal to the length of the head. Ventral on the vertical from the second scale in front of the dorsal. Ventrals just reaching the first or second anal rays. Pectorals reaching the first scale in front of ventrals. No true humeral spot; pores and margins of the first three or four scales in the lateral line heavily outlined with dusky and a group of large chromato- phores just behind the eye on the head give the appearance of a humeral spot. Web of distal half of dorsal, almost all of the caudal, all of the ventrals, pec- torals, and the web between the first seven anal rays dusky. Often a faint little dark spot at the base of each caudal lobe, no true caudal spot. Scales of the back and upper one third of the sides outlined with dusky. A broad stripe without chromatophores cherry-red in life, extends from the head to the caudal and halfway to the end of the middle caudal rays. Below this lateral stripe a dusky stripe two scales in width extends the length of the body. The belly and a streak on the sides, from just above the bases of the anterior ten anal rays to the mandible, without chromatophores. Bases of the anal and under side of the caudal peduncle black to dusky. Lips dusky. Dorsal lobe and upper part of the iris cherry-red in life. 146 THE AMERICAN CHARACIDAE. 6. HEMIGRAMMUS MARGINATUS Ellis. Plate 20, fig. 1. Hemigrammus marginatus Evuis, Ann. Carnegie mus., 1911, 8, p. 159, pl. 3, fig. 3 (Queimadas). Hasitat.— Head waters of Parana, Paraguay, Guaporé, Itapicurti, and San Francisco Rivers. Specimens examined. Number of Length Catalogue number specimens in mm. Locality Collector 3053 C. Type 1 38 Rio Itapicuri, Queimadas Haseman 3054 C. Paratypes 22 13-39 Rio Itapicuri, Queimadas Haseman 3055 C. Paratypes 3 23-29 Boqueirao near mouth of Rio Haseman Preto 3056 C. Paratypes q 28-30 Santa Rita, Rio Preto Haseman 3057 C. Paratypes 3 29-33 Lagoa da Porto, near Barra, Haseman Rio San Francisco 3058 C. Paratypes 6 26-38 Jacobina, Rio Jacobina, Ita- Haseman picurti Basin 3059 C. Paratypes 18 33-38 Pirapora, Rio San Francisco Haseman 3060 C. Paratypes 42 18-42 Lagoa Pereira, Barra Haseman 3061 C. Paratypes 5 37-42 Jaguara, Rio Grande Haseman 3062 C. Paratypes 5 32-39 Rio Paiaia, Itapicurfti Basin Haseman 3063 C. Paratypes 8 32-38 Barreiras, Lagoas of Rio Haseman Grande, San Francisco Basin 3064 C. Paratypes 6 22-38 Sete Lagoas, Rio das Velhas Haseman 3065 C. Paratypes 3 29-35 Tinho, Rio Itapicurii Haseman 3082 C. Paratypes 1 40 Maciél, Rio Guaporé Haseman 3084 C. Paratypes 1 28 Mogy Mirim, a creek in Sao Haseman Paulo, Parana Basin C. Paratype 2 40-42 Rio Zinga, Itapicuri Basin Haseman 3066 C. Paratypes 9 26-32 Riberao, Azul Lagoa 12 miles Haseman from Tieté 3067 C. Paratype 1 21 Sapucay, Paraguay Haseman 3077 C. Paratype 1 40 Caceres, Paraguay Haseman 3083 C. Paratype 1 34 Rio Itapicurt, fazenda de Haseman Amaratu, 6 miles north of Bom Fin Head 3.6 to 3.8; depth 2.8 to 3.25; D.11; A. 20 to 24; scales 5-29 to 34-3 to 4. Eye 2 in the head. Interorbital less than the eye, 2.75 in the head. Compressed; depth of head at the base of the occipital process 1.5 in the greatest depth. Preventral and predorsal regions rounded, without complete series of median scales. THE AMERICAN TETRAGONOPTERINAE. 147 Occipital process 5 or 6 in the distance from its base to the dorsal, bor- dered by 3 scales. Interorbital slightly convex. Frontal fontanel triangular, almost as wide as the parietal and as long as the parietal without the occipital groove. Second suborbital little more than half the eye in width, usually with narrow naked margins behind and below. Mouth large; snout little more than half the length of the eye. Maxillary slender, just, or not quite, equal to the eye; 2 to 2.3 in the head. Mandible equal to the eye. Premaxillary with three or four tricuspid teeth in the outer row, and four or five, rarely six, 3- to 5-pointed teeth in the inner row. Maxillary with two or three, less often four, 3- to 5-pointed teeth, the posterior one sometimes conical. Dentary with a graduated series of four or five 3- to 5- and 7-pointed teeth, followed by a series of seven to twelve minute, conical ones on the sides. Gill-rakers 6 + 10. Caudal scaled over the basal one half. Anal sheath short, consisting of about 6 scales over the bases of the first 10 rays. Lateral line with pores devel- oped on 5 to 14 scales. Origin of the dorsal equidistant from the snout and caudal; penultimate ray short, one fourth of the longest, which is 3.67 in the length. Origin of the anal on the vertical from the first scale behind the dorsal. Anal emarginate, the longest ray 1.25 in the length of the base. Ventrals on the vertical from the first scale in front of the dorsal. Ventrals just reaching the anal. Pec- torals just, or not quite, reaching the ventrals. No humeral spot. Caudal spot faint or lacking. A heavy leaden lateral stripe often somewhat expanded near the end of the caudal peduncle, nar- rowed in the region just below the dorsal. Dorsal and anal somewhat dusky. A broad black marginal or submarginal band across the caudal lobes. When this band is submarginal the middle caudal rays are black also. The base of the caudal lobes hyaline, probably orange or red in life. Seales of the back and sides, above the lateral stripe outlined with dusky. Sides below the lateral stripe with pale bluish iridescence. 7. HEMIGRAMMUS NANUS (Liitken). Plate 18, fig. 1; Plate 78, fig. 2, 7. Tetragonopterus nanus LiitKEn, Overs. K. Dan. selsk. Forh., 1874, p. 133 (Lagoa Santa); Vidensk. selsk., 1875, 12, p. 218, pl. 5, fig. 17 (Rio das Velhas); ErgeNMANN & EIGENMANN, Proc. U.S. N. M., 1891, 14, p. 282; Unrey, Ann. N. Y. acad. sci., 1895, 8, p. 286. 148 THE AMERICAN CHARACIDAE. Hemigrammus nanus E1GENMANN & OGLE, Proc. U.S. N. M., 1907, 33, p. 15; Eraenmann, Rept. Prince- ton univ. exped. Patagonia, 1910, 3, p. 435. Hapitat.— San Francisco Basin. 44958 U. S. N. M., 4 Cotypes Lagoa Santa Reinhardt Head 3.9; depth 3.5-4; D.11; A.17-19; scales 35-30 to 32-2.5 to 3; eye 2.2 in the head, interorbital narrower. Compressed; depth of head at the base of the occipital process 1.33 in the greatest depth. Preventral region rounded, without complete series of median scales. Predorsal region rounded with complete median series of 11 scales. Occipital process one seventh of the distance from its base to the dorsal, bordered by two and a half scales. Interorbital region somewhat convex. Second suborbital leaving a narrow naked area below and a much narrower one behind. Maxillary much shorter than the eye, 3.25 in the head. Mandible nearly as long as the eye, 2.75 in the head. Premaxillary with four, 3-pointed, teeth and sometimes one conical tooth in the inner row, and two similar but narrower teeth in the front row. Maxillary without teeth or with one tooth. Caudal probably scaled; anal sheath of probably a single series of scales extending the entire length of the base of the fin. Lateral line with pores on from 4 to 7 scales. Origin of the dorsal half length of the eye nearer the caudal than the snout, penultimate ray one third of the longest which is 4.2 in the length. Origin of the anal on the vertical from the last dorsal ray. Height of the anal nearly equal to the length of its base. Anal emarginate. Base of the ventrals on the vertical from the second or third scale in front of the dorsal. Ventrals not quite reaching the anal, and pectorals almost reaching the ventrals. Fins all hyaline except where the large, diffuse dark caudal spot extends over the caudal, often reaching the ends of the middle rays. No humeral spot. An inconspicuous, silvery lateral band. The scales of the back outlined with pigment, a few chromatophores scattered over the sides except above the body- cavity. 8. HeMIGRAMMUS LEVIS Durbin. Plate 18, fig. 2. Hemigrammus levis DurBin, Bull. M. C. Z., 1908, 62, p. 100 (Lago do Maximo); Ercenmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 486; Exuis, Ann. Carnegie mus., 1911, 8, p. 162 (Santarem). HapiratT.— Amazon. THE AMERICAN TETRAGONOPTERINAE. 