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EIGENMANN,; Ph.D: AND ROSA SMITH EIGENMANN, (Curator of Fishes California Academy of Sciences.) SAN FRANCISCO: CALIFORNIA ACADEMY OF SCIENCES, UNS LS OO) Committee of Publication: H. W. HARKNESS, GEORGE HEWSTON T. S. BRANDEGEE, H. H. BEHR. Editor: TOWNSHEND STITH BRANDEGEE. S$ bb 173 Cope At INTRODUCTORY. = In this paper we have endeavored to give keys to the genera and species of Nematognathi ascribed to South America, to collect the synonymy and bibhography in full to date, and to give descriptions of the forms we have been able to examine. We have thought best to give full descriptions of most of the species in the Museum of Comparative Zoology for several reasons. Many of the forms are rare and contained only in a single museum; and full descriptions of those species in this museum will aid in identifications and revisions of this group by ichthyologists working in other muse- ums. As yet scarcely more than the main streams of South America have been explored, and many new forms will doubtless appear when the smaller streams are searched; in that case detailed descriptions of as many as possible of the known species in some one work will be very desirable, especially since many descriptions are now to be found only in inaccessible journals. Furthermore, short diagnoses, although they may be excellent and quite sufficient at the time they are writ- ten, sometimes become worthless by the discovery of new species which agree with the old in all the charac- ters given in the diagnosis, but differ from them in characters not mentioned. We are fully in accord with the statement recently made by Dr. Cope that ‘‘ descriptive zoology will never be complete until the structure is exhausted in furnish- ing definitions,” and our only excuse for not treating in detail of the internal structure, especially the osteology of the siluroids, was the inability to mutilate series of 2, CALIFORNIA ACADEMY OF SCIENCES. specimens to make the necessary anatomical prepara- tions, or to examine the osteological preparations already made. | Since 1864, the date of the publication of Dr. Gin- ther’s Catalogue of Fishes, no general work on the Nematognathi has appeared, while the number of nom1- nal South American species has been greatly increased since that time. The Central American Siluride, which properly be- long to the South American fauna, have been omitted on account of a lack of material. The same reason has prevented us from giving more than lists of the genera Arges, Hemiancistrus and Cheetostomus. The material studied, several thousand specimens, belongs to the Museum of Comparative Zoology at Cam- bridge, Massachusetts, U.S. A., and was collected chiefly during the Thayer Expedition, a full account of which is given in Agassiz’s ‘‘A Journey in Brazil.”* Collec- tions were made during this expedition in the coast rivers from Rio de Janerio to Rio Paranahyba, and in the Amazon and its tributaries from Para to Tabatinga. During this expedition a valuable collection was made by Senhor Vinhas in the Xingu. A collection made by Senhor Honorio in Goyaz is especially valuable as show- ing the relation between the fauna of the upper courses of the Tocantins with the fauna of the upper courses of the San Francisco, Parahyba, Rio Doce and Rio Jequi- tinhonha. The collection made by Senhor Honorio has “A Journey in Brazil, by Prof. and Mrs. Louis Agassiz. Boston. Tichnor & Fields. 1868. Professor Agassiz was accompanied on this expedition by the following assistants: James Burkhardt, artist; John G. Anthony, conchologist; Frederick C. Hartt and Orestes St. John, ge- ologists; J. A. Allen, ornithologist; Geo. Sceva, preparator; and the following volunteers: Newton Dexter, William James, Edward Copeland, Thomas Ward, Walter Hunnewell and S. V. R. Thayer. INTRODUCTORY. 3 not been examined before, and many of the forms are new. A most valuable collection was made by His Majesty Dom Pedro II. in the Rio Grande do Sul, which has not been studied before, and many of the forms are new or otherwise interesting. The collection of the Thayer expedition is by far the richest collection of fresh water fishes ever made in South America. It is scarcely necessary to enumerate here the advantages which would have accrued to Ameri- can students and to this museum had this enormous collection been studied shortly after it was made. No systematic attempt has before been made to examine all the specimens of any of the families of fresh water fishes collected during this expedition. The result has been that most of the new forms having been rediscovered by other collectors the types of numerous species are now scattered through various museums in America and Europe which would be found in the Museum of Com- parative Zoology if this collection had been studied at once. Even those specimens which have hitherto served as the types of new species are not so labeled, rendering very difficult the identification of the rest at this time. A large collection was made during the Hassler expe- dition around South America; specimens were secured at Santiago, Callao and Panama. Part of this material had not been studied and has yielded new forms. A valuable collection was made by Mr. Alexander Agassiz and Mr. Samuel Garman in Lake Titicaca. Many small collections came from private travellers. The names of the collectors are mentioned with the de- scriptions of the specimens. We are indebted to Mr. Alexander Agassiz, the di- rector of the Museum of Comparative Zoology, for the 4 CALIFORNIA ACADEMY OF SCIENCES. privilege of studying this material, and for the use of the museum libraries, and to Mr. Samuel Garman for aid in making the collection available for study. We wish to express our thanks to Miss Frances M. Slack of the museum library, and to Mr. Thomas J. Kiernan of the Harvard University library, for many favors. To Dr. G. A. Boulenger of the British Museum, to. Dr. E. D. Cope of Philadelphia, and to Mr. Alexander Thominot of the Jardin des Plantes, we are indebted for the examination of types. To Dr. David S. Jordan we are indebted for advice concerning some of the questions of nomenclature and other favors. The species are numbered consecutively. Varieties. have the letters ‘‘a,” ‘‘b,” ‘‘c,” etc. attached to the number of their respective species. Doubtful species have the decimals ‘‘.1,” ‘‘.2,” ‘‘.3,” ete. ; attached to the number of the valid species preceding. In the descriptions the tsual formulas have been em- ployed. The length of the head is measured from the tip of the snout to the end of the bony opercle in all fam- ilies but the Loricariide, in which it is measured from the tip of the snout to the end of the temporal plate. The length is measured from the tip of the snout to the base of the middle caudal rays. The ‘‘interocular”’ is measured between the nearest edges of the eyes, the ‘ in- terorbital” between the nearest edges of the bony orbits. Unless otherwise stated, the color descriptions have been taken from alcoholic specimens. In the matter of nomenclature we have followed the canons of the A. O. U. Code as far as possible and prac- ticable. Cari H. EIGENMANN, Rosa 8. EIGENMANN. A REVISION OF THE SOUTH AMERICAN NEMATOGNATHI. The order Nematognathi was established by Dr. Gill in 1870, and characterized by Dr. Cope as follows: ‘‘Preecoracoid arch present. No coronoid or sym- plectic bones. Parietals and suproccipital confluent; four anterior vertebre coéssified, and with ossicula auditus. No mesopterygium. Basis cranii and pterotic bone sim- ple; third superior pharyngeal bone wanting, or small and resting on the fourth; second directed backward. One or two pairs of basal branchihyals; two pairs of branchihyals. Suboperculum wanting, premaxillary forming mouth-border above. Interclavicles present.” As in Diplomystes the maxillary forms the mouth- border above, and the symplecticum is sometimes pres- ent ( fide J. A. Ryder), a, revision of this diagnosis is necessary. Various views have been held as to the number of families into which the order ought to be divided. Cuvier, Valenciennes and Giinther have united all the forms under the family name Siluride. Agassiz was the first to insist, in 1829, that the differences existing between some of the genera were of family value and separated his Goniodontes. Bleeker, in 1858, divided the Siluride of Cuvier into four, and in 1864 into six families. Cope in 1870 recognized three families, and Gill, in 1872, gave names to eleven families of Nematognathi. Without critically examining non-American forms we recognized in 1888 seven families as inhabiting the Americas. In 1890, we proposed to raise Diplomystes to family rank.* * A-cursory examination of the skeletons of Asiastic forms leads us to believe that all the families named by Dr. Gill will probably be found tenable. 6 CALIFORNIA ACADEMY OF SCIENCES. Seven of these families are confined to tropical America. In several cases the gradation from one family to another is so gradual that the present classification may be looked upon as provisional: The inter-relation of the families and their subfamilies is illustrated in the dia- gram on opposite page. The general distribution of these families and their subfamilies is as follows: I. BunocrPpHALIDH—Amazons from Para to Pebas, Nauta and Canelos; Guianas. BuNocEPHALINEe®—Solimoens, Maranon; Guiana. PLATYsTacIN=—Amazon; Guiana. II. DipLomystip#—Chile. Ill. Srurip#z—Cosmopolitan. TacHisurInNe—Atlantic and coast rivers from La Plata to North America; Pacific, from Callao to Mexico; Africa, Asia. CALLOPHYSIN&—Amazons to Calderon; Guiana. PIMELOoDIN#—KEastern rivers from La Plata to Mexico; western rivers from Callao to Mexico; Africa. DoraDInNex—Rio Plata; Rio San Francisco to Peru and Colombia. Not in Rio Parahyba, Rio Doce or Jequitinhonha. AUCHENIPTERINE—Rio Janeiro to Rio Magdalena and Peru. AGENEIOSINe®—La Plata; Rio Paranahyba, to Guiana and Peru; not in Rio Parahyba, Doce or Jequi- tinhonha. IV. HypopurHatmMipm—Amazons from Para to Rio Huallaga; Guiana region. V. Pyaipip#—Chile and Argentine Republic north to Colombia; chiefly in mountain streams. SOUTH AMERICAN NEMATOGNATHI. 7 Loricariids Argiida Callichthyide Nematogenyine + Hypophthalmide Auchenipterine * Pygidine + Ageneiosins StegophilineT topsi Sp gop Cetopsinie Doradine ¥ VA A Bagrine * Bunocephalidc - Pinvlodine * fa | Callophysinex Tachisurine ¥* Diplomystide Primitive Nematognathi Primitive Ostariophysie * Siluride ‘+ Pygidide 8 CALIFORNIA ACADEMY OF SCIENCES. Crropsine—Amazons from Rio Cupai to its upper courses; Guayaquil (Irisanga?). Pyaipine—Mountain streams from Chile to Col- ombia; Amazons eastward to Cudajas; mountain streams of Southeastern Brazil and center of Argentine Republie. STEGOPHILIN®—Brazil, chiefly in headwaters of rivers. VI. Arerpa—Andes of Peru, Ecuador and Colombia. VII. Loricartrp®—FEastern slopes of South America from the Argentine Republic to Central America; western slopes of Ecuador and Colombia. LoricaruNa&—La Plata to the Orinoco and Rio Mag- dalena; both slopes of Panama. Hypopropomin&—Rio Janeiro and Rio Parahyba; Amazon from Rio Negro to Rio Ambyiacu; Venezuela. PLEcostomIn®—Cordova; Rio Plata to Rio Magda- lena; western slopes of Ecuador; both slopes of Panama. VII. Caniicnrntip»—Rivers between La Plata and Orinoco; Amazons to Nauta. ANALYSIS OF THE AMERICAN FAMILIES AND SUBFAMILIES OF NEMATOGNATHI. a. Air bladder well developed, simple or with trans- verse constrictions (except in Ageneiosus); lying free in the abdominal cavity. Mouth terminal, teeth villiform, conical, incisor or molar-like: intestines short, arranged in longitudinal folds. Body naked or with a single series of lateral plates. Diaphragm mem- branaceous. Tip of scapular process touching basi occipital. SOUTH AMERICAN NEMATOGNATHI. 7) 6. Dorsal and anal nearly co-extensive with the cau- dal portion of the vertebral column; opercle pres- ent. Chacide, Plotoside, Clariide. (Exoties.) bb. Dorsal short, confined to the abdominal portion of the vertebral column. c. Opercle none; adipose fin none; neural spines of the coalesced vertebrae forming a ridge from the occipital to the dorsal. Giull-opening re- duced to a slit in front of the pectorals. Cau- dal vertebre greatly compressed, their neural spines expanded. BUNOCEPHALIDS I. a. Tail short, vent nearly equidistant from tip of snout and base of cau- dal. Anal with less than 10 rays Bunocephaline . aa. Taillong; vent in anterior third of body; anal with 50-60 rays. Platystacine. cc. Opercle well developed and movable; adipose fin normally present; occipital process sometimes forming a bony bridge from the occipital to the dorsal plate. Gill openings usually wide. Cau- dal vertebree not compressed, the neural spines simple, spine-like. d. Maxillary well developed, provided with teeth and forming the sides of the Jaw; nares approx- imated; gill membranes somewhat joined, but free from the isthmus. DIPLOMYSTID® II. dd. Maxillary vestigiary, the intermaxillaries only forming margin of upper jaw. SILURID# III. a. Gill membranes usually entirely free, sometimes united and forming a free membrane across the isthmus, or in some species of Vachisurus joined to the isthmus. 6. Anal much shorter than the caudal portion of the vertebral column; nares without barbels. c. Nares approximated (partly marine). Tachisurine. cc. Nares remote; barbels six; adipose fin well developed. d. Teeth incisor-like, in two series in the upper, in a single series in the lower jaw. Callophysine. 10 CALIFORNIA ACADEMY OF SCIENCES. dd. Teeth villiform, in bands. Pimelodine. ad. Gill membranes united and joined to the isthmus; nares remote, with- out barbels. e. Air bladder lying free in the abdominal cavity; mallei turned outward behind, their tips greatly expanded, forming the ante- rior wall of the single air bladder; modified vertebre with- out lateral processes. Jf. A series of bony plates along the sides. Doradine. Jf. Sides naked. Auchenipterine. ee. Air bladders vestigiary, almost wholly surrounded by bone, one on either side of the centrum of the modified vertebra. Lateral processes of the modified vertebrze well developed. A geneiosine. aa. Air bladder vestigiary, one on either side of the coalesced vertebre and entirely surrounded by a bony capsule. e. Air bladder enclosed in a capsule formed by cé. ray the lateral processes of the coalesced vertebre, by the scapula, and by the process connect- ing the scapula with the basi occipital; the external opening of the air bladder capsule bounded by the scapula and lateral processes, its anterior side open. Adipose fin present, dorsal on anterior half of body over the anal which is scarcely shorter than the caudal portion of the vertebral column. Gill mem- branes entirely free from the isthmus. Nares without barbels. Derm naked. ‘‘Dia- phragm” membranaceous. HyPoPHTHALMID# IV. Air bladder enclosed in a capsule formed by the lateral processes of the coalesced verte- bre only; the external orifice of the air bladder capsule as in Hypophthalmide, its anterior side closed. Adipose fin none; dor- sal usually on the caudal, sometimes on the abdominal portion of the vertebral column; SOUTH AMERICAN NEMATOGNATHI. 11 anal short. Derm naked. Dorsal and pec- toral spines scarcely developed. PYGIDIDH Vv. a. Dorsal entirely in front of the ventrals; vomer with teeth; head com- pressed; anterior nares almost labial; gill membrane broadly united with the isthmus; air bladder capsule entirely free from the skull; occi- pital with a prominent process. Cetopsine. aa. Dorsal above or behind the ventrals; no teeth on vomer. Head de- pressed. 6. Gill openings broad, the gill membrane almost free or forming a free membrane across the isthmus; air bladder capsule joined to the skull. Pygidine. bb. Gillmembrane confluent with the skin of the isthmus, the gill open- ings a narrow slit in front of the pectoral. Stegophelini. eee. Air bladder enclosed in a capsule formed by the skull and by the lateral processes of the anterior vertebre; diaphragm partly or wholly osseous, formed by the expansions of the clavicle and scapular process. Scapula and its process firmly joined to the skull. Gill membranes joined to the isthmus. f. Derm naked, mouth inferior, lower lip re- verted; teeth bicuspid, in several series. ARGIIDE VI. ff. Derm covered with bony plates. g. Caudal vertebree compressed, the neu- ral and hemal spines expanded forming a continuous ridge above and_ below. Sides with several series of plates. Mouth inferior, the lower lip reverted; teeth turned abruptly back above and usually expanded; a single series of teeth erect, the intermaxillaries and dentaries box- shaped, filled with numerous relay teeth; intestinal canal coiled. Cavity of the air bladder communicating with the ex- 12 CALIFORNIA ACADEMY OF SCIENCES. terior at a notch in the posterior margin of the temporal plate at the beginning of the lateral line. LorIcARIID# VII. a. Tail long, depressed, with a single series of plates on the sides; intes- tinal canal usually not much longer than the body. Loricariine. aa. Tail short, compressed or rounded. b. Belly with two or three series of large plates. Hypoptopomine. bb. Belly naked or with minute granular plates; intestinal canal many times as long as the body. Plecostomine. gg. Caudal vertebre normal, the neural and heemal spines spike-like, separated from each other. Sides with two series of plates. Mouth terminal, lower Hp not reverted; teeth villiform; cavity of the air bladder communicating with the ex- terior by means of a long narrow slit in the temporal plate and by the last of a series of slits below the long one. CALLICHTHYID.E VIII. Famity l. BUNOCEPHALID A. = Aspredinoidei Bleeker, Nederl. Tijdschr. Dierk. i, 1863, 117. = Aspredinina Giinther, Cat. Fish. Brit. Mus. v, 266, 1864. = Aspredinidw Gill, Arrangement of the Families of Fishes 19, 1872. =Bunocephalidw Eigenm. & Eigenm. Am. Nat. July, 1888. Air bladder large, free in the abdominal cavity and touching the skin in the area bounded by the humeral process and by the lateral process of the anterior ver- tebree. Anterior vertebre coalesced, with broad lateral processes which are bent downward behind, their pos- terlor margins strengthened and prolonged outward, SOUTH AMERICAN NEMATOGNATHI. 13 touching the skin. Coracoid and humeral processes large. Teeth villiform, in bands on the jaws, none on the yomer; intestinal canal short. Derm naked. Mouth terminal or subterminal, never truly inferior. Ante- rior nares remote from the posterior, neither with a barbel. Gill membrane joined to the isthmus, the gill- opening reduced to a narrow slit in front of the pec- toral. Dorsal short, placed over the ventrals. Pectoral with a strong spine; anal very variable. Habitat: Whole course of the Amazons; Guiana. The Bunocephalinw are found in the upper and mid- dle course of the Amazons and in Guiana, while the Platystacine are found only in the lower course of the Amazon (Para River) and in Guiana. ANALYSIS OF THE GENERA OF BUNOCEPHALID2&. a. Tail short; vent nearly equidistant from tip of snout and base of caudal. Anal with less than 10 rays. (BUNOCEPHALIN2.) b. Dorsal vestigiary, of 2 rays only; barbels 6; head broad and de- pressed, its depth less than that of the posterior portion of the com- pressed tail; anterior margin of the pectoral spine smooth. BUNOCEPHALICHTHYS I. bb. Dorsal well developed, of 5 rays, the last of which is adnate; head deeper than the posterior portion of the tail. c. Barbels 6. BUNOCEPHALUS IT. cc. Barbels 2, on the maxillaries only. DyYSICHTHYS III. aa. Tail long, with a median dorsal fold; distance of vent from tip of snout less than half its distance from base of caudal. A. 50-60. (PLATYSTACINZ) PLATYSTACUS IV. SUBFAMILY ,BUNOCEPHALIN ZA. I. BunocErPHALICHTHYS. Bunocephalichthys Bleeker, Nederl. Tijdschr. Dierk. i, 18635, 118, (hypsiurus). Type: Bunocephalus hypsiurus Kner. This genus is characterized by its rudimentary dorsal fin. 14 CALIFORNIA ACADEMY OF SCIENCES. Tail compressed, higher than broad; head lower than the tail; dorsal surface of the head with osseous pro- tuberances. Outer surface of pectoral spine smooth, caudal rounded. 1. Bunocephalichthys hypsiurus. Bunocephalus hypsiurus Kner, SB. Ak. Wien, xvii, 1855, 98, pl. 1, fig. 1. (Rio Branco.) Bunocephalichthys hypsiurus Giinther, Catal. Fish. Brit. Mus. v, 267, 1864 (copied); E. & BK. Proc. Cal. Acad. Sci., 2d Ser. ii, 1889, 48. (Name only.) Habitat: Rio Branco. Protuberances of the head in two curved series; tail with undulating ridge above and below. Light yel- lowish spots along the lateral line; anal white edged. kine) Il. BuNocEPHALUS. Aspredo Bleeker, Nederl. Tijdschr. Dierk. i, 1863, 117 (batrachus=aspredo). Platystacus Bloch, Ausl. Fische, viii, 1794 (sp.) >Platystacus Bleeker, 1. ¢., 118 (cotylephorus). >Cotylephorus Swainson, Fish, Amph. & Rept. 11, 308. 1839 (blochii=cotylephorus). > Aspredinichthys Bleeker, 1. c. 118 (tibicen). Type: Silurus aspredo Linneeus. The name Aspredo, according to the generally adopted rules of nomenclature, is not available for this genus. It was proposed before 1758, but not adopted in the Xth edition of the Systema Nature; the name Platystacus, SOUTH AMERICAN NEMATOGNATHI. 2 being the oldest name adopted during the binomial era, must be substituted. This genus is characterized by the increased number of caudal vertebre. The anal is very long, being almost co-extensive with the tail. Barbels 6, short. The belly of the females, during the breeding season, is covered with short tentacles, to which the eggs are attached. The pectoral spine is broad, depressed; its inner margin with introrse teeth which are strongest at the tip; its outer margin with shorter extrorse teeth. Habitat: Guiana; Rio Para and Rio Muria. ANALYSIS OF THE SPECIES OF PLATYSTACUS. a. Tip of snout smooth. b. Sternal and abdominal region without tentacles. c. Barbels 6, there being no barbel at the base of the maxillary. (PLATYSTACUS.) d. First dorsal ray not or scarcely produced. Head to gill open- ing, 9 in the length, with the caudal. cotylephorus 10. dd. First dorsal ray produced. Head to gill opening, 10 in the length, with the caudal. nematophorus 11. ec. Barbels 8, there being a small one on the anterior margin of the maxillary bone; snout broad, greatly depressed, spatulate. (ASPREDO.) e. Head to tip of nuchal plate more than 4 in the length to base of caudal. aspredo 12. ee. Head to tip of nuchal plate less than 4 in the length with the caudal; barbels longer than in aspredo. Brownish above, with white dots; anal with a black margin. (Cuv. & Val.) sicuephorus 13. 6b. Sternal and abdominal region with a marginal series of tentacles. Barbels 8, there being a minute one on the anterior margin of the maxillary bone; snout rather pointed; first dorsal ray produced in a very long filament; posterior anal rays and caudal black. Jjilamentosus 14. aa. Tip of snout with four broad spines, the inner ones fixed, belonging to the ethmoid, the outer movable, belonging to the nasals. (ASPRE- DINICHTHYS.) tibicen 15. 10. Platystacus cotylephorus. Platystacus cotylephorus Bloch, Ausl. Fische, vili, 54, pl. 372, 1794; Bloch & Schneider, Syst. Ichthyol. 372, 1801; Bleeker, Silures de Suriname, 95, 1864 (Surinam); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 50 (Vigia; Para; Tajapuru). 22 CALIFORNIA ACADEMY OF SCIENCES. Silurus cotylephorus Lacépéde, Syst. Ichthyol. v, 78, 1803. Aspredo cotylopherus Giinther, Cat. Fish. Brit. Mus. v, 269, 1864, (Surinam). Silurus hexadactylus Lacépéde 1. c. 82. Aspredo sex-cirrhis Cuv. & Val., Hist. Nat. Poiss. xv, 441, 1840: (Surinam); Kner, SB. Ak. Wien, xvii, 1855, 93 (Surinam). Aspredo spectrum Gronow, ‘‘Syst. Ichthyol. 137, 1854.” Habitat: Surinam and Rio Para. Head greatly depressed, narrowed forward; interorbital width 33 in the distance from base of pectoral to tip of snout; width of mouth equals the interorbital plus the orbits, the snout projecting half its length. Inter- maxillaries with 2 rhomboidal patches of villiform teeth, lower jaw with wider patches of similar teeth. Maxillary barbels reaching to gill-opening, mental not to postmental barbels which are as long as width of mouth. Coracoid processes slightly diverging backward, the length of the processes 14 in the distance between their bases. Humeral processes co-extensive with but not. overlapping the coracoid processes. Pectoral pore below the tip of humeral process. Distance of dorsal fin from tip of snout 383-33 in the length; first dorsal ray scarcely prolonged. Outermost caudal rays prolonged. Four rows of papille on the sides. Color uniform dark brown in some specimens, pro- fusely mottled with lighter in others; one example is. abruptly lighter behind the dorsal fin, another has the dorsal surface of head and nape to the dorsal fin plain light, with marblings of light on the brown ground posteriorly; fins uniform brown, or mottled lke the body or the anal, sometimes white anteriorly. A. 538-57; greatest width, before pectoral spine, 53; length of head to gill opening 9 in the length, with the caudal fin. Nine specimens .14-.33 m. Vigia; Para; Tajapuru. Thayer Exped. SOUTH AMERICAN NEMATOGNATHI. 23 11. Platystacus nematophorus. Platystacus nematophorus Bleeker, Silures de Suriname, 96, pl. i, fig. 1, 1864 (Surinam); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 50. Aspredo nematophorus Ginther, Cat. Fish. Brit. Mus. v, 270, 1864 (copied). Habitat: Surinam. 12. Platystacus aspredo. Silurus aspredo Linneeus, Syst. Nat. Ed. x, 304, 1758; Ed xii, 502, 1766; Bonnaterre, Tableau Encyel. Ichthyol. 150, 1788; Lac- épéde Syst. Ichthyol. v, 78, 1803. Platystacus aspredo E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 50 (Para; Arary). Platystacus levis Bloch, Ausl. Fische viii, 58, 1794; Bloch & Schneider, Syst. Ichthyol. 373, 1801. Aspredo levis Cuy. & Val. Hist. Nat. Poiss. xv, 431, 1840 (Guiana); Miller & Troschel, Schomburgk’s Brit. Guiana, 630, 1848 (Waini). Aspredo batrachus (Linneus Mus. Ad. Fred. 73) Gronow, ‘Cat. Fish.” 137, 1854; Bleeker, Silures de Suriname, 93, 1864 (Suri- nam); Giinther, Cat. Fish. Brit. Mus. v, 269, 1864 (British Guiana; Cayenne; Surinam). Habitat: Guiana; Rio Para and Lake Arary. Head greatly depressed, spatulate; interorbital width 3% in the distance from base of pectoral to tip of snout. Mouth broad, the snout projecting almost its entire length; each jaw with two patches of small teeth. Max- illary barbel reaching to base of pectoral, an accessory barbel in front; mental barbels placed near the lip, ex- tending to the postmental, which is equal to the inter- orbital. Coracoid processes slightly diverging backward, the length equal to the space between them. A minute pectoral pore at the extremity of the cora- coid process. Humeral process a little longer than the coracoid process and overlapping it. Distance of dorsal fin from tip of snout 3% in the length; first ray rarely prolonged. Outermost caudal rays slightly produced. Pectoral spine as in A. tibicen. Dorsal surface uniform purplish brown, the ventral 24 CALIFORNIA ACADEMY OF SCIENCES. surface plain light shading into light purple or pinkish; dorsal fin dusky, usually with a dusky median stripe on the interradial membrane; caudal dark except the outer- most rays; pectoral smutty, ventrals usually white, the posterior half sometimes dusky; anal fin white anteriorly becoming dusky backward; maxillary barbels more or less dusky. Greatest width, before pectoral fins, 53-6 in the length; A. 51-55. Twelve specimens .14-.19m. Para; Arary. Agassiz & Bourget. 13. Platystacus sicuephorus. Aspredo sicuephorus Cuyv. & Val. Hist. Nat. Poiss. xv, 439, 1840 (Mana). Aspredo sicyephorus Giinther, Cat. Fish. Brit. Mus. v, 269, 1864 (copied). Platystacus sicuephorus EB, & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 50. Habitat: French Guiana. 14, Platystacus filamentosus. Aspredo jilamentosus Cuv. & Val. Hist. Nat. Poiss. xv, 437, pl. 450, 1840 (Cayenne); Giinther, Cat. Fish. Brit. Mus. v, 270, 1864 (Demarara). Platystacus jfilamentosus E. & E. Proce. Cal. Acad. Sci. 2d Ser. 1i, 1889, 50. Habitat: Guianas. 15. Platystacus tibicen. Aspredo tibicen (Temmink) Cuv. & Val. xv, 438, 1840 (Surinam); Giinther, Catal. v, 270, 1864 (Brit. Guiana). Platystacus tibicen E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 50 (Curuca; Rio Muria). Habitat: Guiana; Curuca, Rio Muria. This species may readily be distinguished by the nasal spines. Head somewhat elongate, subconical. Interorbital width 5 in the distance between base of pectoral and tip of snout. Mouth narrow, the snout little projecting; teeth fine and long, the intermaxillary band continuous. Maxillary barbel about reaching to gill-opening, an ac- bo Ol en SOUTH AMERICAN NEMATOGNATHI. cessory barbel on anterior margin of its bony base. Lower surface of the head with four irregular series of cirri, the outer series continued backward to behind the pectoral. Coracoid processes diverging backward, their length about 13-14 in the distance between them at base. Hu- meral process co-extensive with the coracoid process, the pectoral pore almost immediately below its termination. Distance of dorsal fin from tip of snout about 4 in the length; first dorsal ray greatly prolonged, filiform, some- what longer than its distance from tip of snout. Outer caudal rays slightly produced. Pectoral spine flattened, curved upward and _back- ward, its posterior margin with a series of spines which are longer and stronger toward the tip, its anterior with somewhat weaker teeth, its tip reaching beyond origin of ventral fins. Dorsal surface chocolate colored, a series of squarish darker spots on either side of the dorsal fold which are more or less confluent; ventral surface plain, nearly white; dorsal, pectoral, caudal and posterior portion of anal dark brown; ventrals and anterior part of anal light, the upper surface of ventrals dotted with dusky. Greatest width, before pectoral fins, about 7 in the leniothe vA b- Five specimens .20—.22m. Curuca, Rio Muria. Thayer Expedition. . Paminy Il. DIPLOMYSTIDAL. = Diplomystide Kigenm. Zoe, vol. 1, 14, 1890. This differs from the remaining families in possessing dentiferous maxillaries. V. DIPLOMYSTES. Diplomyste Dumeril, ‘‘Ichthyol. Analyt., 487.” Diplomystes Bleeker, Nederl. Tijdschr. Dierkunde, 1, 18638, 92 (papillosus). 26 CALIFORNIA ACADEMY OF SCIENCES. Diplomystax Ginther, Cat. Fish. Brit. Mus., v, 180, 1864 (papillosus). The distinctive character of this genus is the develop- ment of the maxillary bone. It forms the sides of the mouth and carries a very narrow band of teeth. No mental barbels; maxillary barbels thick, compressed at the base. Occipital process not visible externally; no bony orbit. Skull with two nearly parallel median ridges above. Fontanel extending to the base of the occipital process, with a rather broad interruption behind the eyes. Habitat: Chile, near Valparaiso and Santiago. 16. Diplomystes papillosus. Molina ‘‘ Hist. Nat. Chile, 199, No. 9.” 2? Silurus chilensis Linneeus Syst. Nat. Ed. xiii, 1359, 1788 (Chile). 22 Pimelodus chilensis Lacépéde Hist. Nat. Poiss. v, 114, 1803 (Fresh waters of Chile). Arius papillosus Cuy. & Val. Hist. Nat. Poiss. xv, 118, pl. 431, 1840 (Valparaiso; San Jago); Gay, Hist. Chile, ii, 305, pl.: fig. 1, 1848 (Chile); Philippi, MB. Ak. Wiss. Berlin, 1866, 710 (Chile). Diplomystax papillosus Giinther, Cat. Fish. Brit. Mus. v, 180, 1864 (Chile). : Diplomystes papillosus Kigenm. & Eigenm. Proc. Calif. Acad. 2d Ser. vol. i, 1888, 149 (Rivers of Santiago). Arius carcharias ‘‘Leybold, Anales de la Universidad de Chile, 1883 (Chile)”; Philippi, MB. Ak. Wiss. Berlin, 1866, 711 (Chile). Arius villosus Philippi, 1. ¢. 712 (Santiago). Arius squalus Philippi, 1. c. 713 (Santiago). Arius micropterus Philippi, 1. ¢. 713 (Santiago). Arius synodon Philippi, 1. ¢. 713 (Santiago). Habitat: Central portion of Chile. The numerous species of Philippi seem to be based on individual differences. The seventh dorsal ray is al- ways divided to near its base, and in one of the speci- mens examined by us there are eight dorsal rays. Slender, terete forward, compressed toward the tail; the width, below the dorsal spine, equals the depth. Head short and blunt, somewhat pointed in young, the profile strongly decurved in front; head entirely covered SOUTH AMERICAN NEMATOGNATHI. 27 with a layer of muscle and skin, the surface of the bones irregular, rugose, the interorbital portion flattish, post- orbital portion with two nearly parallel median ridges. Fontanel between the two median ridges, extending from the occipital process to in front of the eyes, witha broad bridge behind the eyes. Occipital process a deep but short crest. Eye small, circular, 3 in snout, little more than 1 in the interorbital, 3 in the interocular, 73 in the head. Nostrils close together, with a membrane around the entire margin forming an 8-shaped figure, the portion of the membrane separating the nasal openings highest. Maxillary barbel broad and flattened at its base, scarcely reaching the base of the pectoral. Snout sometimes long and pointed, usually rounded, projecting considerably beyond the lower jaw. Lips thick and strongly papillose. Maxillary bones reaching to below the eye, 23 in head. The anterior half of the maxillary consists of a slender peduncle bearing two series of teeth; the posterior portion is flattened and about three times.as wide as the anterior portion. In- termaxillaries with a crescent shaped patch of teeth, the outer four or five series compressed, incisor-like, teeth of the inner series very much smaller, not incisor- hke. Vomer with two oval patches of large, conical teeth, the patches becoming united with age. Teeth of the lower jaw compressed, incisor-like, the band deep in front tapering rapidly to the rictus. Gill membranes usually separate to below the eye, en- tirely free from the isthmus. Gill-rakers 548. Pseudo- branchie well developed, not covered by a membrane. Skin covered with minute cirri or papille, which are especially conspicuous over the humeral region and head, the tail sometimes smooth. Distance of dorsal fin from tip of snout 23-24 in the 28 CALIFORNIA ACADEMY OF SCIENCES. length, the spine stout and smooth, 13-13 in head. Dis- tance of the adipose fin behind the dorsal about equal to the length of the adipose fin or one-half longer, 5-6 in the length. Caudal emarginate with numerous, short, accessory basal rays. Free margin of the anal straight or shghtly convex, the fifth ray highest, about 13 in the head, rapidly de- creasing to the last ray, which is about half the height of the fifth. Ventrals inserted under the last dorsal ray 13-2 in the head. Pectoral spine very strong and with a leathery pro- longation; height of the spinous portion 13-2 in the head; outer margin of the spine smooth, inner margin with strong recurved teeth along its entire length. Bases of all the fins, lower part of head, suborbital region and opercles and a median line on the back pur- plish; rest of body and fins yellowish, and under the lens dark. Head 4-43; depth 44-53; Br. 7; D. I, 7or8; A. 9-12. Eight specimens .12-.20 m. Rivers of Santiago. Famity LiL SipURiIDA Siluride Gill, Arrangement of Families of Fishes, 195 Siz: iota Snout somewhat blunt, less decurved ad Saar ei than in platypogon; uppre jaw slightly xe I projecting; teeth villiform, the inner margins of the palatine patches con- \ cave, distant 14 longitudinal diameters of \ the eye. ) e 74 CALIFORNIA ACADEMY OF SCIENCES. Gill-membranes forming a much narrower fold across the isthmus than in platypogon. Vertical series of pores on the sides of the body. Distance of dorsal fin from tip of snout little more than 24 in the length, the spine 1? in the head, its an- terior margin with low, blunt granules. Distance {of the adipose from the dorsal fin 4 in the length, adipose fin as long as the dorsal fin minus the fulcrum. Caudal widely forked, 53 in the length. Anal little longer than high, deeply emarginate. Ventral 2 in the head. Metallic blue above, shading into silvery below; inner surface of the pectcrals wholly blue-black, except the posterior margin which is light; ventrals lighter, but marked in the same way. Head 33; depth 53; D. I, 7; A. 17. 44, Tachisurus osculus. Arius osculus Jordan & Gilbert, Bull. U. 8. Fish Comm. 1882, 46 (Panama). Galeichthys osculus Jordan, Proc. U.S. Nat. Mus. 1885, 366 (name only). Tachisurus osculus Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 142 (Panama). Habitat: Panama. Rather slender, the greatest width equals the depth. Head short and broad, the greatest width 14 in its length; its greatest depth 17 in its length; interorbital area flattish, smooth; top of head, dorsal plate and humeral process coarsely granular; opercles faintly striate. Occipital process little broader than long, ridged rather than keeled, the margins concave; middle of fon- tanel over the posterior margin of the eye; fontanel produced backward in a groove which is about as long as the eye. . Eye 2 in snout, 6 in head, 23 in the interocular. Maxillary barbels not reaching beyond the gill-open- SOUTH AMERICAN NEMATOGNATHI. 15 ing, not to base of pectoral; mental barbels not reaching to edge of gill-membrane; postmentals to gill opening. Upper jaw considerably projecting; width of the mouth 2 in the head; teeth all villiform; the depth of the inter- maxillary band 4 in its width; vomerine ne patches of teeth small (the patch on one side 2 \ twice as large as on the other), and separ- Gi D ated by a groove from the large sub-rhom- boidal patches on the palatines. 7% Gill-membranes meeting in an angle and forming a fold across the isthmus. Gill-rakers 4++9. Pectoral pore none, vertical series of pores incon- spicuous. Distance of the dorsal fin from tip of snout 23 in the length, the dorsal spine equal to the length of the head, granular in front and on the sides, minute teeth on its inner margin, the first soft ray higher than the spine; distance of the adipose fin from the dorsal 34 in the length. Adipose fin more than twice as long as high, as long as the dorsal fin, adnate. Anal emarginate, scarcely longer than high, the high- est ray about 2 in the head. Ventrals reaching the anal, 13 in head, the inner ray with a dermal fold. Pectoral spine strong, curved, depressed, little shorter than the dorsal spine, both margins with small, irregu- lar teeth. Light brown, fins somewhat dusky. Head 4; depth 54; D. I, 7; A. 18. Asinglespecimen, ? .26m. Panama; Steindachner. This specimen differs from the description of the type, but the difference may be due to the sex. 45. Tachisurus elatturus. - Arius elatturus Jordan & Gilbert, Bull. U.S. Fish Comm. 1882, 45 (Panama). 76 CALIFORNIA ACADEMY OF SCIENCES. Galeichthys elatturus Jordau, Proc. U.S. Nat. Mus. 1885, 366 (name only). Tachisurus elatturus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 142 (name only.). Habitat: Panama. 46. Tachisurus barbus. Pimelodus barbus Lacépéde, Hist. Nat. Poiss. v, 94, 106, 1803. Galeichthys barbus Jordan, Proc. U.S. Nat. Mus. 1886, 559 (name only). Tachisurus barbus Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1885, 142 (Campos; Rio Doce; Rio Grande do Sul). Pimelodus commersonii Lacépéd, Hist. Nat. Poiss. v, 95, 108, pl. 3, fig. 1, 1803 (locality ?). Bagrus commersonii Valenciennes, in d’Orbigny, Voy. Amér. Mérid. Poiss. Atlas ii, pl. 3, fig. 1, 1847; Cuvier & Valenciennes Hist. Nat. Poiss. xiv, 449, 1839 (Montevideo; Rio Janeiro); Kner, SB. Ak. Wien, xxvi, 1857, 386 (Rio Janeiro). Arius commersonii Giinther, Cat. Fish. Brit. Mus. v, 143, 1864 (Bahia); Hensel, Wiegm. Arch. 1870, i, 69 (Guahyba and larger tributaries); Steindachner, SB. Ak. Wien, lxxiv, 1876, Siiss- wasserfische siidéstlichen Brasiliens, iii, 85 (Bay of Rio Janeiro; Rio Grande do Sul; Rio Parahyba near Campos; Rio Doce; Santos). Bagrus barbatus Quoy & Gaimard, ‘‘ Voy. Uran. Zool. 230, pl. 49, figs. 1 and 2, 1824.” Pimelodus versicolor Castlenau, Anim. Amér. Sud, Poiss. 35, pl. 16, fig. 3 (Rio Araguay; Goyaz). Habitat: Rio Plataand northward, ascending rivers. Body rather slender, little deeper than wide, the cau- dal peduncle compressed. Head large, somewhat de- pressed, its width 13 in its length, width at angle of the mouth 2, its depth 13. Interorbital area flattish, hav- ing four obscure ridges in the old. Top of head coarsely granular, the granules in series along the fontanel and toward the eyes; opercles and occipital process smooth. Occipital process $ times as long as broad, sharply keeled in the young. Fontanel 33 times as long as the eye, its centre over the middle of the eye, continued as a groove to the occipital process. Kye 2-25 in snout, 53-83 in head, 3-43 in the inter- ocular. SOUTH AMERICAN NEMATOGNATHI. @i Maxillary barbel reaching little beyond base of pec- toral, mental barbel not to gill-opening, postmental barbel extending considerably beyond the gill-opening. Snout blunt, little decurved, upper jaw little produced. Teeth ee aie viliform, the intermaxillary a ee band emarginate on the sides and behind; teeth on the roof of the mouth in from 3-5 con- fluent patches on each side; vomerine patches separated from each other. Gill-membranes meeting in an angle, forming a fold across the isthmus. Gill-rakers 6+-10. Distance of dorsal spine from tip of snout 25-23 in the length. Dorsal and pectoral spines granular in front, striate on the sides, the dorsal spine scarcely roughened behind, 13-13 in the head; the pectoral spine serrated behind, its length about 13 in the head. Space between the dorsal and adipose fins 3$ in the length. Adipose fin scarcely shorter than the dorsal, its posterior margin Tree: Upper caudal lobe longer, falcate, 35-4 in the length. Anal fin about as high as long, 24 in the head. Ventrals not reaching to the anal, about 2 in head. Color, in specimen No. 7702, light brown, silvery on sides, white below; tip of dorsal and pectoral fins dusky; all the fins more or less dotted with brown: all the other specimens plumbeous above, white below; fins dusky. Head 33-32; depth 5-53; D. I, 7; A. 19. The specimens examined, .13-.48 m. long, are from (7702) Campos; Rio Doce; Rio Grande do Sul,—(the smaller specimens from this locality have the occipital keel very strongly developed). A specimen from the Rio Grande do Sul, .42 m. long, ay 78 CALIFORNIA ACADEMY OF SCIENCES. has a much stouter form, the dorsal and pectoral spines more or less covered with a membrane, the pectoral spine 14 in the head, the dorsal spine 14; the granula- tions of the head covered with skin and much less con- spicuous than in the other examples; the space between dorsal and adipose fins 4 in the length; the barbels all thick and fleshy. 47, Tachisurus seemanni. Arius seemanni Giinther, Cat. Fish. Brit. Mus. v, 147, 1864 (Central America); id, Fish. Cent. Am. vi, 1866, 393; Jordan, Proc. Phil. Acad. Nat. Sci, 1883, 282 (notes on type specimen). Galeichthys seemanni Jordan, Proc. U. 8. Nat. Mus. 1885, 366 (name only). Tachisurus seemanni Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 142 (Panama). 2? Arius assimilis Jordan & Gilbert, Bull. U. S. Fish Comm. 1882, 47 (Mazatlan). (Not Arius assimilis Giinther.) Habitat: West Coast of Tropical America. Body about as deep as wide, tapering to a slender peduncle. Head flat, depressed in front, top of the head coarsely granular; opercles smooth or with faint striations; humeral process slightly granular, covered with skin; the greatest depth of the head 13 in its length, greatest width 13-12; the width at angles of the mouth 23. Occipital process wider than long; fontanel open to above the posterior margin of the eye, witha deep backward-extending groove. Interorbital area smooth, without ridges. Eye 2 in snout, 7 in head, 33-4 in the interocular, 23 in the interorbital. Maxillary barbels reaching slightly beyond base of pectorals, mental barbels two-thirds toward the gill opening, the postmentals half a diameter of the eye behind the gill opening or farther. SOUTH AMERICAN NEMATOGNAHTI. nm Upper jaw longer; teeth all villiform; _ vomerine teeth in two small ovate patches Ca which are separated from each other but ye joined to the much larger palatine —/ \ ) patches. ra Gill-membranes forming a moderate fold across the isthmus. Gill-rakers 5-12. Pectoral pore large; vertical series of pores present. Distance of dorsal fin from tip of snout 23-23 in the length, the spine rather stout, 13 in head; its outer edge granular toothed, its inner edge with short, recurved teeth; distance of the adipose fin from the dorsal 33-3} in the length; adipose fin slightly longer than high, shorter than the dorsal fin. Caudal 4 in the length. Anal emarginate, little longer than high. Ventrals 1/—2 in the length of the head. Pectoral spine 14 in head, its anterior margin granu- lar toothed, its inner edge with long, straight teeth. Plumbeous, silvery below; fins dusky, inner surface of ventrals and pectorals dark. Head. 32>-depth: 5>D,'1,.'75 Ay 18. One ¢ .28 m. Panama. One 6 .21 m. Panama. 48. Tachisurus jordani. ? Arius assimilis Jordan & Gilbert (not of Giinther) Bull. U. 8. Fish Comm. 1882, 47 (Mazatlan). Tachisurus jordani Kigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser; vol. i, 1888, 142 (Panama). The specimens agree very closely with the description of assimilis by Jordan & Gilbert. They differ in the width of the mouth and in having a pectoral pore. Rather robust, the width little less than the depth; caudal peduncle compressed. Head heavy, little broader than high, its height 14 in its length, its width 13-15, width at the angle of the mouth 2-2}. Interorbital area 80 CALIFORNIA ACADEMY OF SCIENCES. flat and smooth; posterior portion of the head finely and sparsely granular; opercle and humeral process smooth; occipital process about as long as broad, unusually sharply keeled. Fontanel extending to above the pos- terior part of the orbit, continued as a deep groove to base of occipital process. Eye large, 1? in snout, 53 in head, 2 in the interor- bital, 22-3 in the interocular. Maxillary barbels extending to the pectoral pore, post- mentals at least to the gill opening, mental about three- fifths as long as the postmental barbels. Snout blunt, decurved; upper jaw a little produced. Teeth all villiform, those on the One vyomer forming two small, separate, ovate patches, which are contiguous to the twice 27 or thrice as large palatine patches. Gill-membranes ‘forming a fold across the isthmus. Gill-rakers 6+-9. Pectoral pore large; vertical series of pores present. Distance of dorsal spine from tip of snout 22-24 in the length; the spine of the dorsal and pectoral fins granular on the basal half of their outer margin; almost the entire inner margins serrate, the spines of equal length, 13 in head. Distance of adipose fin from the dorsal 32 in the length; the adipose more than half as long as the dorsal fin, its posterior margin free. Caudal deeply forked, the upper lobe longer, some- what faleate, 33-4 in the length. Anal fin about as long as high, deeply emarginate, its highest ray 22 in the head. Ventral fins not reaching to the anal, 2 in the head. Dorsal surface dark blue with metallic lustre, becoming silvery below; lower caudal lobe dusky; basal half of the inner surface of the paired fins black. Head 32-33; depth 53-53; D. I, 7; A. 18. SOUTH AMERICAN NEMATOGNATHI. 81 49, Tachisurus cerulescens. Arius cerulescens Gunther, Cat. Fish. Brit. Mus. vy, 149, 1864 (Guate- mala); id. Fish. Cent. Am. vi, 1866, 393 (name only); Jordan, Proc. Acad. Nat. Sci. Philad. 1883, 282. Galeichthys cerulescens Jordan, Proc. U. S. Nat. Mus. 1885, 366 (name only). Tachisurus cerulescens Bigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 142 (name only). Habitat: West Coast of tropical America. 50. Tachisurus guatemalensis. Arius guatemalensis Giinther, Cat. Fish. Brit. Mus. v, 145, 1864 (Guatemala); Giinther, Fish. Cent. Am. vi, 1866, 393 (Chiapam; Panama); Jordan & Gilbert, Bull. U.S. Fish Comm. 1882, 48 (Mazatlan; Colima); not Arius guatemalensis Steind. Galeichthys guatemalensis Jordan, Proc. U. 8S. Nat. Mus. 1885, 366 (name only). Tachisurus guatemalensis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 143 (name only). Habitat: West Coast of tropical America. 51. Tachisurus assimilis. Arius assimilis Giinther, Cat. Fish. Brit. Mus. v, 146, 1864 (Guate- mala); id. Fish. Cent. Am. vi, 1866, 393, 475 (Lake of Yzabel); id. Trans. Zool. Soc. 1868, |475 (locality ?); Steindachner, Fisch- Fauna Magd. Stromes, 23, 1878 (Magdalena River); Jordan, Proc. Acad. Nat. Sci. Philad. 1883, 281. Galeichthys assimilis Jordan, Proc. U.S. Nat. Mus. 1886, 559 (name only). Tachisurus assimilis Eigenm. &- Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 143 (name only). Habitat: East Coast of Central America. 52, Tachisurus surinamensis. Hexanematichthys surinamensis Bleeker, Versl. & Mededeel. Akad. Wet. Amsterd. 