149 Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 20738 Type 1 47 Lago do Maximo Agassiz 20738 Paratypes 201 35-48 Lago do Maximo Agassiz 20838 Paratypes 18 33-45 Chidas James 20829 Paratypes 3 38-44 Chidas James 20716 Paratypes 63 34441 Villa Bella Agassiz 20749 Paratypes 35 44-47 Lake Jose Assu Agassiz 3088 C. 2 31, 38 Santarem Haseman Head 3.5 to 3.66; depth 3.2 to 3.6; D. 11; rarely 10; A. 17-20; scales 5-30 to 34 to 3.5; eye 2.5 to 2.67 in the head; interorbitals slightly less than the eye. Compressed, head short, depth of head at the base of the occipital process 1.5 in the greatest depth. Preventral region rounded, usually without com- plete series of median scales; sometimes a more or less regular series of 12 or 13 scales, the last enlarged. Predorsal region rounded, a regular median series of 9 scales. Occipital process one sixth of the distance from its base to the origin of the dorsal. Bordered on the side by two or three scales. Interorbital slightly convex. Frontal fontanel narrowly triangular, just or a little less than equal to the parietal without the occipital groove. Second suborbital leaving a narrow naked margin behind and below it. Maxillary equal to the length of the eye. Mandible a little longer than the eye. Snout short, about 1.3 in the length of the eye; mouth large. Premaxillary with three, sometimes four, 3-pointed teeth in the outer row, and five, the middle 6- to 7- and the rest 7- to 9-pointed teeth in the inner row. Maxillary without teeth. Dentary with five large or four large and one small, 7- to 9-pointed teeth, several minute coni- eal teeth on the sides. Gill-rakers 8 + 12. Anal sheath short, consisting of 2 or 3 scales covering the bases of the first 6 or 7 rays. Lateral line developed on from 6 to 11 scales. Origin of the dorsal equidistant from snout and caudal. Penultimate ray 2.33 in the longest which is 3.67 to 4 in the length. Caudal equal to the length of the head. Origin of the anal on the vertical from the first or second scale behind the dorsal. Ventrals on the vertical from the origin of the dorsal. Pectorals not reaching the ventrals; ventrals almost reaching the anal. 150 THE AMERICAN CHARACIDAE. Middle caudal rays with a round black spot; all other fins unmarked. A slate-black lateral stripe beginning on the vertical of the adipose fin and gradu- ally fading out again just below the origin of the dorsal. A silvery stripe on the scales below the lateral stripe. All of the scales below and half of the row just above the lateral stripe more or less covered with greenish golden iridescence that partakes of a turquois tinge as it approaches the anal, especially in speci- mens from Lago do Maximo and Lake Jose Assu, Brazil.’ 9. HEMIGRAMMUS MICROPTERUS Meek. Plate 18, fig. 3; Plate 78, fig. 6. Hemigrammus micropterus MEEK Ms., Proc. U. 8. N. M., 1907, 33, p. 15 (Los Castillas); E1GENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. One specimen 10802 I 35 mm. Los Castillas, Venezuela O. Riddle Head 3.8-4; depth 3.2; D.10 or 11; A. 24; scales 4-32-4; eye 2.75 in the head, interorbital about equal to the eye. Compressed, depth of head at the base of the occipital process 1.5 in the greatest depth. Preventral region rounded, with complete median series of 10 scales. Postventral region not so narrow as in most species of the genus. Predorsal region rounded with complete median series of 9 or 10 scales. Occipital process 5 or 6 in the distance from its base to the dorsal. Inter- orbital slightly convex. Frontal fontanel triangular and equal to the parietal without the occipital groove. Second suborbital in contact with the preopercle behind and below. Snout short and narrow, mouth rather small. Maxillary about equal to the eye. Mandible a little longer, 2.25 in the head. Pre- maxillary with an inner series of five, 5- to 7-pointed teeth and an outer series of two narrowly tricuspid teeth. Maxillary with one 7-pointed tooth. Dentary with a graduated series of five, 3- to 5-pointed teeth and a row of minute conical teeth on the sides. Gill-rakers 6 + 9. Anal sheath short, consisting of 1 or 2 scales. Lateral line with pores on 4 or 5 scales. Origin of the dorsal equidistant from snout and caudal, the penultimate ray four ninths of longest which is 4 in the length. Origin of the anal on the vertical from the second scale back of the dorsal, anal slightly emarginate, 1 One specimen from Lago do Maximo with a complete lateral line. THE AMERICAN TETRAGONOPTERINAE. 151 rather narrow. Caudal equal to the head. Ventral on the vertical from the first dorsal ray. Ventrals not quite reaching to the anal. Pectoral reaching to within one scale of the ventrals. Fins all a little dusky, without definite markings. No humeral spot. A narrow black lateral stripe, faint from the head to the vertical from the origin of the anal and ending abruptly before it meets the caudal spot, which is con- tinued to the end of the middle caudal rays. Scales of the back with rather broad dark margins. 10. HrmMIGRAMMUS HYANUARY Durbin. Plate 18, fig. 4. Hemigrammus hyanuary Durpin Ms. Etcenmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. Eight specimens 20955 40-44 mm. Lake Hyanuary Navez Head 3.5-4; depth 3.6-3.8; D.11; A. 14-15; scales 5-32 or 33-3; eye 2.67 in head, snout 1.5 in the eye; interorbital almost equal to the eye, very nearly 2.75 in the head. Compressed, depth of head at base of occipital process 1.25 to 1.33 in the greatest depth. Preventral region rounded without complete series of median scales. Predorsal region rounded with regular median series of about 9 scales. Occipital process about 8 in the distance from its base to the dorsal, bor- dered by 2 and 1.5 scales. Interorbital almost flat. Frontal fontanel much narrower than the parietal, equilaterally triangular, very small about one fourth the parietal without the occipital groove. Second suborbital leaving a narrow naked margin behind and below. Snout short but not so short as in H. matei; mouth large. Lower jaw included only when the mouth is closed. Maxillary 1.25 in the eye. Mandible about equal to the eye, 2.75 in the head. Premaxillary with four, narrow, tricuspid teeth in the outer row, and five, rarely six, large 3- to 5-pointed teeth in the inner row. Maxillary with one or two narrow 4-pointed teeth. Dentary with four or five large 4- to 6-pointed teeth in a graduated series followed by five or six minute teeth on the sides. Gill-rakers 6 + 8. Lateral line with pores developed on 8 to 10 scales. Origin of the dorsal less than the length of the eye nearer the snout than the caudal; penultimate ray one third of the longest which is 3.75 in the length. Origin of the anal on the vertical from the second scale behind the dorsal. Anal 152 THE AMERICAN CHARACIDAE. emarginate, the longest ray equal to the base. Anal armature developed on males. Ventrals on the vertical from the second scale in front of the dorsal. Ventrals reaching the first to third anal rays. Pectorals usually just reaching the ventrals. Humeral spot absent, (a small and faint round spot on two specimens). Caudal spot very dark, round or vertically elongate, entirely covering the middle caudal rays. Usually extending forward onto the caudal peduncle so as to give the spot a roughly triangular shape, placed rather below the middle of the peduncle. Scales of the back dusky; those on the sides above the narrow lateral stripe outlined with dusky. The first half of the anal rays, all of the dorsal, ventrals, and pectorals dusky. Scales below the lateral stripe with bright greenish iridescence. An uneven iridescent spot on the caudal peduncle above and in front of the caudal spot. 11. Hemicrammus MATE! Eigenmann. Plate 19, fig. 1. Hemigrammus matei EIGENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. One specimen 11438 I. Type 43 mm. Argentina Head 3.75-4; depth 3; D.10; A. 23; scales 5-32 to 34-3; eye 2.2 in the head, snout 2 in the eye, interorbital slightly less than the eye, 2.6 in the head. Compressed; depth of the head at the base of the occipital process, 1.5 in the greatest depth. Preventral region rounded, without complete series of median seales. Predorsal region rounded, with complete median series of 10 scales. Occipital process 5 in the distance from its base to the dorsal, bordered by 3. scales. Interorbital slightly convex. Frontal fontanel not narrower than the parietal, triangular and 1.25 in the length of the parietals without the occipital groove. Second suborbital in contact with the preopercle. Snout short and blunt, mouth large. Maxillary equal to or slightly less than the eye. Mandible a little longer than the eye, 2.14 in the head. Opercle incised above. Premaxillary with five or six 2- to 5-pointed teeth in the inner row and two or three similar but narrower ones in the outer row. Maxillary with three teeth, the posterior one 3-pointed, the anterior one 5-pointed. Dentary with graduated series of four or five teeth and several minute conical ones on the sides. THE AMERICAN TETRAGONOPTERINAE. 