1862, xiv, 380; id. Silures de Suriname, 55, plate vi, fig. 2, and plate xii, fig. 1, 1864 (Surinam). Arius surinamensis Giinther, Cat. Fish. Brit. Mus. v, 148, 1864. Galeichthys surinamensis Jordan, Proc. U. 8. Nat. Mus. 1886, 559 (name only). Tachisurus surinamensis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 143 (name only). Habitat: Surinam. 53. Tachisurus dasycephalus, Arius dasycephalus Giinther, Cat. Fish. Brit. Mus. vol. vy, 157, 1864 (Sandwich Islands); Steindachner, SB. Ak. Wien, lxxiv, 1876, 6 82 CALIFORNIA ACADEMY OF SCIENCES. Ichthyol. Beitr. iv, 26 (Panama); Jordan & Gilbert, Bull. U.S. Fish Comm. 1882, 51 (Panama); Jordan, Proc. U. S. Nat. Mus. 1882, 622 (Panama). Galeichthys dasycephalus Jordan, Proc. U. 8. Nat. Mus. 1885, 366 (name only). Tachisurus dasycephalus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 143 (name only). Habitat: West Coast tropical America; Sandwich Islands. 54. Tachisurus longicephalus. Tachisurus longicephalus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 143 (Panama). Elongate, slender; greatest width little greater than the depth. Head long and depressed, its greatest width 14 in its length, its greatest depth little more than half its length. Top of head with faint granules almost en- tirely concealed by the skin; interorbital area flat and with four ridges which are obscurely granular, the in- ner two bordering the fontanel, the outer ones curved in front extending obliquely backward from near the posterior nasal opening; occipital process as long as broad, its margins concave; fontanel produced as a deep groove to the base of occipital process; opercle faintly striate; humeral process entirely covered with thick skin, not granular. Kye lateral, well above the angle of the mouth, its diameter 14 in snout, 6 in head, 38 in interocular; snout depressed and rounded in front. Maxillary barbels extending scarcely beyond base of pectorals, mentals not to gill opening. Upper jaw little projecting; width of the mouth 24 in the head; intermaxillary teeth long and slender, the depth of the band 43 in its width; vomer- ine and palatine teeth obtusely conical, the CSD vomerine patches separate, contiguous to, but cP & not confluent with the palatine patches. a Gill-membranes not forming an angle where they meet, with a rather broad free margin. Gill-rakers short and thick, 4-65. SOUTH AMERICAN NEMATOGNATHI. 83 Pectoral pore small; vertical series of pores present. Distance of dorsal fin from tip of snout 23 in the length, the spine 1? in the head, its outer margin gran- ular toothed near its base, its inner margin with short teeth; distance of adipose fin from the dorsal 3} in the length. Adipose fin much longer than high, as long as the dorsal fin. Caudal forked, the upper lobe one-third longer than the lower, very nearly as long as the head, 34% in the length. Anal fin emarginate, scarcely longer than high, its height 23 in the head. Ventrals reaching almost to the anal, about 2 in head. Pectoral spine a little longer than the dorsal spine, 13 in the head; its outer edge roughened, inner edge with rather sharp teeth. Brown above, the sides silvery, entire ventral surface sprinkled with brown dots; a black median line on the back; fins dusky; barbels blackish. Head 32; depth 64; D. 1, 7; A. 20. 4972. One specimen ¢ .29m.long. Panama. Stein- dachner. 55, Tachisurus rugispinis. Arius rugispinis Cuy. & Val. Hist. Nat. Poiss. xv, 77, 1840 (Cay- enne); Kner, SB. Ak. Wien, xxvi, 1857, 388 (Para); Giinther, Cat. Fish. Brit. Mus. vy, 156, 1864 (copied). Galeichthys rugispinis Jordan, Proc. U.S. Nat. Mus. 1886, 559 (name only). Tachisurus rugispinis Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 145 (Para). Habitat: Para and northward. Slender, compressed on the tail. Head broad and de- pressed, tapering forward; width of the head, 14-12 in its length, at the angle of the mouth 22-24; depth of the head 13-2; profile rather steep. Top of head, hum- eral process, front and sides of the spines, and dorsal 84 CALIFORNIA ACADEMY OF SCIENCES. plate granular, the granulation not extending forward to above middle of cheeks. Occipital process triangular, about as long as broad, the median ridge not very prominent. Middle of fontanel behind the eye, the posterior portion separated by a bridge, not continued backward as a groove; interorbital region with four ridges. Eye small, 3 in snout, 10 in head, 3} in the interocu- lar. Barbels villiform. Maxillary barbel reaching to or beyond base of pectoral; postmental to gill-opening, mental barbels much shorter. Mouth inferior, lower jaw included, lips thick; teeth villiform, the anterior ones in the jaws longer; Gas depth of the intermaxillery band 4 in its width; palatine patches 1 diameter of the eye [7 ww apart, the width of the patches less than one 29 diameter of the eye. Gill-membranes meeting in an angle, forming a fold across the isthmus. Gill-rakers 6-++11. Pectoral pore none; vertical series of pores present. Distance of dorsal spine from the snout 23-24 in the length, the spine broken in the specimens. Space be- tween dorsal and adipose fins 4-43 in the length. Adipose fin adnate, as long as the anal fin. Ventrals 2} in the head. Pectoral spine serrated behind (broken). Head 33-4; depth 53-6; D. I, 7; A. 19-21. Two specimens .22 and .26 m. long. Para. Agassiz and Bourget. 55a. Tachisurus rugispinis phrygiatus. Arius phrygiatus Cuv. & Val. Hist. Nat. Poiss. xv, 79, 1840 (Cay- enne); Giinther, Cat. Fish. Brit. Mus. v, 156, 1864 (copied). Galeichthys phrygiatus Jordan, Proc. U. 8. Nat. Mus. 1886, 559 (name only). Tachisurus phrygiatus Eigenm. & EKigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 145 (Maranhao). SOUTH AMERICAN NEMATOGNATHI. 85 Arius dieperinki Bleeker, Silures de Suriname 50, pls. x, and xii, fig. 3, 1864 (Surinam). Habitat: Maranhao and northward. This example differs from those described | above, in having the sides of the spines — striate, the fontanel broadly rounded be- we) hind, the intermaxillary band of teeth 6 30 times as wide as deep, the palatine patches 1} diame- ters of the eye in width and length. No. 7694, one specimen .27 m. Maranhao. 56. Tachisurus grandoculis. Arius grandoculis Steindachner, SB. Ak. Wien, Ixxiv, 1876. Stiss- wasserfische siidéstlichen Brasilines ili, 86, pl. xi (Rio Doce). Tachisurus grandoculis Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 145 (Rio Doce). Habitat: Rio Doce. Form compressed, the width about a third less than the depth, the nose rather pointed. Head a little higher than broad, its height (at base of occipital process) 13-13 in its length, its width 14, at the angle of the mouth 23. Granulations of the head rather fine, extending usually, to above the anterior part of the orbit, forming striz. ‘Occipital process long, its width, at base, about 13 in its length; at tip nearly 3; granular, its ridge somewhat blunt. Fontanel long, its center nearly over the middle of the eye or a little in front, continued backward as a groove. Eye very large, 14 in snout, 44-5 in head, 14 in inter- orbital, about 13-2 in interocular. Maxillary barbels reaching past the middle of the pectoral, the mentals past the gill-opening and the post- mentals beyond base of pectoral fin. All the barbels shorter in larger specimens. Snout decurved, projecting beyond the lower jaw, the mouth wholly inferior. Teeth all villiform, on ean the palate in two small,widely separated patches; > no teeth on the vomer. a) » 86 CALIFORMIA ACADEMY OF SCIENCES. Gill-membranes forming a fold across the isthmus. Gill-rakers 5-++11. Pectoral pore moderate; vertical series of pores present. Distance of dorsal spine from tip of snout 24 in the length; outer margin of the spine shghtly granular, the inner margin somewhat serrate; its length 1}-14 in the head. Space between dorsal and adipose fins 34-32 in the length; adipose fin shorter than the dorsal fin, its pos- terior margin free. Caudal fin deeply forked, the upper lobe longer, some- what falcate, 3} in the length. Anal fin emarginate, about as long as high, the high- est ray 2 in the head. Pectoral spine longer than the dorsal spine, its outer margin roughened, its inner margin sharply serrate, its length 14-14 in the head. Plumbeous above, white below; all the fins beautifully peppered with brown spots. Head 37-34; depth 44-53; D. I, 7; A. 19-20. Three specimens .25 m.—.32 m. long.. Rio Doce; Hartt & Copeland. 57. Tachisurus nuchalis. Arius nuchalis Giinther, Cat. Fish. Brit. Mus. v, 171, 1864 (British Guiana). Galeichthys nuchalis Jordan, Proc. U. 8. Nat. Mus. 1886, 559 (name only). Tachisurus nuchalis Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. vol. i, 1888, 145 (name only). Habitat: British Guiana. 58. Tachisurus agassizii. Tachisurus agassizi Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 145 (Rio Grande do Sul). Habitat: Rio Grande do Sul. Body compressed, especially backward, the depth greater than the width. Head narrowed forward, its great-. est width 14 in its length, its greatest depth about 13; width SOUTH AMERICAN NEMATOGNATHI. 87 at the mouth 2} in the length of the head. Top of head granular, the granulations forming striz nearly every- where; occipital process as broad as long, with a median ridge, the margins concave. Middle of the fontanel over | the posterior margin of the pupil, continued backward as a triangular groove to near base of occipital process; interorbital area with the usual four smooth ridges; hu- meral process roughened, covered with skin; sides of the head with reticulating mucous canals. Eye 13 in snout, 53 in head, about 3 in interocular, 2 in interorbital space. Maxillary barbels about reaching gill-opening; men- tals extending about half way to gill-opening, the post- mentals not much longer. Upper jaw projecting; teeth villiform in the jaws, sub- granular or bluntly conical on the palate, small; no gran- ular teeth in the inner series of the mandible; the palatine patches smaller and more diverging than in spiaii. Gill-membranes united, joined to the isthmus. Guill- rakers 8+14. Pectoral pore moderate. Distance of dorsal spine from snout 25 in the length, the spine 13 in head, serrate on its posterior margin, granulate in front along basal half, becoming nearly smooth above. Space between dorsal and adipose fins 3 in the length; the adipose shorter than the dorsal fin, free posteriorly. Caudal forked, 4% in the length. Anal fina little longer than high, its highest rays about half length of head. Ventral fins about 2 in the head. Pectoral spine as long as the dorsal spine, but stronger, serrate on its inner margin, granular along its outer margin. Dorsal surface brown; sides and ventral surface sil- very; fins smutty. 88 CALIFORNIA ACADEMY OF SCIENCES. Head 3; depth 5; D. I, 6; A. 19. This species is known only from the type. One specimen, No. 7,670; length .285 m., Rio Grand do Sul. Senhor Albuquerque. 59. Tachisurus fissus. Arius fissus Cuy. & Val. Hist. Nat. Poiss. xv, 107, 1840 (Cayenne); Gunther, Cat. Fish. Brit. Mus. vol. vy, 172, 1864 (Cayenne); Bleeker, Silures de Suriname, 52, pl. iv, fig. 1, 1864 (Surinam). Galeichthys jissus Jordan, Proc. U. S. Nat. Mus. 1886, 558 (name only). Tachisurus fissus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 146 (name only). ¢ Arius puncticulatus Cuv. & Val. Hist. Nat. Poiss. xv, 108, 1840 (Buenos Ayres). i Habitat: Northern coast of South America. 60. Tachisurus melanopus. Arius melanopus Giinther, Cat. Fish. Brit. Mus. v. 172, 1864 (Rio Motagua); id. Fish. Cent. Am. vi, 1866, 393 (name only); Stein- dachner, SB. Ak. Wien, lxxiy, 1876, Ichthy. Beitr. iv (Panama). Galeichthys melanopus Jordan, Proc. U. 8. Nat. Mus. 1885, 366 (name only); Jordan, Proc. U. S. Nat. Mus. 1886, 558 (name only). Tachisurus melanopus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 146 (name only). Habitat: West Coast tropical America. 61. Tachisurus spixii Pimelodus albidus Spix, Gen. Spec. Pisce. 19, pl. vii, fig. 1, 1829 (Equatorial Brazil). Pimelodus spixii Agassiz in Spix. Gen. Spec. Pisce. 19, 1829. Arius spixii Cuv. & Val. Hist. Nat. Poiss. xv, 76, 1840 (copied). Tachisurus spixii Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 146 (Maranhao; Bahia; Rio Janerio; Para; Santos in Sao Paulo; Abrolhos). Arius arenatus Cuy. & Val. Hist. Nat. Poiss. xv, 106, 1840 (Cay- enne); Giinther, Cat. Fish. Brit. Mus. vol. v, 172, 1864 (cop- ied); Bleeker, Silures de Suriname 53, pl. iv, fig. 2, 1864 (Surinam). Galeichthys arenatus Jordan, Proc. U.S. Nat. Mus. 1886, 558 (name only). Arius laticeps Giinther, Cat. Fish. Brit. Mus. v, 171, 1864 (Brit. Guiana; Trinidad). Galeichthys laticeps Jordan, Proc. U.S. Nat. Mus. 1886, 559 (name only). Habitat: Santos to Surinam. SOUTH AMERICAN NEMATOGNATHI. 89 Tachisurus jissus seems to differ from this species in the proportions of the head. As the figure of spixii in this respect agrees with the description of A. arenatus C. & V., it is more probable that Agassiz figured this species and not fissus, as Dr. Ginther supposed. More- over, fissus has not yet been found in Brazil, and the P. spivw Agassiz is said to have come from equatorial Brazil. The name Pimelodus albidus is preoccupied, and the name spixii should supersede arenatus. We are unable to distinguish Arius luticeps Giinther from A. spixit Ag. and A. arenatus Cuv. & Val. Body compressed, especially toward the caudal fin; the depth greater than the width. Head narrowed forward, its greatest width 15 in its length, its greatest depth 13; width at the mouth 24 in the jength of the head. Top of the head granular in the young, the granules becom- ing more or less united in the adult, forming fine reticu- lating ridges, especially on the occipital process; occi- pital process longer than broad, with a blunt median ridge, the margins concave. Fontanel narrow, without interruptions, continued as a deep tapering groove to near the base of the occipital process; interorbital area with four ridges; opercles and humeral process rough- ened, covered with skin; sides of the head and snout with reticulating mucous canals. Eye 14-2 in the snout, 5-64 in the head, 27-3 in the interocular. Maxillary barbels varying in extent, from about the middle of the pectoral to the base of the ventrals; post- mental barbels extending to base of pectoral or to near its tip; mentals to edge of gill membrane or to beyond base of pectoral. Upper jaw projecting; lips more or less papillose; teeth, on the intermaxillary and the outer ones of the 90 CALIFORNIA ACADEMY OF SCIENCKS. mandible, villiform; the inner series of the q——> mandible and the palate with granular teeth; the palatine patches of teeth small, subovate, Wi \ sometimes contiguous in front. 32. Gill-membranes united, joined to the isthmus, not forming a free margin across it. Gill-rakers 6+11-138. Pectoral pore moderate. Distance of dorsal spine from snout 24-2% in the length; the spine 14-13 in the head, serrated on its in- ner margin, granular or almost smooth on its outer margin. Distance of adipose from the dorsal fin 34-33 in the length, the adipose fin shorter than the dorsal fin, free posteriorly. Caudal forked, the upper lobe slightly the longer, 4—5 in the length. Anal fin scarcely longer than high, its highest ray about 2 in the head. Ventral fin 12-2 in the head. Pectoral spine strong, about as long as the dorsal spine, serrated on its inner margin, granular or scarcely rough- ened on the outer margin. Color brownish above, sides and ventral surface silvery, sometimes with brown dots. Head 33-4; depth 5-54; D.1I, 7; A. 21. We have examined over 70 specimens measuring from .07—.24 m. from Maranhao; Bahia; Rio Janeiro; Para; Santos in Sao Paulo; Abrolhos, Brazil. The specimens from Para are much darker in color, the lips more papillose, the barbels longer than those of other specimens. The Santos specimens are ashy above, white below the lateral line, with rather large brown dots on sides, becoming fewer below. 62. Tachisurus firthii. Arius fiirthii Steindachner, SB. Ak. Wien, Ixxiv, 1876, Ichthyol. Beitr. iv, 29 (Panama); |Jordan & Gilbert, Bull. U.S. Fish Comm. 1882, 39 and 52 (copied). SOUTH AMERICAN NEMATOGNATHI. On Galeichthys firthii Jordan, Proc. U.S. Nat. Mus. 1885, 366 (name only). Tachisurus fiirthii Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 146 (Panama). Habitat: Panama. Body compressed posteriorly; profile slightly convex. Head broad, tapering forward, its greatest width 12-13 in its length; width, at the angle of the mouth, 23-24 in the head. Top of head densely covered with fine gran- ules. Occipital process about as long as broad, with a median ridge, emarginate on its sides and at tip; inter- orbital region with four smooth ridges, the inner bordering the fontanel, the outer extending obliquely backward from near the posterior nasal opening; sides of head and snout with vermiculating mucous pores.: Middle of the fontanel over the pupil. Eye strictly lateral, not entirely above the angle of the mouth, its center in front of the posterior end of the mandible, 2 in snout, 6-7 in head, 3}-4 in the distance between the eyes. Maxillary barbels thin, reaching to the middle of the pectoral or shorter, postmentals beyond base of pectorals, or sometimes not beyond edge of gill membrane; mentals to edge of gill-membrane or shorter. Jaws about equal, the upper rather thin; teeth on the intermaxillaries villiform; the mandible with villiform teeth except the inner two or three series which are granular; like the palatine patches irregular, suboval, sometimes the anterior end, sometimes the posterior and sometimes both ends pointed. Gill-membranes united, joined to the isthmus without a free margin. Gill-rakers long and slender, 4+-11. Axillary pore small; vertical series of pores present. Distance of dorsal from snout 27-2? in the length; the dorsal spine 12-31 in the head, on sides and front gran- ular, with small, sharp teeth on its inner margin; the 92 CALIFORNIA ACADEMY OF SCIENCES. first soft ray, little, if any, higher than the spine. Dis- tance of adipose fin from the dorsal 3-34 in the length, the fin longer than high, shorter than the dorsal fin. Caudal fin forked, the lobes rounded, 43 in the length. Anal little longer than high, the highest ray 2 in the length of the head. Ventrals short, 13-22 in head. Pectoral spine long and slender, 1-412 in the head, outer margin granular, inner margin with short teeth. Ashy above, white below. Head 34-37; depth 5-53; D. I, 7; A. 20. We have examined 15 specimens, the largest measur- ing .29m. The sexes do not differ externally. Panama. 63, Tachisurus variolosus. : Arius variolosus Cuy. & Val. Hist. Nat. Poiss. xv, 107, 1840 (Cay- enne); Giinther, Cat. Fish. Brit. Mus. vol. vy, 173, 1864 (copied). Galeichthys variolosus Jordan Proc. U. S. Nat. Mus. 1886, 558 (name only). Tachisurus variolosus Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d. Ser. vol. i, 1888, 146 (name only). Habitat: Cayenne. 64, Tachisurus multiradiatus. Bagrus (?) arioides Kner and Steindachner, SB. Ak. Wiss. Miinch, 1864, 227 (Rio Bayano, Panama) (not of Cuv. & Val.) Galeichthys arioides Jordan, Proc. U. 8S. Nat. Mus. 1885, 365 (name only). Arius multiradiatus Giinther, Cat. Fish. Brit. Mus, vol. v, 173, 1864 (copied); Kner & Steindachner, Abhandl. Bayr. Wiss. x, 47, 1865; Giinther, Fish. Cent. Am. vi, 1866, 393 (name only). Tachisurus multiradiatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. Vol. i, 1888, 146 (name only). Habitat: Western slope of Panama. 65. Tachisurus hypophthalmus. Arius hypophthalmus Steindachner, SB. Ak. Wien, Ixxiv, 1876, Ichthyol. Beitr. iv, pl. x (Panama); Jordan & Gilbert, Bull. U. S. Fish Com. 1882, 53 (Panama). Galeichthys hypophthalmus Jordan, Proc. U.S. Nat. Mus. 1885 (name only). Tachisurus hypophthalmus Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 146 (name only). Habitat: Panama. SOUTH AMERICAN NEMATOGNATHI. 93 66. Tachisurus gulosus. Tachisurus gulosus Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 146 (Panama). Elongate slender, the width scarcely less than the depth. Head broad, strongly depressed, the profile, to the tip of the snout nearly straight; greatest width of the head 13 in its length; depth at base of occipital process about 2 in the length of head. Occipital process about as broad as long, obtusely keeled. Fontanel very narrow, its center above the posterior margin of the eye, con- tinued as a groove backward. Posterior portion of the head rugose. Fontanel anteriorly margined by a bony ridge; a ridge extending obliquely between it and the eye; opercle faintly striate; sides of head and snout with reticulating canals. | Eye oblique, its center over the posterior end of the mandible and about on a level with the angle of the mouth, its diameter 24 in snout, 8 in head, 5 in the interocular distance. Maxillary and postmental barbels reaching to the middle of the pectoral or shorter, mental barbels to near the base of the pectoral. Jaws subequal, very thin; the intermaxillary band of teeth very shallow in the middle; vomerine teeth none; distance between palatine patches of teeth 1; diameters of the eye; the teeth obtusely conical, in about three series in front, in a single series behind; mandibulary band Va os of teeth little shallower than the inter- /” 33 maxillary band. Gill-membranes united, and with a free margin. Gill- rakers 13 times as long as the eye, 12+30. Pectoral pore large; vertical series of pores conspic- nous. ? Distance of dorsal from snout 2} in the length; dorsal 94 CALIFORNIA ACADEMY OF SCIENCES. 4 spine rather slender, high, 15 in head; distance of adi- pose from the alensal fin 8$ in the length; adipose fin as high as‘long, its posterior margin wholly free. Lower caudal lobe somewhat the wider, the upper lobe 13-14 in head. Anal ,fin emarginate, the highest ray 28 in the head. Ventrals truncate, 22-24 in head. Pectoral spine 13 in head, outer margin roughened, inner margin with recurved teeth. Bluish gray above, silvery below; dorsal and caudal slightly dusky, other fins plain; pelos faa Head 3}; depth 53-52; Br. 5; D. I, 7; A. 28. Two specimens, ¢ .285 m. “al cue m. Panama. Stein- dachner. SuBFAMILY CALLOPHYSIN ZZ. X. CALLOPHYSUS. Callophysus Miller & Troschel, Hore Ichthyol. iu, 1, 1849 (sp.) Callophysus Bleeker, Nederl. Tijdschr. Dierkunde i, 101, 1865 (macropterus). Pimelotropis Gill, Proc. Acad. Nat. Sci. Philad. 1859, 196 (lateralis = macropterus). Pseudocallophysus Bleeker, Nederl. Tijdschr. Dier- kunde, 1, 102, 1863 (ctenodus = macropterus). Type, Pimelodus macropterus Lichtenstein. This genus is distinguished by its dentition, having but one series of teeth in the lower and two series in the upper jaw. Inner series of teeth concealed or partly con- cealed,the teeth being much smaller than those of the outer series. The first dorsal and pectoral rays not spine-like, longer than the following rays. Adipose fin long. A wedge-shaped fontanel between the eyes, and a circular one at the base of the occipital crest. This genus has been divided into three different SOUTH AMERICAN NEMATOGNATHI. S15) genera, but the species are too suspiciously alike, and the genera are based on characters easily mistaken; so we do not feel any hesitancy in uniting the species and genera. If there are three genera, we have the anoma- lous fact that three closely related genera inhabit the Amazon, the species of which agree in everything but their generic characters. 67. Callophysus macropterus. : Pimelodus macropterus Lichtenstein, Wiede. Zool. Mag i, part iii, 59, 1819 (Brazil). Callophysus macropterus Miller & Troschel in Schomburek Brit. Guiana, 629, 1848 (Essequibo); Idem Hore Ichthyol. iii, 1, 1849. (Brazil; Guiana); Gtinther Cat. Fish. Brit. Mus. 137, 1864 (copied); Peters, MB. Ak. Berl. 470, 1877, (Apure); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 120 (Obidos; Lake Jose Assu; Cameta; Rio Negro; Santarem; Tonantins; Manaca- puru). Pimelodus ctenodus Agassiz, Gen. Spec. Pisce. 21, plate viii, a, 1829 (Equatorial Brazil); Cuy. & Val., Hist. Nat. Poiss. xv, 186, 1840 (copied); Castelnau, Anim. Nouy. Rares de l’Amer. de Sud. 35, 1855 (Amazon). Callophysus ctenodus Miiller & Troschel, Horw Ichthyol. iii, 2, 1849 (Brazil). ? Kner, SB. Ak. Wien, xxvi, 1857, 422 (loc.?); Giinther, Cat. Fish. Brit. Mus. 137 1864 (copied). Pimelodus insignis Schomburgk, Fish. Brit. Guiana, i, plate vi (not description). Pimelotropis lateralis Gill, Proc. Acad. Nat. Sci. Philad. 1859, 196 (Amazon). Callophysus lateralis Giinther, Cat. Fish. Brit. Mus. 136, 1864 (copied); Steindachner, SB. Ak. Wien, Ixxiv, 1876, Ichthyol. Beitr. v, 105. (Santarem; Tabatinga; Montalegre; Obidos; Rio Negro; Tonantins; Lake Manacapuru; Jose Assu); Cope. Proce. Am. Philos. Soe 17, 1878, 676 (Peruvian Amazon); Vaillant, Bull. Soc. Philom. series 7, iv, 1880 (Calderon). Habitat: Amazon and its tributaries and northward. We have examined 30 specimens measuring from .125 m. to .48m. They are from Obidos; Lake Jose Assu; Cameta; Rio Negro; Santarem; Tonantins; Lake Man- acapuru; Villa Bella; Serpa. The inner ray of the ventral fins is sometimes divided to the base, accounting for the number ‘‘7” of the ven- trals in P. ctenodus Agassiz. 96 CALIFORNIA ACADEMY OF SCIENCES. The description of macropterus given by Miller & Troschel agrees with the specimens before us except in the length of the head, but the expression ‘‘ bis zum Hinter- hauptfortsatz’’ probably means ‘‘ to the base of the oc- cipital process,” and not ‘‘ to its tip,” as Dr. Steindach- ner interprets it. If our interpretation is correct the measurements agree with our specimens. Width at the origin of the dorsal fin scarcely less than the depth, the body highest at the origin of the adipose fin, gradually tapering to the caudal. The profile forms a nearly straight, oblique line from the tip of the occip- ital process to the posterior nostrils, thence decurved for- ward; sometimes depressed above the eyes. Head rather broad, its greatest width being little less than its length in an example .43 m. long, about one-fourth less in a specimen .24 m. Top of head entirely covered with skin; very fine papille over the fontanel, on the back part of the head and on the shoulders. Eye 3-4 in the snout, 2-3 in the interorbital, 7-8 in length of head. Barbels all flattened, those of the maxillaries reaching about to the end of the adipose, or sometimes beyond the base of the caudal fin; mental barbels to or beyond the base of the pectorals, the postmentals to or beyond the base of the ventral fins. Upper jaw a little longer than the lower; teeth in two series on the intermaxillaries, the outer ones small, flattened, truncated or incisor-like, very conspicuous, the inner series of much smaller teeth so hidden by the skin as to be readily overlooked; a trenchant, bony ridge close behind the teeth on the man- dible, which might be mistaken for a series of minute teeth, the inner series of the upper jaw set into a simi- lar trenchant bone and moyable in it. Occipital process not, or scarcely meeting the dorsal plate, the process long, tapering, about twice as wide at SOUTH AMERICAN NEMATOGNATHI. Sit base as at tip. Fontanel extending from posterior nasal openings to posterior margin of eye; a circular fontanel at the base of the occipital process. First dorsal ray simple and its basal half as stiff as the b] ‘‘spines”’ of some species, but not separating into a spinous and soft portion, higher than the following rays, nearly equal to the length of the head in smaller indi- viduals, one-fifth longer in the largest specimen, the rays evenly and rather rapidly decreasing in height backward, the last about one-third the height of the first; the tips of the dorsal reaching past the origin of the adipose fin. Adipose fin long, 23-3 in the length. Caudal deeply emarginate; anal emarginate, the fifth ray highest, 13-1? in the head. Ventrals large, little shorter than the head. Pectoral longer than the head in most of the speci- mens, the outer ray not spine-like, longest, the follow- ing rays rapidly shortening. Color light brownish, sometimes uniform, sometimes with darker spots along the sides and on the adipose fin; other fins plain, sometimes smutty. Head 4-42; depth 5-6; Br. 8-9; D. 7; A. 12. SuBFAMILY PIMELODIN 2. DOUBTFUL SPECIES OF PIMELODIN. 67.1. Bagrus flavicans Castelnau, Anim. Amér. Sud, Poiss. 32, pl. xiii, fig. 2, 1855 (Amazon). Width of body equals its depth. Head large, flat, the skull not roughened; with an angle on each side behind. Dorsal spine large, curved, striate but not serrate. Adipose fin 91 in the total length. Pectoral spine large, curved, flattened, much longer than the dorsal spine, not serrated. Maxillary barbels shorter than the head. Depth (62 inghe total length. D..1, 6; A. (2, Unie form light yellow. Caudal scarcely emarginate. ri 98 CALIFORNIA ACADEMY OF SCIENCES. 67.2. Bagrus punctulatus Castelnau, 1. ¢. 33, pl. xiv, fig: 2. Deeper than wide. Head with striations. Adipose 4 in the total length; pectoral spine much longer than the dorsal spine and serrated. Eye nearer snout than to opercle. Maxillary barbels longer than the head. Anterior portion of the back with yellow spots. Caudal emarginate. Depth 4 in the total; width 63; D. I, 6; saith, ANALYSIS OF THE AMERICAN GENERA OF PIMELODINE. a. Teeth on vomer none; adipose fin long or moderate; top of head cov- ered with skin, not granulated. 6b. Snout pointed, produced considerably beyond the lower jaw; denti- tion of both jaws weak, consisting of narrow bands of loosely-set teeth. Adipose fin long; first ray of the dorsal and pectoral fins articulated, not pungent, as long as, or longer than the following rays; dorsal and anal fins emarginate. PIMELODINA XI. bb. Snout rather broad, scarcely produced beyond the lower jaw; teeth well developed. c. Barbels broad and long, and having a broad membranaceous border on the posterior margins; first ray of the dorsal and pectoral fins articulated, not pungent, as long as, or longer than any of the fol- lowing rays; dorsal and anal fins emarginate. Head entirely cov- ered with skin. PINIRAMPUS XII. cc. Barbels terete or flattened, little, if at all, margined. } d. Snout broad and produced, spatulate. First ray of the dorsal and pectoral fins articulated, not pungent; Occipital process a narrow ridge. Head entirely covered with skin; upper portion of the cheek, nasal and occipital surfaces reticulated. Dorsal and anal fins emarginate. LUCIOPIMELODUS XIII. dd. Snout not produced. e. Top of head entirely covered with skin. jf. Head as broad as long, or very little narrower; orbit without a free margin; occipital process reaching, or almost reaching the dorsal plate; adipose fin short. . PSEUDOPIMELODUS XIV. jf. Head longer than broad. g. Occipital process if present, not reaching the dorsal plate. h. Fontanel not continued behind the eye. RHAMDIA XV. hh. Fontanel continued to base of occipital process. 7. Orbit with a free margin; dorsal placed at least par- tially in front of the ventrals; dorsal and pectoral with a pungent spine. RHAMDELLA XVI. SOUTH AMERICAN NEMATOGNATHI. 99 #. Orbit without a free margin; eye small; dorsal with- out a pungent spine. j. A. 18-20. k. Caudal obliquely rounded. HEPTAPTERUS XVII. kk. Caudal widely forked.A CENTRONICHTHYS XVIII. jj. A. 8; dorsal entirely behind the ventrals. NANNOGLANIS XIX. gg. Occipital process narrow, reaching the dorsal plate; fontanel continued to base of occipital process, with a bridge across it, above the posterior margin of the eye. Dorsal and pectoral spines strong. Humeral process spine- like. D. TI, 6. PIMELODELLA XX. aa. Teeth on vomer none, or in minute patches. 1. Adipose fin longer than high. Head granulated above, naked or par- tially naked; occipital process usually tapering to the dorsal plate; fontanel not continued behind the eyes. Humeral process broad, not spine-like. PIMELODUS XXI. ll. Barbels compressed, ribbon-like; occipital process not reaching the dorsal plate (Gen. ? One species, agassizii, not seen). XXII. lil. Adipose fin higher than long; head compressed; snout produced, pointed; occipital process reaching the dorsal plate; fontanel con- tinued to near the occipital process. Humeral process long, spine- like. Anal rays 19 or 20. CONORHYNCHOS XXIII. aaa. Teeth on vomer in moderate or large patches or bands. m. Upper jaw little, if at all, projecting beyond the lower. n. Head more or less conical, about as high as wide. D. TI, 6. o. Top of head striate. Vomerine teeth in two separate patches which are remote from the palatine patches. Fontanel not con- tinued behind the eyes; occipital process reaching the large dorsal plate (closely related to PsEUDARIODES). BAGROPSIS XXIV. oo. Top of head granulated. Vomerine and palatine teeth form- ing a continuous band. Fontanel continued to near base of occipital process; occipital process scarcely reaching the dorsal plate. Barbels flattened. PIRAMUTANA XXV. nn. Head broader than deep, flattened, not conical. p. Barbels very broad, flattened, band-like. Palatine teeth none; vomer with a band of villiform teeth; jaws with very broad bands of teeth. Occipital process reaching the dorsal plate. Dorsal spine produced. PLATYNEMATICHTHYS XXVI. pp. Barbels not band-like. q. Head as broad as long. D.I, 7. Upper surface of head with vermiculating ridges. Vomerine patch of teeth large, penta- gonal, contiguous to the palatine patches. Occipital process large, semicircular, not meeting the reniform dorsal plate. Upper half of the adipose fin usually rayed. PHRACTOCEPHALUS XXVII. 100 CALIFORNIA ACADEMY OF SCIENCES. qq. Head longer than broad; inner surface of gill-cover usually with one or more dermal pouches. rv. D. I, 9-10. Teeth on the vomer in two transversely ovate patches, which are sometimes united—always remote from the small palatine patches. SCIADES XXVIII. rr. D. I, 6-8. s. Caudal long and lanceolate, the middle rays more than 4 of the length; adipose fin long and low, joined to the caudal. D.8. No evident occipital process. Dorsal placed over the ventrals. NEMUROGLANIS XXIX. ss. Caudal forked or rounded. t. Inner teeth of the upper jaw slender and freely movable, the band scarcely narrowed in the middle; teeth of vomer and palatines much smaller, (the palatine teeth smaller than those on the vomer), villiform. Adipose fin equal to or longer than the anal fin; caudal deeply forked, the lobes pointed. BRACHYPLATYSTOMA XXX. tt. Teeth all similar in the upper jaw and on the vomer. u. Head narrowed forward, its width at the mouth scarcely if any more than two-thirds its greatest width; adipose fin longer than the anal fin. v. Upper jaw little longer than the lower. Caudal rays normal. Intermaxillary band of teeth not or scarcely narrowed in the middle. Dorsal spine equidistant. from snout and middle of adipose fin. w. Palatine patches of teeth present but very remote from the vomerine patches; vomerine patches sep- arate in young, united in adult specimens, forming a /\-shaped patch. Caudal deeply forked, the lobes long and pointed. DUOPALATINUS XXXI. ww. Palatine teeth present, joined to the vomerine patches, together forming a shallow band immedi- ately behind the intermaxillary band of teeth. (Gen. ? One species, liitkeni, not seen.) XXXII. www. Palatine teeth none; vomerine teeth in two transverse ovate patches which are sometimes. united; intermaxillary band not narrowed in the middle. Caudal broadly rounded, or deeply emar- ginate. STEINDACHNERIA XXXIII. vv. Lower jaw produced beyond upper. Intermaxillary band of teeth much narrowed in the middle. Vomer- ine teeth in a single patch, much wider than the intermaxillary band; palatine patches closely con- tiguous to the yomerine patch. HEMISORUBIM XXXIV. SOUTH AMERICAN NEMATOGNATHI. 101 uu. Head depressed, its width at the mouth about equal to its greatest width. Adipose fin shorter than the anal; caudal forked, the rays much branched. Maxil- lary band of teeth much narrowed in the middle; teeth on the vomer separated on the median line, closely joined to the palatine patches, together forming, on either side, a figure somewhat like a comma. Top of head osseus; the occipital process produced, meeting or nearly meeting the dorsal plate; fontanel. extending from the middle-of the snout to behind the eyes and continued to the occipital as a groove. PSEUDOPLATYSTOMA XXXV. mm. Upper jaw greatly produced. x. Snout broad, the width at the mouth being equal to the greatest width of the head. Teeth of the upper jaw ina broad crescent- shaped patch. Barbels fleshy. y. Head abnormally depressed, the eyes strictly lateral. SORUBIM XXXVI. yy. Eyes superior. SORUBIMICHTHYS XXXVII. ax. Snout long and pointed, the width at the mouth 1} in the greatest width of the head. Teeth of the upper jaw in a long arrow-shaped patch; palatine patches longitudinally ovate, remote from the yomerine patch. Maxillary barbels very much longer than the body. PLATYSTOMATICHTHYS XXXVIII. XI. PIMELODINA. Pimelodina Steindachner, SB. Ak. Wien, lxxiy, 1876, Ichthyol. Beitr. v, 101 (flavipinnis). Type: Pimelodina flavipinnis Steindachner. This genus is characterized by its prolonged, sub- conical snout; by its dentition and by the nature of its fins. 68. Pimelodina flavipinnis. Pimelodina flavipinnis Steindachner, 1. ¢. 102, pl. 13, fig. 2 (Amazon near Para). Habitat: Para. 69. Pimelodina nasus. Pimelodina nasus Figenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. vol. i, 1888, 120 (Para). Habitat: Para. 102 CALIFORNIA ACADEMY OF SCIENCES. The differences between flavipinnis and nasus may be seen from the following: flavipinnis. Maxillary barbels beyond base of caudal. Adipose fin 2} in the length. Eye nearly six in head. Head compressed behind the eyes. Interorbital almost flat. Depth above ventrals 54-52 in the length. Greatest width of head 3(?) in its length, its width between maxillary barbels 3. Eye 1% in (Stirnbreite) interor- ~ bital. Entire upper portion of head covered with a net work. Distance of adipose from dorsal } the length of the dorsal. Pectoral lower than the dorsal. Upper half of body reddish-brown. Lower half of body yellow. Several rows of brown spots on upper half of body. Length to base of caudal .267 m. NaASUS. Maxillary barbels to end of adi- pose. Adipose fin 2 in the length. Eye 8 in head. Head not compressed behind the eyes. Head everywhere strongly convex in a cross-section. Depth above ventrals 44 in the length. Greatest width of head 1} in its length, its width between maxillary barbels 3. Eye 2} in the interorbital. Upper portion of head not coy- ered with a network. Distance of adipose from dorsal equals the diameter of the eye. Pectoral higher than the dorsal (damaged) equal to the head. Caudal lobes equal, longer than the head. A dark humeral area, otherwise plain yellow. Length to base of caudal .34 m. Elongate fusiform, the back compressed, trenchant; width, above the ventrals, 1? in the greatest depth. Head short, flat below, regularly convex above; profile very steep and almost straight. The thick skin obliter- ates the outlines of all the bones. Occipital process long and narrow, not reaching half way to the first dorsal ray, not to the dorsal plate. Eye smali, its anterior margin equidistant from the snout and the free border of the opercle; its diameter 4 in the snout, 8 in the head, 23 in the interocular. Posterior nasal opening a transverse slit. Maxillary barbels reaching to the end of the adipose SOUTH AMERICAN NEMATOGNATHI. 103 fin, or longer; mental and postmental barbels inserted in a straight line, the mentals reaching beyond base of the pectorals, the postmentals beyond their tips. Mouth entirely inferior, the snout projecting beyond it farther than one diameter of the eye; lower jaw weak, the teeth scarcely evident, in a very narrow band; the teeth of the upper jaw in a somewhat wider band. Gill-rakers 7-+17. Distance of dorsal fin from the snout 33 in the length; first dorsal ray high and slender, scarcely spinous, the free margin of the fin straight. Adipose fin beginning immediately behind the dorsal, its base 2 in the length. Caudal deeply forked, the lobes of equal length, longer than the head. Fourth anal ray highest, higher than the fin’s base, 2 in the length of the head. Ventrals inserted little nearer to the anal than to tip of the snout, 14 in the head. First pectoral ray scarcely spinous, slight serrations on its inner margin, about as long as the head. Axil and humeral region blackish, otherwise uniform yellowish. Head 53; depth 53; depth of peduncle 13; Br. 9; D. 7; A 12: XII. PmInrRAMPUS. Pinirampus Bleeker, Ichth. Arch. Ind. Siluri, 198, 1858 (pinirampu); id. Nederl. Tijdschr. Dierkunde, 1, 100, 1863 (typus=pirinampu). Pinirampus Giinther, Cat. Fish. Brit. Mus. vy, 135, 1864 (typus=pirinampu). Type: Pimelodus pirinampu Spix. This genus is characterized chiefly by its barbels which are broadly margined by a membrane. 104 CALIFORNIA ACADEMY OF SCIENCES. 70. Pinirampus pirinampu. Pimelodus pirinampu Spix, Gen. et Spec. Pisce. Bras. 20, pl. viii, 1829 (Brazil); Schomburgk, Fishes Guiana, part i, 183, 1841 (Guiana); Castelnau, Anim. Amér. Sud, Poiss. 35, 1855 (Amazon). Pinirampus pirinampu Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 121 (Cameta). Pimelodus pirinampus Cuy. & Val. Hist. Nat. Poiss. xv, 196, 1840 (Brazil); ? Kner, SB. Ak. Wien, xxvi, 1857, 416 (loc. ?). ? Pimelodus barbancho Humboldt, Ree. Obs. Zool. 11, 172, 1833 (Venezuela). Pinirampus typus Bleeker, Nederl. Tijdschr. Dierkunde, i, 100, 1863 (name only). Pirinampus typus Giinther, Cat. Fish. Brit. Mus. v, 135, 1864 (copied). Habitat: Rio Tocantins to Venezuela. From Dr. Steindachner’s statement that his Piniram- pus agassizii differed from pirinampu Kner only in hay- ing the postorbital portion of the head granulated, we judge that the specimens mentioned by Kner, |. ¢. (which Steindachner had for comparison) were not the piri- nampu Ag., for the specimen figured by Steindachner as agassizii is wholly unlike and generically distinct from specimens which agree in all respects with Agas- siz’s description of pirinampu. Two specimens .455 m. and .38 m. long, collected by Professor Louis Agassiz at Cameta. Body elongate, compressed to a ridge above, the caudal peduncle subcylindrical. Head depressed above the eyes, and forward to the posterior nasal openings, the profile rather steep from the occipital crest to the poste- rior margin of the eyes, thence less inclined, again de- curved from the posterior nostrils forward, the tip of the snout convex, the upper jaw little longer than the lower; the greatest width of the head (from opercle to opercle) one-fifth greater than the depth at base of the occipital process, and 1{ in its length; its width at the angle of the mouth 1{-14 in its length. Fontanel not continued behind the eye, but a groove extends to the occipital SOUTH AMERICAN NEMATOGNATHI. 105 process. Occipital process very narrow, extending to near the dorsal plate. Eye small, its center behind the middle of the head, its diameter 33—4 in the snout, 7$—9 in head, 24-3 in the interorbital. Maxillary barbels extending to, or nearly to the anal, mental barbels to the middle of the ventral fin, postmen- tal about as long as the maxillary barbels, all the barbels flattened and margined posteriorly, with a broad mem- branaceous border. Mouth wide, the gape extending more than half way to the eye; teeth of both jaws very minute, those of the mandible in a band one-half as deep as the diameter of the eye, inter- rupted in the middle; a strongly / < arched band of teeth in the upper jaw, seven times as wide as deep. Branchiostegal membranes separate to in front of the rictus; gill-rakers 7+17. Distance of the first dorsal ray from tip of snout 34-32 in the length. First dorsal ray not pungent, continued in a filament, which is equal in height to its distance from the snout, the rays rapidly decreasing in height, the last ray. one-third the length of the first divided ray. The distance of the adipose fin from the dorsal equals less than one-half the length of the latter. Adipose fin 24-23 in the length. Caudal lunate in the smaller specimen, the longest rays being shorter than the head; 43 in length of body; deeply forked in the larger specimen, the longest rays being one-third longer than the head, 52 in the length. Free margin of the anal emarginate, the third ray ex- tending beyond the tips of the last; more than half the length of the head. F4. 106 CALIFORNIA ACADEMY OF SCIENCES. Ventrals inserted behind the vertical from the last dor- sal ray, 13-1 in the head. Pectoral spine longer than any of the other rays, flex- ible and flattened, roughened in front, with straight teeth along its Inner margin. Color silvery below, hght brown above. Head 43-43; depth 5; depth of caudal peduncle 113; Bro eT 6: Awa ts XIII. LuctopimmELopus. Luciopimelodus Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. vol. i, 1888, 122 (paiz). Type: Pimelodus pati Valenciennes. First dorsal and pectoral rays not spinous, flexible and longer than any of the succeeding rays. Free margins of the dorsal and anal emarginate. Barbels scarcely margined. Head depressed. Snout elongate and spatu- late. Fontanel continued to above the eye, a circular depression at base of occipital process. Occipital pro- cess narrow, not touching the dorsal plate. ANALYSIS OF THE SPECIES OF LUCIOPIMELODUS. a. Dorsal plate present, concealed under the thick skin. Adipose fin 3-4 in the length, equal to its distance from the first dorsal ray or from the occipital process. Upper jaw projecting beyond the lower for not more than } the diameter of the eye. Eye 11 in head. pati 71. aa. No dorsal plate (pre-dorsal scute). Adipose fin 44 in the length, equal to its distance from the fifth dorsal ray. Upper jaw much project- ing beyond the lower. Eye 9 in head. Head covered with thin skin above, occipital process narrow. Maxillary barbels extending to the origin of the adipose fin, postmentals beyond the base of the pectorals. Eye nearly median. Caudal fin deeply forked. Coloration uniform. Head little less than 4 in the length. D. I, 6; A. 12 (Giinther). platanus 72. 71. Luciopimelodus pati. Pimelodus pati Valenciennes, Voy. d’Orbigny. pl. i, figs 7-9, 1847. Cuv. & Val., Hist. Nat. Poiss. xv, 176, 1840 (Parana; La Plata; Corrientes; Buenos Ayres); Kner. SB. Ak. Wien, xxvi, 1857, 416 (Forte de S. Joaquim, Rio Branco); Giinther, Cat. Fish. Brit. Mus. v, 128, 1864 (copied). SOUTH AMERICAN NEMATOGNATHI. 107 Luciopimelodus pati Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 122 (Buenos Ayres). Habitat: Pio Plata; Rio Branco near British Guiana. Width below the first dorsal spine less than the depth, tapering to a slender caudal peduncle. Head wide, its width 13 in its length; snout elongate, depressed, spatu- late, its width at the rictus 2 in length of head; upper half of cheek, nasal and occipital regions covered with reticulated skin. Occipital process a mere ridge. Eye behind the middle of the head, 5} in snout, 11 in head, 23 in interorbital, 3? diameters behind the rictus; mouth large, the upper jaw slightly projecting; width of the mandibulary band of teeth equal = / aes to the diameter of the eye; in- ‘ vA Y termaxillary band of teeth deep- oe "4 est at the outer edges which are JIS emarginate. Maxillary barbels somewhat compressed, reaching to tips of ventrals or beyond region of anal; mentals in- serted almost directly in front of the postmentals, reach- ing beyond base of pectoral; postmentals beyond base of ventrals. Gill-rakers short, scarcely overlapping, 4413. First dorsal ray slender, articulated on its upper half, but not branched, longer than the following rays, 1} in head; dorsal rays rapidly decreasing in height to the last, which is less than one-half as high as the first. Adi- pose fin 34-44 in the length. Caudal deeply forked, both lobes long and pointed, about equal to the head in length. Free margin of anal emarginate, the fourth ray high- est, 21 in head. Ventrals inserted behind the vertical from last dorsal _ ray, 13-13 in the head. 108 CALIFORNIA ACADEMY OF SCIENCES. First pectoral ray similar to the first dorsal ray, with short teeth on its posterior margin, not shorter than the longest ray, reaching a little beyond base of ventral in the larger specimen, 14 in head. Color light brown, silvery below, with dark spots along sides of body; a dark streak forward from eye; tips of dorsal dusky. Head 4; depth 7; Br. 9’or 10; BD. 7; A. 12. Fourteen specimens; Buenos Ayres. 72. Luciopimelodus platanus. Pimelodus platanus Giinther, Annals Nat. Hist. (5) vi, 10, 1880 (Parana, Rio Plata). Habitat: Rio Plata. This species is known only from the types. XIV. PSEUDOPIMELODUS. Pseudopimelodus Bleeker, Ichthol. Arch. Ind. Siluri, 196, 1858 (sp.); id., Nederl. Tijdschr. Dierkunde, 1, 1863 (bufonius=zungaro ). Batrachoglanis Gill, Ann. Lyc. Nat. Hist. N. Y. 1858 (raninus). Zungaro Bleeker, |. c. 101, 1863 (zungaro). Lophiosilurus Steindachner, SB. Ak. Wien, Ixxiv, 1876. Ichthyol. Beitr. v, 106 (alexandri). Type: Pimelodus raninus Cuy. & Val. Kye covered with skin; orbit without a free margin; dorsal plate well developed, usually joined to the oeccipi- tal process. Head broad, depressed. Dorsal and pec- toral spines well developed. Caudal rounded or emar- ginate. Habitat: Region between the Rio Plata and Rio Magdalena. ANALYSIS OF THE SPECIES OF PSEUDOPIMELODUS. a. Head very large; very much depressed, flat; mouth oblique; lower jaw projecting. (LoPpHIOSILURUS). b. ad. SOUTH AMERICAN NEMATOGNATHI. 109 Top of head fiat. Occipital process meeting the dorsal plate. Width of head little less than its length. Eye minute. Snout 5} in head. Intermaxillary band of teeth turned back at the outer edges. Maxil- lary and postmental barbels reaching to the posterior margin of the orbit. Adipose fin 3 in head. Pectoral spine serrate on both margins Caudal rounded. Dorsal fin short. Light brown with darker mark- ings. Head 3; D. I, 6; A. 11. alexandri 73. Head moderate, not greatly depressed; teeth villiform. Intermaxillary band of teeth without a backward projecting angle. (BATRACHOGLANIS). d. Dorsal plate longer than the occipital process. Serration of the pectoral spine strongest on its inner margin. A light bar across the nape from base of pectoral to base of pectoral. parahybe 74. dd. Dorsal plate as long as the occipital process. e. Inner and outer margins of the pectoral spine with equally strong teeth. Head at least as broad as long. Eyeoval. Maxil- lary barbels reaching to near tip of the pectoral, or shorter. Caudal rounded. Brown, marbled with darker; no distinct cross bands; dorsal, adiposeand anal fins blackish-brown with margins of white, the dorsal sometimes with a light cross band near its base; caudal dotted with black, and having, at its tip, a black band which is sometimes edged with white. The markings varia- ble. Head 33; D. I, 6; A. 10-11 (compiled). raninus 75. ee. Inner margin of pectoral spine much more strongly serrated than the outer margin. Head slightly longer than broad, naked above; occipital process short, about equal to dorsal plate, contigu- ous toit. Maxillary barbels reaching base of pectoral, the postmen- tals a little shorter. Eye very small, directed upwards, covered with skin. Intermaxillary band of teeth of moderate breadth, without prolonged lateral portion. Dorsal fin a little higher than long, with strong serrated spine. Length of adipose fin equals about three-fourths its distance from the dorsal. Pectoral spine very stout, depressed. Caudal forked. Pale brownish; head dotted with brown; a wide dark brown band encircling body and covering dorsal fin to a broad margin which is white; tail and caudal dark brown, a large light spot on each side the peduncle (sometimes confluent); two large white spots near base of cau- dal, tip of the fin whitish; adipose fin dark brown, whitish in front and behind; pectoral and ventral with one, anal with two dark brown cross bands. Head 34; depth 5-9; D. I, 6; A. 9 (Boulen- ger). pulcher 76. cc. Intermaxillary band of teeth with a backward projecting angle. (PSEUDOPIMELODUS.) - f. Teeth of the pectoral spine all short, those of the outer margin straight or retrorse, the spine blunt at theend. Depth of the inter- maxillary band of teeth at the middle 3-4 in its width. Outer mar- 110 CALIFORNIA ACADEMY OF SCIENCES. gin of the dorsal spine with recurved notches, the inner margin with short recurved teeth. Dorsal I, 6 or 7. zungaro 77. ff. Teeth of the pectoral spine scarcely shorter than the width of the spine, those of the outer margin extrorse, those on the inner margin retrorse; the spine ending inasharp point. Depth of the intermaxillary band of teeth near the middle 6 in its width. An- terior margin of the dorsal spine without notches, but with teeth which are straight or point toward the tip, the inner margin smooth. acanthochira 78. 73. Pseudopimelodus alexandri. Lophiosilurus alexandri Steindachner, SB. Ak. Wien, Ixxiv, 1876, Ichthyol. Beitr. vy, 106, pl. xv (? Amazon). Pseudopimelodus agassizii Steindachner, Fisch-Fauna des Cauca and Fliisse bei Guayaquil, 9, 1880 (name only). Habitat: Rio San Francisco. One specimen .24 m. Januaria. 74, Pseudopimelodus parahybe. 2. Pseudopimelodus charus Steindachner, SB. Ak. Wien, Ilxxiv, 1876, Siisswasserfische Siidéstl. Bras. iii, 74 (Rio Parahyba; Santa Cruz). Pseudopimelodus parahybe Steindachner, Fisch-Fauna des Cauca & Fliisse bei Guayaquil, 8, 1880, pl. i, figs. 2-2b (Rio Parahyba; Santa Cruz); Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. vol. i, 1888, 122 (Santa Cruz). Habitat: Rio Parahyba north to the Rio Doce. This species resembles very closely in color Pseudopim- elodus acanthochira Kigenm. & Kigenm. Width behind humeral process about equal to the depth, tapering to the caudal peduncle. Head depressed, about as wide as long, somewhat flattened above. Fon- tanels as in bufonius. Occipital process meeting the much longer dorsal plate. Head with large round pores. Eye very small. Width of mouth at the angles more than half the length of the head. Intermaxil- y lary band of teeth very narrow, without a C*- backward projecting angle. 36 Humeral process strong, about reaching the middle of the pectoral spine. Distance of dorsal spine from tip of snout 24 in the length, the spine smooth in front, about 2 in head. Distance of the adipose from the dorsal fin SOUTH AMERICAN NEMATOGNATHI. Laat longer than the base of the dorsal, about as long as the adipose. Caudal slightly emarginate, about as long as the head. Tips of anal rays reaching to the caudal. Pectoral spine stout, longitudinally striate, with very strong and long recurved teeth on the inner margin, minute teeth on the anterior margin. Color brown; a light scalloped band on opercles ex- tending across the nape, the band margined with white; usually a light spot under the dorsal spine, and a light band across the back immediately behind the dorsal fin, extending horizontally along sides, meeting again across caudal peduncle; dorsal fin sometimes uniform brown, but usually with a lght bar on the center of the last four rays; base of caudal dark, the tips dusky, light be- tween, dotted with darker; anal spotted with light and dark, a black spot at the base of the anterior rays. Head 33-32; depth 53-6; D. I, 6; A. 10-11. The very numerous examples examined are from Santa Cruz. 75. Pseudopimelodus raninus, Pimelodus raninus Cuy. & Val. Hist. Nat. Poiss. xv, 157, 1840 (Mana; Rio Janeiro); Kner, SB. Ak. Wien, xxvi, 1857, 421 (Barra do Rio Negro; Guaporé; Matogrosso); Giinther, Cat. Fish. Brit. Mus. v, 133, 1864 (Essequibo). Pimelodus (Pseudopimelodus) raninus Peters, MB. Ak. Berl. 1877, 470 (Apure). Pseudopimelodus raninus Steindachner, Flussfische Siidamerika’s iv, 4, 1883 (Rio Huallaga). Habitat: Rio Janeiro to Essequibo; Rio Huallaga and Matto Grosso. This species is known to us only from descriptions. 76. Pseudopimelodus pulcher. Pimelodus (Pseudopimelodus) pulcher Boulenger, Proc. Zool. Soc. London, March 1887, 276, plate xxi, fig. 1 (Canelos). Habitat: Eastern Ecuador. This species is known only from the types. 112 CALIFORNIA ACADEMY OF SCIENCES. 77. Pseudopimelodus zungaro. Pimelodus zungaro Humboldt, Obs. Zool. ii, 170, pl. xlvi, fig. 1, 1833 (Maranon); Cuv. & Val. Hist. Nat. Poiss. xv, 160, 1840 (copied); Schomburgk, Fish. Guiana, ii, 205, 1843 (Tomependa, Am- azon). ’ Pseudopimelodus zungaro Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. vol. 1, 1888, 122 (Goyaz). Pimelodus bufonius Cuy. & Val. Hist. Nat. Poiss. xv, 155, 1840 (Cayenne); Kner, SB. Ak. Wien, xxvi, 1857, 421 (Cujaba); Giinther, Cat. Fish. Brit. Mus. v, 133, 1864 (Rio Cipo tributary to the Rio das Velhas); Cope, Proc. Am. Philos. Soe. 17, 1878, 675 (Peruvian Amazons); Steindachner, Fisch-Fauna des Cauca and Fliisse bei Guayaquil, 7, pl. ii, figs. 1-lb. (Cauca). Pimelodus charus Cuy. & Val. Hist. Nat. Poiss. xv, 159, 1840 (Rio Sabara). Pseudopimelodus charus Liitken, Dan. Selsk. Skr. 1875, 180 (Rio das Velhas). Pimelodus mangurus Valenciennes, Voy. d’Orbigny, pl. i, figs. 4-6, 1847 (Rio Plata); Cuv. & Val. Hist. Nat. Poiss. xv, 156, 1840 (Brazil; Paraguay); Giinther, Cat. Fish. Brit. Mus. vy, 134, 1864 (copied). Zungaro humboldtii Bleeker, Nederl. Tijdschr. Dierkunde, i, 1863, 101 (name only). Habitat: Rio Plata, Rio Magdalena and the region between. We have examined four specimens of this species col- lected by Senhor Honorio at Goyaz. They measure .12, .14, .20, and .21 m. respectively, to the base of the caudal fin. One of these specimens has 7 dorsal rays and represents mangurus. Thus, like several species of Rhamdia the southern representatives of this species are seen to be lable to have more rays. The two forms, mangurus and bufonius, cannot be separated. There can be little doubt but that Pimelodus zungaro is identical with P. mangurus. The head and adi- pose fin of zwngaro are shaped as in a Pseudopimelodus; the eye is small and placed well forward. The dorsal and pectoral spines of mangurus are short, with a long, flexible prolongation and the skin covering them very thick, accounting for the statement that zungaro has no spiny rays. The ventral rays of mangurus are SOUTH AMERICAN NEMATOGNATHI. ES divided for more than half their length and the basal portion covered with very thick skin; unless the skin is removed, the rays, in large specimens, would appear to be more, rather than fewer than ten, the number stated by Humboldt. - Mangurus is covered with spots which are smallest on the head; if then, we attribute to the per- sonality of the artist the regularity of the spots in the figure of zungaro the identity of that species with mangurus rust be conceded. Width behind the head decidedly greater than depth, the body wedge-shaped, compressed at the caudal. Head as wide as long; frontal reduced to a very narrow slit between the frontal bones above the eyes; occipital pro- cess short, deeply notched at the tip, receiving the point of the much longer dorsal plate. Profile straight, nearly horizontal. Eye small; distance from the anterior edge of the eye to the tip of snout 3 in head, distance between the eyes 2 in head. Maxillary barbels not as long as the head; mental bar- bels reaching to the base of postmentals which extend to the edge of the branchiostegal membrane, or shorter. Jaws sub-equal; intermaxillary band of teeth very wide, its depth at the sym- physis 3—4 in its width, the teeth all villi- form, the inner ones slightly longer; mandibulary band of teeth very deep in ye front, tapering to a point backward, the widest part equal at least to 2 diameters of the eye. Humeral process very oblique, scarcely projecting be- yond the arch. Distance of dorsal spine from tip of snout 23-3 in the length. Dorsal spine perfectly straight, 2-2; in head, the 8 114 CALIFORNIA ACADEMY OF SCIENCES. entire anterior margin with recurved notches; the pos- terior margin with fine recurved teeth; the soft rays broken in the specimens. Distance of the adipose fin from the dorsal fin 13-13 times as long as the base of the dorsal. Adipose fin little longer than the dorsal fin. Tips of anal extending to the base of the caudal fin, beyond the vertical from tip of adipose fin. Ventrals inserted little or not at all behind the vertical from last dorsal ray, the rays divided for about half their length giving the appearance of having 10 or more rays. Pectoral spine scimitar-shaped, very blunt and broader at tip than at base, its inner margin with numerous short, blunt teeth near its tip; outer margin with similar teeth on its upper two-thirds, the basal third with longer, pointed, recurved teeth; in the adult the teeth become more or less obliterated; the spine is hollow, open at the tip, a flexible prolongation of the spine nearly as long as the spinous portion of the ray, which remains after the leathery ‘‘skin” of the spine is removed. The specimens are mutilated, the fins having their soft portions broken and the color washed out, except traces of small dark brown spots on top of the head in the larger specimen. Head 32; depth 57-67; depth of peduncle 73-83; Br. 8-9; D. I, 6 in the smallest, I, 7 in the three larger specimens; A. 9-10. 78. Pseudopimelodus acanthochira. Pseudopimelodus acanthochira Kigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. i, 122, 1888, (Gurupa; Tajapuru; Teffé; Jutahy). Habitat: Amazon from Para to Tabatinga. Depth behind the humeral process less than the width, tapering to the caudal peduncle. Head depressed, as wide as long. Frontal fontanel not continued behind the eye; an elongate occipital fontanel. Occipital process SOUTH AMERICAN NEMATOGNATHI. LS short, but meeting the longer dorsal plate. Large round pores on the head, most numerous on the snout and chin. Kye small, 25 in the snout, 84 in the head, 3 in the interorbital. Barbels all short, those of the maxillaries extending little, if any, beyond middle of the pectoral fin. Mouth more than half as wide as the length of the head; intermaxillary band of teeth with a sharp, back- ward projecting angle; mandibulary band of teeth shallower than the intermaxillary band, about as deep as one diameter of the 37. eye, scarcely deeper in front than at the NY, sides. Humeral process almost horizontal, strong, triangular, not reaching to the middle of the pectoral. Distance of the dorsal spine from end of snout 2} in the length. Dorsal spine toothed on the outer margin, stout, 2 in head, the rays higher, nearly uniform. Dis- tance of the adipose fin from the dorsal longer than the length of the dorsal. Adipose about as long as the dorsal fin. Caudal fin long, scarcely shorter than the head, rounded. Anal fin beginning and ending a little in front of the anterior and posterior ends of the adipose; the tips of the anal rays extending to the base of the caudal when laid back. Ventrals inserted under the vertical from the last dor- sal ray, 13-12 in the head. — Pectoral fin extending to the ventrals in young, much shorter in adult specimens; the spine 13 in the head, not much shorter than the longest ray, very much de- pressed, the teeth equally strong and long on the inner and outer margins of the spine, those on the outer mar- 116 CALIFORNIA ACADEMY OF SCIENCES. gin pointing toward the tip, on the inner margin toward the base. Abdominal region sometimes covered with small papille; anterior portion of the lateral line with larger papille or short tentacles. Lateral line sometimes not extending to the caudal fin. Chocolate color; head faintly marked with lighter; a zig-zag light bar from the gill-openings across the nape; dorsal dark brown, a short transparent bar on the lower half of the last four dorsal rays; base and posterior third of the caudal dark brown, the intermediate region trans- parent, with dark mottlings; anal dark brown, margined with white, and a white bar on the lower half of the last. five rays; ventrals and pectorals dark brown. Headis2; depth 5; Br. Sor 9;D: Ties Ae 10; No. 8183, one specimen .063 m. Gurupa. No. 8157, one specimen .045 m. Tajapuru. No. 7732, two specimens .093m. and .114m. Teffé, collected by Professor Louis Agassiz. No. 7332, one specimen .12m. Jutahy. Thayer Ex- pedition. XV. RHAMDIA. Pimelodus Lacépede, Hist. Nat. Poiss. v, (sp.) Pimelodus Cuvier, Regne Animal, 1817 (sp.) Pimelodus Giinther, Cat. Fish. Brit. Mus. v, 1864 (sp.) Pteronotus Swainson, Hist. Fish. Rept. Amph. 11, 309, 1839 (5-tentaculatus) preoccupied in Mollusks. Rhamdia Bleeker, Ichthyol. Arch. Ind. Siluri. 197, 1858 (sp.) . Rhamdia Bleeker, Nederl. Tijdschr. Dierkunde, i, 1863, 101 (quelenz). Pimelonotus Gill, Ann. Lyc. Nat. Hist. N. Y. iv, 391, 1859 (vilsont). Notoglanis Giinther, Cat. Fish. Brit. Mus. v, 186, 1864 (multiradiatus). SOUTH AMERICAN NEMATOGNATHI. 10 Type: Pimelodus quelen Quoy & Gaimard. The name Rhamdia seems to be the oldest available name for this genus. Notoglanis can scarcely be separ- ated on account of its ten dorsal rays as quelen and sapo sometimes have eight rays and hilarii occasionally has nine. Undoubtedly on account of insufficient descriptions some species have been placed here which ought to be placed in Rhamdella. The young of these species usually have the fontanel extending to the base of the occip- ital process with a bridge behind the eye and another in front of the occipital bone. The occipital fontanel sometimes remains in the adult as a shallow pit from which the ridges of the posterior portion of the head radiate. The postfrontal fontanel usually disappears entirely and in one specimen of quelen the frontal fonta- nel had also disappeared. Habitat: Rio Plata to Mexico and Western Peru. DOUBTFUL SPECIES OF RHAMDIA. 78.1. Pimelodus velifer Humboldt, Obsery. Zool. ii, 171, 1805 (Magdalena River). The substance of the de- scription is: Elongate; adipose dorsal covering the whole median part of the body. D.7; A. 10; V. 6. 78.2. Pimelodus argentinus Humboldt, 1. ¢. 171, 1805 (Magdalena River near Chilloa). White; back bluish. Maxillary barbels % as long as the body. D. 7; V. 5; pectoral and dorsal spines not serrated. 16 inches long. 78.3. Laukidi Schomburgk, Fish. Brit. Guiana, 1, 176, 1845. Rhamdialaukidi Bleeker, Ichthyol. Arch. Ind. 208, 1858 (copied). Body blue-black; belly whitish, finely spotted with black. Eyes placed in middle of head. Teeth a fine series, thickly set in both jaws. Ventrals midway between pectorals and anal. Air bladder heart-shaped. Reaches a length of 18-20 inches. De AG Ge Bie. er 118 CALIFORNIA ACADEMY OF SCIENCES. 78.4. Pimelodus grunniens Humboldt, Rec. Observy. Zool. 127, 1833 (Orinoco). Olivaceous above, spotted with black; white below. Head obtuse truncated, 4 in length of body; body compressed. All fins except caudal olivaceous, margined with red. Adipose dorsal small; barbels 6. The plaque of the neck large. Pectoral fins longer than the others. The Indians call it ‘‘ Carxaro.” 2 feet 2 inches. ANALYSIS OF THE SPECIES OF RHAMDIA. ‘ a. Occipital process and fontanel wanting. (2) 6. Dorsal fin more than twice as high as long, the first ray highest. Snout somewhat pointed; eye 5 in head, less than 2 in the inter- ocular, more than 2 in snout; posterior nasal opening nearer edge of mouth than to the eye. Upper jaw somewhat the longer. Maxillary barbels reaching anal, postmentals to last third of the pectoral fin. Dorsal spine smooth, ending ina filament; adipose fin very long; pectoral spine flattened, its inner margin serrated, teeth near tip of its outer margin, reaching to below beginning of the dorsal; a small pectoral pore. Caudal deeply forked, the upper lobe somewhat longer, 5 in the length. Uniform brown. Head 64 in the total lenetihs @DsG; Ase.) a (Kerrer,) . breviceps 79. aa. Occipital process present. c. Fontanel not continued behind the eye in the adult;* sometimes a. small round fontanel at the base of the occipital process. (RHAMDIA.) d. Mandible projecting beyond the intermaxillary. e. Head depressed. Dorsal and pectoral spines serrated. Opercle striated. Adipose fin very large; vent about the middle of body. Bluish-green with lighter spots; nearly white on belly and lower part of head. D.I, 6; A. 12; Br. 8. (Schomburgk.) schomburgkii 80. ee. Caudal portion of the body considerably deeper than the abdom- inal. Eye 2 in the interocular. Maxillary barbels extending beyond the caudal, postmentals to below middle of dorsal fin. Dorsal spine very slender, smooth, shorter than the pectoral spine; adipose fin 4.3 in the length; pectoral spine finely serrated on both edges, as long as the snout and half the orbit; supra-occi- pital process six times as long as wide, not reaching to the basal bone of the dorsal spine. Head 3} in the length; depth of cau- dal portion of body 6,3,; D. I, 6; A. 9. (Cope.) bathyurus 81. *Not examined in schomburgkii, bathyurus, foina, humilis, cinerascens, pentlandi, multiradi- atus, longicauda, dorsalis. SOUTH AMERICAN NEMATOGNATHI. LL dd. Jaws equal, or the upper jaw longer. f. Intermaxillary band of teeth of about equal depth throughout. g. No dark lateral band. h. Pores on the head not aggregated, or at most, 3 in a place; D. I, 6, except sometimes in quelen. i. Maxillary barbels extending beyond middle of adipose fin in the adult. j. Vent midway between the bases of caudal and pectoral fins; depth above first anal ray 44 in the length; depth of caudal peduncle 8 in the length; base of anal oblique. Maxillary barbels extending beyond base of caudal fin. obesus 82. jj. Vent midway between base of caudal fin and eye. Body rather elongate; depth above first anal ray about 6 in the length. Eye smaller, about 7 in length of the head. sebe 83. jjj. Bye large, 32 (in young)—6 in the head. sebe kneri 88a. vi. Maxillary barbels not extending to middle of adipose fin in the adult. k. D.I, 5-8. 1. Adipose fin 34-4 in the length. m. Eye situated in the middle of the head. Inter- ocular equal to one-half diameter of eye. Posterior nasal opening nearer eye than to the snout. Head flat, the eyes superior; occipital process very short. Maxillary barbels reaching tips of pectoral fins; post- mental barbels to base of pectorals. Dorsal spine little more than half as high as the rays; adipose fin originates above tips of ventrals, twice as longas the dorsal fin; caudal forked, upper lobe longer than the lower; anal under middle of adipose; pectoral spine strongly serrated, especially along its outer margin. Head more than 5 in the totallength. Br. 6; D. I, 6; A. 11. (Miller & Troschel.) foina 84. mm. Kye in the anterior half of the head. n. Distance of adipose from dorsal fin equals 2-3 its own length. Maxillary barbels extending on to root of ventrals; intermaxillary band of teeth 8 times as wide as deep; eye 2-3 in interocular, 6 in head; the eye occupies the third sixth of the head. Pectoral spine 2} in head, slightly serrated along both edges; caudal fin cleft to the base, the upper lobe more pointed than the lower. Head 4%in the length; depth 63; D. I, 6; A. 12. (Giinther.) humilis 85. 120 CALIFORNIA ACADEMY OF SCIENCES. nn. Distance of adipose from dorsal fin equals 4 its own length. Maxillary barbels extend nearly to origin of adipose fin; intermaxillary band of teeth 5-6 times as wide as deep; eye 24 in the interocu- lar. Pectoral spine less than half as long as the head. Head 4 in the length; depth about 5. Br. 7; D. I, 6; A. 13. (Giinther.) cinerascens 86. nnn. Distance of adipose from dorsal fin scarcely less than the length of the adipose. Maxillary barbels extending to base of ventrals; intermaxillary band of teeth 7 times as wide as deep; eye 2} in the interocular; pectoral spine two-fifths the length of the head, serrated along both edges. Head 4 in the length; depth 5%; D.I, 6; A. 12. (Giinther.) pentlandi 87. ll. Adipose fin 23-34 in the length; D. I, 6-8. quelen 88. kk. D.I, 10. Head granular (in dried specimens), its width not much less than its length. Snout semicircular. Hye in middle of head, 2+ in the interocular, 6 in the head. Maxillary barbels reach to the anal; postmentals to be- low dorsal fin. Dorsal rays subequal in height, the spine with longitudinal furrows, without serration; pec- toral well developed, the spine almost as long as the rays, roughened in front, serrated behind; caudal deeply forked, the upper lobe longer; adipose fin one-third longer than the dorsal fin. Brownish with lghter marbling. Head 5 inthe totallength. A.10. (Kner.) multiradiatus 89. hh. Pores on the head aggregated in several places or not. D. I, 7-8. Intermaxillary band of teeth about 4 times as wide as deep. sapo 90. hhh. Pores on the head aggregated in several places; the most conspicuous groups are between the eyes and on lower part of opercle. D.I, 7-9. Intermaxillary band of teeth about 7 times as wide as deep. hilarii 91. gg. A dark lateral band. Maxillary barbels not extending much beyond beginning of adipose fin. Pectoral spine short, about half as long as the head; top of head flat. wagneri 92. ff. Intermaxillary band of teeth deeper at the outer edges.* o. Head 6 in the length; depth 9-10. Dorsal spine nearer origin of anal than to tip of snout, the last dorsal ray nearer snout than to end of adipose fin; dorsal fin higher than long, the spine very weak. Adipose fin about 34 in the length. Lower jaw shorter; intermaxillary band of teeth about 4 times as wide *Young of sapo 90. SOUTH AMERICAN NEMATOGNATHI. ee as deep; eye equidistant between end of snout and gill-open- ing. Pectoral spine very feeble, not striate. Head naked above; occipital process short, widely separated from the dorsal spine. Maxillary barbels extend to base of ventrals, postmen- tals to base of pectorals. Depth of body above the anal equals the depth below the dorsal; caudal peduncle as deep as its free portion (behind adipose) is long; caudal fin deeply forked, upper lobe much produced, more than one-fourth of the total length. Brownish above, whitish below. Total length .175 m. D.I, 6; A. 10. (Boulenger.) longicauda 93. oo. Head 4-44 in the length. p. Adipose fin between 3 and 4 in-the length. q. Head three-fourths as wide as long; occipital process mod- erate; eye in anterior portion of the head, 8 in its length, its distance from the snout equals the interocular; depth of intermaxillary band of teeth more than one-sixth of its width. Maxillary barbels reach to or beyond middle of ventrals. Head 4 in the length; depth about 5; depth of caudal peduncle 11. Br. 6; D. I, 6; A. 9. (Gill.) dorsalis 94. qq. Inner margin of pectoral spine with strong teeth its en- tire length, outer margin smooth or slightly roughened near the base; vent equidistant between base of caudal and base of pectoral spine; a dark lateral band; adipose fin 3} in the length; maxillary barbel reaching to below the an- terior half of the dorsal. Anal rays 13. poeyi 95. pp. Adipose fin 2} in the length. Inner margin of pectoral spine roughened on its basal half, thence deeply grooved to the tip, outer margin with strong recurved notches on its upper two-thirds; vent much nearer to base of pectoral than to the caudal fin; no dark lateral band; maxillary barbel reaching beyond base of ventrals. tenella 96. 79. Rhamdia breviceps. Pimelodus breviceps Kner, SB. Ak. Wien, xxvi, 1857, 418 (Mara- bitanos); Gtinther, Cat. Fish. Brit. Mus. vy, 122, 1864 (copied). Rhamdia breviceps Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 124, 1888, (name only). Habitat: Marabitanos. This species is known from a single specimen in the museum at Vienna. If, as Kner states, this species really does not possess a fontanel nor an occipital process, it of course repre- sents a genus distinct from Rhamdia as here understood. apy CALIFORNIA ACADEMY OF SCIENCES. 80. Rhamdia schomburgkii. Pimelodus maculatus Schomburgk, Fish. Brit. Guiana, i, 175; 1843. Rhamdia schomburgkii Bleeker, Ich. Arch. Ind. 208, 1858 (Brazil; Guiana). Habitat: Guiana; Brazil. 81. Rhamdia bathyurus. Pimelodus bathyurus Cope, Proc. Am. Phil. Socr xvii, 674, 1878, (Pe- ruvian Amazons). Rhamdia bathyurus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 124, 1888 (name only). Habitat: Marafion. 82, Rhamdia obesa. Rhamdia obesa Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 124, 1888 (Teffé). Habitat: Teffé. Body short and deep; its greatest width less than its greatest depth; head short, its width 14 in its length; width at the angle of mouth 2 in its length, the head flat above, covered with very thin skin, the surface of the bones deeply furrowed, the striations radiating from the eyes and from the pit at the base of the occipital process. J ontanel a narrow fissure between the frontal bones. Occipital process very long, partly concealed by skin, reaching more than half way to the dorsal spine, to near the large, concealed dorsal plate. Pores scattered over the head. Eye round, 24 in snout, 64 in head, 2 in the interor- bital; its posterior margin in front of the middle of the head. Maxillary barbel (torn on one side) extending to the tips of the middle caudal rays; mentals to the middle of the pectoral; postmentals to half way between tips of pec- torals and base of ventrals. Jaws equal, mouth comparatively small, teeth of the mandible as usual; teeth of the upper jaw in a band which is shallowed and interrupted in the middle, its depth about 9 in its width. SOUTH AMERICAN NEMATOGNATHI. L235 Gill-rakers 3-+-9. Distance of dorsal spine from snout 2? in the length. d Dorsal fin shorter than high, the highest ray 12 in head. Distance of adipose fin from the dorsal equal to } the length of the latter. Adipose fin twice as long as the dorsal, 3 in the length. Caudal deeply cleft, the lobes longer than the head, about 3 in the length. Anal short and mgh, its free margin narrowly rounded; the highest ray 2 in head. V éninals inserted below the vertical from the last dor- sal ray, 14 in head. Pectoral spine strong, terete, with short hooks on the anterior margin near tip and short teeth nearly the en- tire length of the posterior margin; 14 head. A large dark humeral spot; fins all dusky; the usual pale bar on the dorsal fin near its base. Head 3}; depth below dorsal spine 5, above first anal ray 43; depth of caudal peduncle 8; Br. 7; D. I, 6; A. 10. Type: No. 7518. ‘Teffé. Agassiz. Length .26 m. 83. Rhamdia sebe. Seba iii, plate 29, fig. 5. Rhamdia ou bagre de Rio Maregrave, 149. Mystus No. 83, Gronow, Mus. Ichthyol. i, 34; No. 384, Zoophyl. 125. Pimelodus sebe Cuy. & Val. Hist. Nat. Poiss. xv, 169, 1840 (Suri- nam; Cayenne; Rio Janeiro; Buenos Ayres); Hyrtle, Denk. Ak. Wien, xvi, 1859, 16 (vertebrae 11+2+-26); Quoy & Gaimard, Voy. de Freycinet, Zool. 228, plate xlix, figs 3 and 4; Giinther, Cat. Fish. Brit. Mus. v, 119, 1864, (Demarara; British Guiana; Brazil). Pimelodus (Rhamdia) sebe Steindachner, SB. Ak. Wien, Ixxiv, 1876, Siisswasserfische stidéstlichen Brasiliens, i1i, 68 (Dema- rara; Essequibo; St. Martha, mouth of the Magdalena); Steindachner, Fisch-Fauna, Magd. Stromes, 17, 1878 (Magda- lena); Steindachner, Fisch-Fauna des Cauca & Fliisse bie Guayaquil, 7, 1879 (Cauca). Rhamdia sebe Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 126, 1888, (Tonantins; Gurupa; Rio Janeiro; Bahia; Xingu; Santa Cruz; Cudajas; Sao Matheos; Rio Doce; Serpa; Taba- tinga; Goyaz; Para; Teffé; Surinam; Villa Bella). 124 CALIFORNIA ACADEMY OF SCIENCES. Pimelodus stegelichii Miller & Troschel, Hore Ichthyol. iii, 3, 1849 (Surinam); Giinther, Cat. Fish. Brit. Mus. v, 121, 1864 (Dema- rara; Surinam). Pimelodus musculus Miller & Troschel, Hore Ichthyol. iii, 4, 1849 (America). Pimelodus holomelas Giinther, Ann. & Mag. Nat. Hist. xii, 1863, 442 (Essequibo); Giinther, Cat. Fish. Brit. Mus. v, 120, 1864 (Essequibo). Pimelodus milleri Giinther, Cat. Fish. Brit. Mus. vy, 119, 1864 (River Capin, Para; Surinam). Habitat: Rio Janeiro to Rio Magdalena; Amazons to Tabatinga. Width below the first dorsal ray equals the depth; body strongly compressed near the caudal; head flat above, the sides of the head sometimes making a decided angle with the top, sometimes sloping without any distinct angle; greatest width of the head about 14 in its length, its width at the angle of the mouth 2 in itslength. Top of the head covered with a usually thin skin, the surface of the bones smooth in the young, becoming roughened with age. Fontanels in the young, three. In speci- mens .10 m. long they are reduced to a narrow slit in the center of the occipital bone: this remains in the adult as a circular depression; a small circular opening above the posterior margin of the eye, which usually disappears with age; and the usual frontal fontanel, per- sistent in all stages of growth, but reduced to a narrow slit with age. Occipital process extending half way to the dorsal spine. Large pores regularly distributed about the head, sometimes innumerable pores on cheeks. Eye sometimes circular, sometimes elliptical. In speci- mens .10m. the eye measures 2 in snout, 13 in interocu- lar, 5 in head; in specimens .25 m. 3 in snout, 3 in in- terocular, 74 in head. Maxillary barbels either compressed or filiform, ex- tremely variable in Jength; when shortest extending to the middle of the adipose fin—when longest extending beyond the caudal. They are longest in specimens from .10 to .15 m. and are shorter in both young and adult. SOUTH AMERICAN NEMATOGNATHI. 125 The postmentals vary in length, their tips extending to middle of the pectorals or as far as the middle of the ventrals. Sometimes the barbels are much shorter on one side than on the other. Mouth wide, terminal, the jaws usually équal, but the lower sometimes considerably shorter. Teeth of the lower jaw as usual, those of the upper in a very shallow interrupted band; its depth 7-10 in its width. Gill rakers long and slender, simple, 2-8. Distance of dorsal fin from snout 2? to 3 in the length; dorsal spine slender, pungent, with a few notches near the tip in front; 2-25 in head; highest dorsal ray 14-13. Distance of adipose fin from the dorsal fin variable, always less than the length of the dorsal; adipose fin 24-3 in the length. Caudal cleft to near its base, the lower lobe broader and rounded, 33-43 in the length. Anal higher than long, the tips reaching to below the vertical from the end of the adipose or sometimes two diameters of the eye shorter. Ventral inserted below the vertical from the last dorsal ray, 13 in head. Pectoral spine roughened with minute straight teeth behind, and recurved teeth near the tip on the anterior margin, 13-13 in head. Color brown, a darker humeral spot; fins all dusky; dorsal with the usual light transparent band, sometimes with a black spot between the last two rays. The color sometimes uniform black; sometimes very light brown. Head 4-43; depth 43-7; depth above first ray 53-6; depth of caudal peduncle 8-10. Brits Dee Ga An 9-13: The specimens examined, more than sixty, are from Tonantins, Gurupa; Rio Janeiro; Bahia; Xingu; Santa Cruz; Cudajas; Sao Matheos; Rio Doce; Serpa; Taba- 126 CALIFORNIA ACADEMY OF SCIENCES. tinga; Goyaz; Para. The three Para specimens have a shorter and less angular head; head 43 in the length. Teffé have the head more pointed; Surinam: maxillary barbel much shorter on one side than on the other; Rio de Janeiro head angular; Villa Bella .09 m. spec. nov.? head 3$ in the length; ventrals almost to anal; pectoral spine 1 in head; maxillary barbels beyond base of caudal; adipose 23. 83a. Rhamdia sebe kneri. Pimelodus sebe Kner, SB. Ak. Wien, xxvi, 417, 1857, (Marabitanos); not P. sebe C. & V. Pimelodus (Rhamdia) kneri, Steindachner, SB. Ak. Wien, Ixxiv, 1876, Siisswasserfische stidéstl. Bras. iii, 73, foot note (Cujaba). Rhambia sebe kneri Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 126, 1888 (Tabatinga; Jutahy). ?Pimelonotus vilsoni Gill, Ann. Lyc. Nat. Hist. N. Y. vi, 391, 1858 (Trinidad). ?Pimelodus wilsonit Giinther, Cat. Fish. Brit. Mus. v, 122, 1864 (copied); Jordan, Proc. U. 8. Nat. Mus. 1886, 559 (name only). Rhamdia queleni Bleeker, Silures de Suriname, 75, 1864 (Surinam). Habitat: Upper Paraguay and northward. The specimens examined are from Tabatinga and Jutahy. This variety differs from sebw only in the size of the eye. ‘‘ Kye in young 3? in head,” in specimens .27 m. long, 53; ‘‘ head in young 5 in the length,” in adult 4; adipose fin ‘‘in young less than 2 in the length,” in adult 23-3. Jaws equal or the lower shorter. » P. vilsoni seems to differ from kneri only in having a projecting lower Jaw. 84, Rhamdia foina. Pimelodus foina Miller & Troschel, Schomburgk, British Guiana, 628, 1848 (Takutu); Miller & Troschel, Hore Ichthyol. iii, 5, 1849 (Guiana); Giinther, Cat. Fish. Brit. Mus. vy, 130, 1864 (copied). Rhamdia foina Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 126, 1888 (name). Habitat: Guiana. 85. Rhamdia humilis. Pimelodus humilis Giinther, Cat. Fish. Brit. Mus. v, 129, 1864 (Venezuela); Cope, Proc. Am. Philos. Soc. xvii, 1878, 674 (Peru- vian Amazon). SOUTH AMERICAN NEMATOGNATHI. 127 Rhamdia humilis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i 126, 1888 (name only). Habitat: Marafion to Venezuela. ’ 86. Rhamdia cinerascens. Pimelodus cinerascens Gunther, Proc. Zool. Soc. Lond. 1860, 237, pl. 10, fig. A (Esmeraldas); Giinther, Cat. Fish. Brit. Mus. v, 130, 1864 (Guayaquil; Esmeraldas); Steindachner, Fisch-Fauna des Cauca & Fliisse bei Guayaquil, 44, 1880 (Rivers near Guaya- quil). Rhamdia cinerascens Figenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 126, 1888 (name). Habitat: Western slopes of Ecuador. 87. Rhamdia pentlandi. Pimelodus pentlandi Cuv. & Val. Hist. Nat. Poiss. xy, 183, pl. 435, 1840 (tributaries of Lake Titicaca); Hyrtle, Denk. Ak. Wien, xvi, 1859, 16 (vertebre 12-+4-+ 24); Giinther, Cat. Fish. Brit. Mus. y, 129, 1864 (types); Steindacher, SB. Ak. Wien, Ixxiv, 1876, Ichthyol. Beitr. iv, 48 (Monterico; Tullumayo); Stein- dachner, Flussfische Stidamerika’s, iv, 25, 1882 (Rio de Huam- bo.) Rhamdia pentlandi Eigenm. & Higenm. Proc. Cal. Acad., 2d Ser. i, 126, 1888, (name). Habitat: Peruvian Andes. 88. Rhamdia quelen. Pimelodus quelen Quoy & Gaimard, Voy. Uran. Zool. pl. 49, figs. 3-4, 1824. Rhamdia quelen Eigenm. & EKigenm. Proc. Cal. Acad. 2d Ser. vol. i, 126, 1888 (Santa Clara; Rio Mucuri; Juiz de Fora; Cam- pos; Rio Jequitinhonha; Mendez; Rio de Janeiro; Macacos; Sao Matheos; Rio Parahyba; Cannavierias; Rio Grande do Sul). Pimelodus queleni Giinther, Cat. Fish. Brit. Mus. v, 123, 1864 (Bra- zil). Rhamdia queleni Bleeker, Nederl. Tijdschr, Dierkunde, i, 101, 1863 (name only). Pimelodus (Rhamdia) quelenit Steindachner, SB. Ak. Wien, Ixxiv, 1876, Siisswasserfische siidéstl. Bras. iii, 64 (Rio Parahyba, near Juiz de Fora; Campos; Rio Doce; Porto Alegre; Cannavierias; Amazon, near Para; Bahia). Heterobranchus sextentaculutus Agassiz, Gen. Spec. Pisce. Bras. 28, plate 11 (12 in. long, loc. ?) Pimelodus sellonis Muller & Troschel, Hore Ichthyol. iii, 2, 1849 (Brazil). ?Pimelodus bahianus Castlenau, Anim. de l’Am. du Sud, 35, pl. xvi, fig. 2, 1855 (Bahia). 128 CALIFORNIA ACADEMY OF SCIENCES. Pimelodus sebe Kner, SB. Ak. Wien, xxvi, 417, fig. 19, 1857 (Mara- bitanos). Silurus sapipoca (Natterer MS.) Kner, 1. ¢., 418. Pimelodus wuchereri Giimther, Cat. Fish. Brit. Mus. v, 123, 1864 (Bahia). Pimelodus (Rhamdia) queleni cuprea Steindachner, SB. Ak. Wien, lxxiv, 1876, Siisswasserfische stidéstl. Bras. iii, 65 (Juiz de Fora). Pimelodus (Rhamdia) cuyabe Steindachner, 1. ¢., 76, foot-note (Cuy- aba). Habitat: Rio Plata, north to the Amazon. This species seems to be most abundant southward; it is subject to many variations. It is very closely related to Pimelodus seba C. & V.; the only constant difference is the length of the barbels. Heterobranchus sextentacu- latus Ag. agrees better with quelen than with any other known species. The plate of Pimelodus bahianus Castel- nau probably represents one of the variations of quelen. We give a description of the species, and then add the variations with the localities. Width of body less than its depth, strongly compressed towards the tail. Head flat above, the sides sometimes making an angle, sometimes not; greatest width of head 4-1} in its length; width at the angles of the mouth 2 in head; head covered with (usually) thin skin, the sur- face of the bones either smooth or striate. Fontanel as in sebw. Occipital process extending about half way to the dorsal spine; large pores distributed in definite re- gions about the head. Kye 24-2? in snout, 6-7 in head, 23-2} in interocular space. Maxillary barbels extending to the posterior third of the adipose in young, much shorter in adult; mentals not to pectoral, postmentals beyond base of pectoral. Mouth wide, terminal; teeth of the lower jaw as usual, those of the upper jaw ina band of uniform depth which is 63-8 in its width. Gill-rakers sometimes simple, some- times profusely branched, 2--10. SOUTH AMERICAN NEMATOGNATHI. 129 Distance of dorsal spine from tip of snout 27-3 in the length. Distance of adipose from dorsal variable, always much less than length of dorsal. Adipose fin 2-34 in the length. Caudal deeply forked, the lobes rounded, 43-5 in the length. Anal either higher than long or longer than high, the tips about reaching as far as the end of the adipose fin. Ventrals below the vertical from last dorsal ray, 1}-14 in head. Pectoral spine strong, its posterior mar- gin with short teeth; with recurved hooks near tip of anterior margin, 1? in head. Color from uniform black to light brown or coppery. Head 4-44; depth 4-63; depth above first anal ray 5-6; depth of caudal peduncle 8-94; D. I, 6-8; A. 10-12; Br. 6-7. The specimens examined are from Santa Clara; Rio Mucuri .11 m. long: light-brownish mottled with darker; adipose fin, 3-34 in the length; Juiz de Fora: light brownish, adipose fin margined with black; maxil- lary barbels not extending to the end of the dorsal; Campos: colored as the Juiz de Fora specimens; depth 5-6 in the length; Rio Jequitinhonha; Mendez: adipose fin 22 in the length beginning immediately behind the dorsal; Rio de Janeiro: depth 43-63; the largest speci- men has the head depressed between the eyes; maxillary barbels not extending to the end of the dorsal; depth of the intermaxillary band of teeth 8 in its width; fontanel none, the region replaced by honeycomb structure; Sao Matheos: agrees with Dr. Giinther’s description in all respects; the gill-rakers are profusely branched; Rio Mucuri: entirely black, dorsal rays 7; maxillary barbels reach to the adipose fin; Macacos: 11 specimens, 4 of them with D. I, 7; Rio Parahyba: 3 specimens, D. I, 7 in one specimen; Cannavierias .31 m. has a very deep 9 130 CALIFORNIA ACADEMY OF SCIENCES. body and rather small eyes; Rio Parahyba: reddish brown with dark markings, caudal black; Rio Grande do Sul, Emperor’s collection, one specimen, has D. I, 7. 89. Rhamdia multiradiatus. Pimelodus multiradiatus Kner, SB. Ak. Wien, xxvi, 414, 1857, (Borba on the Rio Madeira; Forte do Rio Branco on the Rio Facutu). Notoglanis multiradiatus Giinther, Cat. Fish. Brit. Mus. v, 136, 1864 (copied). Rhamdia multiradiatus Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 126, 1888 (name). Pimelodus arekaima Schomburgk, Fish. Brit. Guiana, part i, 178 (not plate v), 1841 (Upper Essequibo). Habitat: Amazon and its tributaries, and northward. 90. Rhamdia sapo. Pimelodus sapo Valenciennes, in Voy. d’Orbigny, ix, Atlas ii, pl.ii, figs. 6-8, 1847; Cuv. & Val. Hist. Nat. Poiss. xv, 179, 1840 (Bue- nos Ayres); Kner, SB. Ak. Wien, xxvi, 417, 1857 (loc.?); Gun- ther, Cat. Fish. Brit. Mus. v, 132, 1864 (Rio Plata); Steindach- ner, SB. Ak. Wien, lx, 1869, Ichthyol. Notiz. ix, 5 (Montevi- deo); Hensel, Wiegm. Arch. 1870, 1, 69 (Guahyba). Pimelodus (Rhamdia) sapo Steindachner, SB. Ak. Wien, lxxiv, 1876, Susswasserfische siidéstl. Bras. iii, 60 (La Plata; Rio Grande do Sul). Rhamdia sapo Figenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 126, 1888 (Rio Grande do Sul). Habitat: Rio Plata; southern Brazil. Five specimens from .18-.405 m. in length, from the Rio Grande do Sul, the Emperor’s collection. Body rather robust, its greatest width less than its greatest depth. Head elongate, flat above, its greatest width 13 in its length; width at the angle of the mouth 2 in head; the head entirely covered with skin; fontanel not continued behind the eye; occipital process small, imbedded. Large patches of radiating pores between and behind the eyes, on the upper and lower angles of the opercle; the patches with fewer pores in some individuals; in the adult the pores on top of the head become detached and circular; minute, inconspicuous pores scattered everywhere about the head. SOUTH AMERICAN NEMATOGNATHI. 1Sf Eye nearly median, slightly nearer tip of snout than to edge of opercle, 54-8 in head, 2-3) in snout, 1)-23 in interorbital. Maxillary barbels extending past middle of adipose fin in the young, scarcely to end of dorsal in adult; post- mentals little beyond base of pectorals. Jaws subequal, the upper sometimes a little longer; width of intermaxillary band of teeth 22-3 in head, the band rather deep, its depth 4-43 in its width; mandibulary band very aie deep in front, tapering to a fine point. Lips conspicuously papillose. Distance of dorsal spine from snout 2} in the length; the length of the spine 2-2) in the head, the base of the fin much longer than the highest ray. Distance of adi- pose fin from the dorsal 3-} the dorsal’s base. Adipose fin 3-34 in the length. Caudal deeply forked, the lower lobe broader, 1} in head. Tip of anal ray scarcely reaching the vertical from the end of the adipose fin. Ventrals 13-21 in head. Pectoral spine stout, recurved teeth on its anterior margin, strongest near the tip of the spine, 25-2? in head. Color uniform brown. Head 33-34; depth 43-63; depth of caudal peduncle 9-103; D. I, 7-8; A. 11-12. 91. Rhamdia hilarii. Pimelodus hilarii Cuvier & Valenciennes, xv, 180, 1840 (Rio San Francisco; Montevideo); Ginther, Cat. Fish. Brit. Mus. vy 132, 1864 (copied). Rhamdia hilarii Liitken, Dan. Selsk. Skr. 175, with figure, 1875, (Rio das Velhas); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1, 126, 1888 (Bon Jardin). : Habitat: Rio San Francisco and its tributaries; Porto Alegre south to Rio Plata. ’ 132 CALIFORNIA ACADEMY OF SCIENCES. Width below the dorsal spine about equal to its depth, tapering to the caudal peduncle. Head rather short and broad, its width 13 in its length. Skin of the head very thin, the surface of the bones little if at all roughened; snout flat and broad, its width at the angle of the mouth 2 in the head. Fontanels in the young three: 1, a small round one at the base of the occipital process— present in the largest specimen; 2, a small one be- hind the orbital bridge—obliterated in the adult, and 3, the usual one between the frontal bones. Occipital process continued to half way to dorsal spine. Numer- ous groups of pores about the head; a group behind the posterior nasal opening, a larger group between the middle of the eyes; a group above the posterior margin of each eye and a group behind each of these; a group. behind the eye; one at the upper angle of the opercle another near its lower angle, other groups below the eye and elsewhere. Eye in smallest specimen 13 in snout, 5 in head, 13 in interorbital; in largest specimen 24 in snout, 63 in head, 2 in interorbital. Maxillary barbel extending scarcely beyond the end of the dorsal fin in the largest specimen, to its middle in some of the smaller specimens; mental barbels reaching to the base of the pectoral, postmentals to the middle of the pectoral. Mouth wide terminal; in the largest specimen the jaws are equal, in the smaller the upper jaw projects. Teeth of the lower jaw as usual; those of the upper jaw in a band of uniform depth, 7 times wider than deep, interrupted in the middle. Gill membranes separated to below the angle of the mouth; gill-rakers 2-4-7. Distance of the dorsal fin from tip of snout 3 in the length; the fin not longer than high;-highest ray 13-13 SOUTH AMERICAN NEMATOGNATHI. 133 in the head; the rays nearly of the same height. Distance of the adipose fin from the dorsal $—} the length of the latter. Adipose fin 23-3 in the length. Caudal deeply cleft, the lower lobe wider and slightly longer, little shorter than the head. Anal shorter than high; its free margin rounded; its longest ray about half as long as the head. Ventral fins inserted under the vertical from the seventh or eighth dorsal ray, 1? in the head. Pectoral spine slender, with strong recurved hooks on its anterior margin near the tip, and much weaker teeth along its posterior margin; its length 2 in head, longest ray 13. Color brownish with indistinct darker spots and mot- tlings; caudal and anal dusky, the membrane of the dorsal thickened at the base, a transparent bar above it, the upper half of the membrane dotted with dark points. Head 4; depth 6-7. Caudal peduncle 10. Br. 7; D. 7-9; A. 12. One specimen .21 m. and another .095 m. have 9 dorsal rays, one .107 m. has 7 dorsal rays, the rest .12 m. -085 m. and .07 m. have 8 dorsal rays each. Bon. Jar- din on the Rio San Francisco; Porto Alegre, D. I, 7. Four specimens, locality unknown, have 7 dorsal rays each, one has 8. 92. Rhamdia wagneri. Pimelodus cinerascens Kner & Steindachner, Abh. Bay. Ak. x, 49 (not of Gunther). Pimelodus wagnerit Giinther, Fishes Cent. Am. 393 and 474, 1866 (Pacific and Atlantic rivers of Panama); Steindachner, Fluss- fische Siidamerikas, i, 14, 1879 (Mamoni river near Chepo). Rhamdia wagneri Higenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 126, 1888 (Gorgona; Rio Chagres; Rio Obispo; Turbo; Atlantic coast Central America). Rhamdia bransfordii Gill, Proc. Acad. Nat. Sci. Philad. 1876, 337 (Panama). Habitat: Eastern and western slopes of Central America. 