153 Gill-rakers 4 + 10. One third of caudal scaled. Anal sheath of about 5 scales covering the basis of the first 8 anal rays. Lateral line with pores on 3 to 7 scales. Origin of the dorsal one third of the length of the eye nearer to the caudal than to the snout, its penultimate ray two fifths of the longest which is 3.5 in the length. Origin of the anal on the vertical from the seventh anal ray. Anal emarginate, the longest ray 1.33 in the length of the base. Caudal somewhat shorter than the head. Ventrals on the vertical from the second scale in front of the dorsal. Ventrals not quite reaching the anal; pectorals reaching a little beyond the origin of the ventrals. No shoulder-spot; a black lateral band beginning over the middle of pec- torals as a thin line, becoming gradually broader to the caudal peduncle where it expands more rapidly, abruptly contracted at the base of caudal but con- tinued for a short distance on the middle rays, the markings on the caudal being arrow-shaped. Back dusky, except the upper surface of upper caudal rays, and a spot behind the adipose. Fins all dusky. Spot on the back behind the adipose iridescent, yellowish, practically free from pigment. 12. HermiGRAMMUS RODWAYI Durbin. Plate 2a ties. Hemigrammus rodwayi Dursin, Ann. Carnegie mus., 1909, 6, p. 58 (Georgetown Trenches), E1aenmMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Mem. Carnegie mus., 1912, 5, p. 334, pl. 48, fig. 3; Exurs, Ann. Carnegie mus., 1911, 8, p. 162 (Braganga; above Cachoeira, Rio Nova, Goyaz, Piabana). Hasrrat.— Lowland rivers from the Orinoco to Para, also Rio Nova. Specimens examined. Number of Length Catalogue number specimens in mm. Locality Collector 1450 C. Type 1 46 Georgetown Trenches Eigenmann 1451 C., 11906 I. 183 38-49 Georgetown Trenches Eigenmann Paratypes 1452 C., 11907 I. 112 28-53 Botanic Garden, Georgetown Shideler 1453 C., 11908 I. 4 24-26 Mud Creek in Aruka River Shideler 1454 C., 11909 I. 7 34—40 Creek in Barima River Shideler 3045 C. 6 31-40 Bragan¢a Haseman 2 42-45 Georgetown Trenches Ellis 12656 I. 3 31-36 Lama Stop-Off Eigenmann 2949 C. 1 27 Above Cachoeira Rio Nova Haseman into Somno, into Tocan- tins, Goyaz 154 THE AMERICAN CHARACIDAE. Head 4; depth 2.75-3; D.11; A. 22-24; scales 5-32 to 342.5 to 3.5; eye 2-2.33 in the head; snout 7.5 in the eye, interorbital very nearly equal to the eye, 2.4 to 2.5 in the head. Compressed; depth of head at the base of occipital process 1.5 to 1.2 in the greatest depth. Preventral region rounded, without complete series of median scales. Predorsal region rounded, sometimes with complete series of 9 or 10 median scales. Occipital process 6 in the distance from its base to the dorsal, bordered by 3 seales. Interorbital convex. Frontal fontanel narrower than the parie- tal, triangular and almost as long as the parietal without the occipital groove. Second suborbital in contact with the preopercle. Snout short, mouth moder- ately large. Maxillary not quite equal to the eye. Mandible a little longer than the eye, 2-2.4 in the head. Preopercle not deeply incised above. Pre- maxillary with four or five, 4- to 5-pointed teeth in the inner, and three or four tricuspid teeth in the outer row. Maxillary with two or four small uni- bi- or tricuspid teeth. Dentary with a graduated series of four, 5- to 7-pointed teeth, and several minute conical ones on the sides. Gill-rakers 10 + 6. Caudal much sealed. Anal sheath of about 5 seales covering the bases of the first 6 to 8 anal rays. Lateral line with pores on 9 to 12 sometimes on 15 scales. Origin of the dorsal equidistant from snout and caudal, penultimate ray one third of the longest which is 3.5 in the length. Origin of the anal on the vertical from the first or second scale behind the dorsal. Anal deeply emarginate, longest ray 1.5 to 1.33 in the length of the base. Caudal half the length of the eye longer than the head, ventral lobe slightly larger than the dorsal lobe. Ventrals on the vertical from the first scale in front of the dorsal, just reaching the anal. Pectorals either not quite or just reaching the ventrals. No shoulder-spot. A silvery lateral stripe extending from the caudal to about the vertical from the first dorsal rays, and continued forward by a few large scattered chromatophores. The black caudal spot usually extending nearly or entirely to the end of the middle caudal rays. Scales of the back and sides outlined with pigment above the lateral stripe, an olive stripe along the back, sides above stripe straw colored, scales below the stripe with a light blue iridescence. No iridescent spot on the back of the caudal peduncle. All fins somewhat dusky. Males with a cherry-red spot on the base of each caudal lobe, anterior anal margin with a white bar, broadest towards the tip, the rest tes nw rey al THE AMERICAN TETRAGONOPTERINAE. 155 of anal and the base of dorsal tinged with red. Females with yellow on caudal, anal, and dorsal in place of the red described in the case of males. The white bar on anal lacking in females. 13. H®rMIGRAMMUS BREVIS Ellis. Hemigrammus brevis Euuis, Ann. Carnegie mus., 1911, 8, p. 161, pl. 3, fig. 4 (Barreiras). Hasitat.— San Francisco Basin. Specimens examined. Number of Size Catalogue number specimens in mm. Locality Collector 3068 C. Type 1 35 Barreiras, Lagoas of Rio Grande Haseman of San Francisco Basin 3069 C. Paratypes 2 31, 33 Penedo, Rio San Francisco Haseman 3070 C. Paratypes 3 34-36 Barreiras, Lagoas of Rio Grande Haseman 3071 C. Paratypes 33 20-27 Boqueirao, Rio Preto Haseman Head 3.5; depth 2.6; D.11; A. 20 to 22; scales 5-29 to 33-3 to 4. Eye 2 to 2.3 in the head; interorbital less than the eye, 2.7 in the head. Compressed; depth of head at the base of the occipital process about 1.6 in the greatest depth. Preventral and predorsal regions rounded. Occipital process about 5 in the distance from its base to the dorsal, bor- dered by 2 scales. Interorbital slightly convex. Frontal fontanel triangular, as wide as the parietal, and almost equal to the parietal without the occipital groove. Second suborbital in contact with the preopercle. Mouth large, snout short, little more than one half the eye. Maxillary and mandible approxi- mately equal to each other and to the eye. Premaxillary with three to five tricuspid teeth in the outer row, and five, rarely four, 3- to 5-pointed teeth in the inner row. Maxillary with one to three, 3- to 5-pointed teeth. Dentary with a graduated series of five 5-pointed teeth followed by a series of seven to eleven minute tricuspid and conical ones on the sides. Gill-rakers 10 + 9 with 5 minute spines behind the last two on the shorter limb. Caudal sealed over the basal one half. Anal sheath short, composed of 5 scales covering the bases of the first 9 anal rays. Lateral line with pores developed on the first 5 to 9 scales. Origin of the dorsal equidistant from the snout and the caudal; penulti- mate ray about one fifth of the highest, which is 3.67 in the length. Caudal 156 THE AMERICAN CHARACIDAE. very little longer than the head. Origin of anal on the vertical from the last dorsal ray. Anal deeply emarginate, the longest ray 1.25 in the anal base. Ventrals on the vertical from the first scale in front of the dorsal. Ventrals reaching the second to fourth anal ray. Pectorals reaching to the first scale in front of the ventrals or to the second scale behind the ventrals. No humeral spot. Caudal spot not quite as wide as the caudal peduncle, but extending from the tips of the middle caudal rays to the vertical from one of the last five anal rays, more diffuse at the anterior end. Lateral stripe very faint, heavily overlaid with silvery. Fins all a little dusky. Scales of the back outlined with dusky. Cheeks and sides below the lateral stripe with bluish iridescence. 14. HemicrRaMMus TRIDENS Eigenmann. Plate 19, fig. 2; Plate 78, fig. 4. Hemigrammus tridens E1GENMANN, Proc. U. S. N. M., 1907, 83, p. 15 (Arroyo Pypucu); Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. Hapirat.— Arroyo Pypucu, Paraguay. Specimens examined. Catalogue Number of number specimens Size in mm. Locality Collector 11262 I. Type 1 20 to base of Arroyo Pypucu, Paraguay Anisits , caudal 11262a I. 2 17, 18 to base Arroyo Pypucu, Paraguay Anisits of caudal Head 3.4; depth 3; D.11; A. 16-19; scales probably 4 to 5-30 to 35-3; eye 2.4 in head, interorbital 3+ in the head. Compressed, depth of head at the base of the occipital process 1.75 in the greatest depth. Preventral region rounded without complete series of median scales. Predorsal region rounded or very slightly keeled, with complete regu- lar series of 11 scales. Occipital process 6 in the distance from its base to the dorsal, bordered by 2-2.25 seales. Interorbital slightly convex. Frontal fontanel triangular, its base narrower than the parietal and half as long as the parietal without the occipital groove. Second suborbital in contact with the preopercle. Snout short, mouth large; maxillary shorter than the eye, 3 in the head. Mandible about equal to the eye. Premaxillary with an inner row of five teeth, with 5 long points, the middle one much the longest, the outer row with two nar- THE AMERICAN TETRAGONOPTERINAE. 157 row tricuspid teeth. Maxillary with two 5-pointed teeth, the points nearly equal in length. Dentary with a graduated series of four large, 4- or 5-pointed teeth and two quite small tricuspid ones. Gill-rakers 6 + 10. Anal sheath short. Lateral line with pores on 4 to 7 scales. Origin of the dorsal almost the length of eye nearer the caudal than to the snout, longest ray 4 in the length. Origin of the anal on the vertical from the second scale behind the dorsal. Anal faleate, the longest ray equal to the length of the base; origin of ventrals on the vertical from the first scale in front of the dorsal, reaching the anal. Pectorals not reaching the ventrals. Dorsal and anal very slightly dusky. No distinct humeral spot, a few seattering chromatophores forming a horizontally elongate bar extending from the head to vertical from the base of the ventrals, where the narrow black line-like lateral stripe begins. The caudal spot forms a jet-black band across the end of the tail, continued forward to a blunt median point upon the lateral stripe, and backwards along the edge of each caudal lobe and along the middle caudal rays, but not to their tips. Scales of the back outlined with pigment. 15. HEMIGRAMMUS OCELLIFER (Steindachner). Plate 19, fig. 3; Plate 21, fig. 2. Tetragonopterus ocellifer STEINDACHNER, Flussf. Siidamer., 1882, 4, p. 32, pl. 7, fig. 5, (Villa Bella; Cudajas); EtGENMANN & EIGENMANN, Proc. U.S. N. M., 1891, 14, p. 54; Unrey, Ann. N. Y. acad. sci., 1895, 8, p. 286 (Amazon and Solimoes Basin). Holopristis ocellifer EIGENMANN, Smith. misc. coll. quart., 1903, 45, p. 145; Eraenmann & OcLp, Proc. U.S. N. M., 1907, 33, p. 11. Hemigrammus ocellifer Exxis, Ann. Carnegie mus., 1911, 8, p. 162 (Braganca); Eracenmann, Mem. Carnegie mus., 1912, 5, p. 335, pl. 48, fig. 4; Fowxmr, Proc. Acad. nat. sci. Phil., 1913, p. 544, fig. 13 (Rio Madeira). Hasrrat.— Amazon; British Guiana. Specimens examined. Number of Length Catalogue number specimens inmm. Locality Collector Part of 20842 33 28-44 Obidos Col. Bentos 21017 1 38 Curupira Maj. Cotinho 20774 16 37-28 Tabatinga Bourget 20969 5 31-36 Cudajas Thayer & Bourget 1455 C., 11910 I. 109 26-37 Gluck Island Eigenmann 1456 C., 11911 I. 3 small Konawaruk Eigenmann MS aG. Aoi e 4 28-29 Malali Shideler 3046 C. 11 31-40 Braganca Haseman 158 THE AMERICAN CHARACIDAE. Head 3.25 to 3.5; depth 2.5 to 2.75; D. 10 or 11; A. 22 to 26; scales 5-30 . to 33-8 to 3.5; eye 2.25 to 2.5 in head, snout little more than one half of the eye, interorbital about equal to the eye, 2.5 in the head. Compressed; depth of head at base of occipital process 1.33 in the great- est depth. Preventral region rounded, sometimes with a regular median series of 11 seales. Predorsal region rounded with complete median series of 11 scales. \ Occipital process 5 in the distance from its base to the origin of the dorsal, bordered by about 3 seales. Interorbitals slightly convex. Frontal fontanel not narrower than the parietal, equal to the parietals without the occipital groove. Second suborbitals leaving a narrow naked margin behind and below. Snout rather short; mouth large. Maxillary slightly less than the eye. Mandible very little longer than the eye, about 2.33 in the head. Premaxil- lary with five, 3- to 5-pointed teeth in the inner row, and two to four smaller, 3- to 4-pointed teeth in the outer row. Maxillary with two or three small tricuspid or conical teeth. Dentary with a graduated series of four large 5- pointed teeth, followed by nine or ten minute tricuspid and conical teeth. Gill-rakers 6 + 11. Anal sheath of about 13 scales, the first 7 extending over the bases of the first 11 anal rays, the remaining 5 or 6 quite small and inserted between the scales above the anal, but not touching the anal rays. Caudal scaled over the basal one third. Pores developed on 6 to 8 scales. Origin of the dorsal half the length of the eye nearer the caudal than the snout, the penultimate ray one third of the longest, which is 3+ in the length. Origin of the anal on the vertical from the middle or last dorsal ray. Anal emar- ginate, the longest ray 1.33 to 1.5 in the length of the base. Caudal less than the width of the eye longer than the head. Ventrals on the vertical from the second scale in front of dorsal; ventrals reaching to second or third anal ray. Pectorals reaching a little beyond the base of ventrals. Humeral spot distinet, vertically elongate, paralleled in front and behind by a bright bar nearly as wide as the humeral spot itself; a secondary, fainter, dark bar behind the posterior bright bar. A black (brown in very old aleoholic specimens) caudal spot not extending much, if at all, onto the middle caudal rays; a bright ring around the entire caudal peduncle, from the caudal spot to last anal ray, iridescent above the narrow sharp gray lateral stripe. The base of the caudal lobes and upper part of the peduncle a rusty red in life. Dorsal somewhat dusky, with an orange tinge when alive, caudal and anal THE AMERICAN TETRAGONOPTERINAE. 159 rays tipped with dusky black, distal third of second anal rays white. Anal, ventrals, and pectorals yellow in life. Scales of the back outlined with pig- ment, a few large chromatophores scattered over the cheeks. 16. HeMIGRAMMUS BOULENGERI Higenmann. Plate 78, fig. 3. Tetragonopterus fasciatus interruplus K1GENMANN (in part, non Liitken) Ann. N. Y. acad. sci., 1894, 7, p. 634 (Rio Grande do Sul). Hemigrammus boulengeri EIGENMANN & OGLE, Proc. U. 8. N. M., 1907, 33; p. 15; Eraenmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. Hasrrat.