134 CALIFORNIA ACADEMY OF SCIENCES. The Rhamdia bransfordii Gill differs from specimens of wagnert only in color and their identity can scarcely be doubted especially as the color is frequently oblit- erated in alcohol. Width of body behind the pectorals about equal to its depth, much compressed toward the tail. Head flat above, its sides almost vertical, its greatest width 13-12 in its length. Profile from tip of occipital process to snout nearly straight. Width of the snout at the rictus about 2in the head. Occipital process narrow, extending about half way to the dorsal spine. Bye 23 in snout, 7 in head, 24 in interorbital. Max- illary barbel sometimes extending to near the posterior end of the adipose fin, sometimes scarcely beyond the base of the dorsal; mental barbel to base of pectoral; postmentals beyond middle of pectoral. Lower jaw shorter than the upper; mandibulary band of teeth scarcely interrupted in the middle, tapering to a point behind the rictus; depth of intermaxillary band of teeth 7 in its width. Gill-membranes separate, over- lapping; gill-rakers 34-7. Distance of dorsal fin from snout about one-third of the length. Free margin of the dorsal rounded, the base of the fin about equal to its height, 13-1} in head. Distance of the adipose fin from the dorsal more than half the length of the dorsal. Caudal divided to near its base, the lower lobe broad and rounded, the upper pointed, about equal to the head in length, usually shorter. Tips of the anal rays when laid backward, not reach- ing the vertical from the tip of the adipose fin; free mar- gin of the anal rounded; the longest ray 2—24 in length of head. Ventrals inserted below last dorsal ray, 13-13 in head. Pectoral spine short, stout, with recurved hooks or notches near its tip in front, the posterior margin with short straight teeth; the longest ray 13 in head. SOUTH AMERICAN NEMATOGNATHI. 1135 Color brownish, with numerous minute dark dots; a dark lateral band, deepest at the shoulder. Head 44-43; depth 53-7; Br. 7; D. I, 6; A. 9-11. The specimens examined are from Gorgona; Rio Chagres; Rio Obispo; Turbo, Atlantic Coast Centr. Am. 93. Rhamdia longicauda. Pimelodus longicauda Boulenger, Proc. Zool. Soc. Lond. March 1887, 275, plate xx, fig. 2 (Canelos). Rhamdia longicauda Kigenm. & Eigenm. Proc Cal. Acad. 2d Ser. i, 126, 1888 (name). Habitat: Eastern Ecuador. This species is known only from the description and figure quoted above. 94. Rhamdia dorsalis. Rhamdia dorsalis Gill, Proc. Acad. Nat. Sci. Philad. 1870, 94 (Up- per Amazon). Habitat: Maranon. This species is known only from the types. 95. Rhamdia poeyi. Rhamdia poeyi Figenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 127, 1888 (Goyaz). Habitat: Goyaz. Width of body about equal to its depth, much com- pressed toward the caudal. Head short, flat above, the sides not very steep, its greatest width 14 in its length; fontanel not continued behind the eye; occipital process very short, triangular, reaching two-sevenths the dis- tance from its base to the dorsal spine. A few large pores about the head. Eye 3 in snout, 7 in head, 13 in interorbital. Maxillary barbels scarcely reaching the vertical from the dorsal spine; postmental barbels about reaching to the edge of the branchiostegal membrane, the mentals less than half as long. Branchiostegal membrane separate to below the ante- rior part of the eye. Gull-rakers 3-+-7. Distance of dorsal spine from tip of snout less than 3 186 CALIFORNIA ACADEMY OF SCIENCES. in the length. Distance of adipose fin from the dorsal equals the length of the dorsal. Adipose fin very low in front, its length about 54 in the length. Pectorals and ventrals very short. Pectoral spine short, terete, about half as long as the head, its outer margin smooth, the inner margin with strong teeth the entire length. Color brown, the sides and back densely covered with small brown dots and more minute black ones; a dark humeral spot; a narrow, dark lateral band. Head 43; depth above first anal ray 7; depth of the peduncle 93° Brio: Da -6. ACs: One specimen .175 m. (to base of caudal). Goyaz. Senhor Honorio. 96. Rhamdia tenella. Rhamdia tenella Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 127, 1888 (Cudajas). Width behind the head equal to the depth, tapering to the strongly compressed caudal peduncle. Head broad and flat transversely, its greatest width 13 in its length; profile regularly and strongly convex; width at angle of mouth 2 in length of head. Fontanel a narrow slit between the frontal bones. Occipital process ex- tending a third of the space from its base to the dorsal spine. Eye 3 in snout, 9 in head, 23 in the interorbital. Maxillary barbels reaching beyond the dorsal fin, men- tal barbels to base of pectoral, postmentals to middle of pectorals. Lower jaw shorter than the upper; intermaxillary band of teeth twice as deep at outer margins as at the mid- he 40. dle; the greatest depth of the band 33 in its width. Gill-membranes separate to below angle of mouth; gill-rakers slightly branched, 3-+-10. SOUTH AMERICAN NEMATOGNATHI. 137 Distance of dorsal fin from snout 3 in the length; dorsal rays of nearly uniform height, higher than the spine. Distance of the adipose from the dorsal fin 2 in the length of the dorsal fin, its distance from the caudal less than a diameter of the eye. Caudal deeply forked, the lower lobe broader, reunded, + in head. Anal longer than high, its longest ray 24 in head; tip of the anal fin not reaching the vertical from the end of the adipose by the length of the snout. Ventrals inserted behind the vertical from last dorsal ray, 2 in head. Pectoral spine very strong, scarcely shorter than the longest ray, recurved hooks on upper three-fourths of its outer margin; a deep groove almost the upper half of its inner margin, the basal third roughened; its length 1? in head. Color brownish; fins dusky; adipose margined with black. Head 41; depth 63; depth, above first anal ray, 8; depth of caudal peduncle 10; Br.. 7-8; D. I, 6; A. 11. Type No. 7547. Length .31 m. Cudajas. XVI. RHAMDELLA. Rhamdella Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1, 129, 1888 (eriarcha). Type: Rhamdella eriarcha KE. & E. Fontanel continued to the occipital process, a bridge behind the eyes. Dorsal and pectoral fins with strong spines. Ventrals placed below or behind the dorsal. A free orbital margin. Habitat: Rio Janerio to Mexico. \ ANALYSIS OF THE SPECIES OF RHAMDELLA,. a. A. 15-18. b. Adipose fin little longer than anal. 138 CALIFORNIA ACADEMY OF SCIENCES. c. Color plain; occipital process minute; eye small, turned upward, much nearer snout than to posterior margin of opercle, 6-7 in head, 2 in the interocular; posterior nares much nearer the eye than to the anterior nares. Width of mouth 2 in head; jaws equal; maxillary barbels do not reach beyond tips of pectorals, postmentals not beyond their base; base of dorsal 2 in its distance from the adipose which begins behind the vertical from the insertion of the anal and reaches to the caudal. Pectoral spine smooth, about 3 in head; dorsal spine shorter but not stronger than the rays; caudal fin shghtly emarginate. Grayish with darker markings. Head 5in the length. D. I, 5-6; A. 16-18. (Liitken.) microcephala 97. cc. Back and dorsal fin with numerous small black spots. Dorsal spine produced in a filament; dorsal and anal fins concave. Max- illary barbels extending to ventrals. Adipose fin scarcely longer than the dorsal fin. Br. 9; D.I,6;A.17. Vertebre 44. Grows to large size. (Schomburgk.) notata 98. bb. Adipose fin twice as long as anal. Eye large, nearer edge of opercle than to tip of snout. Mavxillary barbels extending scarcely beyond head. Depth of intermaxillary band of teeth about 4 in its width. AGUS: eriarcha 99. aa. A. 9-14. d. Jaws equal; numerous pores about the head. Maxillary barbels ex- tending to a point between the ventrals and anal. Eye elliptical, 5 in head, 2 in interocular, nearer snout than to opercular margin, Humeral process one-third as long as pectoral spine. Adipose fin 1} times as longas the dorsal; caudal lobes equal. Dark brownish, with traces of a longitudinal band; no spot on adipose. Head 5; depth 5; D. I, 7; A. 18-14. (Jenyns.) exsudans 100. dd. Upper jaw longer than lower. e. A dark lateral band; occipital process moderate. Jf. Dorsal spine very weak, low, 24-23 in head; pectoral spine 2-2! in head; caudal fin 44-53 in the length (Mexican). parryi * ff. Dorsal spine strong, high, 14-1} in head; pectoral spine 14-14 in head; caudal fin about 32 in thelength. jenynsii 101. ee. Several dark cross-bars, or plain; occipital process minute; head short, 5 in the length. minuta 102. 97. Rhamdella microcephala. Rhamdia microcephala (Rheinhardt MS.) Liitken, Dan. Selsk. Skr. 177, pl. iii, fig. 7, 1875 (Rio das Velhas). Habitat: Rio das Velhas. This species is known only from the types; it is most nearly related to R. notatus (Schomb.) and R. laticauda Kner. *Rhamdia parryi Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 130, 1888(Rio Zanaleneo; Chiapas; Mexico). We have dedicated this species to Dr. C. C. Parry of Davenport, lowa, SOUTH AMERICAN NEMATOGNATHI. 139 98. Rhamdella notata. Pimelodus notatus Schomburgk, Fish. Brit. Guiana, i, 181, pl. 7 (Fort St. Joaquim on the Rio Branco); Giinther, Cat. Fish. Brit. Mus. v, 131, 1864 (copied). Rhamdia notata Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 129, 1888 (name). Habitat: Rio Branco. The type of this species was over a metre long. d oD 99, Rhamdella eriarcha. Rhamdia eriarcha Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 129, 1888 (Rio Grande do Sul). : Habitat: Rio Grande do Sul. A single specimen .26 m. from the Emperor’s collec- tion made at Rio Grande do Sul. Body elongate slender, the width below the dorsal spine less than the depth. Head long, pointed, the fontanel continued to base of the occipital process which reaches about half way to the dorsal spine. Entire sur- face of the head covered with skin. Head flattish above, snout long and pointed, the width at the angle of the mouth 2% in length of head. Kye large, its center one-third or one-fourth nearer the posterior margin of the opercle than to the tip of the snout, 2 in snout, 45 in head; the interorbital less than the diameter of the eye. Maxillary barbels extending to the edge of the opercle; postmental barbels not reaching edge of branchiostegal membrane if drawn straight back. Upper jaw projecting. Lips thick and strongly pli- cate. Intermaxillary band of teeth deep and narrow, the teeth minute. No teeth on vomer or palate. Teeth of the lower jaw in a narrower band which tapers backward, the teeth similar to those of the upper jaw. Gill membranes separate to below middle of eye. Gill-rakers 1-+5. Distance of dorsal fin from end of snout 24 in the length; the first ray of the dorsal scarcely spine-like, 140 CALIFORNIA ACADEMY OF SCIENCES. smooth; its height, including filament, 13 in head; highest ray longer than the base of the fin, 12 in the head. Distance of adipose fin from the dorsal equals the length of the dorsal; adipose fin 24 in the length. Caudal forked to the base, the upper lobe greatly pro- duced, much longer than the head (broken off in the Specimen). Anal long and low, the posterior rays highest, 2} in head, the tips when depressed not reaching the vertical from the end of the adipose by more than one diameter of the eye. Ventrals broad, reaching to the anal, 12 in head. Pectoral spine strong, 14 in head, roughened along both edges, the rays 1} in head. A black lateral band; region above it chocolate, below, much lighter. Fins plain. Head 47; depth 7; caudal peduncle 14; D. I, 6; A. 15. 100. Rhamdella exsudans. Pimelodus exsudans Jenyns, Voy. Beagle, Fishes, 111, 1842 (Rio Janeiro?); Giinther, Cat. Fish. Brit. Mus. v, 132, 1864 (copied). Rhamdia exsudans EKigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 130, 1888 (name). Habitat: ? Rio Janeiro. This species is known from the description of the types which measure .089 and .057 m. 101. Rhamdella jenynsii. Pimelodus gracilis Jenyns. Voy. Beagle, Fishes, 110, 1842 (Rio de Janeiro). Pimelodus jenynsii Giinther, Cat. Fish. Brit. Mus. vol. y, 128, 1864 (copied). Rhamdia jenynsii Higenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 130, 1888 (Maldonado). Habitat: Rio de Janeiro south to the Rio Plata. This species has so far been known only from the types. The Museum of Comparative Zoology contains 9 specimens from Maldonado which, while they do not agree with the description of the types in all respects are too near to be considered distinct. SOUTH AMERICAN NEMATOGNATHI. 141 Body short, compressed; head broad, its width 14 in its length, its depth 13; width of mouth at the rictus 24; profile straight to above the eyes, decurved in front of the eyes; interorbital region flat, postorbital convex in transverse profile; occipital process not reaching to the dorsal plate, covered with thick skin. Snout depressed, flattish; upper jaw projecting; teeth of the upper jaw in a rather deep subcrescentic patch, interrupted in the middle, the width of the band little more than three in the head. Maxillary barbels reaching about to the adipose fin; mental barbels little beyond eye; postmentals to base of pectoral. Eye small, 5 in head, 2 in the snout, 1} in the inter- orbital. Gill membranes separate to below the anterior portion of the eye; humeral process extending about to middle of pectoral spine. Dorsal spine equidistant between the snout and the anal; entirely smooth in front, its length 14 in the head, the longest dorsal ray 14. Distance of adipose fin from the dorsal fin equals the length of the dorsal fin; adipose fin about 4 in the length. Caudal deeply lobed, the upper lobe longer, 4 in the length. Anal fin sometimes extending beyond tip of adipose fin, the longest ray 14 in head. Ventrals 13 in head. Pectoral spine 14 in head, its anterior margin almost smooth, its posterior margin with about ten teeth, largest along the middle third or half of the spine. A Depth of caudal peduncle 2? in head. Color dark brown, everywhere with minute darker dots; a dusky lateral band which is continued forward on head in some specimens. 142 CALIFORNIA ACADEMY OF SCIENCES. Head 4-44; depth about 5; Br. 7; D. I, 6; A. 10-12. 102. Rhamdella minuta. Rhamdia minuta Liittken, Dan. Selsk. Skr. 179, pl. ili, fig. 6, 1875 (Rio das Velhas); Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 131, 1888 (Rio Janeiro; Macacos). Habitat: Rio Janeiro to Macacos. One specimen .083m. Rio Janeiro. Dr. Emil Géldi. Two specimens .10m., and .11]m. Macacos. W. M. Roberts. Body subterete, tapering, and somewhat flattened to- ward the caudal. Head very short, smooth and covered | with skin above; profile convex, transverse section rounded. Occipital process reduced to a minimum, about one-third as long as the pupil; fontanel long, ex- tending from in front of the eye to the occipital process, a bridge above the posterior part of the orbit. Some long, simple pores about the head. Eye 1} in snout, 43 in head, 1 in the interorbital. Maxillary barbels reaching about to the end of the dorsal fin; mental barbels to the base of the pectoral, postmentals a little beyond. Snout rather broad and depressed, the width at the rictus 2 in the head; greatest width of the head 1} in its length. Intermaxillary band of teeth narrowed in the middle, the greatest depth of the band about 5 in the width, the teeth all alike, villiform. Branchiostegal membranes separate to in front of eye. Gill-rakers about 3+10. Distance of dorsal from the tip of snout 2% in the length, the dorsal spine produced in a filament, its height with the filament about equal to the length of the head; the rays rapidly decreasing in height to the last, the free margin truncate. Distance of adipose fin from the dorsal equals the length of the adipose fin, 5 in the length. Caudal forked, the upper lobe little longer than the lower, less than 4 in the length. SOUTH AMERICAN NEMATOGNATHI. 143 Anal well developed, placed under the middle of the adipose fin, the tips of the last rays reaching the verti- cal from tip of adipose fin. Ventrals inserted under the third dorsal ray, 14-14 in the head. Pectoral spine short, with a flexible portion, which is 1 times as long as the spinous portion; the spinous por- tion 2 in the head; length of the pectoral fin about equal to the head. Ground color light, the sides thickly covered with jet- black dots, about six short cross-bars on the back; top. and sides of head profusely covered with minute black dots; caudal and adipose dotted with black, other fins plain. Head 5; depth 74; Br. 7; D. I, 6; A. 10. Air-bladder narrow, reniform, its longitudinal axis transverse, lying under the lateral processes of the first vertebre. XVII. HeEpraptTeRus. Heptapterus Bleeker, Ichthyol. Arch. Ind. Silur., 197, 1858 (mustelinus ). Type: Pimelodus mustelinus C. & V. Caudal obliquely rounded. Dorsal fin without a spine, placed above the ventrals. Eye small, without a free orbital margin; adipose fin long and low, confluent with the caudal. Air-bladder reniform. Anal rather long. Fontanel very narrow, continued to the base of the oc- cipital, with a narrow interruption behind the eyes. This genus has been placed by Dr. Ginther with his Siluride Opisthoptere; it has been entirely overlooked by Gill in his arrangement of the families of fishes. The fact that it possesses a free air-bladder seems to us to be of much more significance than the mechanical position of the dorsal or ventrals, especially as Rhamdella minuta 144 CALIFORNIA ACADEMY OF SCIENCES. and microcephala have the dorsal placed over the ven- trals. 103. Heptapterus mustelinus. Pimelodus mustelinus Valenciennes, Orbigny, Voy. Amér. Merid. Poiss. pl. 2, fig. 1-4, 1847; Cuv. & Val. Hist. Nat. Poiss. xv, 165, 1840 (La Plata); Hensel, Wiegm. Arch. 1870, i, 77 (St. Cruz, Rio Grande do Sul). Heptapterus mustelinus Giinther,-Cat. Fish. Brit. Mus. v, 271, 1864 (copied); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 172, 1888 (Maldonado). Habitat: Rio Grande do Sul; Rio Plata. Caudal portion compressed, the abdominal portion very little depressed. Head depressed, its depth 13 in its width, entirely covered with smooth skin. Eye an orbital diameter nearer tip of snout than to the gill opening. Maxillary barbels reaching to middle of pectoral fins, the mental and postmental barbels to the edge of gill- opening. Width of mouth 2 in length of head, the gape about 2 in the snout. Teeth villiform in both jaws. Gill-membranes separate to below the eye. Distance of dorsal fin from tip of snout 2% in the length, the first ray not stiffened. Adipose fin very long and rather low, originating a little nearer the dorsal fin than the length of the latter, continuous with the cau- dal fin. Caudal fin rounded, its accessory rays continued for- ward below to the anal fin, but wholly free from it, anterior portion scarcely rayed, adipose-like. Anal long and low, inserted a little posterior to the adipose fin. Ventrals inserted a very little posterior to the origin of the dorsal fin, reaching about half way to the anal, the pectoral fins not quite so near to the ventrals. Color uniform grayish, everywhere dotted with dark except on the belly; fins also punctate, the anal and ven- trals least so. . SOUTH AMERICAN NEMATOGNATHI. 145 Head 5; depth 8; D. 7; A. 24. Two specimens .045-.05 m. Maldonado. Th. Carey. XVIII. AcENTRONICHTHYS. Acentronichthys E. & E. Proc. Cal. Acad. Sci. 2d Ser. i, 28, 1889 (A. leptos). Type: Acentronichthys leptos E. & E. Caudal widely forked; occipital process small, not con- tinued to the dorsal; fontanel extending to the base of the occipital. Orbit without a free margin. Dorsal and pectorals without spines; ventrals under anterior half of dorsal; anal long. Allied to Heptapterus. ANALYSIS OF THE SPECIES OF ACENTRONICHTHYS. a. Adipose fin confluent with the caudal fin; first ventral ray below third dorsal ray; origin of anal slightly behind origin of adipose. D. 7; A. 19. Head 7}. leptos 104. aa. Adipose fin not confluent with the caudal fin, its distance from the caudal equal tothe length of its base; first ventral ray in front of the vertical from origin of dorsal. 6. D.7; A. 18. Depth more than 2 in the head, which is 6 in the length. surinamensis 105. bb. D. 8; A. 20. Head 5-6; depth 8-9; caudal forked, the upper lobe much the longer; anal fin long and low, its origin midway between end of dorsal and origin of adipose. (Steindachner.) collettii 106. 104. Acentronichthys leptos. KE. & E. Proc. Cal. Acad. Sci. 2d Ser. i, 29, 1889 (Sao Matheos). Type: No. 7532; onespecimen .105m. Sao Matheos. Hartt & Cope- land. Extremely elongate, the depth of the caudal peduncle not much less than the greatest depth. Head long and narrow, not greatly narrowed forward, its width 13 in its length. Cheeks steep. Eye minute, one orbital diameter nearer tip of snout than to end of opercle; interocular about 2 in the snout. Maxillary barbels reaching beyond middle of pectoral, mental and postmental beyond base of pectoral. Mouth wide, terminal, the jaws equal, its width 2 in the length 10 146 CALIFORNIA ACADEMY OF SCIENCES. of the head; each jaw with a band of strong villiform teeth. Origin of dorsal fin from tip of snout 3{ in the length. Adipose fin long and low, its origin in advance of the anal, confluent with the caudal fin. Caudal with num- erous accessory rays, widely forked, its upper lobe longer, about 53 in the length. Origin of anal a little nearer base of caudal than to gill opening, the rays of about equal height. Ventrals high and narrow, inserted be- low the first dorsal ray. Pectorals long and narrow, scarcely shorter than the head, the middle rays longest. Brownish, with traces of a dark lateral band; a dark bar extending forward from the eye; two dark lines on base of caudal and parallel with its root. Head 74; depth 10; D. 7; A. 19. 105. Acentronichthys surinamensis. Heptapterus surinamensis Bleeker, Silures de Suriname, 91, pl. xv, fig. 1, 1864 (Surinam); Giinther, Cat. Fish. Brit. Mus. v, 271, 1864 (copied). Habitat: Surinam. This species is known from the types only. 106. Acentronichthys collettii. Heptapterus collettii Steindachner, Flussfische Siidam. iii, fig. 1, 1881 (Maldonado). Habitat: Mouth of the Rio Plata in brackish water. This species is known from the types only. od Teale Vic XIX. _ NANNOGLANIS. Nannoglanis Boulenger, Proc. Zool. Soc. Lond. 278, 1887 (fasciatus). A. 8. Adipose fin present; dorsal fin without a pun- gent spine and placed behind the ventrals. Barbels six; Fontanel ? Occipital process ? We have not seen the only known species of this ge- nus but its general structure is so much like that of Heptapterus and Rhamdella that we think we are war- SOUTH AMERICAN NEMATOGNATHI. 147 ranted in believing it to agree with those genera in the air-bladder, fontanel and occipital process. 107. Nannoglanis fasciatus. Nannoglanis fasciatus Boulenger, 1. c. 278, pl. xxi, fig. 3 (Ecuador) Habitat: Ecuador. Eye 38 in snout, 1} in interocular. Maxillary barbels extending to the middle of the pectoral. Origin of dor- sal fin midway between tip of snout and end of adipose which is as long as the head. Pectorals not reaching ventrals. Vent below origin of dorsal. Yellowish, with four broad, brown, black edged cross bands above; a dark brown line from eye to maxillary barbel. Head 5; depth 9; D. 7; A. 8. (Boulenger.) XX. PIMELODELLA. Pseudorhamdia Steindachner, SB. Ak. Wien, lxxiv, 1876, Sisswasserf. siiddstl. Bras. 111, 46 (ateristriga), not Pseudorhamdia Bleeker. Pimelodella Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 181, 1888 (cristatus). Type: Pimelodus cristatus Miller & Troschel. The name Pseudorhamdia is not available for this genus as the original type of it was maculatus. Itisa synonym of Pimelodus. The characters of this genus are given in the key. ANALYSIS OF THE SPECIES OF PIMELODELLA. a. Adipose fin 24-24 in the length. b. No dark lateral band. Lower caudal lobe much broader than the upper, the lobes sometimes longer than the head, sometimes much shorter. Dorsal spine with fine teeth behind and several large notches near the tip in front. Pectoral spine rather stout, with fine, recurved teeth on its posterior margin }+-! of the width of the spine, anterior margin roughened, with recurved hooks near the tip. Maxillary barbels not extending beyond tip of adipose except in young. cristatus 108. bb. A dark lateral band; upper caudal lobe sometimes produced in a filament. 148 CALIFORNIA ACADEMY OF SCIENCES. c. Dorsal spine with rather strong recurved hooks on both edges near the tip; height of the spine about equal to the pectoral spine, some- times a little higher, sometimes a little lower. Maxillary barbels reaching to tip of adipose in specimens .22 m. long. wesselii 109. cc. Dorsal spine smooth on its outer edge, its inner edge scarcely if at allroughened. Dorsal spine uniformly one-half a diameter of eye or more shorter than pectoral spine. Maxillary barbels reach- ing to beginning of anal in a specimen .11 m. long, scarcely shorter in larger specimens. gracilis 110. aa. Adipose fin 3 or more in the length. d. Dorsal I, 6; pectoral fins not extending to the ventral fins; ventrals not to the anal. : e. Pectoral spine strong, compressed, with 23 or 24 strong, re- curved hooks on its posterior margin, the hooks not as long as. the spine is wide; anterior margin with straight, minute teeth on its central half, recurved notches near its tip. Dorsal spine strongly curved, the posterior margin roughened near the tip, numerous recurved hooks on the upper half of the anterior mar- gin. Eye 4 in head; interorbital three-fourths as wide as the orbital diameter. Maxillary barbel to beginning of the adipose fin. pectinifer 111. ee. Pectoral spine with from 8-15 recurved hooks or teeth; dorsal spine straight. Jf. Color plain, no dark lateral band; free margin of the dorsal rounded. Body rather elongate, slightly compressed posteriorly, head moderately broad and long, depressed, truncate ante- riorly; snout somewhat produced, broad, 22 in head; distance between angles of mouth nearly equal to the length of the snout. Maxillary barbels reaching to the origin of the anal; postmentals to middle of pectorals. Eye 4 in head, 1 in interor- bital, equidistant from snout and gill-opening. Humeral pro- cess distinctly striate. Dorsal somewhat higher than long, the length of its base nearly equal to its distance from the head, the spine slender, stiff, rough superiorly and ending in a ray-like filament. Adipose fin about 3 in the length. Caudal deeply lobed, the lobes pointed, the upper longer, about equal to the head in length. Ventral inserted immediately behind the ver- tical from the dorsal. Pectoral spine not much shorter than the rays, the posterior margin serrate. Head 4; depth 54; Br. 6; D. I, 6; A. 12. (Giinther.) modestus 112. ff. A dark band on sides, not continued forward on head. The band is sometimes obsolete in alcoholic specimens. g. Snout produced, nearly half the head in length; distance be- tween the angles of the mouth nearly equal to the snout in length. Maxillary barbel reaching to the tip of the pectoral; postmentals to the root of the pectoral. Eye 4 in head, nearer SOUTH AMERICAN NEMATOGNATHI. 149 gill-opening than to snout. Interorbital slightly wider than the diameter of the eye. Humeral process indistinctly striate. Dorsal higher than long, the length of its base equals its dis- tance from the head. Adipose 32 in body. Caudal deeply forked, the lobes pointed, upper lobe longer than head. Pec- toral extending to below middle of dorsal, its spine stout, compressed, its posterior margin spiny. Uniform grayish above, white below; dorsal and caudal fins minutely dotted with black. Head 43; depth 5}; Br. 6; D.I, 6; A. 11. (Giinther.) elongatus 113. gg. Snout not produced. h. Pectoral spine strong, compressed, with from 10-15 recurved hooks behind, the length of the hooks equals, or almost equals, the width of the spine. i. Head conical or subconical. lateristriga 114. ai. Head depressed, the sides slanting outwards, snout and postorbital portion of head slightly convex in cross-sec- tion; the occipital process scarcely reaching the basal bone of the dorsal spine. Eye nearer opercular margin than to snout. (Steindachner.) harttii 115. hh. Pectoral spine curved, flattened, comparatively slender; its posterior margin ‘‘smooth” or with teeth which are not more than } or 4 the width of the spine, recurved notches near its tip in front. Maxillary barbel extending to the sec- ond fourth of the adipose dorsal. buckleyi 116, JSff. A dark band along the sides, continued forward on head; teeth of pectoral spine one-half the width of the spine. j. Eye 4 in head; lateral band continued on head but not on caudal; pectoral spine slender, much as in buckleyi, but the teeth stronger. vittata 117. jj. Eye 34-33 in head, lateral band continued on head, and on the middle rays of the caudal; pectoral spine very broad, de- pressed, almost straight. chagresi 118. dd. Dorsal rays I, 7; pectoral fin extending to the ventral fins, which reach to the anal; head flat; eye median; distance between the angles of the mouth 24 in head. Maxillary barbels extending beyond origin of adipose dorsal; postmental barbels not to middle of pecto- ral. First dorsal ray slightly longer than head; dorsal spine shorter than the head; distance between dorsal and adipose fin longer than the base of the former; adipose dorsal 3% in the length. Upper lobe of caudal 14 times as long as head. Posterior serration of pectoral much weaker than in gracilis. Reddish-brown; a dark brown hume- ral spot; a narrow dark bar along the lateral line. Head 44; depth 5. D.I, 7; A. 12. (Steindacher.) brasiliensis 119. 150 CALIFORNIA ACADEMY OF SCIENCES. 108. Pimelodella cristatus. ?Pimelodus insignis Schomburgk, Fish. Brit. Guiana, 180 (not plate). Pimelodus cristatus Miiller & Troschel, Schomburgk, British Gui- ana, 628, 1848 (Takutu and Mahu Rivers); Miiller & Troschel, Hore Ichthyol. iii, 4, 1849 (Guiana in Essequibo); Giinther, Cat. Fish. Brit. Mus. v. 117, 1864 (Guiana; Essequibo; River Capin, Para); Vaillant, Bull. Soc. Philom. Series 7, iv, 152, 1880 (Calderon); Steindacher, Flussfische Siidamerikas, iv, 4, 1882 (Rio Huallaga). Pimelodetla cristatus Eigenm & Eigenm, Proc. Cal. Acad., 2d. Ser. i, 132, 1888 (San Gongallo; Avary; Villa Bella; Jutahy; Tapajos; Rio Mucuri; Tabatinga; Hyavary; Coary). Pimelodus agassizii Steindachner, SB. Ak. Wien, lxxiv, July, 1876, Ichthyol. Beitr. v, 99 (Peruvian Amazon; Hyavary) Pimelodus ophthalmicus Cope, Proc. Am. Philos. Soc. xvii, 675, 1878 (Upper Amazon). Habitat: Rivers emptying into the Atlantic north of Cape San Roque; whole course of the Amazon. The Pimelodus cristatus M. & Tr. and Pimelodus insig- nis Sch. are evidently identical. The description of insignis does not agree with the plate which represents Callophysus lateralis Gill=macrop- terus Lichtenstein. Schomburgk, |. c., says that ‘‘The Wapisiana Indians call this fish ‘ Konnairu,’ it grows to about the length of eighteen inches.” Miller & Troschel quoting Schomburgk’s notes say the ‘¢ Wapisianas call it ‘ Komairu;’ it reaches a length of 16-18 inches. ” The statement that insignis has 10 ventral rays may be true, in which case it is of course distinct from crista- tus; but such statements, never verified by any ichthy- ologist, are to be distrusted. Pimelodus agassizii does not differ from cristatus. The characters assigned to P. ophthalmicus are also present in one or another of the specimens examined. We have found the anal rays to vary from 12-15, and the dorsal in some is very much higher than in others. The specimens in the museum are from San Goncallo; SOUTH AMERICAN NEMATOGNATHI. 151 Avary; Villa Bella; Jutahy; Tapajos; Rio Mucuri; Tab- atinga; Hyavary; Coary. The largest specimen exam- ined is .384 m. long. Body much depressed towards the caudal, elongate. Head conical, covered with thin skin, its greatest depth 1% in its length; occipital crest narrow and long, reach- ing the comparatively large dorsal plate. A pore be- tween the nasal openings, nearer the anterior. Maxillary barbels extend sometimes to the beginning of the adipose, sometimes to near its tip; mental barbeis thin, the distance between them greater than their distance from the postmental barbels, extending to the base of the pectoral; postmentals to middle of pectoral. Eye large, 1% to 23 in snout, 4-5 in head, 1-1} in interorbital region, 13 to 1? diameters behind the rictus. Mouth small, its width 3 in the head; teeth of the lower jaw in a shallow band which is interrupted in the middle and tapers backwards beyond the angle of the mouth. Teeth of the upper jaw in a narrow band, not deeper than the deepest part of the mandibulary band, sometimes interrupted in the middle. Gill-membranes separate to below anterior margin of the eye; gill-rakers as long as pupil, 2-4-++-9-12. Dorsal spine slender, with very fine notches behind and several large ones at the tip in front. Height of the spine and rays very variable, sometimes twice as high as the length of the fin. Dorsal spine midway between snout and anal. Adipose fin very long, 25 in the length. Caudal cleft to near its base; the upper lobe sometimes shorter than the head, sometimes as long as the head to tip of humeral process. Ventrals 14-13 in head. Pectoral spine strong, 14-13 in the head, fine recurved teeth behind, and a few much larger recurved teeth near the tip. Caudal peduncle very broad, 25-3 in head. Head 6; depth 6; Br. 7; D: 1, 6; A, 12-15. £52 CALIFORNIA ACADEMY OF SCIENCES. 109. Pimelodella wesselii. Pimelodus (Pseudorhamdia) wesselii Steindachner, SB. Ak. Wien, lxxiv, Noy. 1876. Flussfische stidéstl. Bras. iii, 56, foot note (Essequibo). Pimelodella wesselii Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 132, 1888 (Cudajas; Para; Marajo; Rio Madeira; Rio Puty; Santarem). Habitat: Rio Puty to Rio Essequibo; Amazon from Para to Cudajas. This species is very closely related to cristatus; when the color is obliterated they can scarcely be distinguished. Body elongate, strongly compressed. Head rounded, obtusely conical, covered with very thin skin on the top; greatest width 13 in its length, its greatest depth 13; oc- cipital crest striate, its greatest width 23 to 3 in its length. Distance between covered with very thin skin, anterlor and posterior nares 13 in the eye. Maxillary barbel reaching tip of adipose fin or beyond the tips of the middle caudal rays; mental barbels to base of pectoral; postmental about to tip of pectoral. Kye 13-13 in snout, 4 in head, 1-14 in interorbital, 1 diameter behind the rictus. Width of mouth 3 in head; teeth of the upper jaw slightly smaller than those of the lower, the width of the upper band 33 in head. Gill-membranes separate to below anterior portion of eye; gill-rakers about as long as diameter of pupil, 3--6-9. Dorsal spine high and slender, very small recurved hooks on the upper half of both margins, its height 1-14 in head; highest rays about one-sixth longer than head; the dorsal spine inserted about midway between snout and anal. Adipose fin beginning immediately behind first dorsal, about 25 in the length. Caudal deeply forked, one of the rays sometimes pro- duced in a filament, sometimes the upper, sometimes the lower lobe longer—always longer than head. Anal rather high, the highest ray 1? in head, its tip not reaching the end of the adipose. SOUTH AMERICAN NEMATOGNATHI. 153 Ventrals inserted in front of the vertical from the last dorsal ray, their tips sometimes reaching to the anal, 14-12 in head. Pectoral spine, much stronger than dorsal spine and usually shorter, 1{ in head, with sharp recurved teeth behind and recurved notches in front. Color hght brown; a dark lateral band, sometimes con- tinued on head. Head 43; depth 6; Br. 6; D..1,,6: A. 14. 110. Pimelodella gracilis. Pimelodus gracilis Valenciennes, Voy. d’Orbigny, atlas ii, plate ii, fig. 5, 1847; Cuv. & Val. Hist. Nat. Poiss. xv, 181, 1840 (Buenos Ayres; Corrientes; Parana); Kner, SB. Ak. Wien, xxvi, 418, 1857 (Caicara, Matogrosso; Rio Guaporé, Cujaba); Giin- ther, Cat. Fish. Brit. Mus. vy, 121, 1864 (copied). Pimelodus (Pseudorhamdia) gracilis Steindachner, Flussfische Siidamerika’s, i, 9, 1879 (Orinoco near Ciudad Bolivar). Pimelodella gracilis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 182, 1888 (Goyaz). Habitat: Rivers from the La Plata to the Orinoco. Twelve specimens from .11 m. to .17 m. in length. Goyaz, Brazil. Senhor Honorio. Body slender, the width at the pectoral about equal to the depth, much compressed toward the tail. Head short, flat above, the profile slightly arched, the width of the head 14-13 in its length; occipital process of the same width throughout, the sides parallel, its width 33 in its length. Fontanel narrow, pointed in front and behind, reaching to the base of the occipital process, a bridge across it above the posterior part of the eye. Eye round, 12 in snout, 4 in head, its diameter slightly less than the interorbital. Maxillary barbel reaching to tip of ventrals or to be- ginning of anal; mental barbels beyond base of pecto- rals, postmentals to tips of pectorals. Lower jaw slightly shorter than the upper, the width at the rictus 2-25 in the head. Intermaxillary band of 154 CALIFORNIA ACADEMY OF SCIENCES. teeth not wider than the mandibulary band at the sym- physis. Gill-membranes separate to below anterior margin of orbit. Gill-rakers 3+7. Distance of dorsal spine from tip of snout equals its distance from the tip of the ventral rays, 33 in the length; the height of the dorsal spine 13-13 in the head; highest ray equals the length of the head. Distance of the adipose from the dorsal fin equals the base of the dorsal or sometimes only half as long. Adipose fin 23-23 in the length. Caudal broken in all the specimens. Anal higher than long, the longest ray 1} in head, its free margin rounded. Ventrals 14 in head. Pectoral spine broad, minute teeth on its outer edge on the basal half, and notches near the tip; the inner margin with strong recurved teeth to near its tip; the height of the spine 14-14 in head, the soft rays a little higher. Color dark brown, everywhere with dark punctulations; a dark lateral band; the fins all punctate. Head 5; depth 6-74; Br. 7; D.1,96;;A..12. 111. Pimelodella pectinifer. Pimelodella pectinifer Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 132, 1888 (Campos). Habitat: Rio Parahyba. Body robust, compressed posteriorly; head conical, its width 13 in its length, its depth at base of occipital pro- cess equal to its width. Upper profile straight, curved in front of the eyes, head convex transversely. Lateral margins of occipital process concave. Distance between the nasal openings 13 in eye. Maxillary barbels not reaching to adipose fin. Men- tal barbels to base of pectorals, postmental to middle of SOUTH AMERICAN NEMATOGNATHI, 155 pectorals. Gill-membranes separate to below anterior margin of eye. Humeral process extending to middle of pectoral spine. Eye 14 in snout, 4 in head, nearer opercular margin than to snout. Dorsal spine nearer snout than to the anal, its height 1% in head; the highest ray about equal to the length of the head. Adipose fin 4 in the length, its distance from the dorsal equals three-fifths of its basis. Caudal about 4 in the length. Free margin of anal rounded, the highest ray 1? in head. Ventrals behind the vertical from the last dorsal ray, their tips one-third their length from the anal. Pectoral spine equal to length of head, the tips of the rays one-half their length from the ventral. Uniform light brownish. Head 42; depth 53; Br. 6; D. I, 6; A. 12, Type: No. 7508 .19m. Campos. Hartt & Copeland. 112, Pimelodella modestus. Pimelodus modestus Giinther, Proc. Zool. Soc. Lond. 28, 239, pl. x, fig. C., 1860 (Esmeraldas); id. Cat. Fish. Brit. Mus. v, 117, 1864 (Esmeraldas); id. Fish. Central America, 393, 1866 (Rio Chagres; Esmeraldas). Pimelodella modestus Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. i, 133, 1888 (name). Habitat: Rivers of Western Ecuador and Eastern Panama. This species is known to us only from the plate and description by Dr. Giinther. 113. Pimelodella elongatus, Pimelodus elongatus Giinther, Proc. Zool. Soc. Lond. 28, 238, pl. x, fig. B, 1860 (fresh waters of the Esmeraldas); Giinther Catal. Fishes Brit. Mus. v, 118, 1864 (Esmeraldas). Pimelodella elongatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. i, 133, 1888 (name only). Habitat: Rivers of Western Ecuador, This species is known to us only from the plate and description by Dr. Giinther. 156 CALIFORNIA ACADEMY OF SCIENCES. 114. Pimelodella lateristriga. Pimelodus lateristrigus Muller & Troschel, Hore Ichthyol. iii, 3, 1849 (Brazil). Pimelodas lateristriga Ginther, Cat. Fish. Brit. Mus. v, 118, 1864 (Brazil); Hensel, Wiegm. Arch. 1870, i, 69 (Porto Alegre); ? Cope, Proc. Philad. Acad. Nat. Sci. 1872, 270 (Ambyiacu River); Liitken, Dan. Selsk. Skr. 1875, 171, fig. (Rio das Velhas); Stein- dachner, SB. Ak. Wien, lxxiv, 1876, Sitisswasserfische siidéstl. Bras. iii, 45. (Rio Parahyba; Rio Doce; Rio Jequitinhonha; Cannavierias; Muriahé and Rio Janeiro); Vaillant, Bull. Soc. Philom. series 7, iv, 52, 1880 (Calderon). Pimelodella lateristriga Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 133, 1888 (Santa Clara; Rio Mucuri; Rio Doce; Cannay- ierias; Sao Matheos; Mendez; Rio Trombetas; Obidos; I¢a). Habitat: Rivers emptying into the Atlantic north of the Rio Parahyba. The specimens examined are from Santa Clara; Rio Mucuri; Rio Doce; Cannavierias; Sao Matheos; Mendez; Rio Trombetas; Obidos; Ica; in all more than one hun- dred specimens. Body elongate, slender, considerably compressed pos- teriorly, head entirely covered with thin skin; fontanel narrow. Occipital process reaching to the dorsal plate, its margins nearly parallel. Eye rather large, 13-13 in snout, 33-33 in length of head, the interorbital 13 in the orbital diameter. Maxillary barbel about to tips of ventrals and origin of adipose dorsal; mentals to edge of gill-membrane or about to base of pectorals. Lower jaw little included; width of mouth at the rictus 22-3 in head; teeth of the lower jaw in a narrow cres- cent; teeth of the upper jaw in a broad band, its depth 4 in its width; both bands interrupted in the middle. Gill-membranes separate to below front of eye. Gill- rakers slender and short, 3-++8. Dorsal spine slender, roughened on its posterior mar- gin, the anterior margin with notches at the tip, its height 14 in the length of the head; the highest ray nearly equal to the length of the head. Dorsal spine SOUTH AMERICAN NEMATOGNATHI. for nearer snout than to the anal fin. Base of adipose fin 3-4 in the length; its distance from the dorsal 3 its own length. Caudal deeply forked, the lobes pointed, the upper lobe } longer than the lower, about 4 in the length. Anal convex, the longest ray 1?-2 in head. Ventrals 12 in head; scarcely reaching more than half way to the anal, inserted a little behind the vertical from the last dorsal ray. Pectoral spine strong, unusually strong and sharp retrorse hooks along the inner margin; the outer margin roughened. The pectoral fin reaches to somewhere be- low the anterior half of the dorsal, not nearly to the ventrals. Color hight brown, a dark lateral band (obsolete in some specimens); fins with dark punctulations at their tips; the adipose fin narrowly margined with dusky. Dorsal and anal fins with the membrane thickened at the base, hyaline above. Head 4-5; depth 63-7; depth of caudal peduncle 2-2; in heads? oD. TGs As 12. The three specimens from Obidos and those from Ica, about eighty in number, are all very small, about .06 m. long. There is a trace of a lateral band, below which there is a broader silvery band. At the humeral re- gion the abdominal wall is transparent. There are in some of these specimens traces of a dark line along the side of the head. They differ from specimens of vittata of the same size in the size of the eye, the slope of the head, the serration of the pectoral spine and the slenderness of the body. The pectoral spine with straight teeth along the anterior margin to near the tip; in the smallest specimens of lJateristriga the serration on the anterior margin of the pectoral spine is entirely obliterated near the base and greatly reduced all along. 158 CALIFORNIA ACADEMY OF SCIENCES. The maxillary barbels reach to the end of the adipose fin. The adipose fin is contained 33 in the length; head 4 in the length; depth 53. 115. Pimelodella harttii. Pimelodus harttii Steindachner, SB. Ak. Wien, Ixxiv, 1876, Siiss- wasserfische stidéstl. Bras. iii, 53 (Rio Parahyba). Pimelodella harttii Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 133, 1888 (name). Habitat : Rio Parahyba. This species is known only from the types. 116. Pimelodella buckleyi. ?Pimelodus lateristriga Cope, Proc. Acad. Nat. Sci. Philad. 1872, 270 (Ambyiacu River, near Pebas). Pimelodus buckleyi Boulenger, Proc. Zool. Soc. Lond. March, 1887, 275, pl. xx, fig. i (Canelos). ? Pimelodella buckleyi Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 183, 1888 (Rio Parahyba; Macacos). Habitat: Rio Parahyba; Amazon. The specimens examined, five in number, measure from .13-.18 m. and are from the Rio Parahyba and from Macacos. The type described by Boulenger differs from the specimens in the collection in having the pectoral spine ‘smooth on its inner edge;” in the longer postmental barbels which extend ‘‘ to the extremity of the pectorals ” and in the longer adipose fin which is ‘‘a little more than one-third of the total length (without caudal).”’ The specimens described below may represent a distinct species. See also description in the key. Body robust, compressed posteriorly, head sub-conical, its width 12 in its length; depth at the base of the occi- pital process 1; width at the angle of the mouth 23-3 in head. Profile decurved, a transverse section of the head convex, occipital process long and slender, its width at the base 3 in its length. Maxillary barbel reaching beyond origin of the anal; mental barbel not reaching to the base of the,pectoral, postmentals about to the middle of the pectoral. SOUTH AMERICAN NEMATOGNATHI. 159 Gill-membranes separate to below the anterior margin of the eye. Eye 13-13 in snout, 33-4 in head, equidistant from snout and posterior margin of opercle; interorbital 1} in eye. Dorsal spine equidistant from snout and anal, its height + In head, the longest rays equal to the head in length. Adipose dorsal 32-4 in the length, its distance from the dorsal fin equals the base of the latter. Caudal lobes of equal width, the upper longer, 4 in the length. Anal rounded, its longest rays 1$-1; in head. Ventrals inserted behind the vertical from the last dorsal ray, 14-1? in head, their tips about 4 of their length from the anal. Pectoral spine little less than the head in length. Color, ight brown; a dusky lateral band; tips of the fins dusky. Head 44-5; depth 54-64; Br. 7; D. I, 6; A. 12-14. 117. Pimelodella vittata. Pseudorhamdia vittata (Kroyer) Liitken, Velhas Flodens Fiske Vidensk. Selsk. Skr. 1874, 34 (Riodas Velhas); id. 1. c. 1875, 173, fig. (Rio das Velhas). Pimelodella vittata Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 133, 1888 (Rio San Francisco; Minas Geraes; Sao Matheos; Rio Jequitinhonha). Habitat: Streams of Minas Geraes and Bahia emptying in the At- lantic. Thirty-five specimens. Rio San Francisco; Minas Geraes; Sao Matheos; Rio Jequitinhonha. Elongate, compressed posteriorly. Head rather broad, its width 14 in its length, at the rictus 25, the depth at base of occipital process 14 in its length; profile convex longitudinally, strongly convex transversely. Occipital process scarcely extending to the dorsal plate. Teeth in bands of equal depth in both jaws, the 160 CALIFORNIA ACADEMY OF SCIENCES. width of the intermaxillary band 33 in the length of the head. Eye 13 in the snout, 4 in the head, about equal to the interorbital space, 1 diameter behind the rictus. Maxillary barbels extending to the adipose fin, mental not to base of pectoral fin, postmental to middle of pec- toral. Gill-opening not extending forward beyond anterior margin of eye. Humeral process reaching about to middle of pectoral spine. Dorsal spine nearer end of snout than to the anal fin, slightly rough on posterior margin, recurved notches near the tip in front, its height 17-13 in the head; high- est dorsal ray about equal to length of head. Adipose fin + in the length, its distance from the dorsal fin 3 the length of its base. Caudal deeply forked, the upper lobe longer, 33 in the length. Anal rounded, 1? in the head. Ventrals in- serted behind the vertical from last dorsal ray, reaching about 2 the distance toward the anal fin. Pectoral spine terete, curved, 1-14 in the head, the rays somewhat longer reaching to below anterior half of the dorsal fin. Depth of caudal peduncle about 3 in the head. Brownish, a dark band along middle of sides extend- ing forward to the snout, sometimes not evident on the head in alcoholic specimens; tips of the fins dusky; basal portion of the dorsal membrane thickened, the re- mainder hyaline. Head 44; depth 6~7; D. I, 6; A. 12. 