— Rio Grande do Sul. One specimen 11073 I. Type 45 mm. Rio Grande do Sul Von Ihering Head 3.33; depth 2.66; D.11; A. about 22, scales 5-30-3; eye 2.6 and interorbital 2.75 in the head. Compressed; depth of head at the base of the occipital process 3 in the greatest depth. Preventral region rounded, without complete series of median scales. Predorsal region rounded, with regular series of 11 scales. Occipital process 7 in the distance between its base and the dorsal, bordered by 3.25 scales. Interorbital slightly convex. Frontal fontanel triangular, broader than, and two thirds as long as, the parietal without the occipital groove. Second suborbital in contact with the preopercle. Snout short; mouth large. Maxillary 2.75 and mandible 2.33 in the head. Premaxillary with five 5-pointed teeth in the inner series, and three tricuspid teeth in the outer series. Maxillary with one 3-pointed tooth. Dentary with a graduated series of five 5-pointed teeth and three very small, 3-pointed teeth. Gill-rakers 6 + 8. Caudal probably scaled. Lateral line with pores on about 7 scales. Origin of dorsal half the length of the head nearer to the caudal than to the snout, penultimate ray 2.75 in the longest, which is almost 4 in the length. Origin of anal on the vertical from the first or second dorsal ray. Anal some- what emarginate, longest ray 1.25 in the base. Ventrals on the vertical from a point 1.75 the length of the eye in front of the dorsal. Ventral reaching to the base of the fourth anal ray. Pectorals a little more than reaching the ventrals. Humeral spot vertically elongate, distinct; a narrow black lateral line lying deeper than the caudal spot and not connected with it; caudal spot well 160 THE AMERICAN CHARACIDAE. defined, not quite extending to the end of the middle caudal rays, lower half of the caudal with many pigment-cells and blackish, upper half hyaline; basal two thirds of anal dusky. 17. HemiGcrRamMus 1oTA Durbin. Plate 22, fig. 7. Hemigrammus iota Dursin, Ann. Carnegie mus., 1909, 6, p. 60 (Gluck Island); Ergenmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. Haxirar.— Essequibo River. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 1458 C. Type 1 18 Gluck Island Eigenmann 1460 C. 11914 I. dq 19-21 Rockstone Eigenmann Paratypes 1459 C., 11913 I. 7 18-21 Gluck Island Eigenmann Paratypes. Head 3.6; depth 3.4; D. 11; A. 15-17; scales 5-30-3; eye 2.33-2.5; snout 1.67 in the eye. Interorbital slightly less than the eye, 2.8 in the head. Compressed; depth of head at the base of occipital process 1.33 in the greatest depth. Preventral region rounded, usually without complete series of median scales. Predorsal region rounded, usually with complete series of 9 to 11 median scales. Occipital process 7 or 8 in the distance from its base to the dorsal, bordered by 2 seales on each side. Interorbital convex. Frontal fontanel much nar- rower than the parietal, triangular, three fourths of the parietal without the occipital groove. Second suborbital covering the entire cheek. Snout short, mouth comparatively large. Maxillary 1.4 in the eye. Mandible a little longer than the eye, 2+ in the head. Premaxillary with five, 3- to 5-pointed teeth in the inner row and two or three narrow tricuspid teeth in the outer row. Maxillary with one or two broad teeth with 4 or 5 points. Dentary with a graduated series of four or five large, 5-pointed teeth, followed by four or five minute conical ones on the side. Gill-rakers about 9 + 7. Anal sheath short, of 7 scales, covering the base of the first 8 or 9 anal rays. Lateral line with pores on the first 6 to 8 scales. THE AMERICAN TETRAGONOPTERINAE. 161 Origin of dorsal less than half the length of the eye nearer the caudal than the snout. Penultimate ray two fifths of the longest, which is 3.2 in the length. Origin of the anal on the vertical from the first to third scale behind the dorsal. Anal deeply emarginate, the longest ray almost equal to the base. Caudal a very little longer than the head. Ventrals on the vertical from the second or third scale in front of the dorsal. Ventrals just reaching the anal, pectorals barely reaching the ventrals, more often only reaching to the second or third scale in front of the ventrals. Humeral spot conspicuous, black, vertically elongate, surrounded by a small light area. Caudal spot variable in intensity, vertically elongate, I-shaped, not extending on to the caudal rays, and not continuous with the narrow black lateral stripe, which is overlaid with silvery. Scales of the postdorsal region each marked with a round dark spot in addition to a few scattered chromato- phores. Scales of the predorsal region with round spots less distinct and the general dusky shading more pronounced. Scales of the sides above the lateral stripe outlined with dusky. A few chromatophores scattered over the region between the anal and the lateral stripe. Some indications of a very faint secondary humeral spot. Fins all a little dusky. Caudal with an orange spot on the base of each lobe (evident in fresh specimens only). 18. HEMIGRAMMUS BARRIGONAB Eigenmann and Henn. Plate 93, fig. 2. Hemigrammus barrigonae K1geNMANN & HENN, Indiana univ. studies, 1914, no. 24, p. 232 (Barrigona). Hasitat.— Rio Meta, Colombia. Specimens examined. Number of Size Catalogue number specimens in mm. Locality Collector 13423 I. Type 1 41 Barrigona, Rio Meta Gonzales 13424 I. Paratypes 65 25-43 Barrigona, Rio Meta Gonzales Head 4; depth 2.6-3; depth of caudal peduncle 9-10; D. 11; A. 24-25. Scales 33-35 in a longitudinal series, about 11 in a transverse series. Develop- ment of scales with lateral line pores extremely variable and not even equal on both sides of the same specimen. Usually a continuous series of at least 14 seales with pores, thence lateral line discontinuous; pore usually developed on last scale in the series. One specimen has the lateral line 7/6 + 3 + 7 + 162 THE AMERICAN CHARACIDAE. 11 + 2, (the italicized numerals represent scales with pores). Another has 17+6+2+4+4+2+483. A specimen of 41 mm. has the lateral line 17 + 14 + 2 on the left side and /6 + 18 + 1 on the right side. Of others, one, 34 mm. has respectively 24 + 8 + 3 and 20 +8 +7; one, 37 mm. has 16 + 19 and 1/6 + 18; and one, 42 mm., has 24 +5 +5 on the left and 24+7+3 on the right side. The lateral line is developed on the seventh transverse series of scales. Scales in the type are 6-/6 + 18 + 1-4. Eye 2.6 in head, about equal to or slightly greater than the interorbital. Compressed, rather deep, caudal peduncle slender; predorsal area arched or rounded with a variable median dorsal series of from 9 to 12 (usually 10) scales; preventral area rounded, with an ill-defined median series of about 12 large scales. Occipital process about 5 in the distance from its base to the dorsal, bordered by three seales. Skull convex; fontanels moderately large; second suborbital in contact with the preopercle behind. Mouth terminal; snout blunt, about one half the eye; maxillary short, about three fourths the length of the eye. Premaxillary with three tricuspid teeth in the outer row and five 5- to 6-pointed teeth in the inner row. Maxillary with four or five minute, 6-pointed teeth, visible only in preparations. Man- dible with four or five 6-pointed incisors in each ramus, their tips flaring out- wards. Caudal scaled over one third of the basal lobe. Gill-rakers 7 + 6. Origin of dorsal about equidistant from snout and base of middle caudal rays, its height 3.5 in the length. Origin of anal on vertical from last ray of dorsal, fourth to sixth rays elongate, forming an anterior lobe, its height about 4.7-5 in the length, two large scales overlapping on the anterior margin. Caudal deeply forked, its lobes about equal to the height of the dorsal; pectorals do not reach the ventrals, the latter just overlap on the anal. General coloration light olivaceous; operculum, cheeks, and snout under- laid with bright silvery. Top of head dusky, no predorsal median line. A broad horizontal lateral stripe from the hind margin of the operculum to the caudal base, here expanded to form an ill-defined, oval caudal spot. An in- distinct humeral spot is overlaid by this lateral stripe. A conspicuous dark band along the entire anal base, outer margin of anal sometimes dark tipped. Fins otherwise without color. THE AMERICAN TETRAGONOPTERINAE. 163 19. H®rMIGRAMMUS SCHMARDAE (Steindachner). Plate 20, fig. 2; Plate 78, fig. 1. Tetragonopterus schmardae STEINDACHNER, Flussf. Siidam., 1882, 4, p. 37, pl. 7, fig. 6 (Tabatinga); EraEn- MANN & EIGENMANN, Proc. U.S. N. M., 1891, 14, p. 54. Hemigrammus schmardae Fower, Proc. Acad. nat. sci. Phil., 1906, p. 333 (Peruvian Amazon); ErcEn- MANN & Oats, Proc. U.S. N. M., 1907, 33, p. 13; Eraenmann, Rept. Princeton univ. exped. Pata- gonia, 1910, 3, p. 486; Exuis, Ann. Carnegie mus., 1911, 8, p. 163 (Santarem). Tetragonopterus santaremensis UuREY, Ann. N. Y. acad. sci., 1895, 8, p. 283 (Santarem). Hemigrammus melanochrous Fowurr, Proc. Acad. nat. sci. Phil., 1913, p. 548, fig. 12 (Tributary of Rio Madeira near Porto Velho). Hasitat.