118. Pimeiodella chagresi. Pimelodus (Pseudorhamdia) chagresi Steind. SB. Ak. Wien, lxxiv, 1876, Ichthyol. Beitr. iv, 34 (Rio Chagres and its tributary near Obispo). Pimelodella chagresi Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 184, 1888 (Obispo River). Habitat: Rio Chagres and its tributaries. SOUTH AMERICAN NEMATOGNATHI. 161 We have examined two specimens from the Obispo River, Panama, .146 m. and .12 m. They were col- lected by Dr. Steindachner, Hassler Expedition, in 1872, and are probably two of the four type specimens. Body elongate, slender, much compressed posteriorly ; greatest width of head about 1% in its length, its depth at base of occipital process 14; width of snout at the rictus about 23. Profile curving very gently from origin of the dorsal fin to the posterior nostrils, thence ab- ruptly decurved. The fontanel forms a depression be- tween the eyes, otherwise the interorbital is flat; post- orbital convex transversely. Teeth in bands of about equal width in both jaws, in- terrupted in the middle in the lower jaw, the width of the intermaxillary band 35% in the head. Occipital process reaching quite to the dorsal plate, articulating with it, the process notched at its tip to re- ceive the dorsal plate. Eye 12-13 in snout, 33 in head, the interorbital about one-sixth less than the diameter of the eye. Maxillary barbels extending to origin of adipose fin and tips of ventrals, mental about to base of pectoral, and postmental barbels to middle of pectoral ffn. Gill-membranes meeting under anterior portion of eye. Humeral process about to middle of pectoral spine. Dorsal spine inserted nearer the tip of the snout than to the origin of the anal fin; straight, scarcely roughened in front except near the tip where there are several notches, its posterior margin with very short teeth along the basal portion in the larger—perfectly smooth in the smaller specimen, with short notches near the tip in both; dorsal spine 1-12 in head, the first ray very nearly as high as length of head, the base of the fin less than its height. Adipose fin 33-32 in the length; in the larger ila 162 CALIFORNIA ACADEMY OF SCIENCES. specimen the space between the beginning of the adipose fin and end of first dorsal is 14 in the base of the adipose, while in the smaller specimen it is nearly 2. Caudal 33-37 in the length, deeply forked, the upper lobe much longer than the lower, pointed; lower lobe rounded. Anal 1? in head. Ventrals inserted immediately behind the vertical from last dorsal ray, their tips reaching the beginning of the adipose, one-fourth their length from the origin of the anal fin. Pectoral spine flat, 13-12? in head, the rays a little longer. Depth of caudal peduncle 2-2} in head. Color brown above, sides lighter, ventral surface white; a well defined dark brown band from tip of snout to caudal, continued on middle caudal rays, widest on shoulder; the dorsal fin with a narrow dark bar on the membrane close in front of each ray and parallel with it; adipose dorsal very narrowly margined with dark; caudal dusky; pectorals, ventrals and anal with very minute punctulations on the margins of the rays. Head 43-45; depth 5-6; D. I, 6; A. 11 or 12. 119, Pimelodella brasiliensis. Pimelodus (Pseudorhamdia) brasiliensis Steindachner, SB. Ak. Wien, lxxiv, 1876, Siisswasserfische siidéstl. Bras. iii, 50, pl. vii (Rio Parahyba). Pimelodella brasiliensis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 133, 1888 (name). Habitat: Rio Parahyba. This species, if the characters assigned to it will prove constant, is the most aberrant of the genus. It is known from a single specimen. XXII. PIMELODUS. Pimelodus Lacépede, Hist. Nat. Poiss. v, 1803 (species of several genera). Pimelodus Cuvier, Regne Animal, 11, 203, 1817 (species having a single band of teeth in the upper jaw). SOUTH AMERICAN NEMATOGNATHI. 163 ? Pimelodus Swainson, Fish. Amph. & Rept. i, 305, 1887 (quadrimaculatus). Pimelodus Liitken, Velhas Flodens Fiske, 43, Vidensk. Selsk. Skr. xii. 2, 163, 1875 (maculatus = clarias). Pseudariodes Bleeker, Nederl. Tijdschr. Dierkunde, i, 1868, 99 (clarias). Pseudorhamdia Bleeker, |. ¢. 101 (maculatus = clarias). Pseudorhamdia Litken, 1. c. 49, 169, 1875 (fur). Type Pimelodus maculatus Lacépede. Bleeker, assuming that the first species mentioned by Lacépede under Pimelodus was the type of Pimelodus, re- stricted the genus Pimelodus to the Silurus bagre Bloch. There is, however, no evidence that the first species men- tioned by Lacépede was his type of Pimelodus, and as Cu- vier restricted the name to those ‘‘ qui ont des dents en velours aux deux machoires, mais ou la supérieure n’en a quwune band intermaxillaire,” the type of the genus must be selected from among them. In 1839 Swainson restricted the genus to quadrimaculatus, one of the species enumerated by Cuvier, and also included in the Pimelodus of Lacépede. The genus Pimelodus must therefore have for its type Silurus quadrimaculatus Bloch, whatever that may be. In 1861 Gill restricted the name Pimelodus with macu- latus as its type. Litken also proposes maculatus as the type. He also restricted the name Pseudorhamdia Bleeker to fur, a spe- cies entirely unknown io Bleeker. Still more inexcusa- ble is the restriction of Steindachner of the same name to still another species not belonging to this genus. If we disregard the many synonyms, the genus is composed of well-defined species inhabiting the region north of the Rio Plata and east of the Andes. Teeth on the vomer in small patches or none; teeth on the pterygoid in one species, otherwise the palate 9 164 CALIFORNIA ACADEMY OF SCIENCES. edentulous. Fontanel not extending backward beyond the eyes. Humeral process broad, not spine-like. Crown of head granulose; in one species covered by very thin skin. Dorsal I, 6. Dorsal and pectoral spines stout. DOUBTFUL SPECIES OF PIMELODUS. 119.1. Rhamdia cyanostigma Cope, Proc. Am. Philos. Soc. 11, 569, 1870 (Pebas, Ecuador). We are unable to tell to which genus this species be- longs. Dr. Cope says (Proc. Am. Philos. Soc. 1878, 675), that this species is allied to Pimelodus ophthalmicus —Pimelodella cristatus. But cristatus is generically dif- ferent from Rhamdia, and was generally considered so when the statement was made. Top of head smooth or with a slight rugosity on the postfrontal region. Depressed dorsal not reaching adi- pose fin. Pectoral reaching 3% to ventral, ventrals $ to anal. Caudal deeply forked, thelobes equal. Maxillary barbels reaching to near the end of the adipose fin. Color plumbeous; head above blackish, with an irrides- cent blue spot above the posterior margin of the orbit on each side. Head less than 5 in the length; depth 73; adipose fin = ea Bien Ce oye 2 Nose) 119.2. Sitlurus quadrimaculatus Bloch, Ausland. Fische, part 8, 37, plate 368, 1794(America); Cuv. & Val. Hist. Nat. Poiss. xv, 185, 1840 (America). Adipose fin long, covering almost the entire postdor- sal region. Head flat, opercles granular. Palate rough. Maxillary barbels as long as the entire fish. Vent equi- distant from snout and caudal. Only the pectoral spine stiff, and with teeth. Body brown with violet reflec- tions, ashy below, fins yellowish. Br. 5; D. 7; A. 9. Bloch says nothing in his description about the four fantastical spots of his figure. Perhaps the spots were placed there to have the fish agree with its name. SOUTH AMERICAN NEMATOGNATHI. 165 ANALYSIS OF THE SPECIES OF PIMELODUS. a. Head granulated, entirely naked above. b. Length of adipose dorsal 34 in the length or shorter; caudal rays not produced, not much longer than head; maxillary barbels not extend- ing much beyond tips of caudal, mostly much shorter. c. Intermaxillary band of teeth present. d. Anal rays 11 to 13; adipose dorsal longer than base of anal. e. Caudal obliquely rounded, the lower rays much the longer; occipital crest as wide as long, its tip deeply forked, receiving dorsal plate in its notch; anal narrowly rounded. eques 120. ee. Caudal deeply forked. f. Anal rounded. Intermaxillary band of teeth twice as wide as the mandibulary band. Snout projecting. ornata 121. Jf. Anal emarginate, some of the first rays extending beyond the tips of the last. Intermaxillary band of teeth scarcely broader than the mandibulary band. g. Teeth on pterygoids usually present; the vomerine patches of teeth reduced to a minimum or absent. h. Teeth on the yomer, none on the pterygoids; head rather broad, flattish, granulose; eye small, 7-9 in head. albicans 122. hh. Minute patches of teeth on vomer or none; pterygoid teeth usually present; eye large. i. Caudal with brown bars. pictus 123. zi. Caudal without brown bars. clarias 124. gg. No teeth on vomer or pterygoids. j. Lips thin, normal; body thickly covered with black spots. Dorsal spine 4 longer than head; adipose dorsal longer than head. Maxillary barbels reaching past anal, mental barbels past middle of pectorals; postmental past base of ventral. Eye 3 in snout, 6} in head. Lower jaw in- cluded; depth of intermaxillary band of teeth 4 in its width. Opercle } longer than the diameter of the eye. Pectoral plate elongate, subelliptical, its width 34 in its length. Caudal lobes pointed, the upper longer than head. Adipose dorsal about 3} in the length. Pectoral spine about equal to the head in length. (Steindachner.) grosskopfit 125. jj. Lips very thick; teeth on intermaxillaries in a very short band. Head pointed, almost conical, granulated to near posterior nostrils. Maxillary barbel extending to near tip of caudal, sometimes shorter. Hye midway be- tween posterior nasal opening and gill-opening, more than 5 in head, less than two in interorbital. Mouth very narrow. Dorsal spine serrate behind, as high as 166 CALIFORNIA ACADEMY OF SCIENCES. the length of the adipose dorsal; pectoral spine serrated on both edges, 1} in length of head. Uniform dark above, lighter below. (Liitken.) labrosus 126. dd. Analrays 17. Adipose dorsal equals anal. Body rather high and compressed; head depressed; profile straight; width of the head 24 in its length. Eye 6 in length of head, 2 in interorbital. Upper jaw somewhat projecting; teeth in both jaws in shallow and narrow bands. Maxillary barbel to anal; post-mental bar- bels to ventrals; mentals slightly shorter. Dorsal spine serrate behind, little shorter than the pectoral spine which is serrated on both margins; pectoral spine 11 in head. Head 4}in total length; depth 54. D.I,6. A.17. (Liitken.) valenciennis 127. cc. Intermaxillary teeth none; snout long, sub-conical, lips broad; mouth small. Eye 5 in head; interorbital area little narrower than eye; dorsal spine serrated behind, shorter than head; pectoral spine 12 in head. Adipose dorsal 4 in the length; maxillary barbels to caudal; mental barbels to gill-opening; postmental to pectoral. Head 4; depth 54; D. I, 6; A. 12 or 13. (Liitken.) westermanni 128. bb. Length of the adipose fin 22-23 in the length; caudal lobes pro- duced, twice as long as head; maxillary barbels extending much be- yond tips of caudal. altipinnis 129. aa. Head granulated above but covered with a very thin skin; upper anterior half of body with dark spots; anal emarginate. Sur 130. 120. Pimelodus eques. Pimelodus eques Miller & Troschel, Schomburgk Brit. Guiana, 628, 1848 (in all rivers of Guiana); Miller & Troschel, Horx Ich- thyol. iii, 5, 1849 (Guiana); Giinther, Cat. Fish. Brit. Mus. v, 116, 1864 (copied); Steindachner, SB. Ak. Wien, lxxiv, 1876, Ichthyol. Beitr. vy, 99 (Amazon near Fonteboa; Teffé; Obidos; Villa Bella; Jose Fernandez; Xingu; Tonantins; Hyutahy; Lake Hyanuary); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 134, 1888 (localities mentioned by Steindachner). Habitat: Brazilian Amazon and its tributaries and northward. The flat head and peculiar shape of the occipital crest, the shape of the anal, etc., distinguish this from all other related species. Body not as wide as deep at the shoulders, compressed towards the caudal; head flat, depressed, its greatest width 14 in its length, its greatest depth about 23. En- tire upper portion of head granulose or striate; fontanel continued as a narrow groove to the occipital crest. Tip of occipital crest emarginate, articulating with the SOUTH AMERICAN NEMATOGNATHI. 167 shield-shaped dorsal plate. Distance between the nos- trils equal to % the diameter of the eye. A deep groove from maxillary barbel to below eye, the barbel reaching in No. 7574 beyond the caudal, in the longest ‘specimen, No. 7478, to the base of the adipose dorsal; postmental barbels inserted behind and outward from the mentals; mental barbels extending to base of pectorals, slightly shorter in adult; postmentals not to tip of pectoral. Kye large, 5 to 6 in the head, 2 to 23 in the snout, 14-2 in interorbital region, 1} diameters behind the rictus. Jaws subequal, the upper a little longer; width of the mouth 24 in length of head; both lips papillose; teeth of the lower jaw in a band equal to § the diameter of the eye in depth, tapering to behind the rictus; a broad papillose membrane behind it which is not much broader at the rictus; teeth of the upper jaw in a band scarcely deeper than the band of the lower jaw, not interrupted at the middle; the band of the lower jaw broadly inter- rupted at the middle; chin and snout with numerous pores. Gill-membranes separate to nearly underneath the rictus; gill-rakers overlapping, 24-12, in a single series on the first two arches, the inner series being replaced by a scalloped membrane. Dorsal spine rather weak, 13 in head, the highest ray 1? in head, the free margin of the fin rounded; the basal fulerum strong, the spine inserted forward of the middle between base of pectoral and of ventral fins, equidistant from snout and beginning of the anal fin. Adipose fin long, 3-34 in the length. Caudal fin obliquely rounded. the lower portion longer, 14 in head. Anal with its free margin narrowly rounded, the eighth ray highest, 2 in head, the base of the fin equal to two-thirds its height. Ventrals 13 in head. 168 CALIFORNIA ACADEMY OF SCIENCES. Pectoral spine very strong and long, scarcely shorter than the rays, 13 in head; strong extrorse teeth on the anterior and retrorse on the posterior edge of the spine. Depth of caudal peduncle 34 in length of head. Color brownish marbled with darker; gill-membrane broadly edged with white, in front of which is a black bar; a large black spot on shoulder sometimes continued across the back in front of the dorsal spine and as a lateral band to the caudal; base of caudal dark brown; fins dusky, spotted with darker. Eleasd’s=3)> depths; Br? 72D. 1 765 AS ae Twenty-three specimens .13-.30 m. Tonantins; Fonte- boa; Jose Fernandez; Jutahy; Xingu; Obidos; Lake Hyanuary; Teffé; Villa Bella. 121. Pimelodus ornata. Pimelodus ornatus Kner, SB. ,Ak. Wien. xxyi, 411, fig. 18, 1857 (Surinam; Rio Negro; Cujaba); Giinther, Cat. Fish. Brit. Mus. v, 116, 1864 (River Capin; Para); Peters, MB. Ak. Berlin, 470, 1877 (Calabozo); EKigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 134, 1888 (Goyaz). Pseudorhamdia ornata Bleeker, Silures de Suriname, 77, 1864 (Surinam). Silurus megacephalus Natterer in Kner, 1. c. Habitat: Brazilian Amazons and tributaries and the region north- ward. Body slender, elongate. Head depressed, flat above, its depth at base of occipital process 24 in its length, its greatest width 13; fontanel wedge-shaped, its broad end above the posterior margin of the orbit; occipital pro- cess comparatively slender, its width at the tip less than half its greatest width which is 13 in its length. Eye large, 2 in snout, 14 in head, 13 in interorbital. Maxillary barbel reaching to below adipose fin; post- mentals a little beyond base of pectoral. Snout depressed, elongate, subspatulate, the upper jaw projecting beyond the lower. Intermaxillary band of SOUTH AMERICAN NEMATOGNATHI. 169 teeth very deep, its depth 4 in its width; mandibulary band of teeth at the sym- pales physis about one-half as wide as the in- 4! ~ termaxillary band. Gill-rakers 4-+-10. Distance of dorsal spine from snout 23 in the length, the spine high and slender, 2 in head; its anterior mar- gin smooth, the posterior margin verrucose. Distance of adipose fin from the dorsal equal to the length of the dorsal. Adipose fin 53 in the length. Pectoral spine about 2 in head, its anterior margin with short blunt teeth, the posterior margin with long teeth. Head 35°" Bre 9=10=\D. Wy GarA. AS: A single specimen in poor condition .18 m. Goyaz. 122. Pimelodus albicans. Arius albicans Valenciennes, Voy. d’Orb. pl. iii, fig. 2, 1847. Arius albicans Cuv. & Val. Hist. Nat. Poiss. xv, 80, 1840 (Buenos Ayres). Piramutana albicans Giinther, Annals & Mag. Nat. Hist. 1880, 9 (Rio Plata). Arius moroti Valenciennes, Voy. d’ Orb. 6, 1847 (La Plata). Pimelodus albicans Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 134, 1888 (La Plata). Habitat: Rio Plata. Dr. Giinther is the first to have rediscovered this species. All the specimens referred to albicans by Liitken, Steindachner and others belong to P. clarias. As Valenciennes and Giinther state, this species has no teeth on the pterygoids; it always has teeth on the vomer. In the smallest and largest specimens exam- ined they are present on one side only. It is further dis- tinguished by its small eye and depressed head. The vomerine teeth are scarcely sufficient to separate this species from Pimelodus generically. Head rather broad, granulose. Eye small 34-43} in snout, 7}-9 in head, 23-3 in interorbital, 1 in interna- sal space. 170 CALIFORNIA ACADEMY OF SCIENCES. Maxillary barbels reaching to middle of anal, mentals to base of pectoral, postmentals to tips of pectorals. Width of mouth 23-23 in length of head; lower jaw included. Depth of intermaxillary band of teeth 5-6 in its width. Opercle twice as long as the eye. Humeral process broad, pointed. Caudal lobes acute, the upper lode 3—§ longer than the head. Dorsal spine 1}-17 in head; adipose dorsal shorter than the head. Pectoral spine 14-12 in head. Color uniform brownish, the young with traces of longitudinal stripes. Four specimens, the largest .50 m. Buenos Ayres. 123, Pimelodus pictus. Pimelodus pictus Steindachner, SB. Ak. Wien. Ixxiv, 1876. Ich- thyol. Beitrige, v, 96 (Peruvian Amazon; Hyavary). Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 134, 1888 (Hyavary). Habitat: Marafion. Profile steep, convex, interorbital region flattish; post- orbital portion of the head strongly convex in trans- verse profile; occipital process keeled. Bones of the head granular. Entire intermaxillary band of teeth projecting; vomer with small patches of teeth. Eye 33 in head, 13 in the snout; 14 in the interorbital. Maxillary barbels reaching a little past the base of the adipose or to the caudal; mental barbels reaching the base of the pectoral ; post mentals to the tip of the pectorals. Distance of the dorsal spine from the snout 25 in the length. Dorsal spine as long as the head, serrated on its posterior margin, slightly so near the tip in front, finely granular below. Distance of the adipose fin from the dorsal fin equals the length of the adipose fin which is 6 in the length. SOUTH AMERICAN NEMATOGNATHI. 171 Caudal deeply forked, longer than the head. Pectoral spine strongly serrated on both margins, the serrations on the inner margin a little stronger; the spine a little shorter than the head. Pectoral pore pres- ent; humeral process triangular, pointed behind and reaching a little behind the middle of the pectoral spine, its surface granular-striate. Silvery below, becoming brownish above; indistinct darker markings on the back. Dark spots on the bases of the dorsal rays, membrane of the dorsal transparent, the tips of the rays brown, a brown spot between the first and second rays in one of the specimens. A brown spot at the tip of the adipose fin. Two dark spots at the base and two or three brown bars on the lobes of the caudal; other fins plain white. Headia 2 De hogs Ag At, Two specimens .075-.085 m. Hyavary. Bourget. 124, Pimelodus clarias. Silurus clarias Bloch, plate 35, fig. 1-2=Silurus clarias Linneus in part; not Silurus clarias Hasselquist which is Synodontis clarias from the Nile. Pimelodus clarias Lacépéde, Hist. Nat. Poiss. v, 93, 1803 (?8 dorsal rays); Castlenau, Amin. Nouv. Amér. Sud, 34, 1855 (Crixas; Araguay, Ucayale; Amazon); Steindachner, Fish-fauna Magd. Stromes, 15, 1878 (Magdalen River); Steindachner, Flussfische Sudamerikas, i, 10, 1879 (Orinoco near Cuidad Bolivar), 14 (Mamoni River near Chepo); Steindachner, Flussfische Siid- amerikas, iv, 4, 1882 (Rio Huallaga); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 134, 1888. Bagrus (Ariodes) clarias Miller & Troschel, Schomburgk Brit. Guiana, 627, 1848 (Waina Barima). Ariodes clarias Miiller & Troschel, Hore Ichthyol. iii, 10, 1849 (British Guiana); Kner, SB. Ak. Wien, xxvi, 1857, 413. Pseudariodes clarias Bleeker, Nederl. Tijdschr. Dierkunde, i, 99, 1863 (name only); Liitken, Meddel. Nat. Hist. Forening, 1874, Nos. 1 & 2, pages 194 & 199 (Guiana). Silurus callarias Bloch & Schneider, ‘‘Syst. Ichthyol. in part, 379, 1801.” Pimelodus maculatus Lacépéde, Hist. Nat. Poiss. v, 94 and 107, 1801 (Rio Plata); Valenciennes, Voy. d’Orbigny, ix, Atlas ii, 7x2 CALIFORNIA ACADEMY OF SCIENCES. plate i, figs. 1-3, 1847 (La Plata to Mexico, Lake Maracaibo); Cuv. & Val. Hist. Nat. Poiss. xv, 192, 1840 (Cayenne; Mara- caibo); Schomburgk, Fishes of Guiana, part i, 175, 1841 (Rivers of Guiana generally; Rio Negro; Amazon); Steindachner, SB. Ak. Wien, lvi, 1867, Ichthyol. Notiz. vi, 32 (La Plata); Stein- dachner, SB. Ak. Wien, lx, 1869, Ichthyol. Notiz. ix, 6 (Monte- video); Hensel, Wiegm. Arch. 1870, i, 69 (Jacuhy); Liitken, Dan. Selsk. Skr. 163, fig. 1875 (Rio das Velhas); Steindachner, SB. Ak. Wien, Ixxiv, 1876, Siisswasserfische siidéstlichen Bra- siliens, ili, 40 (La Plata; Rio San Francisco; Rio das Velhas; Amazon between Para and Santarem; Rio Grande do Sul; Porto Alegre); Peters, MB. Ak. Berl. 470, 1877 (Calabozo). Pimelodus rigidus Spix, Gen. et Spec. Bras. plate vii, fig. 2, 1829. Pimelodus blochii Cuy. & Val. Hist. Nat. Poiss. xv, 188, 1840 (Cay- enne; Surinam). Piramutana blochii Giinther, Cat. Fish. Brit. Mus. v, 111, 1864 (copied); Vaillant, Bull. Soc. Philom. series 7, iv, 152 (Cal- deron). Pimelodus arekaima Schomburgk, Fish. Brit. Guiana, i, 178, plate not descr. 1841 (Essequibo). Mystus ascita Gronow, ‘‘ed. Gray 156.” Pseudorhamdia ascita Bleeker, ‘‘ Versl. & Meded. Acad. Wet. Amsterd. 1862, 384.” Pimelodus macronema Bleeker, Silures de Suriname, 79, plate 14, 1864 (Surinam). Pseudariodes albicans Liitken, Meddel. Nat. Hist. Foren. 1874, Nos. land 2, pages 194 and 198, not Arius albicans of Valenciennes (La Plata and its tributaries); Steindachner, Fisch-Fauna Magda- lenen Stromes 61, note, 1878. Pseudariodes pantherinus Liitken, Meddel. Nat. Hist. Forening. 1874, Nos. 1 and 2, pages 192 and 199 (Venezuela). Pseudorhamdia piscatrix Cope, Proc. Am. Philos. Soc. xi, 569, 1870 (Pebas); id. Proc. Philad. Acad. 1872, 262 (Ambyiacu River); id. Proc. Am. Philos. Soc. xvii, 674, 1878 (Peruvian Amazon). Piramutana macrospila Giinther, Annals & Mag. Nat. Hist. July, 1880, 10, plate ii (Rio Plata). Habitat: Rio Plata and region to the north of it and east of the Andes. There seems to have been considerable confusion in the nomenclature of this species, owing to its great var- iability, and for other reasons. Linnaeus had two species, this and one from the Nile. Bloch figured the American species, while he gave as a synonym the Nile species. His figure should restrict the SOUTH AMERICAN NEMATOGNATHI. Lie name clarias to the American form; he probably copied his synonymy. Cuvier and Valenciennes restrict the name clarias to the Nile species, and propose the name blochii for the American form. Miiller and Troschel first identified this species with Arius albicans Valenciennes; they were followed by Giinther in his Catalogue; and Steindachner in Siiss- wasserfische stidostl. Bras. iv. Bleeker next supposes he has a new species from Surinam allied to maculatus, and names it macronema. Liitken next gives the differences between what he supposes are albicans and clarias. As Dr. Giinther has shown (Annals and Mag. Nat. Hist. 1880, 10), his albz- cans was not Arius albicans Valenciennes. Liitken also described a new species, pantherinus, from Venezuela, and argues that the northern and southern forms are distinct; he did not have specimens from the Amazon. Dr. Steindachner (Fisch- Fauna des Magdalenen Stromes, 15) says that this species (clarias) is equally abundant in the Magdalen River, the Orinoco, the Amazon and the Rio Plata. He identifies albicans, pantherinus and macronema with clarias. He has ex- amined thirty-six specimens from the Rio Magdalena which are all unspotted and have no teeth on the vomer, and frequently the pterygoid teeth are absent; the only constant character being the black spot at the base of the dorsal spine. The specimens described by Kner belong to the variety pantherinus. ‘‘ Mit Riicksicht auf das Langenverhaltniss der Fettflosse zur Dorsal und Anal;”’ kénnte diese Art ‘‘ wieder in drei kiinstliche Arten zersplittert werden.”’ But later (page 61) in the same paper, in a note, Dr. Steindachner states that since the above was written he has received a specimen of the albicans Liitken (not of Valenciennes), and that it is 74 CALIFORNIA ACADEMY OF SCIENCES. distinct from clarias, and more closely related to macu- latus than to clarias. The piscatriz Cope, and macrospila Giinther, should also be referred to this species. The Mystus No. 84 Gronow was referred successively by Valenciennes to clarias, by Giinther to maculatus, and by Bleeker to macronema. GENERAL DESCRIPTION. Body robust, especially in older specimens; head coni- cal, its greatest depth 2, its greatest width 13 in its length; the ossification of the head exposed, granular; occipital process arched transversely, its width at the base # its length. Maxillary barbel, terete extending beyond the tips of the dorsal; mental and postmental barbels almost equi- distant from each other, the mentals about reaching to the pectoral; the postmentals beyond the middle of the pectorals. Mouth moderate, its width at the angles 24 to 33 in the length of the head; the lower jaw is included, the upper bordered by a broad lip. Teeth in lower jaw in bands which taper to a point behind the rictus, interrupted in the middle; teeth of the upper jaw in a narrow uninterrupted band; some- times minute patches of teeth on the vomer, some- times larger patches on the pterygoid bones. Gill-membranes separate to in front of eye; gill-rakers 6+19. Adipose dorsal short, 384 to 54 in the length. Caudal divided to near its base. Anal emarginate, the fourth ray highest, extending beyond the tip of the last ray. Ventrals short and broad, extending 3 of their length beyond the vent. SOUTH AMERICAN NEMATOGNATHI. iS Pectoral spine roughened in front, strong recurved teeth behind. Depth of caudal peduncle 23 to 3 in head. Head. 34 to 44; depth 3% to 5; Br. 9; D. I, 6; A. 11. We have examined about four hundred specimens of this species, some of which have teeth on the vomer and some have not. Some have teeth on the pterygoid and some have not; some have the sides thickly covered with small spots (pantherinus); some have the sides covered with from three to five series of large spots (macrospila); some have the sides plain (macronemu, piscatriz); some have three or four black bands along the sides; some have long maxillary barbels, and some have shorter ones; some have a long or shallow band of teeth on the intermaxillary, and some have a deeper, shorter band; some have a black spot at the base of the dorsal plate and some have not. They are labelled Pimelodus macu- latus. It seems that the species Pimelodus maculatus Auct. goes through a similar variation of color and other characters. The maculatus has been confounded with clarias by Kner, Steindachner (as shown by the labels), and Liitken, and in fact the only difference between the two species is the presence of teeth on the pterygoids and vomer in the one and their absence in the other; and when these teeth in clarias are absent, as they sometimes are, it cannot be distinguished from maculatus, and maculatus, with all its synonyms, may be placed in the synonymy of clarias. We should perhaps state in this connection that we have examined almost every specimen in the museum at least four times, that we have several times separated the material according to the variation of the different parts, and that we have been enabled to separate the material into several varieties, some of which have not yet been described. 176 CALIFORNIA ACADEMY OF SCIENCES. As already stated Arius albicans is a distinct species. We add here descriptions of the more striking varie- ties represented in the museum. We have not made any reference to the teeth, as they are such a variable quantity in all the varieties. The variety with plicate lips (maculatus?) seems to be more frequently destitute of teeth on the vomer than the others. Intermediate forms between all of these varieties are in the collection. 124a. Lips distinctly plicate; maxillary barbel ex- tending to base of anal, or slightly longer; mental bar- bels about to base of pectoral fin; postmental past mid- dle of pectoral; mentals and postmentals compressed. Eye 23-23 in snout, 5-5? in length of head, 13-1? in interorbital. Width of mouth about 3 in head; the teeth of the upper jaw scarcely projecting beyond the lower; depth of the intermaxillary band of teeth 44-43 in its width. Distance between anterior and posterior nasal open- ings about equal to the eye. Opercle scarcely longer than the diameter of the eye. Pectoral plate elongate, subelliptical, its width about 3 in its length. Caudal lobes pointed, the upper longer than the head. Adipose dorsal 4—43 in the length. Dorsal spine about equal to the head in length; pec- toral spine 1j-13. Ventral fin 13-2 in head. Body with four or five rows of large brown spots; spots on head; sometimes the spots are much smaller and irregularly scattered. ‘‘Lacépede described his Pimelodus maculatus after Commerson who had specimens from the Rio Plata.” (Val.) The specimens in the museum agree closely with the description given by Valenciennes and the figure by Litken in Velhas Flodens Fiske, page 165; they are from the Rio das Velhas; Uraguay; Giquitiba; Rio Grande and Buenos Ayres. SOUTH AMERICAN NEMATOGNATHI. 77 About twenty specimens from Goyaz represent a variety intermediate between this and the next. They have the lips not plicate, the maxillary barbel extending not quite to the caudal, the humeral plate angulated above; numerous spots on head and body. Six other specimens from the Rio Grande do Sul, Emperor’s collection. Some of these have three series of spots, others have six or seven rows covering the sides. Two have teeth on the pterygoids. 124b. Dorsal spine shorter than head; pectoral plate subrhomboidal, its upper and its posterior margins con- cave, decided angle between the two faces. Caudal lobes long and pointed, the rays normal; upper lobe longer than head. Maxillary barbel long, reaching to or beyond base of caudal; mentals beyond base of pectorals, postmentals beyond base of ventrals. Kye 13 in snout, 3 to 3$ in head, 14-2 in interorbital. Mouth at the angle, about equal to snout, 24-2? in head; a portion of the intermaxillary band of teeth pro- jecting beyond the lower jaw; its depth about 4—6 in its width; distance between anterior and posterior nares 13 in eye. Opercle narrower than eye, its length 13-1} in the diameter of the eye. Humeral process more angular and more slender than in any other variety. Adipose dorsal about 5 in the length. Dorsal spine very nearly equal to the head in length; pectoral spine 13 in head, ventral fin 1%. Color silvery, marked with brown; head vermiculated with brown; body with about four longitudinal bands of brown, sometimes more or less broken up into spots; a dark spot at base of dorsal spine; adipose dorsal spotted 12 178 CALIFORNIA ACADEMY OF SCIENCES. with brown; dorsal with smutty tips; other fins plain. Color sometimes uniform. This variety is the one commonest in the Amazon system. The museum contained specimens from Para; Porto do Moz; Santarem; Obidos; Villa Bella; Coary; Teffé; Fonte Boa; Tabatinga; Hyavary; Cudajas; Rio Goncallo; Montalegre; Rio Reto; Rio Puty; Manacapuru; Tonantins; Lago Alexo; Cameta. This variety could again be divided; the most western specimens are more uniform in color; the color markings becoming more distinct eastward as far as Santarem where the color is in well-defined areas as described. In some examples the profile is straight and in others the head is depressed, with a marked angle at the base of the occipital crest. In some specimens the body is much shortened and deepened, and the lateral bands are broken up into spots, making exact counterparts of the plate of macrospila=are- karma. 124c. A single specimen in bad condition differs from the descriptions given above. No. 7461; .16m. Rio San Francisco. Snout pointed; eye large. 323 in head, 13 In snout; maxillary barbels extending beyond anal; humeral pro- cess straight below, curved above, ending in a sharp point. Dorsal spine 13 in head; pectoral spine as high as the dorsal spine, smooth in front, sharp recurved hooks its whole length behind. Internasal distance 3 in eye. 124d. Maxillary barbel to end of adipose; mentals not beyond middle of pectoral; postmental to base of ventral. Eye 2 in snout, 43 in head, 13 in interorbital. Mouth at the angle 3 in length of head. Upper jaw projecting beyond the lower, depth of the intermaxillary band of teeth not wider than the maxillary band; internasal space 2 in the eye. SOUTH AMERICAN NEMATOGNATHI. 179 Opercle as wide as eye. Humeral process very angu- lar rhomboidal, wider than in II. Adipose dorsal 13 in head. Dorsal spine 1 in head; pectoral spine 1} in head; ventral fin 13 in head. Plain dusky, all the fins dusky; a dark spot at base of dorsal spine; sometimes with a light streak along the lateral line. The specimens in the museum are from Avary, Para; Ica; San Gongallo; Jutahy; Rio Puty. The longest specimen measures .25 m. 124e. Dorsal spine longer than head; humeral pro- cess triangular. Maxillary barbel extending beyond base of caudal; mental beyond base of ventral; postmental to near vip of pectoral. Eye 2 in snout, 3-45 im head. Distance be- tween anterior and posterior nares 2 in eye. Width of intermaxillary band of teeth about 6 in its length. Opercle about equal to the length of the eye. Caudal lobes pointed, } longer than head. Adipose dorsal about 5 in the length. Dorsal spine § longer than head; pec- toral spine about as long as the head. Ventral fins little shorter than head. Color brownish, white below. This variety representing the macronema of Bleeker is represented by several specimens from the Amazon. From the descriptions here given it will be seen that not all the varieties so far described are represented; also that some not yet described are in the collection. We have not thought it best to name the old or the new varieties. In order to settle the boundaries of each variety, one should have an unlimited supply of speci- mens of all the varieties; until such a collection is made it is useless to name them as there would assuredly be a shifting of names, and the confusion is already great enough. 180 CALIFORNIA ACADEMY OF SCIENCES. 125. Pimelodus grosskopfii. ; Pimelodus grosskopfii Steindachner, SB. Ak. Wien, lxxx, 1879, Ichthyol. Beitrige, viii, 68 (Cauca); Steindachner, Fisch-Fauna des Cauca & Flisse bei Guayaquil, 5, pl. i, fig. 1-la, 1879 (Cauca). Habitat: Magdalen river and itsjtributaries. We have not seen any specimens of this species; it seems to agree very closely with some forms of clarias. 126. Pimelodus labrosus. Pimelodus labrosus (Kroyer MS.)-Liitken, Vidensk. Meded. 1874, 200 (La Plata). Habitat: La Plata. This may be a valid species. Dr. Liitken even places it in a group distinct from maculatus, but as he has not made the differences evident to one who has not both species or varieties we have placed it here. Only the types are known. 127. Pimelodus valenciennis. Pimelodus valenciennis' (Kroyer MS.) Liitken, Vidensk, Meded. 1874, 200 (La Plata). ? Pimelodus nigribarbis Boulenger, Ann. & Mag. Nat. Hist. Oct. 1889, 266 (Camapuam River). Habitat: Rio Plata. This species is distinguished chiefly by the length of its anal and adipose fins. It is known only from the types. 128. Pimelodus westermanni. Pimelodus westermanni (Reinhardt MS.) Liitken, Dan. Viden. Selsk. 1874, 32 (Rio das Valhas); Dan. Selsk. Skr. 167, plates ii and iii, fig. 4, 1875 (Rio das Velhas). Habitat: Rio das Velhas. This species is distinguished chiefly by the absence of an intermaxillary band of teeth. Only the types are known. 129. Pimelodus altipinnis. Pimelodus altivinnis Steindachner, SB. Ak. Wien, lix, 1864, Ichthyol. Notiz. i, 14, plateii, figs. 3 and 4 (Demarara); id. lxxiv, 1876, Ichthyol. Beitr. iv, 56, plate xi (Para; Santarem; Cameta); Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 135, 1888 (Para). Habitat: Amazon and northward. SOUTH AMERICAN NEMATOGNATHI. 181 The numerous specimens in the museum are from Para. Body deeper than wide, compressed towards the cau- dal; head flat below, regularly convex in a cross-section above; profile straight or making a decided angle at the base of the occipital crest; width of the head about 12 in its length, its width at the angle of the mouth 3; its depth 14; entire upper portion of head granulate or striate; fontanel wedge-shaped, its broad base opposite the posterior margin of the eye. Occipital crest narrow; its width at the base 2 in its length; its tip truncate. Distance between the anterior and posterior nares equal to the diameter of the eye. Maxillary barbel reaching far beyond tips of caudal; mental barbels to middle of pectoral, postmentals beyond tip of ventral. Kye very small, 53-6 in head, 23-3 in snout, 1) in interorbital, 2 diameters behind angle of mouth. Mouth narrow, distinctly inferior, the upper jaw pro- jecting beyond the lower for at least half the diameter of the eye; depth of mandibulary band of teeth 2 in eye; intermaxillary band scarcely deeper, its depth 5 to 6 in ts width; numerous minute pores about the snout. Gill-membranes separated by a deep notch to in front of the eye; gill-rakers 5+10, the first two arches with a single series and a membrane, the third and fourth with two series. Dorsal spine 14 in head, with sharp, short teeth be- hind; longest dorsal ray about as long as the head; the spine equidistant from snout and tips of ventrals, measur- ing in a straight line. Interspace between the dorsals reduced to a minimum. Adipose dorsal long and low, 22 in the length. Caudal very deeply forked, the outer rays about five times as long as the middle rays, twice as long as the head. 182 CALIFORNIA ACADEMY OF SCIENCES. Anal emarginate, the last ray longer than the three rays preceding it, the fourth ray longest. Ventrals equal the head in length; reaching about 3 beyond the vent; distance from vent to anal longer than head; the head 24 in the distance from the vent to the caudal. Pectoral spine flat and curved, roughened near its middle in front, strongiy recurved hooks its entire length behind; its length 1; in head. Depth of caudal peduncle 23-3 in head. Color plain greenish; tips of dorsal dusky. Head 5; depth 4 to 54; Br. 7; D. I, 6; A. 11. 130, Pimelodus fur. Pseudorhamdia fur (Reinhardt MS.) Liitken, Dan. Viden. Selsk. 1874, 33 (Rio das Velhas); Liitken, Dan. Selsk. Skr. 169, plates li and iii, fig. 3, 1875. (Rio das Velhas). Pimelodus fur Figenm. & Kigenm., Proc. Cal. Acad. 2d Ser. i, 135, 1888 (Rio das Velhas; Giquitiba; Rio San Francisco). Pimelodus maculalus Kner, SB. Ak. Wien, xxvi, 413 (Irisanga; Rio Branco; Barra do Rio Negro); in part. Pimelodus microstoma Steindachner SB. Ak. Wien. Ixxiv, 1876, Siisswasserfische siidéstl. Bras. ili, 44, foot note (Irisanga; Rio Branco; Barra do Rio Negro). Habitat: Amazon, Rio San Francisco and its tributaries. We are unable to distingush Pimelodus microstoma from the specimens of P. fur in the Museum. The specimens examined are soft and their depth is not as given by Liitken and Steindachner. They are from the Rio das Velhas and Giquitiba on the Rio San Francisco. Body slender, compressed towards the caudal; head conical, scarcely wider than the body; its width 12 in its length; its depth, at the posterior margin of the eye, 2 in its length; profile regularly curved from the dorsal spine to the snout; head convex in tranverse section. Occipital crest triangular, longer than wide, entirely covered with thin skin; fontanel not extending to oppo- site posterior margin of eye; a small groove or pit at the SOUTH AMERICAN NEMATOGNATHI. 183 base of the occipital crest; distance between anterior and posterior nares equals ? the diameter of the eye. Maxillary barbel extending to the base of the caudal or posterior margin of anal; mental barbels to base of pectoral; postmental to near tip of pectoral. Kye 13 to 14 in snout, 33 to 4 in head, 3 in interor- bital. Mouth narrow, 3 in head, bordered by a broad lip; depth of intermaxillary band of teeth about 3 in its width, the outer row of teeth longer than the others. Gill-openings separate to a little in front of eye; gill- rakers 412. Humeral process as wide as in clarias. Dorsal spine nearer snout than anal fin, measuring in a straight line; rather strong teeth behind, 1} in head. Adipose dorsal high and thin; its distance from the dorsal longer than the base of the dorsal, about 43 in the length. Caudal deeply forked, upper lobe slightly longer, longer than head. Anal concave, the third ray longest, 14 in head. Ventrals 14 in head. Distance between the vent and anal one-half a diameter of the eye shorter than head. Pectoral spine roughened in front, close-set recurved hooks its whole length behind; 1% in head. Upper half of body greenish-gray (olivaceous), below the lateral line white; a dusky area behind the humeral arch; upper anterior portion of body and sometimes top of head with numerous small round dark spots. Dorsal fin dusky on its free half, and a series of dark spots at its base. Other fins plain. Head 43; depth 63; D. I, 6; A. 12. eile Gen. Noy. 2 131. ?% agassizii. Pirinampus agassizii Steindachner, SB. Ak. Wien, Ixxiv, 1876, Ichthyol. Beitr. iv, 57, pl. 12 (Para); Vaillant, Bull. Soc. Philom. series 7, iv, 153, 1880 (Calderon). Habitat: Amazons. 184 CALIFORNIA ACADEMY OF SCIENCES. This species seems to differ decidedly from other genera. We have not been able to examine any speci- mens, and leave its generic identification to some one who can examine specimens. Head, behind the eyes, granulated; first dorsal ray spinous and much shorter than the next ray. Fontanel not extending behind the eyes. Occipital process not reaching the dorsal plate; barbels compressed, ribbon- like. Profile straight to the base of the occipital crest, some- what steeper behind; transverse section of the head convex; width of head 1% in its length. Upper jaw pro- jecting for about 4 the width of the intermaxillary band of teeth. Occipital process narrow, not reaching to the dorsal plate. Frontal fontanel widest behind, ending abruptly above the posterior margin of the eye. A small occipital fontanel (in specimens .195 m.) Mental barbels long, band-like. Maxillary and postmental bar- bels reaching to end of anal; mentals to near tip of ventral fin. Pectoral and dorsal spines slender, their inner and outer margins with fine teeth. Highest dor- sal ray little less than the head in length. Pectoral spine little less than the head in length, reaching to near the shorter ventrals. Adipose fin 2} in the length. Upper caudal lobe longer. Chocolate brown, with numerous round, dark violet spots everywhere except on belly. Head 3; depth 53; D. I, 6; A. 12. (Steindachner). XXIII. ConorHyncHos. Conostome Dumeril, ‘‘ Ichthyol. Anal. 484.” 1856. Conorhynchos Bleeker, Ichth. Arch. Ind. Siluri, 205 and 209, 1858 (conirostris ). Conorhynchus Bleeker, Nederl. Tijdschr. Dierkunde, 1, 102, 1865 (conirostris). SOUTH AMERICAN NEMATOGNATHI. 185 Adipose fin higher than long; occipital process con- tinued to the dorsal plate. Fontanel not continued be- hind the eye. Dentition very weak, disappearing with age. Snout produced. Anal rays 18 to 20. ANALYSIS OF THE SPECIES OF CONORHYNCHOS. a. Entire postorbital portion of the head granular. No teeth in the lower jaw, all the teeth disappearing with age. (CONORHYNCHOS.) b. Barbels thin, shorter than the head. Dorsal spine longer than the pectoral spine, 14 in head. Caudal and anal fins emarginate. Width of head 2in its length. D. I, 6-7; A. 18-20. conirostris 132. aa. Postorbital portion of the head smooth, covered with skin; teeth in the lower jaw and on the vomer. (subg. 2) glaber 133. 132. Conorhynchos conirostris. Pimelodus conirostris Cuv. & Val. Hist. Nat. Poiss. xv, 204, plate 436, 1840 (Rio San Francisco). Conostome conirostris Dumeril, ‘‘ Ichthyol. Anal. 484.” Conorhynchus conirostris Bleeker, Nederl. Tijdschr. Dierk. i, 1863, 102 (name only); Giinther, Cat. Fish. Brit. Mus. v, 135, 1864 (Rio Cipo, tributary of Rio das Velhas); Liitken, Vidensk. Selsk. Skr, 162, 1875 (Rio das Velhas). * Habitat: Rio San Francisco and its tributaries. 133, Conorhynchos glaber. Conorhynchus glaber Steindachner, SB. Ak. Wien, Ixxiy, 1876, Siisswasserfische siidéstl. Bras. iii, 79, plate viii (Porto Seguro). Habitat: Porto Seguro. XXIV. BAGRopsis. Bagropsis Liitken, Dan. Viden. Selsk. Skr. 1874, 52 (reinhardtc). Type: Bagropsis reinhardti Liitk. This genus is very closely related to Pimelodus. The top of the head is striate, entirely covered with skin. There are two moderately large patches of teeth on the vomer and larger patches on the posterior part of the palate. We have not been able to examine the single species. 186 CALIFORNIA ACADEMY OF SCIENCES. 134, Bagropsis reinhardti. Bagropsis reinhardti Liitken, Viden. Selsk. Skr. 1874, 32(Rio das Velhas); id. 1. c. 1875, 160, plate i, fig. 2 (Rio das Velhas). Habitat: Rio das Velhas. This species is known only from the types. Head broad and depressed; eyes little nearer edge of opercle than tip of snout, 7 in head, 2 in interorbital. Fontanel between the eyes. Upper jaw projecting for half a diameter of the eye. Maxillary barbels reach to the anal. Dorsal spine serrate on its inner margin near the tip, more than haif as long as the head. Distance of the adipose fin from the dorsal fin equals the base of the dorsal or longer. Adipose fin 5 in the length. Pec- toral spine moderately broad, curved, with strong teeth on its posterior margin. Greenish with golden reflec- tions, lower parts white; top of head and sides with dark spots.. Head 33; depth.5$; Br. 10; D. I, 6; A. 11 (Litken). XXV. PIRAMUTANA. ° Piramutana Bleeker, Nederl. Tijdschr. Dierkunde, 1, 1863, 99 (piramuta). Type: Bagrus piramuta Kner. Top of head and occipital process granulated, covered with skin. Occipital process not quite reaching the dor- sal plate. Teeth cardiform; those on the vomer and palatines forming an uninterrupted band. Maxillary barbels flat- tened, band-like. 135. Piramutana piramuta. Bagrus piramuta Kner, SB. Ak. Wien, xxvi, 1857, 382 (Barra do Rio Negro; Borba, Rio Madeira). Piramutana piramuta Bleeker, |. c. (name only); Giinther, Cat. Fish. Brit. Mus. v, 111, 1864 (copied); Steindachner, Flussfische Siid- amerika’s ili, 2, plate iv, 1882 (Para). Habitat: Amazon and its tributaries. First dorsal ray prolonged; adipose fin half its length SOUTH AMERICAN NEMATOGNATHI. ilisy( in front of the anal; anal emarginate. Maxillary bar- bel reaching past base of ventrals. Head 33; D. 1, 6; A. 14. (Steindachner. ) XXXVI. PLATYNEMATICHTHYS. Platynematichthys Bleeker, Nederl. Tijdschr. Dierk- unde, 1, 18638, 99 (punctulatus). Type: Bagrus punctulatus Kner. Both jaws with very broad bands of teeth; vomer with a broad band of teeth; palatines edentulous. Barbels broad, band-like; occipital process reaching to the dorsal plate. Surface of the bones of the skull furrowed and granulate but covered with skin. 136. Platynematichthys punctulatus. Bagrus punctulatus Kner, SB. Ak. Wien, xxvi, 1857, 380 (Forte do Principe, Rio Guaporé; Rio Branco). Platynematichthys punctulatus Bleeker, 1. c. (name only); Giinther Cat. Fish. Brit. Mus. y. 112, 1864 (copied). Bagrus nigripunctatustKuner, Wiegm. Arch. 1858, 345. Habitat: Amazon; Solimoens and their tributaries. Rictus under the anterior edge of the orbit. Jaws equal. Vomerine band of teeth widest at the outer edges, little more than half as wide as the intermaxillary band. Eye nearer snout than free edge of opercle, 4—43 in interorbital. Maxillary barbels extend to the middle of the opercle. Dorsal and anal emarginate. Base of the adipose fin shorter than the anal. Pectoral spine with fine teeth on its outer edge, with strong teeth on its inner edge near the tip; it reaches the vertical from the end of the dorsal fin. Sides and back brown with black spots, lower parts white. Fins immaculate. Head 5.in the:total; Br. 8-9; D. I, 6;;A. 16 (Kner). 137. Platynematichthys ? araguayensis. Galeichthys araguayensis Castelnau, Anim. Am. Sud Poiss. 37, plate 17, fig. 3, 1855 (Araguay River). Platynematichthys araguayensis EKigenm & EKigenm, Proc. Cal. Acad. 2d Ser. i, 135, 1888 (name). 188 CALIFORNIA ACADEMY OF SCIENCES. Maxillary barbels reaching to the tip of the pectorals; adipose fin four times as long as the anal, 3 in the total length, caudal fin slightly emarginate; D. 1, 7; A. 9. This species is known only from Castelnau’s descrip- tion and figure. XXVII. PHRACTOCEPHALUS. Phractocephalus Agassiz, Gen. et Spec. Pisce. Bras. 22, 1829 (bicolor = hemiliopterus). Type: Silurus hemiliopterus Bloch & Schneider. Body rather short, head very broad in proportion; Upper portion of head with vermiculating elevations. Occipital process broad, rounded behind, not quite reach- ing to the broad reniform dorsal plate. Upper half of adipose fin usually rayed. 138. Phractocephalus hemiliopterus. Silurus hemiliopterus Bloch & Schneider, ‘‘Syst. Ichthyol. 385, 1801.” Phractocephalus hemiliopterus Cuy. & Val. Hist Nat. Poiss. xv, 3, plate 421, 1840; Schomburgk, Fishes of Guiana, part i, 169, 1841 (Guiana everywhere); Miiller & Troschel, Schomburgk, Brit. Guiana, 643, 1849 (all rivers of Guiana); Castlenau,. Anim. Amérique du Sud, 47, plate xy, fig. 4, 1855 (Rios Crixas, Araguay, Amazon); Giinther, Cat. Fish. Brit. Mus. y, 110, 1864 (River Cupai); Vaillant, Bull. Soc. Philom. series 7, iv, 152, 1880 (Cal- deron); Cope, Proc. Am. Philos. Soc. 17, 1878 674, (Peruvian Amazons); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1, 135, 1888 (Xingu; Coary; Teffé; Manacapuru; Obidos; Lake Hyan- uary). : Phractocephalus bicolor Agassiz, Gen. Spec. Pisc. Bras. 238, 1829 (Amazon). Pirarara bicolor Spix, Gen. Spec. Pisc. Bras. 23, plate vi, 1829 (Amazon). Habitat: Amazon, Solimoens, Maranon, their tributaries and north- ward. This species attains a size of over 1.20 m. The specimens examined vary in length from .07-1.00 m.; Xingu; Coary; Teffé; Manacapuru; Obidos; Lake Hyanuary; Villa Bella; Rio Negro. SOUTH AMERICAN NEMATOGNATHI. 189 Body rapidly tapering towards caudal; head heavy, broad, flattened between the eyes; greatest width of the head equals its length; width at the angle of the mouth 2 in its length. Eye 9 in head, 3 in snout; 5 in interorbital; 2 diam- eters behind the rictus. Maxillary barbel on edge of lip, opposite anterior nos- tril, reaching beyond the tips of the pectoral fin; mental barbels 3-3 as long as postmental barbels, which reach the pectoral. Lower jaw included; teeth all alike; those on the in- termaxillaries in a_ broad band of equal depth through- out; vomerine teeth in a much broader patch; pala- tine teeth in narrower wedge-shaped patches con- tiguous to the vomerine 2. patch. Gill-membranes separate to below anterior margin of the eye. Gill-rakers short and fleshy, 4+15. Bones behind eye variously grooved and granulated; the occipital process broadly rounded behind, not meet- ing the reniform dorsal plate. Dorsal spine midway between snout and tip of adi- pose dorsal, and between bases of pectoral and ventral fins; last dorsal ray over base of ventral, the length of the spine 2} in head. Adipose dorsal short, high, its upper portion generally transformed into true rays; its base longer than that of the anal. Caudal broad, slightly emarginate. The rays of the dorsal and caudal thick and terete, once or twice branched. Ventrals extending for half their length beyond the vent. 190 CALIFORNIA ACADEMY OF SCIENCES. Pectoral spine two or three times as thick as the dor- sal spine, broad lamelle in front and sharp recurved teeth behind; its length 2 in head. Color: between pectorals and anal dark brown; lower part of head, a narrow band above pectorals and along sides spreading over the lower ? of the tail white (yellow in life), region about this brownish; a round white spot on each side of dorsal spine; orbit bordered with white above, head and ante-dorsal region with darker spots or vermiculations; sometimes all of lower parts are white. Head 33; depth 42> Br, -9:-D: 1; 7A> 9: XXVIII. Scrapszs. Sciades Miller and Troschel, Hore Ichthyol. iu, 8, 1849 (sp.) Sciades Bleeker, Ichthyol. Arch. Ind. Siluri. 62 and 66, 1858 (pictus). Leiarius Bleeker, Nederl. Tijdschr. Dierkunde 1, 99, 1863 (longibarbis = pictus). Sciadeichthys Bleeker, Nederl. Tijdschr. Dierkunde 1, 99, 1863 (pictus). Sciadeoides Kigenm. & Eigenm. Pruc. Cal. Acad. 2d Ser. vol. i, 1888, 186 (marmoratus). Type: Bagrus pictus M. & Tr. Miller & Troschel do not indicate a type for their sub- genus Sciades. Dr. Bleeker in 1858 restricted it to pictus but afterwards to emphysetus, the first species mentioned by Miller & Troschel. The genus is chiefly marked by the number of dorsal rays, 10 or 11, and by the small patches of palatine teeth which are widely separated from the yomerine patches. ANALYSIS OF THE SPECIES OF SCIADES. a. Occipital process large, triangular, meeting the dorsal plate. Entire postorbital portion of the head granulated. Width of the head 1} in its length. (ScIADES.) SOUTH AMERICAN NEMATOGNATHI. 191 b. Eye large, 6 in head; maxillary barbels extending beyond dorsal, be- yond caudal in young. Vomerine teeth in two patches which be- come united in the adult. pictus 139. aa. Surface of the head and occipital process entirely covered with thick skin, outline of occipital process entirely hidden under the skin; head little longer than broad. (SCIADEOIDEs.) c. Eye 10 in head; maxillary barbels extending to the end of the adipose fin. WVomerine teeth always in two patches. marmoratus 140. 139. Sciades pictus. Bagrus (Sciades) pictus Miller & Troschel, Hore Ichthyol. iii, 8, 1849; Kner, SB. Ak. Wien, xxvi, 386. Sciades pictus Giinther, Cat. Fish. Brit. Mus. v, 113, 1864 (copied); Eigenm. & HKigenm. Proc. Cal. Acad. 2d Ser. i, 136, 1888 (Rio Negro; Villa Bella). Arius (?) longibarbis Castlenau, Anim. Nouv. Rares de l’Amerique du Sud, 36, plate xv, fig. 2, 1855 (Amazon). é Sciades longibarbis Giinther, Cat. Fish. Brit. Mus. v, 114, 1864 (copied). Habitat: Amazon and its tributaries. The description and figure of pictus agree with a specimen .28 m. long in all characters except the vom- erine teeth, which are in two separate patches. Miller & Troschel doubtless overlooked the narrow interspace between the vomerine patches, as Castelnau overlooked the palatine teeth. There can be no doubt but that pictus M. & T. and longibarbis Castelnau are identical. A specimen .28 m. long was collected by Prof. Agassiz at Villa Bella, another .60 m. long was collected by Mr. Dexter in the Rio Negro. Head narrow angular, flattish above, its width at the rictus 13 in greatest width, which is equal to 1% in length of head; Fontanel not continued behind the frontals. Body rather deep at the dorsal fin. Hye 24-22 in snout, 5-6 in head, 2—2% in interorbital. Maxillary barbels extending beyond tips of caudal in specimens .28 m. long, little beyond dorsal in specimens .60 m. long; mental barbels to base of pectorals or be- yond; postmentals beyond base of ventrals (.28) or to middle of pectoral (.60 m.) 192 CALIFORNIA ACADEMY OF SCIENCES. Upper jaw slightly the longer. Teeth all firmly set, those of the jaws in bands of equal depth. Vomerine teeth in two patches which become united in the old; palatine teeth remote, in two longitudinally ovate patches. Gill-rakers overlapping, 4+15. Dorsal spine very variable, longer than head in young, ! shorter than head in adult. Base of adipose dorsal equals length of head. Caudal deeply forked, the lobes about equal to the head in length. Pectoral spine roughened on its anterior margin, strong hooks on its posterior margin, its length 14-14 in head. Dorsal fin with large round dusky spots; barbels annulated with light and dark. Head 4; depth 5-53; D. I, 9 to 10; A. 11. 140. Sciades marmoratus. Sciades marmoratus Gill, Proc. Acad. Nat. Sci. Philad. 1870, 95 (Upper Amazons). Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. i, 136, 1888 (Tabatinga). Habitat: Marafion. The specimens examined by us are from Pianeta they measure .50 and .58 m. The teeth on the yomer are longitudinally ovate and not as in Dr. Gill’s specimen ‘‘ transversely ovate.”’ The vomerine teeth are in two patches, even in the largest specimen. Width of head at angle of mouth 13 in greatest width, 1? in length of head; eyes pointing upward and out- wards; no dermal ossification in adult. Body subterete, heaviest under first dorsal spine. Head flattish, de- pressed. Eye small, 4} in snout, 10 in head, 5 in interorbital, 14 diameters behind the rictus. Maxillary barbels extending to end of adipose fin; mentals to base of pectoral; postmentals to tips of pectorals. Teeth as in the young of longibarbis; the palatine SOUTH AMERICAN NEMATOGNATHI. 193 patches one-fourth as large as the vomerine patches, longitudinally ovate. Gill-rakers overlapping at the angle, 4+10. Dorsal spine inserted above the middle between bases of pectoral and ventral; its distance from snout equal to its distance from the adipose dorsal; its length 1} in length of head; base of adipose equals the head in length. Caudal forked, the outer rays more than twice as long as the middle rays, 13 in length of head. Ventrals extending one-third their length beyond the vent. Pectoral spine 14 in head, not roughened in front, fine teeth on its posterior margin; a minute pectoral pore. Color grayish with dark spots; all fins dark with in- distinct markings; barbels annulated with lighter and darker. Head 4; depth 52; Br: er 1054. 1, 10i0r dy AZ. XXIX. NEMUROGLANIS. Hod, B.Proe: Cals Acad Seni2d Ser. vol.i, 1889) 29 (lanceolatus). Type: Nemuroglanis lanceolatus E. & E. This genus belongs with those Pimelodina Ginther having teeth on the vomer. The character of its caudal is sufficient to distinguish it. Caudal long lanceolate; adipose fin long and low, joined to the caudal. Head without any evident occipital pro- cess. No bucklers in front of the dorsal which is placed over the ventrals. 141. Nemuroglanis lanceolatus. Nemuroglanis lanceolatus E. & E. Proc. Cal. Acad. 2d Ser. ii, 29, 1889 (Jutahy). Type: No. 8169; one specimen .035 m. Jutahy. Thayer Expedition. Elongate slender, tail compressed, head and body de- 13 | 194 CALIFORNIA ACADEMY OF SCIENCES. pressed. Head narrowed forward, its greatest width 12 in its length; its width at the angle of the mouth about 2in its length. Surface of the head covered with thin skin. Eye 2-23 in the snout which is equal to the inter- oribital. Maxillary barbel reaching beyond origin of dorsal; mental and postmental beyond base of pectoral. Distance of origin of dorsai from tip of snout 2? in the length. Dorsal without a basal plate or a spine. Distance of adipose from dorsal somewhat greater than the length of the dorsal. Adipose fin low, joined to the caudal. Caudal rays rapidly tapering to the mid- dle ones, which are gratly prolonged, less than 23 in the length. Anal rays all of about the same height. Ventrals long and narrow, inserted under the anterior half of the dorsal and reaching half way to middle of anal. Pectoral long lanceolate, without a spine. Uniform yellow. Bead 44; Du 7; A.:138. XXX. BRACHYPLATYSTOMA. Platystoma Cuv. & Val. Hist. Nat. Poiss. xv, 1840, sp. Brachyplatystoma Bleeker, Nederl. Tijdschr. Dier- kunde, i, 1863, 97 (vaillant?). Piratinga Bleeker, |. c. 99 (reticulata). Malacobagrus Bleeker, 1. ¢. 100 (filamentosus). Type: Platystoma vaillanti Cuv. & Val. This genus differs from all other Pimelodinw in the peculiarity of its dentition. The inner teeth of the in- termaxillaries are long, slender and depressible; the outer ones are shorter, stronger and recurved. The teeth on the vomer and palatines are smaller than those onthe intermaxillaries. Caudaldeeply forked. Branchi- ostegals 11 or 12. Fontanel elongate elliptical. SOUTH AMERICAN NEMATOGNATHI. 195 Habitat: Rio Parahyba to Guiana; Amazon to Cal- deron. The group of long and spatulate Pimelodine of Gimther can scracely be retained, because perfect inter- gradations exist, and because some of the short-snouted genera Piratinga, Piramutana have really longer snouts than Steindachneria, Duopalatinus, and Brachyplatystoma. ANALYSIS OF THE SPECIES OF BRACHYPLATYSTOMA.*~ a. Maxillary barbels reaching past base of ventrals. b. Skin not entirely reticulate; occipital process long, reaching to the dorsal plate or shghty shorter. vaillanti 143. bb. Skin everywhere reticulate; occipital process not reaching to the dorsal plate; longest caudal ray almost as long as the head. Head 4; Toye WR IDS Gos Jo NY (aly) reticulatum 144. aa. Maxillary barbels not extending to the ventrals. rousseauxt 145. 142. Brachyplatystoma filamentosum = veillanti ? Pimelodes jilamentosus Lichtenstein, Wiedem. Zool. Mag. i, part 3, 60 (Brazil). Malacobagrus jilamentosus Bleeker, Nederl. Tijdschr. Dierkunde, i, 1863, 100 (name only). Piratinga filamentosa Gunther, Cat. Fish. Brit. Mus. v, 112, 1864 (copied). Brachyplatystoma filamentosum Eigenm. & Eigenm. Proc. Cal. Acad, 2d Ser. vol. i, 1888, 136 (name). Habitat: Brazil. This species is a true Brachyplatystoma with the teeth as described for this genus. It cannot be separated on account of the number of branchiostegal rays because Lichtenstein states that they cannot be counted, and he estimates them at 7. Br.7;D.7;A.9. Upper caudal lobe produced; length to end of lower caudal lobe 9 inches, to end of upper caudal lobe 22 inches. Maxillary barbels 24 inches. Spine soft. Head flat- tened forward, pointed. Occipital process scarcely noticeable, 1 inch from the dorsal spine. Adipose fin as long as and opposite to the anal. Upper jaw longer, *142. Brachyplatystoma filamentosum is left out of this key. 196 CALIFORNIA ACADEMY OF SCIENCES. vomerine teeth and the inner ones of the jaws velvety. Eyes about in the middle of the head; interocular 1 inch. (Lichtenstein. ) 143, Brachyplatystoma vaillanti. Platystoma vaillanti Cuy. & Val. Hist. Nat. Poiss. xv, 21, plate 423, 1840 (Cayenne & Surinam); Kner, SB. Ak. Wien, xxvi, 1857, 397 (Para); Giinther, Cat. Fish. Brit. Mus. v, 108, 1864 (Demarara); Peters, MB. Ak. Berl. 469, 1877 (Calabozo). Brachyplatystoma vaillanti Bleeker, Nederl. Tijdschr. Dierkunde, i, 1863, 97 (name only); id. Silures de Suriname 70, 1864 (Suri- nam); Eigenm. & Kigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 136 (Tabatinga; Para; Porto do Moz; Avary; Rio Puty; Juiz de Fora). Platystoma affine Cuy. & Val. Hist. Nat. Poiss. xv, 1840 (Brazil); Castlenau, Anim. Am. Sud. Poiss. 40, 1855 (Araguay); Giinther, Cat. Fish. Brit. Mus. v, 109, 1864 (copied). Platystoma mucosa Vaillant, Bull. Soc. Philom. Ser. 7, iv, 151, 1880 (Calderon). Platystoma verrucosum Boulenger, Zool. Record, xix, Pisces, 1880: (name only); a substitute for mucosa Vaillant. Habitat: Eastern slopes of South America, north of the Rio Parahyba. Cuvier and Valenciennes based their description of vaillanti on specimens from .15 to .38 m. long, and their affine on a specimen .60-.65 m. long without the caudal. In affine the occipital process does not reach the dorsal armature. We have examined specimens from .20 to over .80 m. in length and find that in the young the entire upper surface of the head has the skin ossified and the occi- pital process reaching the dorsal armature. In the larger specimens the head is entirely covered with skin and the occipital process is as described in affine; we have, therefore, placed it in the synonymy of vaillanti. Platystoma mucosa is insufficiently described. It is probably identical with vaillanti. Body rather short and deep, its width below first dor- sal spine not equal to its depth. Profile steep, width of SOUTH AMERICAN NEMATOGNATHI. 197 head at the rictus 2 in its length. Occipital process reaching dorsal plate. Maxillary barbel past ventral (past tip of caudal in young); mental barbels half way to pectoral (past ventral in young); postmentals to base of pectoral (to base of cau- dal in young). Eye 8-18 in head, 4-85 in snout, 23-53 in interor- bital, 12-2} diameters behind the rictus. Teeth of the upper jaw in a broad band, the outer ones similar to those in the lower jaw, the inner ones long, slender, depressed and freely movable; those of the vomer much smaller, the teeth on the palatines still smaller. Gill-membranes separate to below the angle of the mouth; gill rakers fine, scarcely shorter than the eye, 6-9-+-15-24. Skin on sides of head and on snout reticulate, the re- ticulations sometimes continued on nape and along anterior portion of the lateral line. Dorsal spine equidistant from tip of snout and middle of adipose, serrated behind, and near its tip in front in young, 13 in head. Adipose fin longer than the anal. Caudal fin very deeply lobed, the lobes filiform, the upper in the young equal to half the length of the body or longer, the rays normal. Ventrals one-half their length beyond the vent (one-fourth in adult), 13-3 in head. The distance from the vent to the anal equals 4 diameters of the eye (11 in the adult); from the vent to the caudal two-fifths more than length of head. Pectoral spine 14—2 in head. Uniform brownish. Head 34-32; depth 53; Br. 11 or 12; D. I, 6; A. 13. The specimens examined are from Tabatinga; Para; Porto do Moz; Avary; Rio Puty; Juiz de Fora, on the Parahyba; Serpa; Rio Negro. The largest 1.19 m. 198 CALIFORNIA ACADEMY OF SCIENCES. 144, Brachyplatystoma reticulatum. Bagrus reticulata Kner, SB. Ak. Wien, xxvi, 1857, 376 (Salto Theo- tonio, on the Araguay; Forte do Rio Branco; Rio Madeira). Piratinga reticulata Bleeker, Nederl. Tijdschr. Dierkunde, i, 1863, 99 (name only); Giinther, Cat. Fish. Brit. Mus. v, 113, 1864 (copied). Brachyplatystoma reticulatum Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 136 (name). Habitat: Rio Tocantins, Amazon and its tributaries; Rio Madeira. This species is known only from the types; it is closely related to, if not identical with, vaillanti. 145, Brachyplatystoma rousseauxil. Bagrus rousseauxii Castelnau, Anim. Nouy. Rares de l’Am. du Sud, 32, plate 14, fig. 1, 1855 (Amazon). Brachyplatystoma rousseauxii Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. i, 1888, 136 (Para). Bagrus goliath (Heckel MS.) Kner, SB. Ak. Wien, xxvi, 1857, 379 (Salto Theotonio). Piratinga goliath Giinther, Cat. Fish. Brit. Mus. vy, 113, 1864 (cop- ied); Steindachner, Flussfische Siidamerika’s, iii, 1, plate 3, 1882 (Para). Habitat: Amazon and its tributaries. We are unable to distinguish rowsseauaii from goliath. Width below the dorsal spine about equal to or greater than the depth. Snout very much produced, spatulate. Width at angle of mouth 2 in head; greatest width of head 13 in its length. Head entirely covered with skin which is very porous and more or less reticulated. The occipital crest triangular, concealed under the thick skin, not reaching the dorsal plate, one-third of the dis- tance to the dorsal spine. Fontanel long, elliptical, its central point over the eye. Eye small, elongate, 75 in snout, 15-18 in head, 4-43 in interorbital; snout about 2 in head. Maxillary barbels reaching little beyond base of pec- toral; mental barbels very short, scarcely reaching be- yond the vertical from the posterior margin of the orbit; postmentals about to middle of pectoral. Jaws equal, or the upper a little longer, the teeth of the outer two or three series of the intermaxillary band SOUTH AMERICAN NEMATOGNATHI. 199 short, stout and recurved, the teeth of the inner slender, straight and freely depressible; teeth on the anterior half of the vomer car- diform, those of the inner half and those of See the palate much small- er, villiform; teeth of the lower jaw similar to those of the inter- maxillary, but the dif- 4? ference not so marked between the anterior and posterior portions of the band. Gill-rakers wide set, little overlapping, the longest scarcely shorter than the long diameter of the eye, 5+-11. Dorsal spine inserted slightly nearer base of ventral than to base of pectoral, its distance from snout equal- ling that to the end of the first third of the adipose fin. Dorsal spine without teeth produced in a filament, its length, including filament, 14 in head, first ray scarcely shorter, the fin emarginate. Adipose fin about as long as the anal. Caudal fin very deeply forked, the lobes long and pointed, the upper ending in a long filament in one ex- ample; the lobe, including filament, which seems to have been broken off, being more than half the length of the body. Ventrals reaching about one-fourth their length be- yond vent, 14-1$ in head. Vent 8 diameters of the eye in advance of the anal. Pectoral spine roughened in front, recurved teeth on the upper portion behind, its length about 2 in head. A pectoral pore. Humeral process short, covered with skin. The skin of the whole side of the body reticulated and very porous with minute pores. Color silvery, with a bluish to bronze or copper lustre above. 200 CALIFORNIA ACADEMY OF SCIENCES. Head 3%; depth 54-6; Br. 12 or 18; D. I, 6; A. 15. Two specimens, from Para. XXXI. DvUOPALATINUS. Duopalatinus Figenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1, 186, 1888 (emarginatus). Type: Platystoma emarginatum Cuy. & Val. Teeth all alike, the vomerine patches far removed from the palatine patches. This genus is closely related to Brachyplatystoma from which it differs in the nature and position of the teeth. 146. Duopalatinus emarginatus. Platystoma emarginatum Cuv. & Val. Hist. Nat. Poiss. xv, 25, 1840 (San Francisco); Liitken, Dan. Selsk. Skr. 1875, 152, fig. (Rio das Velhas). Duopalatinus emarginatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 1888 (Rio das Velhas; Rio San Francisco below the falls). Habitat: Rio San Francisco and its tributaries. This species being the sole representative of the genus can most readily be distinguished by its teeth. Head narrow, little depressed; width at angle of mouth 13 in greatest width, 23 in its length; its greatest depth 24 in its length; upper jaw scarcely projecting. Maxillary barbel reaching to anal; mental barbei ex- tending to base of pectoral, the postmental to tip of pec- toral. Teeth of the upper jaw in a band which is not much narrower at the mid- dle; vomerine teeth, in the young, in two small /., r ovate patches distinct from each other; in much larger united patches in adult; palatine patches ovate, removed from the vo- merine patches. SOUTH AMERICAN NEMATOGNATHI. 201 Hye large, 5 in head, 23 in snout, 13 in interorbital, 14 diameters behind the rictus. Gill- membranes separate almost to angle of mouth; gill-rakers overlapping, 4-11. Dorsal spine slender, weak recurved teeth behind; equidistant from snout and middle of adipose dorsal and from bases of pectoral and ventral; 14 in head. Base of adipose about twice length of anal. Caudal deeply forked, the outer lobes long and pointed, the rays simple or only twice branched. Ventrals extending one-half their length beyond vent; distance from vent to anal 4 diameters of eye. Pectoral spine long and slender, roughened anteriorly, with strong teeth posteriorly; 13 in head, scarcely shorter than the rays. Beadis2) depth 6; Bred? D2 iG.) A. 12. XXXII. ? 147. ? lutkeni. Platystoma litkeni Steindachner, SB. Ak. Wien, lxxiv, 1876, Ich- thyol. Beitr. iv, 59, plate 13 (Amazon). Habitat: Amazon. This species is known only from the types. Its den- tition would prove it distinct from any of the genera enumerated, but as we have not seen any specimens we can not decide about this point. Palatine and vomerine teeth both present and forming a shallow band immediately be- hind the wide intermaxillary band; teeth villiform. Upper / jaw little projecting. Maxil- lary barbels to base or tip of HE. ventrals. Adipose fin much longer than the anal. Occip- ital process reaching the very long dorsal plate. Pectoral spine serrate behind, broader than the dorsal spine. 202 CALIFORNIA ACADEMY OF SCIENCES. Chocolate brown, many dark violet spots on back and sides. D. I, 6; A. 12. (Steindachner.) XXXIII. STEINDACHNERIA. Steindachneria Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1, 1387, 1888 (amblyura). Type: Steindachneria amblyura E. & E. Palatine teeth none; vomerine teeth in one or two patches. Occipital process reaching or almost reaching the dorsal plate. Spines of the dorsal and pectoral short, prolonged in a fleshy ray. No dermal ossification about the head. Adipose fin longer than the anal. Origin of dorsal equdistant from tip of snout and middle of adi- pose fin. Branchiostegals 8-10. The species of this genus, three in number, are con- fined to southeastern Brazil. While the smaller species of other genera are usually common to several or all of the rivers of southeastern Brazil, these basins seem to be well enough separated to prevent too ready intermingling of the larger species, and there are consequently differ- ent species in the different rivers. Duopalatinus emar- ginatus, another of the large species, is found in the Rio San Francisco. ANALYSIS OF THE SPECIES OF STEINDACHNERIA. a. Caudal broadly rounded; teeth of the vomer in two patches; maxillary barbel extending to adipose; postmentals beyond base of pectoral; head 13-14 in distance from vent to caudal; distance from vent to anal equals 4 orbital diameters. D. I, 6. amblyura 148. aa. Caudal deeply lobed; teeth of the yvomer in a single patch; maxillary barbel not extending beyond dorsal; distance of vent from anal 14 orbital diameters. D. I, 7-8. b. Depth of head 2}-3 in its length; greatest depth 2-2} in the length of the head; blackish brown with yellow spots and vermiculations. doceana 149. bb. Depth of head 14-2 in its length; greatest depth 1} in length of head. Maxillary barbel not reaching beyond tip of pectoral; post- mentals to base of pectoral; head 1,1, in distance between vent and caudal; brownish, with darker spots. parahybe 150. SOUTH AMERICAN NEMATOGNATHI. 203 148. Steindachneria amblyura. Platystoma parahybe Steindachner (in part), Stisswasserf. siidéstl. Bras. 111, 82, 1876 (Jequitinhonha). Steindachneria amblyura Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 137, 1888 (Jequitinhonha). Habitat: Jequitinhonha. Dr. Steindachner described his P. parahybe from a specimen .56 m. long and refers the other specimens in the Mus. Comp. Zool. from the Jequitinhonha and Para- hyba to this species. A comparison of all these speci- mens shows that those from the Jequitinhonha differ widely from those from the Parahyba, having scarcely anything in common but the color. We have selected specimens of equal size from the two rivers for comparison. Body slender. Head much depressed, its width at the angle of the mouth is % its greatest width which is equal to the length of the head; greatest depth of the head 2} in its length. aera, Eye 83 in head, 3 in snout, 3} in interocular; one diameter behind ae. Cas the angle of the mouth. a] Gill-rakers 44-9 to 12. Dorsal spine slender, 24 to 3 in head, the rays 1# to 2. Base of the adipose fin almost twice as long as the base of the anal. Pectoral spine 2 in head, sharp teeth on its inner margin; outer margin roughened its whole length. Ventrals extending half their length behind the vent. The membranes of the fins all thin. Upper parts brownish, with round spots which are smallest on head, sometimes confluent into yermicula- tions. Adipose fin and caudal with spots; membrane of dorsal fin sometimes with a vertical series of spots, other fins dusky. Lower parts plain. Head 4» depth. 74; Broo) or10;* Del, 6A 12, 204 CALIFORNIA ACADEMY OF SCIENCES. 149. Steindachneria doceana. Steindachneria doceana EK. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 30, 1889 (Rio Doce). Types: Nos. 23,792, 23,793, 23,794; nine specimens; .37-.74 m. Rio Doce. This species agrees with St. parahybw in the shape of its caudal, the dentition of the vomer, the length of the barbels and the fin rays. It differs greatly in the shape of the head and the color. Head broad, depressed, the depth at the base of the occipital process 23-8 in its length; its width 1}; great- est depth of body 2-23 in the length of the head. Occip- ital process broad, not quite reaching the long, triangu- lar dorsal plate. An elongate frontal fontanel. Eye median, 33-5 in the snout, 5-33 in interocular, 8-11 in the head. Maxillary barbel reaching to middle of dorsal in smallest to middle of pectoral in largest specimen; men- tals to gill opening; postmentals beyond base of pectoral in smallest specimen, shorter in the larger. Dorsal fin as in parahybe. Base of adipose 4-4 longer than base of anal. Pectoral spine stout, strongly serrate on its inner mar- gin in the smallest specimen. Sides and entire upper surface dark brown with spots and vermiculating markings of hght. The unpaired and upper surfaces of the paired fins light, profusely spotted with dark; the spots of the dorsal and pectoral confluent into bars and stripes in the largest specimen, adipose fin colored like the back; ventral surface and lower surface of paired fins plain. Head 33-33; depth 63-73. Br. 8-9. D.I, 7-8. A. 14. 150, Steindachneria parahybe. Platystoma parahybe Steindachner, Siisswasserf. siidéstl. Bras. iii, 82, pl. ix (Rio Parahyba near Juiz de Fora), in part. Steindachneria parahybe Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 137, 1888 (Rio Parahyba). Habitat: Rio Parahyba. SOUTH AMERICAN NEMATOGNATHI. 205 Only the types of this species are known. Body robust. Head not greatly depressed; the profile steep; greatest width of head 1% in its length; greatest depth of ome read’ 1422: bah pee Eye 9-93 in head, 4 in snout, gad 23-32 in interorbital, 2-2 diameters behind the angle of the mouth. Gill-rakers 54-12-14. Dorsal spine 3 in head, the rays 2 in head. Base of adipose fin } longer than base of anal. Pectoral spine as long as the dorsal spine. Ventrals not extending more than + their length be- yond the vent. Membranes of all the fins thick. Ventral surface plain; upper parts brownish with numerous darker spots, which are smallest on head and on lower parts of the sides. All fins similarly spotted. Rarely uniform reddish brown. Head 34; depth-5—-6; Br. 8-9; D. I, 7; A. 12-18. XXXIV. HEMIsoRUBIM. Platystoma Cuv. & Val., Hist Nat. Poiss. xv, 27, 1840, (sp.) (preoccupied in Diptera). Hemisorubim Bleeker, Nederl. Tijdschr. Dierkunde, 1863, 97 (platyrhynchos). Type: Platystoma platyrhynchos Cuv. & Val. This genus differs from all the others in having the upper jaw thin and truncate; shorter than the lower jaw; snout narrowed, the width at the angle of the mouth 13 times in the greatest width of the head; mental barbels approximated and placed near the edge of the lip; inter- maxillary band of teeth much shallower at the middle than at the ends; the palatine patches are large. The occipital process shorter than the dorsal plate and meet- 206 CALIFORNIA ACADEMY OF SCIENCES. ing it. Postorbital portion of the head striated and granulated. Skin on the sides of the head and snout reticulated. Habitat: Northern Brazil and northward. 151. Hemisorubim platyrhynchos. Platystoma platyrhynchos Cuy. & Val., Hist. Nat. Poiss. xv, 27, 1840 (no locality); Castelnau, Anim. Nouv. Rares de ’Amér. du Sud, 40, 1865 (Amazon); Kner, SB. Ak. Wien, xxvi, 1857, 398 (Barra do Rio Negro.) Hemisorubim platyrhynchos Bleeker, Nederl. Tijdschr. Dierk. 1863, 97 (name only); Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 188, 1888 (Manacapuru; Rio Negro; Montalegre; Rio Puty; Lago Alexo; Obidos; Coary; Tabatinga; Hyavary; Tonantins; Sao Paolo.) \ Hemisorubim platyrhynchus Ginther, Cat. Fish. Brit Mus. y, 109, 1864 (copied); Peters, MB. Ak. Berl. 470, 1877 (Calabozo); Cope, Proc. Am. Philos. Soc. xvii, 674, 1878 (Peruvian Amazon); Vaillant, Bull. Soc. Philom. Series 7, iv, 152, 1880 (Calderon). Habitat: Orinoco, Amazons, Paranahyba and their tributaries. This species agrees with Platystomatichthys stwrio in coloration, having large black spots scattered on the sides and a black spot at base of caudal. Head depressed, rounded on occiput. Hye directed upward, 7 in head, 3 in snout, 1#-in interorbital. Lower jaw projecting and entering the profile. Maxillary barbels extending past dorsal; mental bar- bels approximated, extending to below eyes; _post- mentals to pectorals. Teeth in the lower jaw in a nar- row band. Vomerine and palatine teeth close behind the maxillary teeth; the vomerine teeth in a single patch separate from the pal- atine patches. Dorsal spine weak and slender, + in head; its distance from snout greater than its dis- tance from the posterior margin of the adipose fin; much 49 SOUTH AMERICAN NEMATOGNATHI. 207 nearer base of ventrals than base of pectorals; with re- trorse teeth behind. Adipose fin longer than anal. Lower caudai lobe wider and longer than upper, rounded in adult; pointed in young. Ventrals extending 3 their length beyond the vent. Pectoral spine 13 in head, with equally strong teeth in front and behind. White below; olivaceous above, with a few jet black spots scattered on sides, usually a similar spot at base of upper caudal lobe; fins plain. Head: 3zidepthe6=7- D7 I6; 4.102 Bra le XXXV. PSEUDOPLATYSTOMA. Platystoma Agassiz, Gen. et Spec. Pisc. Bras. 1829 (sp.) Sorubim Spix, Gen. et Spec. Pisce. Bras. 1829 (sp.) Pseudoplaystoma Bleeker, Nederl. Tijdschr. Dierkunde, 1, 97, 1863 (fasciatum). Hemiplatystoma Bleeker, l. ¢. (tigrinum). Type: Stlurus fasciatus Linneeus (in part). This genus consists of three closely related species and several varieties. Upper jaw little longer than lower; teeth of the jaws alike; vomerine and palatine patches of teeth more or less united, the two forming a ,-shaped patch on each side of the palate; gill-rakers short, spine-like, not over- lapping; caudal deeply lobed, the lobes rounded (except in very young) the rays very much branched, giving the fin a leathery texture. Branchiostegals 14 or 15; barbels short. Adipose fin shorter than the anal; dorsal spine nearer end of adipose fin than tip of snout. ANALYSIS OF THE SPECIES OF PSEUDOPLATYSTOMA. a. Body usually with vertical bars or lines interspersed with spots; some- times plain dusky. ‘ 208 CALIFORNIA ACADEMY OF SCIENCES. b. Groove of fontanel continued to midway between eye and occipital process; a band of cirri extending to the end of the groove, the tips of the cirri on a level with the surface of the head; a faint transverse groove at base of occipital process. c. Maxillary barbels extending to or somewhat beyond dorsal fin. d. Brown above, abruptly white on sides; sides with 10-12 dark cross bars bordered anteriorly by shorter light bars; sometimes dark spots along the lower margin of the sides; dorsal, caudal, tips of ventrals and tips of anal with a few dark spots; head rarely with similar spots. Mavxillaries reaching tip of dorsal. Sasciatum 152. dd. Black above gradually shading into white below; lateral bars of the abdominal region extending to the edge of the belly; a series of large black spots along the sides; all the fins, the adipose in- cluded, conspicuously spotted with dark. Maxillary barbel reaching to origin of dorsal. fasciatum nigricans 152a. cc. Maxillary barbels not reaching to the dorsal. e. Vertical bars as in fasciatum, enlarged at the lower termination, those on the abdominal portion of the body broken up into spots; a lateral series of very large spots. Maxillary barbels reaching to the edge of the opercle. Jasciatum brevifile 152b. ee. Back and sides with narrow dark wavy lines which extend to the edge of the belly; fins variable, plain or spotted; head with small spots. Maxillary barbels not reaching to the dorsal. fasciatum intermedium 152c. eee. Back and sides with narrow dark lines which form coarse re- ticulations; a series of spots along the lower part of the sides. Maxillary barbels reaching little beyond pectoral. Jasciatum reticulatum 152d. bb. Groove of the fontanel deep, continued to the base of the occipital process; a band of long cirri extending to midway between the eye and occipital process; the tips of the cirri not on a level with the sur- face of the bone bordering the fontanel; a deep transverse groove at base of occipital process and a shorter one extending outward and back- ward. Dark above, light below; about 16 curving cross bands half as wide as the eye, more or less joined below by an irregular lateral band; dorsal, caudal and anal with conspicuous spots; adipose fin barred and spotted with brown; head unspotted. tigrinum 153. aa. Body with round black spots which occasionally are confluent into lines; groove of the fontanel not continued to the occipital process. Maxillary barbel extending beyond preopercle. coruscans 104. 152, Pseudoplatystoma fasciatum. Silurus. fasciatus Linneeus, Syst. Nat. ed. xii, i, 505, 1766; id. ed. xiii, 1359, 1788; Bonaterre, Ene. Ichthyol. 154, 252, 1788; Bloch, Ausland. Fische, part 8, 30, pl. 366, 1794; Bloch & Schneider, Syst. Ichthyol. 382, 1801. SOUTH AMERICAN NEMATOGNATHI. 209 Pimelodus fasciatum Lacépéde, Hist. Nat. Poiss. v, 94, 99 and 100, 1803. Platystoma fasciatum Cuy. & Val. Hist. Nat. Poiss. xv, 14, 1840 (copied); Kner, SB. Ak. Wien, xxvi; 401, 1857 (Surinam); Giin- ther, Cat. Fish. Brit. Mus. v, 107, 1864 (Essequibo; Surinam; River Capin, Para); Peters, MB. Ak. Berlin, 469, 1877 (Calabozo); Steindachner, Fisch-fauna Magd. Stromes, 15, 1878 (Magdalen River); Cope, Proc. Am. Philos. Soc. xvii, 674, 1878 (Peruvian Amazon); Steindachner, Fisch-fauna Cauca & Fliisse bei Guaya- quil 5, 1879 (Cauéa); id. Ichthyol. Beitr. vili, 54 (Surinam); id. Flussfische Siidam. iv, 4, 1882 (Rio Amazonas, Iquitos). Pseudoplatystoma fasciatum Bleeker, Nederl, Tijdschr. Dierk. 1863, 97 (name only); id. Silures de Suriname, 72, 1864 (Surinam); EHigenm. & HEigenm. Proc. Cal. Acad. 2d Ser. i, 138, 1888 (Obidos; Coary; Hyavary). Platystoma truncatum Agassiz, Gen. & Spec. Pisce. Brazil, 27, plate xilia. 1829 (Rio Japura & Solimoens). (Plain, dorsal and caudal spotted); Cuv. & Val., Hist. Nat. Poiss. xv, 20, 1840 (Brazil); Hyrtle, Denk. Ak. Wien. xvi, 17, 1859 (vertebrae 13-+-33); Giin- ther, Cat. Fish. Brit. Mus. vy, 108, 1864 (copied). 5 Platystoma punctifer Castelnau, Anim. Nouy. Rares de l’Amér. du Sud, 40, pl. xix, fig. 2, 1855 (Amazon). Habitat: Amazons and streams north of it. - The color markings in this, as in the nearest related species, are very conspicuous in certain individuals; those about .40 m. long seem to have the color most dis- tinct. In the smallest and largest specimens the black bars are scarcely evident, and the light bars are faint. Platystoma truncatum Agassiz, was based on a specimen .90 m. long, and is doubtless the old form .of fasciatus or one of its varieties. It is doubtful whether the extreme old of the varieties can be told apart. Platystoma punctifer Castelnau does not differ from specimens of fasciatus. Body long, slender, terete. Head long, depressed, scarcely narrowed towards the snout; its width at the angle of the mouth 14 in its greatest width, 23 in its. length. 14 210 CALIFORNIA ACADEMY OF SCIENCES. Eye 13 in head, 4-6 in snout, 2-3 in interorbital, about 4 diameters behind the angle of the mouth. Teeth all alike, those in the lower jaw in a narrow band of uniform depth; those of the up- per jaw in a band which is much shallower at the middle. Vomerine patches slightly sepa- rate along the median line. Dorsal spine nearer ve to end of adipose than to tip of snout; slender, serrate behind and near tip in front. Adipose fin shorter than the anal, placed above the first 8 rays. Ventrals extending one-half their length beyond the vent; distance from vent to caudal equals length of head. Pectoral spine with strong recurved teeth on its entire inner margin, a few teeth near tip in front; 24 in head. Head 23-23; depth 74-73; Br. 14-15; D. I, 6; A. 11-13. About twenty specimens. Coary; Hyavary; Hyan- uary; Jutahy; Teffé; Rio Puty; Obidos. 152a. Pseudoplatystoma fasciatum nigricans. P. f. nigricans EK. & KE. Proc. Cal. Acad. Sci. 2d Ser. ii, 31, 1889. Types: No. 7301 and 7311; two specimens .40-.60 m. Xingu. Habitat: Xingu. This variety is known only from the types; it 1s con- fined to the Xingu river. 152b. Pseudoplatystoma fasciatum brevifile. P. f. brevifile E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 31, 1889 (Goyaz). Type: No. 7317; one specimen, .62 m. Goyaz. Habitat: Goyaz. 152¢c, Pseudoplatystoma fasciatum intermedium. P.f. intermedium Figenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 138, 1888 (Obidos). Four specimens, .37-.65 m. Obidos; Rio Puty. SOUTH AMERICAN NEMATOGNATHI. PAG 152d. Pseudoplatystoma fasciatum reticulatum. P.f. reticulatum KE. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 30, 1889 (Rio Negro). Type: No. 23,813; .77 m. Rio Negro. 153. Pseudoplatystoma tigrinum. Platystoma tigrinum Cuv. & Val. Hist. Nat. Poiss. xy, 10, pl. 422, 1840 (Brazil); Schomburgk, Fishes of Guiana, part i, 185, pl. vili, 1841 (Rivers of Guiana); Castelnau, Anim. Am. Sud, 39, 1855 (Amazons); Giinther, Cat. Fish. Brit. Mus. v, 107, 1864 (copied); Vaillant, Bull. Soc. Philom. series 7, iv, 151, 1880 (Calderon). Platystoma fasciatum tigrinum HKigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 138, 1888 (Obidos). Habitat: Amazon and northward; probably coextensive with fasc?- atum. Eight specimens .25-1.00 m. Manaos; Obidos; Teffé; Jutahy. This species differs from fasciatum in the character mentioned in the key. 154, Pseudoplatystoma coruscans. Platystoma coruscans Agassiz, Gen. et Spec. Pisc. Bras. 26, 1829 (Brazil); Cuv. & Val. Hist. Nat. Poiss. xv, 17, 1840 (Rio San Francisco); Giinther, Cat. Fish. Brit. Mus. v, 108, 1864 (copied); Kigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 138, 1888 (Manaos; Rio das Velhas; Rio San Francisco below the falls). Sorubim caparary Spix, Gen. et Spec. Pisc. Bras. 26, pl. xiii, 1829 (Rio San Francisco). Platystoma caparary Castelnau, Anim. Am. Sud, 40, 1855. Platystoma pardalis Valenciennes, Voy. d’ Orbigny, ix, atlas ii, plate iv, fig. 2, 1847; Cuv. & Val. Hist. Nat. Poiss. xv, 15, 1840 (Buenos Ayres), Giinther, Cat. Fish. Brit. Mus. vy, 108, 1840 (copied). Platystoma punctatum Cuv. & Val. Hist. Nat. Poiss. xv, 20, 1840 (name only). Platystoma orbignianum Valenciennes, Voy. d’ Orbigny, Atlas i, plate iv, fig. 3, 1847; Cuv. & Val. Hist. Nat. Poiss. xv, 12, (Buenos Ayres: Parana to Corrientes); Giinther, Cat. Fish. Brit. Mus. v, 107, 1864 (Cipo, tributary of Rio das Velhas); Liitken, Dan. Selsk. Skr. 1875, 154, fig. (Rio das Velhas). Platystoma forschhammeri Reinhardt MS. in Liitken 1. ec. Habitat: Rio Plata, Rio San Francisco and their tributaries. The fishes named above are undoubtedly identical. The pardalis and orbignianum of Valenciennes were aD, CALIFORNIA ACADEMY OF SCIENCES. based on specimens 1.50 and .50 m. long respectively, and little value can be laid on their differences. The specimens examined are from Rio das Velhas, and Rio San Francisco below the falls. Body long, slender, terete, head very long, more de- pressed than in other species; maxillary barbel extending beyond preopercle; mental barbels to pectoral or shorter; postmental barbels almost to tip of pectoral; width of head at rictus scarcely narrower than its greatest width; 2} in its length; greatest depth of head 4 in its length. Eye 13 in head, 6 in snout, 3} in interorbital, 33 diameters from angle of mouth. Teeth all alike, arranged as in fasciatum. Gill-membranes separate to beyond eye; gill-rakers short, spine-like, not overlapping, 1-58. Dorsal spine nearer posterior margin of adipose dor- sal than to tip of snout. Adipose fin shorter than base of anal. Caudal deeply two-lobed, the outer rays 4 times as wide as an interradial space, the lobes rounded. Ventrals extending 4 their length behind vent. Dis- tance from vent to anal about equal to 6 diameters of the eye, from vent to the caudal 4 longer than the head. Pectoral spine finely serrate behind, 23 in head; pec- toral pore minute. Head 25; depth 7; Br. 15 or 16; D. I,-6; A. 14. XXXVI. SorvuBIM. Platystoma Agassiz, Gen. et Spec. Pis. Bras. 1829 (sp.) (name preoccupied in Diptera). Sorubim Spix, Gen. et Spec. Pisc. Bras. 1829 (sp.) Sorubim Bleeker, Nederl. Tijdschr. Dierkunde, i, 1862, Systema Sil. Rev. 22 (lima). Tpye: Silurus lima Bloch & Schneider. Neither Agassiz nor Spix indicated types for their gen- SOUTH AMERICAN NEMATOGNATHI. Zhe era Platystoma and Sorubim, which, as used by them, are coextensive. Bleeker first restricted the genus Sorubim to the Silurus lima Bloch & Schn.; he also restricted Platystoma to the same species, making Platystoma a synonym of Sorubim. The name Platystoma, however, is preoccupied, and we retain the name Sorubim. Head abnormally depressed, the eyes perfectly lateral; teeth of the upper jaw in a band which is wider than deep; teeth on roof of mouth in four patches, the vo- merine patches joined in the adult; barbels fleshy; adi- pose fin shorter than anal; dorsal spine equidistant from snout and posterior margin of adipose fin; plates on the anterior portion of the lateral line. 155. Sorubim lima. Silurus lima Bloch & Schneider, ‘‘ Syst. Ichthyol. 384,” 1801. Platystoma lima Agassiz, Gen. Spec. Pisc. 24, 1829 (Equatorial Brazil); Cuv. & Val. xv, 7, 1840 (locality?); Kner, SB. Ak. Wien, xxvi, 399, 1857 (Rio Guaporé; Rio Branco; Rio Negro). Sorubim lima Giinther, Cat. Fish. Brit. Mus. v, 105, 1864 (copied); Peters, MB. Ak. Berl. 469, 1877 (Calabozo); Steindachner, Fisch- fauna des Magd. Stromes 15, 1878 (Rio Magdalena); Cope, Proc. Am. Philos. Soe. xvii, 674, 1878 (Peruvian Amazon); Stein- dachner, Fisch-fauna Cauca & Fliisse bei Guayaquil, 5, 1879 (Cauca inthe province Antiochia); Vaillant. Bull. Soc. Philom. Ser. 7, iv, 150, 1880 (Calderon); Steindachner, Flussfishe Sii- dam. iv, 4, 1882 (Rio Huallaga); Eigenm. & Kigenm. Proc. Cal. Acad. 2d Ser. i, 138, 1888 (Manacapuru; Sao Paolo; Fonte- boa; Tabatinga; Hyavary; Teffé; Obidos; Maranon; Ucay- ale; Ica; Lago do Manimo; Para; Rio Puty; Jutahy). Sorubim infraocularis Spix, Gen. et Spec. Pisce. Bras. pl. xv, 1829 (Equatorial Brazil). Platystoma luceri Weyenbergh, Nuevos Pescados, 10, pl. iii, figs. 1-3, 1877 (Santa Fe). Habitat: Rio Plata; Amazons and tributaries to the Rio Magda- lena and its tributaries. Body elongate, subcylindrical; head abnominally depressed, its depth 5 in its length; eye strictly lateral; maxillary barbel extending past front of dorsal; mental barbel extending beyond eye; postmental slightly beyond head. diel CALIFORNIA ACADEMY OF SCIENCES. Eye 103 in head, 5 in snout, 44 in interorbital space; 2 diameters behind angle of mouth. Teeth all alike; those of the upper jaw in a broad crescent-shaped patch; its depth at the middle being one-half its width; teeth on vomer and palate in four patches forming a horse-shoe. Gill-membranes separate to in front of eye; gill-rakers overlapping, 3+13. Dorsal spine 2} in head. Adipose fin shorter than the anal. Caudal deeply lobed, lower lobe longer and wider, 2 in head; the rays normal. Ventrals extending two-thirds their length beyond the vent; eye 33 in distance from vent to anal. Pectoral spine 2 in head; teeth on its posterior edge and near the tip on its anterior margin; pectoral pore moderate. Color brownish above; lower half of body and head white; a dark lateral band extending upon the caudal. Head 3; depth 7$; Br. 13;°D. 1, 637A. -185Aarge thin plates on the anterior portion of the lateral line. Numerous specimens; Manacapuru: Sao Paolo; Fonte- boa; Tabatinga; Hyavary; Teffé; Obidos; Marafion; Ucayale; Ica; Lago de Manimo; Para; Rio Puty; Jutahy; Rio Sario. XXXVII. SorvuBIMICHTHYS. Platystoma Agassiz,Gen. et Spec. Pisce. Bras. 1829 (sp.) Sorubim Spix, Gen. et Spec. Pisce. Bras. 1829 (sp.) Sorubimichthys Bleeker, Nederl. Tijdschr. Dierk. i, 98, 1863 (jandia=spatula). Type: Platystoma spatula Agassiz. The species of this genus are not well known; only one, planiceps, is represented in more than one museum. It is not improbable that all should be referred to one or at most to two species. Snout very broad; eyes superior; upper jaw much SOUTH AMERICAN NEMATOGNATHI. 20S) longer than the lower, teeth in upper jaw in a very deep band, those on roof of mouth in two patches; barbels fleshy; adipose fin shorter than anal; dorsal spine equi- distant from snout and middle of adipose fin. Cau- dal widely forked, the rays normal. ; ANALYSIS OF THE SPECIES OF SORUBIMICHTHYS. a. Upper part of body brownish, with numerous darker spots; maxillary barbels longer than head. planiceps 156. aa. Color of body uniform. 6. Head, dorsal, pectoral and ventral fins with numerous black dots; maxillary barbels extending to the ventrals; caudal lobes pointed; pectoral with teeth along both margins. D. I, 6; A. 10. (Agassiz.) spatula 157. 