— Amazons. Specimens examined. Catalogue Number of number specimens Size in mm. Locality Collector 4 34+43 Manaos Agassiz 5174 1. 1 28 Brazil 5499 I. 2 29 Santarem Menot 8085 C. 1 39 Santarem Hasemann Head 3.4-3.6; depth 3; D.11; A. 20-28; scales 5-30 to 34-3 to 3.5; eye large, 2.3-2.5 in the head; interorbital 3 in the head. Compressed; depth of head at the base of the occipital process 1.33 to 1.5 in the greatest depth. Preventral region rounded, with complete median series of 10 or 11 scales. Predorsal region rounded, with complete median series of 9 scales. Occipital process 6 in the distance from its base to the dorsal, bordered by 2.5 scales on the side. Interorbital region almost flat. Frontal fontanel triangular to truncate triangular, equal to the length of the parietal without the occipital groove. Second suborbital leaving a very narrow naked margin behind and below. Snout short, mouth large. Maxillary and mandible both long and equal to the eye. Premaxillary with 5 teeth in the inner row, four large, 4- to 5-pointed, and one very small; three small tricuspid teeth in the outer row. Maxillary with two or three small conical or tricuspid teeth. Dentary with a graduated series of four large, 5-pointed teeth, one very small tooth and twelve or more minute conical teeth on the sides. Gill-rakers 7 + 9. Anal sheath short, consisting of 4 scales covering the bases of the first 5 rays. Lateral line with pores on 7 to 16 scales. Origin of the dorsal very slightly nearer the snout than the caudal, penul- 164 THE AMERICAN CHARACIDAE. timate ray 2.5 in the longest, which is about 3.5-3.25 in the length. Origin of the anal on the vertical from the eighth or last dorsal rays. Anal emarginate, its longest ray 1.25 in the base. Ventrals on the vertical from the first scale in front of the dorsal. Ventrals reaching to the fifth anal ray. Pectorals often reaching a little beyond the base of the ventrals. Fins all hyaline; humeral spot small, dark and surrounded by a ring of light, an inconspicuous silvery lateral stripe, widest at the vertical from the adi- pose, not reaching the caudal spot and subtended by a faint, slaty gray line; caudal spot almost as wide as the caudal peduncle, terminating abruptly before and more gradually behind, not, however, extending to the tips of the middle caudal rays. Sometimes a little black near the tips of the first anal rays. Seales of back and upper part of the sides broadly outlined with dusky. Scales below the lateralstripe with pale bluish and greenish iridescence. 20. HrMIGRAMMUS LUNATUS Durbin. Hemigrammus lunatus Dursix MS. E1rcenmann, Princeton univ. exped. Patagonia, 1910, 3, p. 436 (Amazon); Exits, Ann. Carnegie mus., 1911, 8, p. 162 (Caceres; Jaurti; Rio Boa Vista). Haprrat.— Amazon Basin. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 20964 Type 1 33 20964 Paratypes 3 27-32 20840 Paratype 1 32 Obidos 3081 C. 5 24-45 Caceres Haseman 2942 C, 4 46, 48 Jauru Haseman Head 3. to 3.2; depth 2.75; D.11; A. 23 to 26; scales 5-33 to 34-3.5; eye 2.25 in the head, interorbital not quite equal to the eye, 2.5 to 3 in the head. Very compressed; depth of head at the base of the occipital process about 1.5 in the greatest depth. Preventral region rounded, with a complete median series of 10 or 11 scales. Predorsal region narrowly rounded, with a complete median series of 10 scales. Occipital process about 5 in the distance from its base to the dorsal, bor- dered by 3 seales. Interorbital slightly convex. Frontal fontanel triangular, very nearly as wide as the parietal, equal to the parietal without the occipital groove. Second suborbital moderately wide, leaving a very narrow naked margin behind but sometimes none below. Snout short, mouth large. Maxil- THE AMERICAN TETRAGONOPTERINAE. 165 lary three fourths of the eye, about 3.25 in the head. Mandible equal to the eye. Premaxillary with four broad, tricuspid teeth in the outer row, and five 3- to 5-pointed teeth in the inner row. Maxillary with two or three conical or tricuspid teeth. Dentary with a series of four large, 5-pointed teeth followed by seven to ten small, conical or notched ones on the sides. Gill-rakers about 6 + 11. Anal sheath short, of about 5 seales covering the bases of the first 8 anal rays. Lateral line with pores developed on the first 10 or 11 scales. Origin of the dorsal equidistant from the snout and caudal, the penulti- mate ray two fifths of the longest, which is 3 in the length. Origin of the anal on the vertical from the last dorsal ray. Anal faleate, the longest ray almost equal to the base. Ventrals on the vertical from the first scale in front of the dorsal. Ventrals reaching to the third anal ray. Pectorals reaching the second scale beyond the base of the ventrals. Humeral spot small, semicircular, the curved margin directed upwards always very faint and often lacking. No caudal spot. Lateral stripe a nar- row, dark line overlaid with silvery. All the fins hyaline. A few chromato- phores at the base of each anal ray. Sides below the lateral stripe faintly iridescent. Two specimens, 45 and 48 mm. Rio Boa Ventura, (2943 c. m.) differ from the typical specimens of H. lunatus as follows:— the maxillary with two or three broad, 3-, 5- and 7-pointed teeth. Humeral spot very diffuse, lateral stripe not overlaid with silvery. 21. HrMIGRAMMUS MICROSTOMUS Durbin. Hemigrammus microstomus DurBin MS. E1cenMann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436 (Amazon); Exiis, Ann. Carnegie mus., 1911, 8, p. 163 (Santarem). Hasrrat.— Amazon. Specimens examined. Number of Size Catalogue number specimens inmm. Locality Collector 20782 Type 1 28 Santarem Bourget ie \ Paratypes 19 23-30 Santarem Bourget 20840 Paratypes 5 30-37 Obidos James 20970 1 34 Cudajas Thayer, Bourget 2944 C. 7 29-34 Santarem Haseman 166 THE AMERICAN CHARACIDAE. Head 3.6 to 4; depth 2.8 to 3.5; D.11; A. 19 to 22; scales 5-31 to 34-3; eye 2.25 in the head; interorbital about equal to the eye, 2.3. Compressed; depth of head at the base of the occipital process about 1.66 in the greatest depth. Dorsal profile only slightly arched. Preventral region rounded, without a complete series of median scales. Predorsal region rounded, often with a complete series of 9 to 11 median scales. Occipital process 5 in the distance from its base to the dorsal. Inter- orbital very slightly convex. Frontal fontanel triangular, as wide as the parietal, three fourths the parietal without the occipital groove. Second suborbital narrow, leaving a narrow naked margin behind and below. Snout short, mouth very small. Lower jaw scarcely projecting beyond upper, even when the mouth is open. Maxillary convex in front, little more than half the eye, 3.5 in the head. Mandible equal to the eye. Premaxillary with two or three, 5-pointed teeth in the outer row, and four or five 5- to 7-pointed teeth in the inner row. Maxillary with two or three 4- to 7-pointed ‘teeth. Dentary with five broad, 5- to 7-pointed teeth, followed by a series of several small teeth on the sides. Gill-rakers 6 + 7. Caudal sealed over the basal half. Anal sheath short, of about 3 scales, covering the base of first 5 or 6 rays. Pores developed on the first 7 to 9 scales of the lateral line. Origin of the dorsal equidistant from the snout and caudal, penultimate ray two fifths of the longest, which is 3.25 in the length. Caudal about one third the length of the eye longer than the head. Origin of the anal on the vertical from the second scale behind the dorsal. Anal almost faleate, the long- est ray about 1.2 in the length of the anal base. Ventrals on the vertical from the first dorsal rays or the first scale in front of the dorsal. Ventrals just reach- ing the anal. Pectorals reaching the first scale in front of the ventrals. No caudal spot, humeral spot small and round, usually faint and often lacking. A narrow, blackish, lateral stripe overlaid with silvery, from the base of the caudal to the humeral spot, if the humeral spot is present. Fins all hyaline. Seales of the back outlined with dusky. Bluish and greenish iri- descence on the sides and cheeks. THE AMERICAN TETRAGONOPTERINAE. 