6b. Uniform grayish brown, darker above. Head covered with skin; maxillary barbels much shorter than the head, mandibulary barbels still shorter; intermaxillary band of teeth broader than the vomerine band, separated from each other by a very narrow interspace; dorsal spine equidistant from snout and origin of adipose fin; adipose fin as long as anal; caudal slightly forked. Head 33; D. I, 6; A. 11. (Giin- ther.) gigas 158. 156. Sorubimichthys planiceps. Mystus No. 6, Artedi, in Seba, iii, 84, pl. 29, fig. 6. Mystus No. 386, ‘‘Gronow Zoophyl. 125.” Platystoma planiceps Agassiz, Gen. Spec. Pisce. Bras. 25, 1829 (Amazon; Solimoens; Rio Negro); Cuv. & Val. Hist. Nat. Poiss. xv, 19, 1840 (Brazil); Schomburgk, Fishes of Guiana, parti, 187 (Rio Branco, not in Guiana); Kner, SB. Ak. Wien, xxvi, 400, 1857 (Rio Negro); Giinther, Cat. Fish. Brit. Mus. v, 106, 1864 (copied); Peters, MB. Ak. Berl. 469, 1877 (Calabozo). Sorubimichthys planiceps Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 139, 1888 (Manacapuru; Teffé; Hyavary). Sorubim piranaca Spix, Gen. Spec. Pisc. Bras. 25, plate xii, 1829. Platystoma artedii Giinther, Cat. Fish. Brit. Mus. v, 106, 1864 (based on Artedi & Gronow); Vaillant, Bull. Soc. Philom. ser. 7, iv, 150, 1880 (Calderon). Sorubimichthys ortoni Gill, Proc. Acad. Nat. Sci. Philad. 1870, 94 (Peruvian Amazon). Habitat: Amazons, Orinoco and their tributaries. The specimens examined are from Manacapuru, Hyavary and Teffé .51—.70 m. The specimen from Teffé has the markings most dis- 216 CALIFORNIA ACADEMY OF SCIENCES. tinct, the back most decidedly ashy and the spots black. Body long and slender, eel-shaped behind the dorsal fin; head more than usually flattened, its width at the rictus scarcely less than its greatest width which is 2 in the length of the head, its greatest depth about 5 in its length. Upper jaw projecting beyond the lower the depth of its intermaxillary band of teeth, or 2) orbital diameters. Eye small, 17 in head, 7 in snout, 53 in interorbital; 1 diameter behind the rictus. Bony base of the maxillary barbel 23-3 orbital diame- ters long, the tip of the barbel reaching past base of ventrals; mental barbels minute, 1$ orbital diameters long; postmentals not reaching base of pectoral. Teeth minute; mandibulary band ? orbital diameter deep; intermaxillary band 2) orbital diameters deep, an angular in- Ve cision in the middle of its \ / posterior border; teeth on the ‘J he vomer and palate in two semi- Y S/. crescentic patches. Gill-membranes separate to below the angle of the mouth; gill-rakers scarcely overlapping, strong, spine- like, 3-12. Dorsal spine 24-3 in head. Adipose dorsal slightly shorter than anal. Caudal widely forked, the lobes pointed. Ventrals extending } their length beyond vent; dis- tance of vent from anal equals 8 diameters of the eye; its distance from the caudal § longer than head. Pectoral spine 2 in head; strong teeth along posterior margin and near its tip anteriorly. Pectoral pore very large. SOUTH AMERICAN NEMATOGNATHI. pa Color ashy above with round spots, most numerous on head, decreasing in number and increasing in size pos- teriorly; middle of sides with a white band bordered above and below with brown; these colors extending on tail; lower parts white with scattered spots. Dorsal with dark brown spots; adipose with larger spots. Head 3; depth 9; Br, 14 07/15; D. 1; 6; A. 12 or 13: 157. Sorubimichthys spatula. Platystoma spatula Agassiz, Gen. Spec. Pisc. Bras. 26, 1829 (Brazil); Cuy. & Val. Hist. Nat. Poiss. xv, 17, 1840 (Brazil); Giinther, Cat. Fish. Brit. Mus. v, 106, 1864 (copied). Sorubimichthys spatula Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 139, 1888 (name). Sorubim jandia Spix, Gen. Spec. Pisc. Bras. plate xiv, 1829 (Equa- torial Brazil). Habitat: ? Amazon. This species was based on a specimen about one metre long, ‘‘more than 3 feet.” It differs from S. planiceps chiefly in color. A second specimen has not yet been found, and it is not unlikely that it is identical with planiceps. 158. Sorubimichthys gigas. Platystoma gigas Giinther, Ann. & Mag. Nat. Hist. 1872, x, 449 (Rio Huallaga). Sorubimichthys gigas Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 139, 1888 (name). Habitat: Rio Huallaga. This species was based on a specimen two metres long. We cannot detect any differences between this species and planiceps that could not be accounted for by age. As we have not been able to examine specimens of such large proportions, we retain this as a distinct species. XXXVIII. PLATYSTOMATICHTHYS: Platystoma Kner, SB. Ak. Wien, xxvi, 1857, 395, fig. 9 (sp). 218 CALIFORNIA ACADEMY OF SCIENCES. Platystomatichthys Bleeker, Nederl. Tijdschr. Dier- kunde, i, 98, 1863 (stwrio). Type: Platystoma sturio Kner. This genus consists of a single species, the most aberrant of the species with depressed and elongate heads. Head rather narrow, depressed anteriorly; snout long and pointed, projecting far beyond the lower jaw, its entire under surface covered with teeth; yvomerine teeth in a single patch, palatine teeth in elongate patches removed from the vomerine teeth; eyes supe- rior. Maxillary barbels much longer than the total length, osseus or wiry; adipose fin longer than anal; caudal deeply forked, the lobes pointed, half as long as body or longer. 159. Platystomatichthys sturio. Platystoma sturio Kner, 1. c. (Rio Branco.) Platystomatichthys sturio Bleeker, Nederl. Tijdschr. Dierkunde, i, 98, 1863 (name only); Giinther, Cat. Fish. Brit. Mus. vy, 110, 1864 (Rio Branco); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 189, 1888 (Para; Curuca, Rio Muria). Habitat: Amazon and its tributaries. The specimens examined were collected by the Conts de Magalhaes and Prof. Agassiz at Para and Curuca on the River Muria. Body rather slender; head long acuminate, the pro- longation of the snout beyond the lower jaw being con- tained 2} in head; width of the head at the mouth 13 in its greatest width, 33 in length of head. Maxillary barbel osseus or wiry more than half its length; mental barbels remote from each other, not extending to pectoral, 2} diameters of eye from lower lip; postmental barbels beyond base of pectorals. Kye 12 in head; 83 in snout, 3 diameters from angle of mouth, 4 diameters from maxillary barbel. SOUTH AMERICAN NEMATOGNATHI. 219 Teeth of lower jaw, as in most species of this group, ina narrow band; those of the upper jaw in an arrow-shaped patch, those of the vomer in an o- shaped patch; the palatine patches long and narrow, remote from the vomerine patches; lower lip plicate. Gill-membranes separate to beyond eye; gill-rakers overlapping, 5--14. TESS) Roughened plates on the lateral line anteriorly. Vas Dorsal spine behind middle from tip of snout and end of adipose dorsal; long, slender, with recurved teeth behind; 23 in head. Adipose fin longer than base of anal. Caudal very deeply forked; the outer rays more than half length of body; numerous basal rays. Ventrals extending for ? of their length beyond the vent; distance from vent to anal equals 4 diameters of the eye; distance from vent to middle caudal rays equals length of head. Pectoral spine 24 in iength of head; with retrorse teeth behind. 3$; depth 5; Br. 10-11; D. I, 6; A. 34. Two specimens .42—.50m. Serpa; Villa Bella. Thayer Exped. 246. Ageneiosus axillaris. Ageniosus axillaris Ginther, Cat. Fish. Brit. Mus. v, 431, 1864 (Surinam). Habitat: Surinam. This species is known only from the types. Famity IV. HYPOPHTHALMIDA. =Siluride anomaloptere Ginther, Cat. Fish. Brit. Mus. v, 3, 1864. = Hypophthalmide Cope, Proc. A. A. A.S. 1871. This family composed of two genera, is confined to the northern Amazon and Guiana region of South Amer- ica. The anatomy of the family has been studied by Prof. R. Ramsay Wright. * The characterization of the family is given in the key. ANALYSIS OF THE GENERA OF HYPOPHTHALMIDHE. a. Jaws and vomer with teeth. Helogenes ly. aa. Jaws and vomer without teeth. Hypophthalmus Wi. LV. HELOGENEs. Helogenes Giinther, Annals and Magazine Natural His- tory, xl, 443, 1863 (marmoratus). Type: Helogenes marmoratus Ginther. * On the Skull and Auditory Organ of the Siluroid Hypophthalmus, Trans. Roy. Soc. Canada 1885, 107-118, plates viii-x. 312 CALIFORNIA ACADEMY OF SCIENCES. This genus differs from Hypophthalmus in having a band of teeth in the jaws and two patches on the vomer. Eye small, covered with skin, above the level of the angle of the mouth. Adipose fin very small; dorsal fin very short, without pungent spine, inserted behind the ventrals; anal very long. Barbels six. No dermal bones. Gill-membranes entirely separate; pectorals without spine; ventrals six-rayed. Branchiostegals 15. 247. Helogenes marmoratus. Helogenes marmoratus Giinther, 1. c. (Essequibo); id. Cat. Fish. Brit. Mus. vy, 66, 1864 (Essequibo). Habitat: Essequibo River. Head small, slightly depressed, short, two-thirds as broad as long. Snout broad, obtusely rounded; mouth of moderate width. Body compressed, upper and lower profiles only slightly convex; a longitudinal groove from nape to origin of the dorsal. Teeth minute, cardiform, forming bands in both jaws, the outer series containing somewhat larger and more widely set teeth; two patches of teeth on the vomer. Barbels thin, and of nearly equal length, extending to, or nearly to, the middle of the pectoral fin; post- mental barbels close behind the mentals and almost be- low the maxillary barbels. Dorsal fin a little behind the middle between the nape and the caudal; its height shorter than head. Adipose fin very short. Caudal equally lobed; 5 in the length. Anal with fleshy base; extending to root of caudal. Pectoral equal to the head in length, extending be- yond the base of the ventral fin; ventral fin extending shightly beyond origin of anal. Blackish brown, finely marbled with black. Head 53; depth 44. Br. 13; D.5; A. 42. « (Giimther:) SOUTH AMERICAN NEMATOGNATHI. 3138 LVI. HyporpHtTHALMUS. Hypophthalmus Spix, Pise. Bras. 16, pl. 9, 1829. (sp.) Hypophthalmus Bleeker, Nederl. Tijdschr. Dierkunde, 1, 109, 1863 (edentatus). Notophthalmus Hyrtle, Denk. Ak. Wien, xvi, 17, 1859 (marginatus = edentatus). Pseudohypophthalmus Bleeker, 1. c. (fimbriatus = eden- tatus). Type: Hypophthalmus edentatus Spix. No teeth in the jaws or on the vomer; eye situated be- hind and partly below the level of the angle of the mouth. Adipose fin very small; dorsal fin short, with a shghtly spinous ray, inserted behind the ventrals; anal long; intermaxillaries very small. Barbels six. Gill-openings wide, extending nearly to the symphysis. Air-bladder rudimentary. Ventrals six-rayed. Branch- iostegals 13 or 14. Gill-rakers long and slender; fourth gill-arch entirely free, the first two with a single series of gill-rakers and a broad membrane. 248. Hypophthalmus edentatus. Hypopthalmus edentatus Spix. Pisc. Brasil. 16, pl. ix, 1829 (Equato- rial Brazil); Gtinther, Cat. Fish. Brit. Mus. v, 67, 1864 (copied); Cope, Proc. Am. Philos. Soc. xvii, 673, 1878 (Peruvian Amazon); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 120, 1888 (Para). Hypophthalmus marginatus Cuy. & Val. Hist. Nat. Poiss. xv, 225, plate 439, 1840 (Cayenne; Surinam); Giinther, Cat. Fish. Brit. Mus. v, 68, 1864 (copied); Vaillant, Bull. Soc. Philom. Ser. 7, iv, 150, 1880 (Calderon); Wright, Trans. Roy. Soc. Can. iii, sect. iv, 107-118, plates 8-10 (important paper on structure). Notophthalmus marginatus Hyrtle, Denk. Ak. Wien, xvi, 17, 1859 (vertebrae 24+5+4 54). Hypophthalmus longifilis Cuv. & Val. 1. c. xv, 230, 1840 (Surinam); Giinther,1.c. (Demarara; Surinam); Bleeker, Silures de Suriname, 88, 1864 (Surinam). Hypophthalmus spixii Cuv. & Val. 1. ¢. xv, 231, 1840 (copied); Kner, SB. Ak. Wien, xxvi, 446, 1857 (Rio Branco). Hypopthalmus edentulus Castelnau, Anim. Amér. du Sud, 47, 1855 (Amazon). le CALIFORNIA ACADEMY OF SCIENCES. Hypophthalmus jfimbriatus Kner, 1. c. 444, plate 9, fig. 30 (Rio Negro); Giinther, 1. c. (copied). Hypophthalmus perporosus Cope, l.c. (Nauta); Steindachner, Fluss- fische Siidamerika’s, iv, 4, 1882 (Rio Huallaga; Rio Amazonas). Habitat: Amazons and tributaries, and northward. The species of Hypophthalmus are based chiefly on the variation of the barbels and the lateral pores. - We have examined specimens from .12—.40 m. long. Some agree with one of the above quoted descriptions, and some with another. They are labeled edentatus, fimbriatus, and longifilis. There is little doubt but that the species have been based on the different stages of one species, as we shall endeavor to prove. Steindachner had two specimens of perporosws, one of which had the pores of the lateral line and its branches much less evident than the other. In some of the specimens examined by us the pores are not evident on a superficial examination, while in others they are so conspicuous as to attract the attention at once, and in the smallest specimen there are no pores except along the lateral line and at end of its very short branches. The barbels in some appear filiform, but a closer in- spection proves that all are margined more or less broadly. The smallest specimen has the membrane of the barbels very broad near the base; the maxillary bar- bel extends beyond tip of dorsal; mental and postmental barbels to the tip of the dorsal. In a specimen .18 m. long the maxillary barbels reach the tip of the dorsal fin and the mental barbels extend to the anal fin. In a specimen .40 m. long the maxillary and mental barbels reach the base of the pectoral, while Professor Cope says the specimen of .50 m. had the maxillary bar- bels extending past the base of the ventral fin and the mental barbels nearly to the opercular border. SOUTH AMERICAN NEMATOGNATHI. 315 H. longifilis was based on specimens of from .13-.15 m. in length and accordingly the maxillary barbels ex- tend beyond the dorsal. H. marginatus and H. edentatus were based on speci- mens .25-.35 m. long and the maxillary barbels are slightly longer than the head and not extending to the end of the pectoral. We do not know the length of the type of H. fimbriatus. This may be sufficient to prove that the different ‘‘species”’ of Hypophthalmus are different stages of the same species. The nine specimens examined are from Para. Body much compressed; greatest width of head 24-3 in its length, its greatest depth 24; profile straight and steep; mouth horizontal, placed low. Eyes 9-13 in head, 5-6 in snout, 25-4 in the space be- tween the eyes measuring below. A long groove from occiput widening forward. Upper jaw thin, papery; no teeth. Maxillary barbels inserted in front of anterior nares; reaching adipose fin in young, scarcely beyond head in adult examples; all the barbels flattened and having their posterior margins membranaceous, especially in the young; the mental and postmental barbels reaching to the tip of the dorsal in the young, shorter in the adult. Gill-membranes separate to below the maxillary; gill- rakers slender, about two diameters of the eye in length, very numerous. Lateral line prominent, sending branches downward and backward to below the level of the pectorals, and others backward and upward; each set of branches ex- tending across the lateral line—the one upward and forward, the other forward and downward to the second branch in front of it, forming a network along each side of the lateral line; the branches becoming irregular on 316 CALIFORNIA ACADEMY OF SCIENCES. the tail, the Lne curving upward at base of the caudal fin; a series of pores extends on either side of the lateral line and its branches. Dorsal fin short, the spine slender, 25-5 in head, its insertion variable; adipose fin very small. Caudal deeply forked, the lobes pointed. Ventrals small, extending to the anal in the young, shorter in the adult. Pectoral spine reaching to the anal, 25 in length of head; shorter in the adult. Color brassy or silvery, darker above; fins sometimes with a dark border. Head 332-44; depth 44-54; Br. 14; D. I, 6; A. 68. Nine specimens, .12-40m. Para. Thayer Expedition. Fawiny V¥.. PYGIDMDA; >Siluroidei trichomycteriformes Bleeker, Nederl. Tij- dschr. Dierk, 1, 112, 1863. >Siluride opisthopterw Ginther, Cat. Fish. Brit. Mus. v, 4, 1864. >Siluride branchicolew Ginther, |. ¢. >Trichomycteride Gill, Arrangement of Families of Fishes, 19, 1872. = Pygidiide E.& EK. Am. Nat. July, ’88. Air bladder rudimentary, enclosed in the lateral pro- cesses of the coalesced vertebrae. Adipose fins none. Dor- sal and anal short. Skull enveloped in a thick coat of muscles and skin. Teeth usually villiform. Nares re- mote. Derm naked. The members of this family vary greatly. Cetopsis is the most aberrant of the genera, approaching most closely some genera of Auchenipterine, with which it has usually been associated. Its coalesced vertebre and air bladder are, however, essentially like those of Pygidium. Its dorsal fin while placed well forward is SOUTH AMERICAN NEMATOGNATHI. lke not connected with the skull by any processes or bucklers, and except for its position is lke that of Nematogenys and Pygidium. ANALYSIS OF THE GENERA OF PYGIDIIDZE. a. Dorsal entirely in front of the ventrals; vomer with teeth; head compressed; anterior nares almost labial. Gill-membrane broadly united with the isthmus. Eye almost entirely concealed under the skin. A single maxillary barbel; two pairs of mental barbels. Opercles un- armed. (CETOPSINZ.) CETOPSIS LVII. aa. Dorsal above or behind the ventrals; no teeth on the vomer. b. Gill-openings: broad, the gill-membranes almost free or forming a free membrane across the isthmus. (PyYGIDINZ.) c. Anal short; eyes superior; mouth terminal; gill-membranes free or almost free from the isthmus. d. Ventrals present. e. A single maxillary barbel; opercle and preopercle unarmed. J. Nasal barbels present; dorsal placed over the ventrals; one pair of mental barbels. NEMATOGENYS LVIII. Jf. Nasal barbels obsolete; dorsal placed behind the ventrals; two pairs of mental barbels. PARIOLIUS LIX. ee. Two maxillary barbels; opercle and preopercle with osseous prickles; nasal barbels present. PYGIDIUM LX. dd. Ventral fins none; otherwise like Pygidium. EREMOPHILUS LXI. ec. Anal long, partly in front of the dorsal; head greatly depressed; eyes infringing on the upper and lower surfaces of the head; mouth inferior; gill-membranes broadly joined to each other, free from the isthmus; opercle and preopercle with osseous prickles; a series of fine labial teeth. TRIDENS LXII. bb. Gill-membranes confluent with the skin of the isthmus, the gill- opening a narrow slit in front of the pectoral; opercle and preopercle armed with spines; vent far behind the middle of the body; anal short. (STEGOPHILINZE.) g. Maxillary barbel single. h. Teeth small, forming several series on each jaw; upper lip with two or more series of movable teeth; mouth inferior. i. Caudal widely forked, the upper lobe produced in a filament. PSEUDOSTEGOPHILUS LXITI. i. Caudal rounded or slightly emarginate. STEGOPHILUS LXIV. hh. Teeth comparatively large, pointed, forming a single series on the intermaxillaries only; mouth subinferior. VANDELLIA LXV. Peale) CALIFORNIA ACADEMY OF SCIENCES. gg. Maxillary barbels double. j. Teeth broad incisor-like, in a single series on the jaws; caudal forked. PAREIODON LXVI. jj. Teeth conical, in several series; caudal rounded. MIvROGLANIS LXVII. SuBFAMILY CETOPSIN A. LVII. CrEropsits. Cetopsis Agassiz, Gen. et Spec. Pisce. Bras. 11. (sp.) Cetopsis Bleeker, Nederl. Tijdschr. Dierkunde, i, 111, 1863 (cweutiens). Hemicetopsis id. 1. c. (candira). Pseudocetopsis id. 1. ¢. (gobioides). Type: Silurws cecutiens Lichtenstein. Barbels six, the mental barbels disposed as to pairs. Eyes rudimentary, covered with skin. Teeth villiform or compressed-conical or incisor-like, in a single series or ina band. ‘Teeth on the vomer. No nasal barbels; caudal forked. Habitat: Amazon and its tributaries; Guayaquil. ANALYSIS OF THE SPECIES OF CETOPSIS. a. Teeth all conical or incisor-like, those on the vomer in a single series. (HEMICETOPSIs). b. Teeth on the mandible and on the intermaxillaries in a single series. Anterior nares 14 times as wide apart as the posterior; gill-openings entirely below the first pectoral ray; inner margin of the ventrals entirely free; pectorals reaching half way to the ventrals. candiru 249. 6b. Teeth on the intermaxillaries in 2 or 3 series, mandible with 2 series of teeth, anterior nares nearer together than the posterior; gill-open- ing as far above as below the first pectoral ray; inner ventral ray con- nected with the belly by a membrane. Distance of the dorsal spine from tip of snout 3 in the length; first dorsal ray as long as the head. Pectorals shorter than the head not quite reaching the ventrals. Cau- dal and dorsal dotted with dark, other fins plain; dorsal surface dark plumbeus, sides of body and head silvery white with irregular spots; lower parts silvery white. Head 4-44; depth 5-6; D. I, 5; A. 26-27; P. 1, 8; V.6. (Steindachner). plumbeus 250. aa. Teeth on the intermaxillaries villiform in a band; those on the vomer and on the mandible incisor-like, in asingle series. (CETOPSIS.) cacutiens 251. SOUTH AMERICAN NEMATOGNATHI. 319 aaa. Teeth on the intermaxillaries and on the mandible villiform, in bands, those on the vomer conical, in a single series. (PSEUDOCETOPSIS). c. Eye moderately large, about 6 in the head; gill-opening as far above as below the pectoral. Distance of the first dorsal ray from tip of snout 3 in the length; ventral fins united by a membrane; pectoral fins reaching in theé4 beyond the base of the ventrals. All fins im- maculate. Head 5; dorsal 7; A. 22. (Kner.) . gobioides 252. aaaa. Teeth all villiform. d. Teeth on the vomer in two patches; head 34. Ventrals behind the vertical from the last dorsal ray, the basal half of the inner margin joined to the ventral surface; posterior nares remote from each other. Eye 102 in the head. Barbels all short. Gill-opening extending above and below the pectoral fin. Distance of first dorsal ray from tip of snout 22 in the length. Caudal somewhat forked; pectoral fin reaching 2 toward the base of the ventrals. Depth 4; D. I, 6; P.I, 9; V.1, 5; A. 29. (Steindachner). occidentalis 253. dd. Teeth on the yvomerin a single series; head 44; width of the head not more than half of its length; ventral fins connected by their inner margins to the ventral surface. Barbels all short. Grayish, darker above; basal half of the dorsal punctate with black. D.I, 6; A. 29; Wis OR Le, MO. (CGrttlle)) ventralis 254. 249, Cetopsis candiru. Silurus candiru Spix. Gen. Spec. Pisce. 13, plate x, fig. 1, 1829 (Equa- torial rivers of Brazil). Cetopsis candiru Agassiz, Gen. Spec. Pisc. 13, 1829. Cetopsis candira Cuy. & Val. Hist Nat. Poiss. xiv, 386, 1839 (copied); Giinther, Cat. Fish. Brit. Mus. v, 199, 1864 (River Cupai); Cope, Proc. Am. Philos. Soc. xvii, 678, 1878 (Peruvian Amazon); Stein- dachner, Flussfische Siidamerika’s, iv, 5, 1882 (Rio Huallaga); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 157, 1888 (Taba- tinga; Jutahy, Tonantins; I¢a). Habitat: Amazons and tributaries from the Rio Cupai to the Rio Huallaga). Subterete, little compressed and scarcely tapering backward. Head short and thick, the bones everywhere covered with thick muscle; profile somewhat arched in front; the depth of the head a little less than the width; anterior nares 1} times as wide apart as the posterior ones. Eye small, but much larger than one of the posterior nares. Barbels rather thick and short, at least partially re- 320 CALIFORNIA ACADEMY OF SCIENCES. ceivable in grooves at their bases; all of about equal length; the mental barbels disposed as two pairs situated behind the rictus. . Mouth terminal, the upper jaw very shghtly project- ing; a single series of somewhat compressed teeth in each jaw and on the vomer; intermaxillaries each with 4 teeth; mandible with 8-12 teeth on each side; vomer with about 8 on each half. Gill-openings very small, entirely below the first pec- toral ray. Pectoral pore present; lateral line simple, straight. Distance of first dorsal ray from tip of snout 32 in the length; the first dorsal ray scarcely higher than the sec- ond, the last half as high as the second ray. Caudal narrow, emarginate, 53-54 in the length. Anal rays gradually decreasing backward, their tips projecting beyond the membrane. Ventrals short, very narrow, the inner margins en- tirely free. Pectorals reaching about half-way to the ventrals, 13 in the head. Faintly dotted with light brown above; sides and be- low white, probably pink in life; pectoral and dorsal fins dark, their free half nearly black; free half of the ventrals dusky; other fins plain white. Head. 6; depth 6;\D2.7: A. 305,V26.°P2o: Seven specimens .10-.18m. Tabatinga; Jutahy; Tonan- tins; Ica.. Thayer Expedition. 250. Cetopsis plumbeus. Cetopsis plumbeus Steindachner, Flussfische Siidam. iv, 31, pl. vi,, fig. 8, 1882 (Canelos); Boulenger, Proc. Zool. Soc. Lond. March, 1887, 276 (Canelos). Habitat; Eastern slopes of Ecuador. 251. Cetopsis cecutiens. Silurus ceecutiens Lichtenstein, Wiedem. Zool. Mag. i, part 3, 61, 1829 (Brazil); Spix, Gen. et. Spec. Pisce. 12, pl. x, fig. 2, 1829 (Rivers of equatorial Brazil). SOUTH AMERICAN NEMATOGNATHI. oe Cetopsis cecutiens Agassiz, Gen. et. Spec. Pisc. 12, 1829; Cuv. & Val. xiv, 384, 1839 (copied); Kner, SB. Ak. Wien, xxvi, 409, 1858. EKigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 157, 1888 (Gurupa). Cetopsis cecutiens Giinther, Cat. v, 199, 1864 (River Cupai, tribu- tary to the Amazon, 800 miles from the sea). Habitat: Lower Amazon; Gurupa to Rio Cupai. Body heavy, little compressed, tapering rapidly to the caudal peduncle. Head bluntly conical, the bones everywhere covered with a thick layer of muscle. Pro- file arched, depth of the head considerably greater than its width. Anterior nares situated near the lip, four times as wide apart as the posterior nares which are large, oval, above the anterior margin of the eye. Kye small, rudimentary, covered with skin, not larger than the posterior nares. Maxillary barbels almost entirely concealed in a slit- like groove, 33 in the length of the head. Mental and postmental barbels of about the same length disposed as two pairs behind the angle of the mouth, receivable in shallow grooves. Mouth inferior, its width at the rictus 2} in the head; a narrow band of fine villiform teeth on the intermax- illaries; mandible and vomer each with a single series of firmly set, thick compressed teeth. Opercle with a broad membranaceous border. Gill- opening extending farther below than above the upper pectoral ray. Pectoral pore an elongate slit; lateral line straight, simple. Distance of dorsal spine from the snout 24 in the length, first dorsal ray somewhat elongate, the rays rapidly decreasing in height backward, the last nota third as high as the second. Caudal deeply emarginate, 43 in the length. _ Anal rays decreasing in height backward. 21 one CALIFORNIA ACADEMY OF SCIENCES. Ventrals short, with the basal half of their inner mag- gins attached to the belly. First pectoral ray lengthened, reaching past the base of the ventrals, a little shorter than the head, its tip broken, probably longer than the head. Dorsal surface grayish brown, becoming gray on sides, lighter below. Head 323 depth, 4;.D. 7; A. 2150 V2.6... 0: One specimen, ?, length .23 m. Gurupa. Louis Agassiz. 252. Cetopsis gobioides. Cetopsis gobioides Kner, SB. Ak. Wien, xxvi, 407, 1857, pl. vi, fig, 16 (Irisanga); Giinther, Cat. Fish. Brit. Mus. v, 199, 1864 (copied). Silurus pygmeus Natterer in Kner. 1. c. Habitat: Irisanga. This species is known only from the types. 253. Cetopsis occidentalis. Cetopsis occidentalis Steindachner, Fisch-fauna des Cauca and Flusse bei Guayaquil, 47, plate viii, fig. 2-2a, 1880 (Rivers near Guaya- quil). Habitat: Guayaquil. This species is known only from the types. 254. Cetopsis ventralis. Cetopsis ventralis Gill, Proc. Acad. Nat. Sci. Philad. 1870, 95 (Upper Amazon). Habitat: Upper Amazon. LVIII. NEMATOGENYs. Nematogenys Girard, Proc. Acad. Nat. Sci. Phila. 1854, 198 (inermis). Type: Trichomycterus inermis Guichenot. Dorsal fin placed over the ventrals, without a spine. Fontanel extending to base of occipital process, interrupted above the posterior margin of orbit. Opercle and pre- opercle unarmed. A single barbel on each maxillary and one pair of mental barbels. Habitat: Central Chile. SOUTH AMERICAN NEMATOGNATHI. 323 255. Nematogenys inermis. Trichomycterus inermis Guichenot, in Gay Hist. Chil. Zool. ii, 312, pl. ix, fig 2, 1848 (Chile). Nematogenys inermis Girard, U.S. Nay. & Astron. Exped. 240, pl. xxx, 1855 (Rio de Maypu near Santiago); Philippi, MB. Ak. Berl. 716, 1866 (Chile); Giinther, Cat. v, 272, 1864 (copied); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 50, 1889 (Curico; Santiago). Nematogenys nigricans Philippi, 1. ce. 716 (Chile). Nematogenys pallidus Philippi, 1. ¢. 716 (Chile). Habitat: Fresh waters of Central Chile. N. nigricans and pallidus seem to be color varieties of N. inermis. Tail compressed, head depressed, the caudal peduncle about as deep as the body. Head entirely covered with soft skin, little longer than wide, its depth 13-2 in its length. Eye small, superior; interocular width little less than length of snout; orbit without a free margin. Mouth wide, terminal, each jaw with a rather deep band of vil- liform teeth. Gill-membranes narrowly joined to the isthmus. Anterior nasal opening with a barbel which is about 1} times as long as the eye; a series of pores extending from it backward below the eye; a prominent pair of pores between the eyes. Pectoral pore minute, above and behind the pectoral spine. Origin of dorsal fin one-fifth nearer tip of snout than to base of middle caudal rays in specimens .12 metre long; one-fifth nearer base of caudal rays than to tip of snout in a specimen .26 metre long. Margin of all the fins rounded. Caudal with numer- ous accessory rays, the middle caudal rays 1-1} in the head. Origin of ventrals below or slightly behind the first dorsal ray. Inner margin of pectoral spine serrate, its lower surface spiny. Light brown mottled with darker, a series of about 5 324 CALIFORNIA ACADEMY OF SCIENCES. light areas along the lateral line; fins speckled; the largest specimen is faded. Head 43-34; depth 7-6; D. 10; A. 11; Br. 10-12. Seven specimens .12-.26m. Curico; Santiago. Stein- dachner. LIX. Partroxtus. Pariolius Cope, Proc. Acad. Nat. Sci. Phila. 1871, 289 (armillatus). Type: Pariolius armillatus Cope. Dorsal fin placed in front of the ventrals. No nasal barbel. Opercle and preopercle unarmed. A single barbel on each maxillary and two pairs of mentals. This genus is closely related to Nematogenys and Tri- chomycterus. 256. Pariolius armillatus. Pariolius armillatus Cope, 1. c. (Ambyiacu); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 50, 1889. Head flat, rounded; eyes small, superior. Interorbital 3% in length of head. Maxillary and postmental barbels reaching beyond base of pectoral. Caudal acuminate. Dark brown, nearly black on the top of the head; under surfaces from anus brownish yellow, brown punctulate. A broad yellow collar at base of pectorals; a dark spot on base of caudal. D.7; A. 11; Head 4§. (Cope.) LX, Pyerprum. Trichomycterus Valenciennes, Humboldt’s Rec. d’Obs. Zool. et Anat. 11, 348, 1833 (nigricans) not Thrichomycterus Humboldt. Thrychomycterus Cuy. & Val. Hist. Nat. Poiss. xvii, 485, 1846 (misquoted). Thrichomycterus Girard, U. 8. Nay. Astron. Exped. i, 242, 1855 (misquoted). Pygidium Meyen, Reise, 1, 475, 1835 (fuscum). Type: Pygidium fuscum Meyen. SOUTH AMERICAN NEMATOGNATHI. 32D Habitat: Andes from Central Chile to Colombia; Callao Bay; Amazon to Cudajas; Southeastern Brazil; Central Argentine Republic. The only claim for retention the name Trichomycterus possesses is its distinctiveness from Thrichomycterus Humb.=Lremophilus Humboldt. Twenty-two years be- fore any species of T'richomycterus Val. was known, the name Thrichomycterus was proposed by Humboldt as an alternative for his Hremophilus, if future investigations should prove Hremophilus to be objectionable. Upon proposing the name TVrichomycterus Valenciennes states: ‘‘Nous prenons pour le nouveau genre le nom de T'rich- omycterus 1maginé par M. de Humboldt,” so the names can hardly be considered distinct. Valenciennes after- wards misquotes himself, spelling the name THRychomyc- terus instead of Trichomycterus. Girard also misquotes Valenciennes, using Thrichomycterus instead of Trichomyc- terus. The only available name for this genus seems to be Pygidium, based on some fish found floating in a river Ol serur DOUBTFUL SPECIES OF PYGIDIUM. As most of the young of the species of Pygidiwm are very much alike in coloration, and usually entirely dif- ferent from the adult, we are compelled to place here most of the species based on young individuals, unless they were collected together with large individuals. 256.1. Pygidium fuscum Meyen, l. c. (Peru); Wieg- man, Wiegman’s Arch. 1835, 11, 269 (copied). By put- ting together the two descriptions quoted and the local- ity, one may infer that this species belongs to the genus Trichomycterus auct. 256.2. Trichomycterus palleus Philippi, MB. Ak. Berl. 1866, 715 (Chile). Light reddish; fins colorless; head Of in tov D2 9=1 0) ANG: 326 CALIFORNIA ACADEMY OF SCIENCES. 256.3. Trichomycterus marmoratus Philippi, l. ec. 714. Blackish gray, marbled with many black spots, as in punc- tatus; fins dark. Depth 103,; D. 10; A. 6. 256.4. Trichomycterus tenuis Weyenbergh, Actas Acad. Nac. Cienc. Exactas, i1i, 12, pl. 111, Buenos Aires, 1877 (Sierra de Cordoba, near Cruz-del-eje). Yellow, eyes and barbels black; head triangular; opercle and preop- ercl well armed. Body much compressed. D. 6; A. 5. 256.5. Trichomycterus corduvensis Weyenbergh, |. c. 11, pl. 111 (Rio Primero). Obscure blotches on the back, the sides with a dusky band. 256.6. Trichomycterus tigrinum Philippi, |. ¢. Light with reddish points; fins immaculate. Head 63; depth 4 in total length. D.9 or 10; A. 6. 256.7. Pygidiwm poeyanum. Trichomycterus rivulatus Cope, Proc. Acad. Sci. Philad. 1874, 182 (Arequipa, Peru); not of Cuv. & Val. Trich- omycterus poeyanus Cope, Proc. Am. Philos. Soc. 1877, 47. Pygidium poeyanum E. & E. Proc. Cal. Acad. Sci. 2d Ser. 11, 50, 1889. Habitat: Western slopes of southern Peru. ANALYSIS OF THE SPECIES OF PYGIDIUM.* a. Origin of dorsal in front of the origin of the anal. 6. Dorsal rays 15-21; first pectoral ray not produced in a filament; gill- membranes joined to the isthmus. c. D. 21; origin of dorsal equidistant from occiput and tip of caudal. Anal inserted below the 9th dorsal ray and terminating under the 17th. macrei 257. cc. D. 15; origin of dorsal equidistant from tip of snout and tip of caudal; last ray of the anal under last ray of the dorsal. Distance of anal from base of caudal 3% in the length. maculatum 258. 6b. Dorsal rays less than 15. d. None of the dorsal rays prolonged. e. Dorsal placed partly over the anal. *In the species examined by us the rudimentary rays of the dorsal and anal are counted. SOUTH AMERICAN NEMATOGNATHI. 327 J. Caudal emarginate; D. 14; gill-membrane free from the isthmus; upper maxillary barbels reaching pectorals. Origin of dorsal equidistant from tip of caudal and occiput. Distance of anal from base of caudal 5 in the length. areolatum 259. Jy. Caudal truncate or rounded. g. First ray of the pectoral prolonged except in very young. h. Teeth in broad bands in both jaws.* i. Maxillary barbels reaching to the preopercle; D. 13; A. 1]. rivulatum 260. ii. Maxillary barbels reaching beyond the gill-opening; D. ACO) : brasiliensis 261. hh. Teeth in two series in each jaw (?). j. Head narrowed forward, heart-shaped, scarcely wider than long; upper maxillary barbels reaching to base of pectoral; origin of anal below end of dorsal; a dark lat- eral band, two series of spots above it; top of head spot- ted. Head 7; D.8;A.6. (Kner & Steindachner.) tenia 262. jj. Head of uniform width; width of mouth more than half length of head. Teeth in the anterior series of each jaw compressed. Maxillary barbels reaching beyond base of pectoral. Head and body with numerous dark spots. Head 7; D.9; A.7. (Kner & Steindachner.) laticeps 263. gg. First ray of the pectoral not prolonged; none of the bar- bels reaching gill-opening. oroye 264. ee. Dorsal entirely in front of the anal. k, Caudal rounded. i. Yellowish, upper half of sides and the back thickly punctate with darker. (Castelnau.) punctatssimum 265. ll. Uniform brown, darkest on the back. knerii 266. kk. Caudal emarginate. m. Back and sides profusely spotted; first pectoral ray pro- longed. n. Dorsal behind the base of the veutrals. o. Head longer than broad by a diameter of the eye. p. Spots as large as or larger than the eye. dispar 267. pp. Spots much smaller than the eye. dispar punctulatum 267a. oo. Head as long as broad; upper maxillary barbel extend- ing to the base of the pectoral. Head 63; D. 8; A. 6. (Boulenger.) nigromaculatum 268. nn. Dorsal partly over the base of the ventrals; D. 8; A. 12. (Cope.) pardum 269. eee * Trichomycterus poeyanus Cope, probably belongs here; as the shape of the caudal and > length of the barbels are not given, we have not been able to give it a place in this key. SS) CALIFORNIA ACADEMY OF SCIENCES. mm. Back and sides uniform yellowish or brownish. q. Eye comparatively large; maxillary barbel not reaching to gill-opening. immaculatum 270. qq. Eye minute, smaller than the posterior nares, maxillary barbel reaching beyond base of pectoral. (Steindachner.) taczanowskii 271. dd. First dorsal ray prolonged in a filament; barbels scarcely extend- ing beyond the eyes; caudal truncate. Blackish, lighter below. D. 11; A. 10. (Cuvier & Valenciennes.) nigricans 272. aa. Origin of the dorsal over the origin of the anal; eye large, in anterior half of head; upper maxillary barbel reaching beyond base of pectoral. Caudal rounded; first pectoral ray prolonged. Chocolate brown; in- distinct spots on the caudal peduncle; dorsal and caudal rays dotted with violet. Head 7; D.8; A. 7. (Steindachner.) amazonicum 273. 257. Pygidium macrei. Thricomycterus macrei Girard, U.S. Naval & Astron. Exped. ii, 245, 1855 (Uspullata(?) east side of the Cordilleras at an eleva- tion of 7,000 feet). Pygidium macrei K. & E. Proc. Cal. Acad. Sci. 2d Ser. 1i, 51, 1889 (Uspullatuo). Habitat: Eastern slopes of Central Chile. The single specimen, No. 8,298, of this species was presented to the Mus. Comp. Zool. by the Smithsonian Institution in 1859. It came from ‘‘ Uspullatuo ”’ most likely Girard’s type. Elongate, rather compressed, especially backward. Head as broad as long, snout rounded; eye small, mid- way between tip of snout and end of opercle; none of the barbels reaching the gill-opening. Gill-opening scarcely continued forward below; joined to the isthmus for a distance equal to half the width of the mouth. ; and is Pectorals obliquely truncate, the first ray not pro- duced; origin of dorsal some distance behind the ventrals, equidistant from occiput and tip of caudal; fourth or fifth dorsal ray highest, then gradually decreasing in height to the last. Caudal emarginate, the upper lobe pointed, the lower rounded. Anal inserted below the 9th dorsal ray and terminating under the 17th. Ventrals SOUTH AMERICAN NEMATOGNATHI. 329 inserted nearer tip of snout than to tips of middle caudal rays, reaching to the vent. Color faded; light below, dark above. Head 61 (7 in the total); depth 6; D. 21; A. 10. 258. Pygidium maculatum. Trichomycterus maculatus Cuyv. & Val. Hist. Nat. Poiss. xvili, 493, 1846 (San Iago); Gay, Hist. Chile ii, 311, 1848 (Chile); Gunther, Cat. Fish. Brit. Mus. v, 273, 1864 (copied); Philippi, MB. Ak. Berl. 716, 1866 (Chile). Thrichomycterus maculatus Girard, U.S. Naval. Astrom. Exped. 243, 1855 (Rio Mapocho) in part. Pygidium maculatum E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889 (Rio Mapocho, Chile). Habitat: Western slopes of Central Chile. The Smithsonian Institution presented the Mus. Comp. Zool. with three specimens, No. 7,736, of Pygidium, col- lected at Mapocho, Chile, during the astronomical expe- dition. If these are the specimens mentioned by Girard his muculatus is a composite of maculatus and areolatus as the specimens belong to these species. The specimens are, however, all somewhat smaller than Girard’s figure. Elongate, somewhat compressed, head as long as wide, caudal peduncle long and slender. Eye small, midway between tip of snout and end of opercle. Lips and lower surfaces of the head thickly covered with warts. Gill- openings not continued forward to below the eye, the membranes joined to the isthmus for a distance equal to one-third the width of the mouth. Pectorals rounded, the first ray not produced; origin of dorsal in front of the vent, but some distance behind the ventrals, equidistant from tip of snout and tip of caudal, its last ray over the last ray of the anal. Caudal long, truncate. Anal short and high, its height about equal to the length of the caudal, its distance from the base of the caudal 3? in the length. Origin of the ven- trals equidistant from tip of snout and base of caudal; their tips reaching beyond the vent. 330 CALIFORNIA ACADEMY OF SCIENCES. Back and sides marbled with light and dark brown; fins pale, immaculate. Head -53 (64 in the total); depth 74; D. 15; A. 9. One specimen .092 m. Rio Mapocho, Chile. 259. Pygidium areolatum. Trichomycterus areolatus Cuy. & Val. Hist. Nat. Poiss. xvili, 492, 1846 (Coast of Chile); Gay, Hist. Chile, 11, 309, 1848; Giinther, Cat. Fish. Brit. Mus. v, 274, 1864 (Chile); Philippi, MB. Ak. Berlin, 714, 1866. Thrichomycterus maculatus Girard, U. 8. Naval Astron. Exped. 243, 1855 (Mapocho), in part. Pygidium areolatum E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889 (Rio Mapocho, Chile). Habitat: Western slope of Central Chile. Elongate, subterete. Lips and lower surface of head thickly covered with small warts. Gull-openings con- tinued forward to below the eye, the membrane free from the isthmus. Upper maxillary barbels reaching to the pectorals. Pectorals rounded, the first ray not prolonged; origin of dorsal slightly in front of the vent, equidistant from tip of caudal and occiput, its last ray over the fourth ray of the anal. Caudal very slightly emarginate. Dis- tance of anal from the base of the caudal 5 in the length. Origin of ventrals equidistant between tip of snout and middle of caudal; tips of the-ventrals not reaching the vent. Light brown, with purple longitudinal streaks. Head 5? (62 in the total); depth 83; D. 14; A. 8. One specimen .103 m. Mapocho, Chile. 260. Pygidium rivulatum, Trichomycterus rivulatus Cuy. & Val. Hist. Nat. Poiss. xviii, 495, 1846 (Guasacona); Giinther, Cat. Fish. Brit. Mus. v, 274, 1864 (copied); Cope, Proc. Am. Philos. Soc. xvii, 47, 1877 (Lake Titicaca). Pygidium rivulatum E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889 (Cuzco; Moho and Puno on Lake Titicaca.. ¢ Trichomycterus ince Cuy. & Val. 1. c. 496 (Rio Guatanai at Cuzco). SOUTH AMERICAN NEMATOGNATHI. 331 Trichomycterus gracilis Cuy. & Val. 1. ¢. 497 (Rio Azangaro near Guasacona; Rio Guatanai near Cuzco; Rio Pontezualo near Coroico; Lake Compucila near Cuzco); Cope, Proc. Am. Philos. Soc. xvii, 681, 1877 (Tinta). Trichomycterus barbatula Cuy. & Val. 1. ec. 498 (Guasacona; Rio Pontezualo near Coroico). Trichomycterus pentlandi Castelnau, Anim. Nouy. Am. Siid, 49, pl. xxiv, fig. 1, 1855 (Lake communicating with the Ucayale). Trichomycterus pictus Castelnau, Anim. Nouy. Am. Siid, 59, pl. xxly, fig. 2, 1855 (Lake Titicaca). Trichomycterus dispar Giinther, Cat. Fish. Brit. Mus. v, 273, 1864 (in part); (Lake Titicaca; Rio de Pontezualo; Andes de la Paz; Guasacona Rio de Azangaro); Garman, Bull. Mus. Comp. Zool. ili, 275, 1875 (Lake Titicaca). Habitat: Lake Titicaca; Ucayale and its tributaries. This species is readily distinguished from dispar and punctulatus by the anterior position of the dorsal, the rounded caudal and the abrupt change from short acces- sory rays to the long caudal rays. The last character was moderately figured by Castelnau. It differs greatly in color and proportions at different ages. Cuv. & Val. described individuals 7 inches long as rivulatus; 44 inches long as ince; 3 inches long as gracilis; 25 inches long as barbatula; while Castelnau represents the full grown, in his pentlandi—the dorsal, however, has been misplaced. We have examined 120 specimens of this species, mostly from Lake Titicaca. While the color markings sometimes approach those of dispar and pwnctulatus, it does not intergrade with them in the characters men- tioned above. Most of the specimens mentioned by Dr. Giinther un- der dispar are evidently rivulatus. The specimen from the River Remac may be the punctulatus of Cuy. & Val. This species is very variable; it is only in the fully grown, or specimens of about .35 m. long, that any con- stancy seems to exist. In general form it resembles the North American Amiurus catus. Doe CALIFORNIA ACADEMY OF SCIENCES. Tail compressed, head depressed, about as wide as long; eye equidistant from tip of snout and end of opercle. Nasal barbels reaching to the posterior margin of the eye, longer in the young. Upper maxillary barbel about to edge of preopercle. Mouth wide, more than one-third the length of the head. Pectoral rounded, the first ray prolonged in a short filament, except in the very young. Origin of dorsal equidistant from tip of caudal and a point between occiput and posterior nares; its posterior portion always over the anterior half of the anal. Accessory rays of the caudal very numerous, their di- vision from the true caudal rays marked. Caudal al- ways rounded, its distance from the anal 4$—4? in the length. Color of largest specimens dark reddish brown, sides with fine white or silvery spots and vermiculations. Spec- imens from .10-.20 m. greatly variable, grayish or dark brown, with darker markings; sometimes the ground color predominating, sometimes only forming reticula- tions between the dark markings; young with an inter- rupted dark band along the sides. Head 43-53 (53-63 in the total); depth 32-64; D. 13; ve\ee Bp More than one hundred specimens .03-.35 m. Cusco, Moho and Puno on Lake Titicaca. Garman and Rand. 261. Pygidium brasiliensis. Trichomycterus brasiliensis Reinhardt, MS. Liitken, Overs. Dan. Selsk. 1873, No. 3, 29 (Rio das Velhas); id. Velhas Flodens Fiske 135 and i, pl. iii, fig. 8, 1875 (Rio das Velhas). Pygidium brasiliensis BE. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889 (Rio Parahyba; Mendez; Lagoa Santa; Santa Cruz). ? Trichomycterus brasiliensis tristis Lutken 1. c. 137 and i, 1875 (Rio das Velhas. Habitat: Rio Janeiro to Rio San Francisco. Elongate, compressed backward. Head greatly de- SOUTH AMERICAN NEMATOGNATHI. 300 pressed, somewhat longer than wide except in the very young. Eye slightly in front of the middle of the head. Barbels all long, in the adult the nasal extend beyond the occiput; upper maxillary barbels extending beyond the base of the pectorals. Gill-opening continued forward to below the eye; the membrane with a free margin across the isthmus. Pectorals short, the first ray curved and prolonged in a long filament. Dorsal rounded, inserted in front of the vent, its bast ray over the fourth anal ray in the adult, over the first in the young; its origin equidistant from tip of caudal and somewhere between occiput and eye. Caudal short, broad, rounded; its distance from the anal 45-53 in the length. Origin of ventrals about equidistant between tip of snout and tip of caudal; their tips reaching to or beyond vent. Color in adult: back dark brown with darker spots; sides variegated with dark brown, purple and gray; fins obscurely spotted. Color in young: yellowish, middle of sides with a series of about 9, more or less confluent spots of purplish, fainter spots on the tail below the median series; back with about ten cross bars, 5 of which are in front of the dorsal; fins plain or with dusky bars; top of head and line behind eye purplish. Head 5-53 (52-6 in the total); depth 6; D. 11; A. 9. Thirty-three specimens 4 and ? .03-.15 m.; Rio Para- hyba; Mendez; 2 miles from Lagoa Santa; Santa Cruz (Dom Pedro II). Thayer expedition. 262. Pygidium tenia. Trichomycterus tenia Kner, ‘‘SB. Ak. Miinch. 228, 1863”; Kner & Steindachner, Abh. Bayer. Ak. Wiss. 52, 1864, pl. vi, fig. 1. (Western slope Peruvian Andes); Gunther, Cat. Fish. Brit. Mus. v, 274, 1864 (copied). JO CALIFORNIA ACADEMY OF SCIENCES. Pygidium tenia Kigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889. Habitat: Western slopes of the Peruvian Andes. 263. Pygidium laticeps. Trichomycterus laticeps Kner, ‘‘l. c.;” Kner & Steindachner, 1. c. 54, pl. vi, fig. 2 and fig. la. (Western slope Peruvian Andes.) Pygidium laticeps Bigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889. Habitat: Western slopes of the Peruvian Andes. 