167 22. HEMIGRAMMUS ORTHUS Durbin. Plate 21, fig. 1. Hemigrammus orthus Dursin, Ann. Carnegie mus., 1909, 6, p. 61 (Tukeit); Ercrnmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 143; Mem. Carnegie mus., 1912, 5, p. 336, pl. 48, fig. 5; Exus, Ann. Carnegie mus., 1911, 8, p. 163 (Santarem). Hasrrat.— British Guiana; Amazon. Specimens examined. Number of Size Catalogue number _ specimens in mm. Locality Collector 1477 C. Type 1 28 Tukeit Eigenmann 1478 C., 11912 I. 7 22-30 Tukeit Eigenmann Paratypes 1479 C., 11922 I. 25 14-21 Gluck Island Eigenmann Paratypes 1480 C. Paratype 1 27 Essequibo below Packeoo 3600 C. 6 25-34 Hubabu Creek Ellis 2945 C. 5 26-31 Santarem Haseman 2948 C. 5 19-21 Konawaruk Eigenmann Head 3.75; depth 3.75; D. 11; A. 19 to 22; scales 5-30 to 33-3; eye 2.5 in the head; interorbital not quite equal to the eye, about 3 in the head. Compressed; depth of head at the base of the occipital process about 1.33 in the greatest depth. Preventral region rounded, without complete series of median scales. Predorsal region rounded, probably with a complete series of 9 median scales. Occipital process about 6 in the distance from its base to the dorsal, bor- dered by 2 or 3 scales on thesides. Interorbital sightly convex. Frontal fon- tanel triangular, narrower than the parietal and not quite equal to the parietal without the occipital groove. Second suborbital leaving narrow naked margins behind and below. Snout a little more than one half the length of the eye. Mouth large. - Maxillary equal to the eye, narrow, slightly curved backwards, the two sides parallel to each other. Mandible equal to the maxillary. Pre- maxillary with three tricuspid or conical teeth in the outer row, and five, 3- to 5- or rarely 7-pointed teeth in the inner row. Maxillary with one to five tri- cuspid or conical teeth. Dentary with a graduated series of four or five large 3- to 5-pointed teeth. Gill-rakers 7 + 14. 168 THE AMERICAN CHARACIDAE. Caudal with 3 to 5 scales on the base of each lobe. Anal sheath short, of 3 scales covering the base of the first 6 anal rays. Lateral line with pores developed on about 7 scales. Origin of the dorsal equidistant from the snout and caudal, penultimate ray one third of the longest which is 3.5 in the length. Origin of the anal on the vertical from last dorsal ray. Anal deeply emarginate, the longest ray about 1.25 in the base. Base of ventrals on the vertical from the second scale in front of the dorsal. Ventrals just reaching anal. Pectorals just reaching ventrals. A diffuse, round or somewhat vertically elongate, humeral spot. A dark lateral stripe, heaviest behind the origin of the anal, but not reaching the base of the caudal. No caudal spot. A black line at the base of the last anal rays not continuous with that at the base of the first seven. Dorsal, caudal, first seven rays of the anal, and first two or three rays of ventrals dusky. Seales of the back dusky, each often bearing a single black spot. 23. HEMIGRAMMUS CUPREUS Durbin. Plate 20, fig. 3. Hemigrammus cupreus Dursin MS. E1cenMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436 (Amazon). Hasirar.— Amazon. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 20952 Cotypes 11 42-53 Jatuarana Navez 21069 Cotypes 6 32-35 Silva, Lake Saraca Thayer Head 4; depth 3-3.75; D. 11; A. 20-22; scales 5 to 7-30 to 33-3 or 3.25; eye 2.9 in head; snout 1.25 in the eye; interorbital slightly less than the eye, 3 in head. Compressed; depth of head at the base of the occipital process 1.25 in the greatest depth. Preventral region rounded, without complete series of median scales. Predorsal region rounded, with complete series of 9 median scales. Occipital process 6 in the distance from its base to the origin of the dorsal, bordered by 3 scales. Interorbital convex. Frontal fontanel narrower than the parietal, triangular, one half the parietal without the occipital groove. Second suborbital having a narrow naked margin below but not behind. Snout moderately long; mouth large; lower jaw protruding beyond the snout when THE AMERICAN TETRAGONOPTERINAE. 169 mouth is open. Maxillary 1.33 in the eye, much arched in front. Mandible longer than eye, 2.25 in head. Premaxillary with five to seven narrow, tri- cuspid teeth in the inner row, and two to three conical teeth in the outer row. Maxillary with three to five conical and tricuspid teeth. Dentary with a graduated series of five to seven tricuspid teeth, grading into a series of several minute conical teeth on the side. Gil-rakers 6 + 10. Anal sheath of 2 or 3 scales covering the bases of the first 7 to 9 anal rays. Lateral line with pores on 8 to 10 scales. Origin of the dorsal equidistant between snout and caudal, penultimate ray one third of longest which is 3.75 in the length. Origin of anal on the verti- cal from the second scale behind the dorsal. Anal emarginate, longest ray a little longer than the base. Caudal the length of the eye longer than the head, slightly less than the basal half scaled. Ventrals on the vertical from the origin of the dorsal. Ventrals barely reaching the anal, pectorals not usually reach- ing the ventrals in specimens over 43 mm. long. A faint, vertically elongate humeral spot, a slender black lateral stripe not reaching the caudal but overlaid with a silvery iridescent stripe which does extend to the caudal. The outer and sometimes the extreme tips of middle caudal rays slightly pigmented. The scales of the back and bases of the anal rays faintly outlined with brownish. A few chromatophores scattered over the dorsal and first anal rays. Iridescence on scales below the lateral stripe shading from rich copper on caudal peduncle to pale bluish on the lower series. No caudal spot. 24. HrMIGRAMMUS CYLINDRICUS Durbin. Plate 22, fig. 5. Hemigrammus cylindricus Dursin, Ann. Carnegie mus., 1909, 6, p. 62 (Tumatumari); ErgenMAnn, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 426; Mem. Carnegie mus., 1912, 5, p. 337, pl. 49, fig. 3. Hasirat.— British Guiana. Specimens examined. Number of Catalogue number specimens Size in mm. Locality Collector 1461 C. Type 1 57 Tumatumari Eigenmann 1462 C., 11915 I. 6 35-58 Tumatumari Eigenmann Paratypes 1163 C., 11916 I. 11 46-54 Crab Falls Eigenmann Paratypes 170 THE AMERICAN CHARACIDAE. Number of Catalogue number specimens Size in mm. Locality Collector 1464 C., 11917 I. 20 Rockstone Eigenmann Paratypes 1465 C. Paratype 1 45 Gluck Island Eigenmann 54 45-108 Gluck Island Gimbel Exped. Head 3.3-3.66; depth 3.66-4.66; D.11; A. 17 to 20; scales 5-30 to 34-3; eye large, slightly longer than wide, 2.75 in the head; interorbital almost flat, almost equal to the eye, 3 in the head. Subceylindrical, or only slightly compressed; depth of head at the base of occipital process 1.25 to 1.5 in the greatest depth. Preventral region rounded, without complete series of median scales. Predorsal region rounded, with a complete median series of 8 to 12 scales. Occipital process about 6 in the distance from its base to the dorsal, bordered by 2 or 3 scales. Interorbital nearly flat. Frontal fontanel small, triangular, narrower than the parietal; two thirds the parietal without the occi- pital groove. Second suborbital leaving considerable naked margins behind and below. Maxillary straight, 1.25 in the length of the eye. Mandible a little longer than the eye, 2.5 in the head. Premaxillary with three or four tricuspid teeth in the outer row, and six tricuspid teeth in the inner row. Max- illary with three to six tricuspid, or occasionally conical teeth. Dentary with a graduated series of four or five teeth also tricuspid. Gill-rakers 6 + 9. Caudal sealed over halfway to the end of the lobes. Anal sheath short, consisting of the edge of 3 large scales. Lateral line with pores developed on 7 to 12 scales. Origin of the dorsal equidistant from the snout and caudal, penultimate ray one third the longest, which is 4 in the length. Origin of the anal on the vertical from the third scale behind the dorsal. Anal very deeply emarginate, the longest ray just reaching the base of the last ray. Ventrals on the vertical from the origin of the dorsal. Ventrals, just barely or not quite, reaching the anal, pectorals reaching the second scale in front of the ventrals. Humeral spot small, roundish or roughly triangular, often intense. A black line at the base of the anal. A narrow black lateral stripe. No true caudal spot, sometimes a dusky spot at the base of each caudal lobe. Each scale of the back often with a single intense dark spot. Scales of the sides often outlined with dusky. Scales of all except the upper three series with THE AMERICAN TETRAGONOPTERINAE. 171 iridescence, the last few on the end and middle of the caudal peduncle rich copper. In life adipose yellow and dorsal yellowish. 25. HeMIGRAMMUS ANALIS Durbin. Plate 22, fig. 2. Hemigrammus analis Dursin, Ann. Carnegie mus., 1909, 6, p. 64 (Rockstone); EIGENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Exxis, Ann. Carnegie mus., 1911, 8, p. 163 (Santarem); Ercenmann, Mem. Carnegie mus., 1912, 5, p. 337, pl. 49, fig. 6. Hapitat.— British Guiana. Specimens examined. Number of Size Catalogue number specimens in mm. Locality Collector 1466 C. Type 1 35 Rockstone Eigenmann 1468 C., 11919 I. 21 24-29 Gluck Island Eigenmann Paratypes 1467 C., 11918 I. 72 19-36 Rockstone Eigenmann Paratypes 1469 C., 11920 I. 2 29, 35 Wismar Eigenmann Paratypes 1 30 Santarem Haseman Head 3.5-3.75; depth 3.25-3.50; D.11; A.12-14; scales 5-30 to 32-3; eye 2.33 in head, snout 1.5 in the eye, interorbital less than the eye, about 2.75 in the head. Compressed; depth of head at base of occipital process 1.33 in the greatest depth. Preventral region rounded, without regular series of median scales. Predorsal region rounded, having a regular median series of 8 scales. Occipital process 5 in the distance from its base to the origin of the dorsal, bordered by 2 or 3 scales. Interorbital flat. Frontal fontanel small, triangu- lar, narrower than the parietal, half the length of the parietal without the occipital groove. Second suborbital leaving a narrow naked margin below and behind. Snout short. Mouth large. Maxillary not so long as the eye. Mandible equal to the eye. Premaxillary with three or four 5-pointed teeth in the outer row, and five, 5- to 7-pointed teeth in the inner row. Maxillary with two or three 6- to 7-pointed chisel-shaped teeth. Dentary with four broad, 7-pointed teeth, followed by three or four minute teeth on the sides. Gill-rakers about 6 + 9. Caudal sealed halfway to the end of the longest rays. Anal sheath of 3 172 THE AMERICAN CHARACIDAE. or 4 normal scales which extend over the bases of the first 7 or 8 rays. Pores developed on 7 or 8 scales. Origin of the dorsal about equidistant from the snout and caudal, the penultimate ray 0.4 of the longest which is 3.67 in the length. Origin of the anal on the vertical from the second scale behind the dorsal; anal emarginate, longest ray equal to the base. Caudal half the length of the eye longer than the head. Ventrals on the vertical from the first dorsal ray; ventrals just reaching the anal. Pectorals not reaching the ventrals. Humeral spot distinct but not heavy, not conspicuously elongated. Lat- eral stripe the width of one scale, not so intense as the humeral spot, expanded on the caudal peduncle, but not extending on the fin; scales overlying the lateral stripe distinctly silvery. No caudal spot. First five anal rays, the caudal and all of the dorsal dusky. Each median dorsal scale with a roundish dark spot. Scales of the upper half of the sides outlined with dusky. A few chromatophores scattered about the base of the anal and aggregated so as to form a small dark spot or line on the ventral side of the caudal peduncle. Top of the head dark. The lateral stripe probably red in life. The single specimen from Santarem resembles very closely H. analis, and has 13 anal rays, but the maxillary has but one tricuspid tooth which is not typical. 10. HypnHrssoprycon Durbin. igjoowv = smaller, Bpvxw = to gnash the teeth, from which Brycon a genus of Characins. Hyphessobrycon Dursin, Bull. M. C. Z., 1908, 62, p. 100 (compressus). Dermatocheir Dursin, Ann. Carnegie mus., 1909, 6, p. 55, (catablepta). Typn.— Hemigrammus compressus Meek. Like Hemigrammus but with the caudal naked. The genus Dematocheir was based on a specimen with arrested pectoral development. Several other species have since been discovered with similar pectorals, but otherwise showing the characters of this and of other, quite distinct genera. Hasrrat.— Mexico to the La Plata, Pacifie Slope of Ecuador. ; Key to the Species. a. Scales 45-48, no lateral band, no caudal or humeral spots. D.11; A. 25-27; scales 8-45 to 48-7. b. Dorsal with a conspicuous spot on basal half of anterior rays; maxillary equals eye. seh, 1. compressus (Meck). bb. Dorsal’dark; anal mostly dark; maxillary less than eye; everywhere densely peppered with GHTOMAPOPNONED | i, wai aie Ss sie tote se a attee oaMRRN iE serie In lce atte en chen 2. milleri (Durbin). THE AMERICAN TETRAGONOPTERINAE. 173 Scales not more than 36. ce. Dorsal black or with a well-defined black spot. (See also melanopleura). d. Humeral spot present, anal unmarked with black or with black only on the tips of the rays. e. Dorsal black, a deep humeral spot, last five anal rays and distal two fifths of remaining anal rays black. D.11; A. 27 to 30; scales 6 to 7.5-31 to 33-3.5. Maxillary with two (ITELCOTSTOVG LTR SCCUIL ANS herd ie Ie ee ae oe 3. callistus (Boulenger). ee. Basal part of dorsal not black. f. Maxillary with two or three teeth; inner row of premaxillary of five teeth. g. Maxillary teeth tricuspid; last few and frequently the first few anal rays with black on or near the tips. h. Humeral spot very small, black on anal subtended with white; depth 3.8; head at base of occipital process 1.33 in. the greatest depth; D. 11; A. 26; scales 5-32 to BEI B)y Ao Roma Oe OC eS EE oe eS eee ey erm 4. minor Durbin. hh. Humeral spot vertically elongate, anal rays often tipped with black; depth 2.75; head at the base of occipital process 1.5 in the greatest depth; D. 11; A. 25-27; S@AGS GPU RBIS Pie ote ae ee ee ee Oe ee, 5. serpae Durbin. gg- Maxillary teeth with 6 to 8 cusps, broad, set: obliquely, overlapping; anal usually not black tipped. D.11; A. 28; scales 5 to 7-24 to 27-3.5.....6. copelandi Durbin. ff. Maxillary with about six, tricuspid or conical teeth; eight tricuspid teeth in the inner row of the premaxillary; base of caudal hyaline; lower fins dusky, ventrals sometimes reaching the fifth anal ray. D.11; A. 27 to 30; scales about 30 to 33 7. bentost Durbin. dd. No humeral or caudal spot. t. The black dorsal spot margined with white above. Maxillary with four to six tricuspid or conical teeth. D. 11; A. 26 or 27; scales 5-31 to 33-3. 8. rosaceus Durbin. it. Maxillary without teeth; D. 11; A. 22; scales 5-34-3..... 9. hasemani Fowler. cc. Dorsal plain. j. No humeral spot. k. Caudal spot lacking or faint; premaxillary with five teeth in the inner row l. Fourteen scales in a vertical series; caudal spot entirely lacking, much compressed. Sides thickly peppered with small inconspicuous chroma- tophores. Maxillary with three conical or tricuspid teeth: D. 11; G20 aa LO SOx O terete aieicienctsreeeieel ssiclons cere 10. panamensis Durbin. ll. Nine scales in a vertical series; caudal sometimes plain, with a faint spot. Maxillary with two minute teeth. Eye2to2.5inthehead. D.10or11; A. 17 to 24; scales 5-29 to 34-3.5 to4......... 11. gracilis (Reinhardt). kk. A small spot at the base of each caudal lobe; a row of spots along the base of the anal. Four to six small teeth in the maxillary. Ten to twelve, conical or tricuspid teeth in the second row of the premaxillary. D. 10 or 11; A. 19 or 20 scales 4 or 5-32 to 34-3.5........... 12. riddlei (Meck). kkk. Caudal spot well developed, single. m. Maxillary without teeth, premaxillary with nine tricuspid teeth in the inner row. Lateral stripe silvery, no black; caudal spot confined to the peduncle. D. 10; A. 27; scales 5-32-3. 13. stramineus Durbin. mm. Maxillary without teeth, very short. Premaxillary with five broad 5- to 7-pointed teeth. Caudal spot continued forward as a heavy lateral stripe, often reaching the head. D.11; A. 14 to 16; scales DOL G-B2 160 .90=4/ OLD 3.002 < e