264. Pygidium oroye. Pygidium oroye EKigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. ii, 51, 1889 (Oroya). Types, No. 3955; eight specimens; .115-.14m. Pochachara, Oroya River. This species is very closely allied to P. brasiliensis. Rather robust; head about as long as wide; none of the barbels reaching the gill-opening. Gill-membrane narrowly joined to the isthmus, without a free margin. Pectoral short, fan-shaped, the first ray not prolonged. Dorsal inserted over the vent, its last ray over or be- hind the middle of the anal, its origin equidistant from anterior margin of eye or occiput and tip of caudal. Caudal broadly rounded, its distance from the anal 4—4# in the length. Origin of ventrals about midway between tip of snout and tip of caudal. Dark chocolate brown; sides, back and unpaired fins with irrregular groups of dark points. Head 52-6; depth 57-7; D. 12; A. 10. 265. Pygidium punctatissimum. Trichomycterus punctatissimus Castelnau, Anim. Am. Stid, 49, pl. 24, fig. 3, 1855 (Araguay). Pygidium punctatissimum BE. & E. Proc. Cal. Acad. 2d Ser. ii, 52, 1889. Habitat: Araguay. SOUTH AMERICAN NEMATOGNATHI. S00 266. Pygidium knerii. Trichomycterus knerii Steindachner, Ichthyol. Beitr. xii, 21, pl. v, fig. l-la, 1882 (Canelos). Pygidium knerit E. & E. Proc. Cal. Acad. Sci. 2d Ser. 11, 52, 1889 (Cumbaca). Habitat: Eastern slope of Ecuador; Cumbaca. Elongate, compressed; head greatly depressed, flat above; the eyes entirely superior; width of the head less than its length. Barbels scarcely extending beyond the eyes, which are equidistant from tip of snout and end of opercle. A broad band of villiform teeth in each jaw. Pectoral rounded, the first ray slightly prolonged. Origin of dorsal above posterior edge of base of ventrals, equidistant from tip of caudal and nares, the last ray over origin of anal. Caudal rounded, its distance from the anal 43 in the length. Ventrals nearer tip of snout than tip of caudal. Uniform brown, darkest on the back. Head 5 (52 in total); depth 53; D. 10; A. 9. One specimen .11 m. Cumbaca. Thayer Expedition. 267. Pygidium dispar. Pygidium dispar Tschudi, Faun. Per. Ichthyol. 22, pl. 3, 1845 (Eastern slope of the Peruvian Andes, at an altitude of 14,000 feet); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 52, 1889 (Callao, Peru). Habitat: Eastern and western (?) slopes of the Peruvian Andes. This species is distinguished by its emarginate caudal and the regularity of its color markings. \It is very doubtful whether the male is of uniform color. Elongate, compressed, the depth everywhere less than the length of the head. Head longer than wide by more than a diameter of the eye. Hye moderate, 4 in the interocular, equidistant from tip of snout and end of opercle. None of the barbels reaching quite to the gill- opening. Gill-openings continued forward to below the - eye. 336 CALIFORNIA ACADEMY OF SCIENCES. Pectorals obliquely rounded, the first ray produced in a filament. Origin of dorsal equidistant from tip of cau- dal and anterior margin of the eye, the whole fin in front of the anal and behind the ventral fins. Caudal emar- ginate. Distance of anal from base of caudal 6 in the length. Origin of ventrals midway between tip of snout and tip of caudal. Reddish brown; sides, back, dorsal and caudal fins with large dark spots, those on the head smallest; lower surface plain. Head 51 (6 in total); D.712; A. 9. One specimen .195 m. Callao?, Peru. Steindachner. 267a. Pygidium dispar punctulatum. Trichomycterus punctulatus Cuy. & Val. Hist. Nat. Poiss. xviii, 488, 1846 (Lima); Liitken, Velhas Flodens Fiske, 137, 1875 (Callao). Trichomycterus punctatus Cuv. & Val. 1. c. pl. 552. Pygidium dispar punctulatum Eigenm. & Eigenm. Proce. Cal. Acad. 2d Ser. ii, 52, 1889 (Rio Remac, near Lima). Habitat: Western slopes of Peruvian Andes. This variety can be distinguished by the small spots covering the sides and back. Origin of dorsal equidistant from tip of caudal and somewhere between occiput and anterior margin of eye; distance of anal from base of caudal 6-63 in the length. Head 54-52 (64-64 in the total); D. 12; A. 10. Twenty-nine specimens .11-.18 m. Rio Remac near Lima. Steindachner. 268. Pygidium nigromaculatum. Trichomycterus nigromaculatus Boulenger, Ann. & Mag. Nat. Hist. Ser. 5, vol. 19, 349, 1887 (Colombia). Pygidium nigromaculatum Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 52, 1889. Habitat: Colombia. This species is very nearly related if not identical with P. dispar. SOUTH AMERICAN NEMATOGNATHI. 301 269. Pygidium pardum. Trichomycterus pardus Cope, Proc. Acad. Nat. Sci. Philad. 1874, 132 (loc.?); id. Proc. Am. Philos. Soc. 1877, 45 (Jequetepeque; Callao Bay). Pygidium pardum Bigenm. & Eigenm. Proc. Cal. Acad., 2d Ser. ii, 52, 1889. Habitat: Callao Bay. 270. Pygidium immaculatum. Pygidium immaculatum Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 1889 (Juizde Fora; Sao Matheos; Goyaz). Habitat: East-central Brazil. Fourteen specimens .06—-.20 m. Juiz de Fora; Sao Matheos; Goyaz. A specimen from Macacos may be a variety of this species. This may be the male of P. brasiliensis. The reproduc- tive organs are, however, all empty asafter spawning, so that it would be difficult to separate male from female, after they had been in alcohol twenty-five years. If it is a species distinct from brasiliensis it must breed earlier than that species, as most of our specimens of P. brasil- iensis are ripe females. Elongate, compressed backward; head gently depressed, the snout broad, spatulate; width of the head less than its length. Eye comparatively large, equidistant from tip of snout and tip of opercle. Barbels all rather short; the nasals scarcely reaching occiput or shorter; maxilla- ries not to gill-opening. Guill-opening continued forward to below the eye; the membrane with a free margin across the isthmus. Pectorals rather short and broad, the first ray pro- longed in a filament. Dorsal truncate, its last ray in front of the anal, its origin equidistant from tip of caudal and base of nasal barbel or slightly nearer tip of caudal. Caudal broad, emarginate, the upper lobe sometimes produced; its distance from the anal 53 in the length. 22 338 CALIFORNIA ACADEMY OF SCIENCES. Origin of ventrals equidistant from tip of caudal and tip of snout, or a little nearer tip of caudal; their tips reaching to the vent. Brownish, lighter below; fins somewhat dusky; speci- men from Sao Matheos uniform blackish brown. Head 53-53 (6-63 in total); D.11; A. 9. 271, Pygidium taczanowskii. Trichomycterus taczanowskii Steindachner, Flussfische Sidam. iv, 22, pl. iv, figs. 1-1b, 1882 (Rio de Huambo; Rio de Tortora). Pygidium taczanowskii EB. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 52, 1889. Habitat: Andes of Peru. 272. Pygidium nigricans. Trichomycterus nigricans Cuy. & Val. Hist. Nat. Poiss. xviii, 494, 1846 (Santa Catharina); ? Gay, Hist. Chile, 311, 1848 (Chile); Giinther, Cat. Fish. Brit. Mus. v, 274, 1864 (copied). Pygidium nigricans Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 53, 1889. Habitat: Santa Catharina. 273. Pygidium amazonicum. Trichomycterus amazonicum Steindachner, Flussf. Siidam. iv, 29, pl. vi, figs. 4-4a, 1882 (Cudajas). Pygidium amazonicum Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. 11, 53, 1889. Habitat: Amazon near Cudajas. LXI. EREMOPHILUS. Eremophilus Humboldt, Ree. d’Obs. Zool. et Anat. 17, pl6 P1611 t(mutise). Thrichomycterus Humboldt, 1. ¢. (alternative of ere- mophilus). Trachypoma Giebel, ‘‘Z.-Ges. Ntrwe 1n,)°97, 1871” (marmoratum=mutisii). Type: ELremophilus mutisii Humboldt. This genus differs from Pygidium in having no ven- tral fins. me SOUTH AMERICAN NEMATOGNATHI. 339 274, Eremophilus mutisii. Eremophilus mutisii Humboldt, 1. c. (Bogota); Valenciennes, Hum- boldt, 1. c. ii, 340, 1885; Cuv. & Val. Hist. Nat. Poiss. xv, 500, pl. 553, 1846 (Bogota); Giinther, Cat. Fish. Brit. Mus. v, 275, 1864 (copied); Kigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. ii, 53, 1889. Trachypoma marmoratum Giebel, 1. c. (loc. 2). Habitat: Tributaries of the Rio Magdalena. Yellowish with reticulating brown lines and dots. Head 6; Br. 8; D. 11; A. 9. (Valenciennes.) DXiie > Perens: Tridens Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1, 538, 1889 (melanops). Type: Tridens melanops E. & E. Ventrals small, nearer tip of snout than to base of caudal. Anal long, inserted in front of the dorsal fin. Head greatly depressed, the eye infringing on the upper and lower surfaces of the head. A series of fine labial teeth; stronger teeth in the jaws. Gill-membranes united, forming a broad, free fold across the isthmus. Opercle and preopercle armed. Maxillary barbels 2. 275. Tridens melanops. Tridens melanops Kigenm. & Eigenm. 1. c. (I¢a). Types, No. 8137. Twenty-seven specimens, the largest .027 m. Ica. James. Body compressed, extremely slender. Head broad, the snout rounded; mouth broad, inferior. Opercle long and slender, terminating in three spines, trident-shaped. Preopercle with similar but smallerspines. Barbels min- ute, scarcely evident. Distance of origin of dorsal fin from extremity of cau- dal 3 in the length; origin of anal fin from extremity of caudal 2} in the length. Anal rays rapidly decreasing in height backward, the last ray about over the last ray of the dorsal. Caudal rounded, without accessory rays. 340 CALIFORNIA ACADEMY OF SCIENCES. Yellowish; posterior half of the caudal fin dusky; a series of black spots along the base of the anal. Head 9; depth 18; D. 10-12; A. 20-25. 276 Tridens brevis. Tridens brevis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 54, 1889 (Tabatinga). Type, No. 8160; one specimen; .021 m. Tabatinga. Bourget. Body short and deep. Head as broad as long; mouth broad, inferior. Opercle with a bunch of six or more spines; preopercle with a smaller bunch of spines. Bar- bels well developed, the outer one extending to the base of the pectoral, the inner to the gill-opening. Eye large nearer end of opercle than tip of snout. Distance of origin of dorsal from tip of caudal little more than 2 in the length. Anal inserted very little in front of the dorsal and ex- tending some distance beyond it, its rays decreasing in height toward the caudal. Origin of anal from extrem- ity of caudal less than 2 in the length. First pectoral ray greatly produced. Caudal emarginate. Yellowish; blackish dots along the bases of the fins; a series of blackish dots along the middle line of the sides, similar spots on the back. Head with brown dots. Head. 6; depth 8; D. 9; A. 22. The two species here described have evidently not at- tained their full growth. They may prove to be the young of some species of Pygidium. If so their char- acters undergo a wonderful change during growth. As nothing is known of the young stages of these fishes we have thought best to describe these specimens as new. They approach the P. amazonicum Steindachner, from the Jutahy most nearly. SOUTH AMERICAN NEMATOGNATHI. 341 LXIII. PsEupDOSsTEGOPHILUS. Pseudostegophilus Kigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. 11, 54, 1889 (nemurus). Type: Stegophilus nemurus Ginther. Caudal widely forked. Mouth inferior, each jaw with series of fine teeth; upper lip with several series of fine movable teeth; no teeth on the yvomer. 277. Pseudostegophilus nemurus, Stegophilus nemurus Giinther Proc. Zool. Soc. 1868, 429 (Upper Am- azon). Pseudostegophilus nemurus KE. & E.1.c. (? Maraiion or Ucayale). Habitat: Maration and its tributaries. On account of its widely forked tail this species is prob- ably generically distinct from the typical Stegophilus, which has a rounded caudal. Body comparatively short and thick; head short, as broad as long, the snout broadly rounded. Eye 1 in the snout, 4 in the head. Mouth broad, upper lip with about four series of fine teeth, those of the inner series longest; intermaxillaries and mandibles with four or five series of closely crowded, pectinate teeth. Opercle with a bunch of about 8 spines; preopercle with similar spines. Origin of dorsal equidistant from tip of snout and tip of middle caudal rays. Upper caudal ray 3 times as long as the middle rays, 3 in the length. Anal placed en- tirely behind the dorsal; origin of ventrals about equi- distant from base of caudal and tip of snout. Pectoral pore small. Light; back with three large dark brown, black edged, saddle-shaped spots, one behind the middle of the dorsal and the other in front of the dorsal; tail with a broad collar of similar color; lower caudal lobe black; upper caudal lobe hght marbled with blackish, its tip black. Heal 55 D9) Ace 7. 342 CALIFORNIA ACADEMY OF SCIENCES. A single specimen .065 m. ‘‘ Marafion & Ucayale” Chas. Sarkaday. ji LIV. STEGOPHILUS. Stegophilus Reinhardt, Naturhst. Foren. Meddel. 1858, 79, pl. 11 (insidiosus). Type: Stegophilus insidiosus Reinhardt. Body elongate, slender, head depressed, the mouth in- ferior, each jaw with fine teeth arranged. in regular series; no teeth on the vomer; upper lip with two or more series of elongate freely movable teeth. Orbit without a free margin; gill-membrane joined to the isth- mus, the gill-opening a narrow sht in front of the pec- torals; opercle and preopercle with a bunch of strong spines. Dorsal and anal placed posteriorly; ventrals in front of the dorsal. Habitat: Rio Plata; Rio das Velhas; Amazon and its tributaries. Reinhardt states that S. insidiosus lives in the gill- cavity of Sorubim. He seems to have taken the labial teeth for intermaxillary teeth, and the intermaxillaries as the branches of the vomer. ANALYSIS OF THE SPECIES OF STEGOPHILUS. a. Caudal emarginate. b. Back spotted, sides with a series of dark spots. D. 8-9; A. 7. c. Dorsal 8; head as long as broad. d. Origin of dorsal nearer tip of snout than tip of caudal; head 8 in the total length; eye 3} in the head; lateral spots most prominent on the tail; tips of the caudal lobes dusky; base of caudal with a double spot. (Steindachner.) maculatus 278. dd. Ovigin of dorsal much nearer tip of caudal than tip of snout; head 64 in the total length, eye 4 in the leneth; lateral spots most prominent under the dorsal; caudal with a dark bar extending from the tips of the lower rays to the middle of the upper; base of caudal with dark spots. (Boulenger.) punctatus 279. ce. Dorsal 9; head longer than broad, 64 in the total length; eye 3} in the head; origin of dorsal much nearer tip of caudal than tip of snout; lateral spots most prominent on the tail; caudal with faint dusky spots. intermedius 280. SOUTH AMERICAN NEMATOGNATHI. 343 bb. Back and sides plain; D. 10; A. 9; caudal with dusky spots, the tip of its lower lobe being black; origin of dorsal much nearer tip of cau- dal than tip of snout; head longer than broad, about 6 in the total length; eye 32 in head; caudal with numerous accessory rays. (Stein- dachner.) macrops 281. aa. Caudal rounded; dorsal much behind the middle of the total length. D. 9-10; color uniform. f. Caudal without accessory rays; dorsal entirely in front of the anal; head about 6 in the total length. D.9; A.7. (Reinhardt.) insidiosus 282. ff. Caudal with numerous accessory rays; dorsal partly over the anal; head about 7 in the total length. D. 9-10; A. 8. (Steindachner.) reinhardtii 283. 278. Stegophilus maculatus. Stegophilus maculatus Steindachner, Denk. Ak. Wien, xli, 25, plate iv, fig. 2, 1879 (La Plata); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 54, 1889. Habitat: Rio Plata. This species is known only from the types. 279. Stegophilus punctatus. Stegophilus punctatus Boulenger, Proc. Zool. Soc. Lond. March, 1887, 279, pl. xxi, fig. 4 (Canelos); Eigenm. & Kigenm. 1. c. Habitat: Eastern Ecuador. 280. Stegophilus intermedius. Stegophilus intermedius Eigenm. & Eigenm. 1. c. (Goyaz). Type, No. 9,842; one specimen .08m. Goyaz. Senhor Honorio. _ This species, found in a region intermediate between the localities where punctatus and maculatus are found combines in a remarkable way the characters of those species. Elongate, compressed behind, depressed forward; head somewhat longer than wide, snout pointed; eye large, 1 in the snout, 3} in the head. Mouth large; upper lip with two series of teeth; intermaxillaries and mandibles with four series of depressible teeth, those of the inner series enlarged at the tip. Lower lip not dilated, barbel shorter than the eye. Opercle with two spines; preopercle with 5 or 6 claw- like spines. Origin of dorsal about equidistant from tip of caudal 344 CALIFORNIA ACADEMY OF SCIENCES. and occiput; caudal emarginate; anal placed entirely behind the dorsal; origin of ventrals equidistant from bases of caudal and pectoral. Light brown; entire upper surface with rather large dark brown spots; a series of larger dark spots along the middle line of the sides, the spots becoming larger to- wards the tail; caudal with a few, faint dark spots. Head 54; D. 9; A. 7. ; 281. Stegophilus macrops. Stegophilus macrops Steindachner, Flussfische Siidam. iv, 28, pl. vi, fig. 2-2a, 1882 (Lake Manacapuru, above Manaos); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 55, 1889. Habitat: Lake Manacapuru. This species is known only from the types; there are ho specimens in the Museum of Comparative Zoology. 282. Stegophilus insidiosus. Stegophilus insidiosus Reinhardt, Naturhist. Foren. Vidensk. Meddel. 1858, 79, pl. 11 (Rio das Velhas); Giinther, Cat. Fish. Brit. Mus. v, 276, 1864 (copied); Liitken, Vidensk. Selsk. Skr. 1875, 135 and i, figs. 1-3 (Rio das Velhas); E. & E. 1. ¢. Habitat: Rio das Velhas. 283, Stegophilus reinhardtii. Stegophilus reinhardtii Steindachner, Flussfische Siidam. iv, 28, pl. vi, fig. 1, 1882 (Lake Manacapuru; Rio Ica; Montalegre; Teffé; Tabatinga); E. & EH. 1. ¢. Habitat: Solimoens and tributaries. This species seems to have been collected at several places during the Thayer expedition, but no specimens could be found in the museum of Comparative Zoology. LXV. sVANDELLIA. Vandellia Cuv. & Val. Hist. Nat. Poiss. xviii, 386, pl. 547, 1846 (cirrhosa). Type: Vandellia cirrhosa Cuv. & Val. This genus is very closely related to Stegophilus from which it differs in the dentition and the position of the mouth. Teeth pointed, in a single series on the intermaxil- SOUTH AMERICAN NEMATOGNATHI. 345 laries only; mouth subinferior. Body terete, greatly elongate; opercle and preopercle with spines. Gill-mem- branes broadly united with the skin of the isthmus, the gill-opening being reduced to a short sht in front of the pectoral. Orbit withoutafree margin. Dorsal fin placed posteriorly and behind the ventrals. Habitat: Solimoens and westward to the Andes. ANALYSIS OF THE SPECIES OF VANDELLIA. a. Head 9 in the total length; caudal rounded. cirrhosa 284. aa. Head about 12 in the total length; caudal slightly emarginate; a dusky median stripe on caudal. plazaii 285. 284, Vandellia cirrhosa. Vandellia cirrhosa Cuy. & Val. Hist. Nat. Poiss. xviii, 386, pl. 547, 1846 (loc. ?); Castelnau, Anim. Amér. du Sud, 51, pl. 28, fig. 2, 1855 (Brazil); Giinther, Cat. Fish. Brit. Mus. v, 277, 1864 (cop- ied); Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. ii, 55, 1889 (Hyavary). Habitat: Hyavary. Head slightly longer than wide; snout rounded. Eye large, less than 1 in the snout, less than 3 in the head. Mouth rather small, the upper jaw little projecting; a few long, pointed teeth on the intermaxillaries. Barbel comparatively long, about 2 in the head; lower lip not dilated. Opercle and preopercle each with a bunch of 6-10 spines. Origin of the dorsal fin twice as far from tip of snout as from margin of caudal, the dorsal fin placed partly over the anal. Uniform lght brown. Head 9 in the total length; D. 9; A. 10. One specimen .04m. Hyavary. Bourget. 285. Vandellia plazaii. Vandellia plazaii Castelnan, 1. c. pl. 28, fig. 1, 1855 (Ucayale); Vail- lant, Bull. Soc. Philom. Series 7, iy, 159, 1880 (Calderon); Higenm. & Eigenm. 1. c. (Lake Hyanuary). Vandellia plaze Ginther, Cat. Fish. Brit. Mus. v, 277, 1864 (copied). Habitat: Ucayale; Calderon; Lake Hyanuary. One specimen .125m. Take Hyanuary. Bourget. 346 CALIFORNIA ACADEMY OF SCIENCES. LXVI. PAREIODON. Pareiodon Kner, SB. Ak. Wien, xvii, 160, 1855 (mi- crops). Pariodon Ginther, Cat. Fish. Brit. Mus. v, 275, 1864 (substituted). Centrophorus Kner, Denk. Ak. Wien, xvii, 161, 1855 (substituted for Pareiodon). Astemomycterus Guichenot, Rev. et Mag. Nat. Hist. x11, 525, 1860 (pusillus). Type: Pareiodon microps Kner. Gill-membrane united with the isthmus; a single series of incisor-like teeth on each jaw; two pairs of maxillary barbels; opercle and preopercle with short spines; caudal forked. 286. Pareiodon microps. Pareiodon microps Kner, SB. Ak. Wien, xvii, 160, 1855 (Borba?); Kigenm. & Eigenm. 1.c. Pariodon microps Giinther, Cat. Fish. Brit. Mus. v, 275, 1864 (cop- ied); Cope, Proc. Acad. Nat. Sci. Phila. 1872, 290 (Ambyiacu). Trichomycterus pusillus Castelnau, 1. c. 50, pl. 24, fig. 4, 1855 (Ara- guay; Amazon). Astemomycterus pusillus Guichenot, l. c. (Araguay; Amazon). Habitat: Amazons and tributaries. Body terete; lips thickly papillose, interopercle with 5 spines; grayish above, lighter below. ‘Head 8; D..93) Ay 7. (khmer) LXViIL MiprogiAnts: Miuroglanis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 11, 55, 1889 (platycephalus). Type: Miuroglanis platycephalus E. & E. This genus is based on a very small specimen. The characters are, however, so well marked that we do not hesitate to describe it as new. Gill-membrane broadly united with the isthmus, with- out a free margin. Maxillary barbels two. Mouth in- SOUTH AMERICAN NEMATOGNATHI. oa ferior. Hach jaw with several series of strong teeth. Opercle and preopercle with numerous strong spines. Caudal rounded. | 287. Miuroglanis platycephalus. Miuroglanis platycephalus Kigenm. & Eigeom. Proc. Cal. Acad. 2d Ser. 11, 56, 1889. (Jutahy.) Type, No. 8172; one specimen .017 m. Jutahy. James, Thayer & Talisman. Body short, compressed and rather deep. Head greatly depressed, wider than long. Eye large, lateral, placed behind the angle of the mouth. Mouth subinferior, the upper jaw projecting slightly. Upper maxillary barbel scarcely extending to the gill- opening; no nasal or mental barbels. The opercular and preopercular patches of spines united. Origin of the dorsal fin little behind that of the anal; its distance from the tip of the snout somewhat less than twice its distance from the tip of the caudal. Head 53 Dr £0* Ax 15. Famity VI. ARGIIDA. >Siluroidet astroblepiformes Bleeker, Neder]. Tijdschr. Dierk. 17 TAO 863. .A. 62 V..cl5 bee Po 6s batade oie Two specimens .10-.12 m. (to base of caudal). W. James. Manacapuru; Hyavary. LXIII. Loricarta. Loricaria Linneus Syst. Nat. ed. x. >Loricaria Bleeker, Nederl. Tijdschr. Dierk. i, 80, 1863 (dura=cataphracta). Sturisoma Swainson, Fishes, Amph. & Reptiles, 11, 1839 (rostrata). >Hemiodon Kner, Panzerwelse, 89, 1853 (sp.) >Hemiodon Bleeker, |. c. 82 (depressus). >Loricariichthys id. 1. ¢. 80 (maculatus). >Pseudoloricaria id. 1. ¢. 80 (leviuscula). >Parahemiodon id. |. ¢. 80 (typus). >Hemiloricaria id. |. c. 81 (caracasensis). >Pseudohemiodon id. 1. e. 81 (platycephalus). >Rineloricaria id. 1. c. 81 (lima). >Oxyloricaria id. 1. ¢. 81 (barbata). Type: Loricaria cataphracta Linneus. SOUTH AMERICAN NEMATOGNATHI. 361 Habitat: Rio Plata to Guiana and Peru; Atlantic and Pacific slopes of Panama. Species of this genus which at present cannot be classified are: 301.1. Loricaria platyura Miller & Troschel, in Schomburgk Reisen in Brit. Guiana 111, 631, 1848 (Ru- pununi). Upper plates of tail truncate behind; lateral keels approximated on the 13th scute; eye 1) in interor- bital, back with six broad black crossbars; one or more bars on the fins. Lat. 1. 29. 301.2. Hemiloricaria caracasensis Bleeker, Nederl. Tijdschr. Dierkunde, i, 81, 1863 (Caracas). Lip scarcely fringed, the posterior broad, the anterior narrow. Teeth present. Lower surface with scutes. 301.8. Loricaria bransfordi Gill, Proc. Phil. Acad. Nat. Sci. 338, 1876 (Panama). 301.4. Loricaria cadew Hensel, Wiegm. Arch. 1, 369, 1868 (Rio Cadea). According to the description, this species would be identical with Z. konopickyi Steindachner. As the lo- calities are so greatly different we have placed it among the doubtful forms. ANALYSIS OF THE SPECIES OF LORICARIA. a. Snout long and narrow, much as in Acestra or Hemiodontichthys; its lower surface granular. b. Margin of the head in both sexes granular; teeth minute, or wanting in one or both jaws; lateral keels becoming parallel, not coalescing; no keels on head or on predorsal scutes. c. Teeth in the lower jaw only. (Hemiopon.) d. Lower surface of head with numerous small plates; eye one in interorbital; orbit with a notch; belly with irregular plates; up- permost caudal ray produced. Head 34-3}; Lat. 1. 27. (Kner.) depressa 302. cc. Teeth minute, numerous in both jaws; lower surface of the head partly naked; eye 13 in interorbital; orbit without a notch; anterior profile concave; belly with 5 series of plates, uppermost and lower- most caudal rays greatly produced. Head 44; Lat. 1. 33. panamensis 303. 362 CALIFORNIA ACADEMY OF SCIENCES. bb. Margin of head in males with numerous bristles; teeth well devel- oped in both jaws; lateral keels coalescing; orbit without a notch; lower surface of the head with small plates; belly with 5 series of plates; orbit 2 in interorbital; outermost caudal rays produced. Head without keels; anterior profile concave. Head 43; Lat. 1. 34. (STURISOMA.) rostrata 304. aa. Snout acute or rounded, not produced. e. Margin of the head in males with numerous bristles, which are very minute in brevirostris; teeth well developed; uppermost caudal ray greatly produced; lips not very greatly expanded, fringed or not, with- out long cirri. (RINELORICARIA.) Jf. Orbit without a notch; lower surface of head with numerous small plates; head without keels; loreal region concave; anterior profile slightly concave; belly with 5 series of plates; superciliary margin slightly raised; orbit 3} in the snout; lips narrow, teeth numerous. brevirostris 305. Jf. Orbit notched; lower surface of head naked; uppermost caudal ray produced, filiform; profile convex. g. A rather large anal plate, bordered anteriorly by three plates; snout more or less pointed. h. Lower lip two-lobed; occipital with x-shaped keels; mucous pores of the head and anterior part of the body black; all the fins spotted. Superciliary margin raised, nuchal plates strongly bicarinate; granulations of the head arranged in longitudinal series. lima 306. hh. Lower lip fringed; occipital with v-shaped ridges; snout pointed; occipital and nuchal plates in the male with bristles similar to those on the cheeks; all fins faintly spotted. (Stein- dachner.) magdalene 307. gg. Region between ventrals with numerous small plates; snout rather blunt; lower lip fringed; plates of the head striate and fur- rowed; all fins with indistinct blackish spots; margin of caudal blackish. (Steindachner.) Jjilamentosa 308. ee. Margin of head in both sexes granular or hispid. i. Plates between ventrals large, more or less firmly connected to form a buckler; a large anal plate. j. Belly with a single series of plates. (Hancock.) brunnea 309 jj. Belly with 3 or more longitudinal series of plates. k. Head as broad as long; orbital notch very shallow; form greatly depressed; no teeth in the upper jaw; occipital keeled; lower lip with cirri; snout with a median groove; margin of snout and sides of the head with many short spines. Fins reddish. (Kner.) (PSEUDOHEMIODON.) platycephala 310. kk. Head longer than broad. (PARAHEMIODON.) SOUTH AMERICAN NEMATOGNATHI. 363 t. Uppermost caudal ray spinous; vertical diameter of the eye 2 in the interorbital; lower lip emarginate, margined with short cirri; each jaw with 8-10 teeth; no keels on occipital or nuchal plates; belly with about six series of plates. (Kner & Steindachner.) uracantha 311. i. Uppermost caudal ray not spinous. m. Head without keels. n. Lateral keels coalescing or becoming approximate. o. Lower lip very broad; teeth few, small; snout plain or spotted. p. Pectoral conspicuously spotted or barred; spots on caudal, ventral and dorsal rays and posterior half of each interradial membrane of the dorsal; uppermost caudal ray greatly thickened, leathery; orbital notch broad; loreal region concave. stiibelit 312. pp. Pectoral and ventral fins blackish; posterior half of each interradial membrane of the dorsal dusky; orbital notch narrow and deep; loreal region convex. spixti 313. ppp. All fins plain; caudal equally lobed; orbital notch narrow and deep; belly with 4 series of plates; upper parts with numerous blackish dots. (Bleeker.) typus 314. oo. Lower lip rather narrow, teeth large and numerous; a rather broad blackish band extends from the eye for- ward, a narrower one downward; base of caudal and a bar parallel to its margin blackish; orbital notch nar- row; snout acute; belly with 5 longitudinal series of scutes. phoxocephala 315. nn. Lateral keels remaining separate to or nearly to the caudal; head high, its sides steep; orbital notch narrow and deep; lips thick, papillose; no teeth in the upper jaw; interorbital flattish. anus 316. mm. Head with keels, at least on the occipital. (LORICARIICHTHYS.) q. Tip of lower caudal lobe blackish; ventrals and pectorals dusky. r. Orbit with a large angular notch, almost or quite as large as the orbit; anal plate rounded in front, mar- gined by 3 plates; lips broad, edged with black; teeth smaller and numerous. acuta 317. rr. Orbital notch parabolic or more or less angular; anal plate attenuate in front, usually margined by 2 plates; lips broad, plain; teeth few, minute.. maculata 318. qq. Margin of caudal light; head and nape arched above; head less than 5 in the length. 364 CALIFORNIA ACADEMY OF SCIENCES. s. Dorsal rays spotted, snout pointed, upper portion of head very rough; orbit with a shallow triangular notch; shields of the anterior portion of the body down to the belly keeled; lower lip rounded, strongly papillose; lat- eral keels united on the 15th plate; lat. 1.29. (Stein- dachner) konopickyi 319. ss. Dorsal, pectorals and ventral each with a broad black a4 = band; teeth very fine, few, or horizontal diameter of eto orbit with notch 14 in interorbital. (Giinther.) : lanceolatus 320. qaq- Margin of caudal black; pectorals, ventrals and anal, each with a broad dark band; two dusky spots on upper lip; orbital notch narrow, deep; lips narrow; teeth rather large, numerous; belly with 5 series of plates; outer ven- tral ray prolonged. teffeana 321. vi. Plates between ventrals small; a large anal plate; orbit with a shal- low notch; eye #-4 in interorbital; upper lip with a fringe of cirri. Head and body with black spots; head short, high, anterior profile steep, straight; pectorals falcate; outer ventral ray produced. (PSEUDOLORICARIA.) leviuscula 322. wz. Plates between ventrals, if present, small; no large anal plate. (LoricaRtiA.) t. Belly at least partially naked; lower lip with numerous cirri and marginal fringes. u. Belly with the middle line and sides armed; teeth few, small; an occipital keel; upper surface with numerous narrow light and dark lines; all fins but the anal spotted with violet. (Stein- dachner.) variegata 323. uu. Belly with a median naked area; the breast and ventral re- gion with small plates; head broader than long to upper angle of gill-opening; teeth in both jaws of the same size and number; eye small, 54 in the snout almost 2 in the interorbital; orbital notch very shallow; occipital with two keels; all fins but the anal spotted with black. (Kner.) macrodon 224. uuu. Belly entirely naked; eye 7 in head, 4in snout, 2 in interor- bital; head without keels. (Cuv. & Val.) nudiventris 325. tt. Belly entirely armed in adult. v. Lower lip with numerous cirri. w. Orbit with a shallow notch. x. Barbel short; margin of head convex, entirely granular; anterior profile convex. y. Width at origin of anal equals the length of the snout; width of head less than its length to upper angle of gill-opening; occipital with very strong keels. cataphracta 326. SOUTH AMERICAN NEMATOGNATHI. 365 yy. Width at origin of anal equal to snout and orbit; width of head greater than its length to upper angle of gill-opening; posterior half of occipital with two indis- tinct keels. lata 327. xx. Barbels extending beyond base of pectoral; margin of snout concave; small teeth in both jaws; horizontal diame- eter of eye not quite equal to interorbital; lateral keels ap- proximated on the 18th scute; thorax and belly with small scutella; upper caudal ray produced. (Giinther.) macromystax 328. ww. Orbit without a notch; eye 5in the snout, 9 in the head; dorsal, pectoral and ventral spotted. (Cuv. & Val.) vetula 329. vv. Lower lip with marginal cirri only; head and body exces- sively depressed, the width of the head much greater than its length to upper angle of gill-opening; teeth few, minute; orbit withits notch 14 in the interorbital; occipital and nuchal plates bicarinate; lateral keels prominent, approximated on the 16th scute; upper caudal ray slightly produced. Olive green, head with vermiculating lines, back with whitish spots. Head 4%. Lat.1. 31. (Ginther.) lamina 380. vvv. Lower lip papillose, without cirri; width of head about equal to its length to upper angle of gill-opening; teeth very numerous and fine; orbit without a notch, its diameter 1} in interorbital; scutes smooth; lateral keels obtuse, approxi- mated on the 2Ist scute; dorsal falcate, the length of the first ray greater than its distance from the snout; outer rays of all fins somewhat prolonged. Head 5. Lat1l.29. (Giin- ther.) platystoma 331. 302. Loricaria depressa. Hemiodon depressus Kner, Panzerwelse, 91, pl. vii, fig. 1 (Rio Negro; Marabitanos). Loricaria depressa Giinther, v, 259, 1864 (copied); Eigenm. & Kigenm. Proc. Cal. Acad. 2d Ser. ii, 34, 1889. Habitat: Rio Negro. This species is known only from the types. 303. Loricaria panamensis. Loricaria panamensis Kigenm. & Eigenm. 1. c. (Panama.) Habitat: Panama. Type No. 8126; one specimen .95 m. to base of caudal. Panama. Dr. Hernberg. Closely related to L. rostrata Spix. Body little depressed. No keels on the head or on the 366 CALIFORNIA ACADEMY OF SCIENCES, nuchal plates. Shields and scutes hispid; a large naked area about the mouth. Orbit without a notch, 4 in the snout, 7 in the head, 2 in the interorbital. Teeth fine, numerous in both jaws. Five series of plates on the belly; anal plate as long as broad; lateral keels remaining distinct to the caudal fin, approximated at about the 16th lateral scute. Distance of dorsal fin from end of snout 32 in the length; first dorsal ray very high, little less than its dis- tance from tip of snout. Caudal forked, the outermost rays greatly produced, the upper filament about equal to the length from tip of snout to its base, the lower somewhat shorter. First anal ray little less than length of head. Ventral fins reach- ing to the end of the base of the anal fin; pectorals to the vent. Brownish; dorsal fin dark brown on its first and sec- ond membranes and second ray, its other rays spotted; base of caudal fin and a longitudinal stripe on each lobe dark brown; other fins plain; a large blackish area in front of each eye. Head 44.-.D 8: A. 165) Velo Pie Ga aie ae, 304. Loricaria rostrata. Loricaria rostrata Spix, Gen. et Spec. Pisc. 5, plate iii, fig. 1-2, 1829 (Rivers of Brazil); Cuv. & Val. xv, 478, 1840 (copied); Kner, Panzerwelse, 83, 1853 (Rio Branco); Giinther, v, 256, 1864 (copied); id. Proc. Zool. Soc. Lond. 1868, 235 (Xeberos); Peters, MB. Ak. Berl. 1877, 471 (Calabozo); Cope, Proc. Am. Philos. Soc. xvii, 681, 1878 (Peruvian Amazon); Steindachner, Flussfische Siidam. i, 17, 1879 (Mamoni River); Vaillant, Bull. Soc. Philom. Series 7, iv, 156 (Calderon); Eigenm. & Kigenm. Proc. Cal. Acad. 2d Ser. ii, 35, 1889 (Manacapuru). Loricaria acuta Cuy. & Val. xv, pl. 452, 1840 (not described). Loricaria barbata Kner, Panzerwelse, 87, pl. v, 1853 (Cujaba— Fluss.); Giinther, v, 257, 1864 (copied). Habitat: Upper course of the Paraguay; Solimoens; Maranon and tributaries westward; Panama; Calabozo. SOUTH AMERICAN NEMATOGNATHI. 367 Body little depressed anteriorly, its depth 1} in its width. Depth of the head little more than half the length of the snout; head without keels or ridges, its surface and all the plates evenly hispid; transverse pro- file of the occiput regularly convex; occipital terminating in a triangular process which is margined by a single nuchal plate; the nuchal plates indistinctly bicarinate. Orbit without a notch, 44 in the snout, 74 in the head, 2 in the interorbital. Anterior profile greatly concave, the snout long and narrow; margin of the head with fine, erectile bristles. Teeth fine, numerous, well developed in both jaws; up- per lip granular, lower lip entire, rounded, thickly pap- illose. Free portion of the Pane g-: long as the orbital diameter. _ Breast and lower surface of nema covered with numerous irregular plates; belly with 5 series of plates, the outer ones broadest. The two lateral keels moderate, coalescing into one keel at about the 20th scute, the up- per obsolete in front. Distance of the dorsal fin from tip of snout 3 in the length; anterior dorsal ray high, longer than the head. Caudal emarginate, the outer- most rays greatly produced, about 3 in the length. Anal about as high as the ventral fins, which are in- serted slightly in front of the dorsal fin, the outer rays thickened and slightly hispid; pectorals similar, their tips reaching little beyond origin of the ventrals. Brownish, lighter below; rays of the dorsal, caudal, pectoral and sometimes ventrals, spotted with darker. Header ies soy Vi. Leb Pr 62. Nat). 34. Two specimens .19-.21 m. (to base of caudal). Mana- capuru. W. James. 305. Loricaria brevirostris. Loricaria brevirostris Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 11, 35, 1889 (I¢a). Type: No. 8,095; one specimen ¢, .21 m. to base of caudal. Ica. W. James. 368 CALIFORNIA ACADEMY OF SCIENCES. Body little depressed anteriorly, its depth 1) in its width. Depth of the head 14 in the snout. Head with- out keels or ridges, its surface and that of all the plates hispid; transverse profile of the occiput regularly con- Were. Orbit without a notch, 3} in snout, 7 in head, 2 in interorbital. Anterior profile little concave; snout triangular, acute, little longer than the rest of the head. Margin of the head with minute movable bristles. Teeth fine, numer- ous, well developed in both jaws; upper lip granular, lower lip entire, rounded, thickly papillose. Breast and lower surface of the head with numerous irregular plates; belly with 5 series of plates. Lateral keels coalescing into one keel at about the 20th scute; the upper keel obsolete in front. Distance of dor- sal fin from tip of snout slightly more than 3 in the length. First dorsal ray longer than the head. Rays of the dorsal and caudal faintly spotted, other fins plain. De Se An Ge Vai 53 (By Ly Gy Lab. 1. (a4: 306. Loricaria lima. Loricaria lima Kner, Panzerwelse, 89, pl. vi, fig. 1, a. b. 1853 (Brazil); Giinther, v, 260, 1864, (copied); id. Fish. Centr. Am. 393, 1866 (Atlantic and Pacific slope of Panama); Hensel, Wiegm. Arch. 1868, i, 366 (Stony brooks near Santa Cruz); Liitken, Velhas Flodens Fiske, 138, 1875 (Rio das Velhas); Steindachner, Flussfische Siidam. iii, 6, pl. i, 1851 (Rio Para- hyba; Rio Macacos; Rio Preto; Rio Quenda; Rio das Velhas); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 1i, 35, 1889 (Mendez; Santa Cruz; Rio Quenda; Rio Parahyba; Campos; Macacos). ? Loricaria strigilata Hensel, Wiegm. Arch. 1868, i, 368 (Stony brooks near Santa Cruz) = 4. Habitat: Coast rivers from Rio Parahyba to Rio Para; Atlantic and Pacific slopes of Panama. Depressed, elongate, the depth about 2 in the width. Head long, tapering; the cheeks of the male thickly cov- ered with fine bristles, of the female slightly hispid; plates of the head with longitudinal series of small serra; SOUTH AMERICAN NEMATOGNATHI. 369 occipital with two ridges which widen backward and are continued upon the nuchal plates; two nuchal plates between the occipital and the dorsal plate with a deep median depression; occipital truncate behind, margined by three plates; superciliary margins raised, the inter- orbital concave. Orbit with a rather large notch behind; eye 4 in the Fol snout, 7$ in the head, 1 in the interorbital. Anterior profile convex. Teeth few, well developed in both jaws. Margin of the lips fringed, short cirri covering the surface of the lips. Free portion of the barbel about equal to the orbital diameter. Lower surface of the head naked; belly with 3-5 series of scutes; anal plate narrowest forward, emarginate be- hind. Lateral keels coalescing on about the 16th lateral scute. Anterior canals and pores of the lateral line dark purplish. Pectoral pore minute. Distance of the dorsal fin from tip of snout 34 in the length; dorsal fin about }-} higher than long. Caudal slightly emarginate, the upper ray produced, 2} in the length. Ventrals short, not reaching to the anal; pectorals about to the ventrals. Back marbled, and with traces of about 4 dark cross bars; mucous pores of the head and anterior portion of the body dark purple; all the fins spotted, the anal least; base of caudal dusky; tips of caudal and dorsal sometimes blackish, the anal sometimes with a dusky bar. Head’42 ap 85 Ay G5 Vo0: 5P. 1,62 Lat.) 27-28: Twenty-eight specimens, .10—-.17 m. to base of caudal. Mendez; Santa Cruz; Rio Quenda; Rio Parahyba; Cam- pos; Macacos. 24 370 CALIFORNIA ACADEMY OF SCIENCES. 307. Loricaria magdalene. Loricaria magdalene Steindachner, Fisch-fauna des Magdalenen. Stromes, 59, 1878 (Magdalen River); id. Denk. Ak. Wien, xli, pl. vii, fig. 2 and 3; Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii 36, 1889. Habitat: Magdalena River. J 308. Loricaria filamentosa. ? Loricaria bransfordi Gill, Proc. Acad. Nat. Sci. Philad. 1876, 338 (Panama). Loricaria filamentosa Steindachner, Fisch-fauna des Maed. Stromes, 29, pl. ix, 1878 (Magdalen River); id. Fisch-fauna des Cauca and Fliisse bei Guayaquil 13, 1880 (Cauca); Boulenger, Proc. Zool. Soc. Lond. March, 1887, 277 (Canelos); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 36, 1889. Habitat: Canelos; Magdalena River. 309. Loricaria brunnea. Loricaria brunnea Hancock, Zool. Journ. iv, 247, 1828 (Demarara); Cuv. & Val. Hist. Nat. Poiss. xv, 479, 1840 (copied); Giinther, v, 260, 1864 (copied); Eigenm. & Eigenm. 1. ¢. 37. Habitat: Demarara. 310. Loricaria platycephala. Hemiodon ? platycephalus Kner, Panzerwelse, 89, pl. vi, fig. 2, 1853 (Rio Cujaba). Loricaria platycephala Giinther, v, 258, 1864 (copied); E. & E. 1. c. Habitat: Rio Cujaba. 311. Loricaria uracantha. Loricaria uracantha Kner & Steindachner, Abh. Bayr. Akad. Wiss. xi, Abth. 56, pl. 6, fig. 3, 1865 (New Grenada; Rio Chagres); Giinther, Fish. Cent. Am. vi, 393 & 478, 1866 (Atlantic and Pa- cific rivers of Panama); Eigenm. & Eigenm.1. c. Habitat: Atlantic and Pacific slopes of Panama. 312. Loricaria stiibelii. Loricaria stiibelii Steindachner, Flussfische Siidam. iv, 7, pl. iii, figs. 2-2b, 1882 (Rio Huallaga); E. & E. Proc. Cal. Acad. 2d Ser. ii, 37, 1889 (Santarem; Hyavary; Teffé; Rio Preto; Rio Puty). Habitat: Amazons, Rio Preto and Rio Puty. This species is closely related to L. maculata Bloch, to L. spiwii, and to L. acuta Valenciennes. It is most read- ily distinguished by its profusely spotted fins and more rounded snout. Depth a little less than 2 in the width. Head short and broad, its depth 2 in its width, which is little less SOUTH AMERICAN NEMATOGNATHI. otk than its length to upper angle of gill-opening; head without ridges or keels, occipital region regularly con- vex; occipital terminating in a broad, triangular pro- cess which is margined by 2 nuchal plates; interorbital slightly concave; snout broad, rounded, its entire mar- gin narrowly naked. Orbital notch large, similar to that of Z. maculatus, diameter of orbit with its notch 45-5 in the head. Eye 34—44 in snout, 64-9 in head, 14-2 in the interorbital. Lower surface of head naked except a narrow marginal band. Teeth few, minute, in both jaws. Lower lip and the sides of upper lip slightly fringed; the male with the lower lip greatly expanded, reaching beyond base of pec- toral fins. Anal plate pointed in front, margined by 2-4 plates; belly with 3-5 series of plates; breast with smaller plates of irregular shape; nuchal plates faintly bicarinate. Lateral keels prominent, remaining separate throughout, approximated on the 17th or 18th plate. Distance of dorsal fin from tip of snout 3 in the length; first dorsal ray about equal to length of head. Caudal obliquely truncate, the upper lobe longer. Anal lower than the ventral; third ventral ray highest, reach- ing beyond origin of anal. Pectoral short, reaching to ventrals. Brown, mottled with darker on the back; a series of blotches between the lateral keels; posterior half of each inter-radial dorsal membrane dusky, spotted with darker. Caudal spotted with black, anal plain or somewhat spot- ted; pectorals and ventrals dusky or blackish, the upper surfaces profusely spotted with darker, the spots bee forming cross-bars. Head 44—4; Lat. 1. 30-31. Fourteen specimens .10-.25m. Santarem; Hyavary; Bia CALIFORNIA ACADEMY OF SCIENCES. Teffé; two specimens, No. 8105, from the Rio Preto .15-.20 m., and three specimens, No. 8103, from the Rio Puty .17-.21 m. differ from typical examples in having a more angular orbital notch, and the fins, especially the pectorals and ventrals, much less spotted. 313, Loricaria spixii. Loricaria spixii Steindachner, Flussfische Siidam. iii, 4, pl. ii, 1881 (Rio Parahyba; Santa Cruz; Rio Muriahe; Sao Matheos; Sam- baia; Rio Grande do Sul); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 37, 1889 (Santa Cruz; Rio Quenda; Sambaia; Mendez; Campos; Muriahe; Sao Matheos). Habitat: Southeastern Brazil. Depth of the body 14-13 in its width. Head long, parabolic; transverse profile of the occiput gently arched; occipital terminating in an attenuate occipital process which is margined by two or three nuchal plates. In- terorbital flattish, loreal region and anterior profile con- vex, the anterior margin of the snout naked, the naked area margined by a narrow granular band below. Oc- cipital without keels. Surface of the head and scutes of body hispid. Orbit with a triangular notch of moderate size. Or- bital diameter without its notch, 3-34 in the snout, 63-7 in the head, 13-1? in the interorbital. Lower surface of the head and snout naked except the narrow marginal band. Both jaws with a few minute teeth. Upper lip and barbels fringed; lower lip of moderate width in females, greatly expanded and reaching beyond the gill-openings in males. Breast covered with plates of irregular shape; middle of belly with 3-4 series of plates; a large anal plate usually margined in front by 2-8 plates which are at- tached to a row of smaller plates in front; these, with the anal plate, form a ventral buckler. Nuchal plates ob- securely bicarinate; lateral keels remaining distinct but — SOUTH AMERICAN NEMATOGNATHI. ota approximated near the 22d scute, thence running par- allel to the caudal. Lateral line complete, composed anteriorly of two pores at the margin of each lateral scute. A small pectoral pore. Distance of dorsal fin from tip of snout 3 in the length; first dorsal ray highest, a little shorter than the head, the last ray less than half as long as the first. Caudal emarginate, the upper lobe longer. Anal well devel- oped, as high as -the ventral and pectoral. Ventrals reaching slightly beyond origin of anal, pectorals beyond origin of ventrals. Dusky above, lighter below; dorsal fin with the pos- terior half of each inter-radial membrane and the tip blackish, the anterior half of the membrane transparent; tip of caudal dusky, the rays indistinctly spotted; tip of anal somewhat spotted; pectoral and ventral fins blackish; upper lip and lower surface of lower lip dark violet. Head 42—42. De 8; A, 63, Vel, 5. PR. 1-6; Lat. 1730: Thirty specimens .19-.30 m. Santa Cruz; Rio Guenda; Sambaia; Mendez; Campos; Muriahe; Sao Matheos. 314. Loricaria typus. Parahemiodon typus Bleeker, Silures de Suriname, 20, pl. vi, fig. 1 and xiii, fig. 1 (Surinam). Loricaria typus Eigenm. & Eigenm. 1. c. Loricaria hemiodon Giinther, v, 258, 1864 (copied). Habitat: Surinam. 315. Loricaria phoxocephala. Loricaria phoxocephala HKigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 37, 1889 (Coary). Types: No. 8030; two specimens .14-.15 m. to base of caudal. Coary. This species can readily be distinguished by its pointed snout and by the black bars on the head. Head long, pointed, the snout acute; depth of the head 12 in its width; occipital with scarcely evident 374 CALIFORNIA ACADEMY OF SCIENCES. keels; interorbital convex; anterior profile concave; tip of snout naked. A narrow orbital notch. Eye 53 in snout, 7 in the head, 12 in the interorbital. Lower surface of head naked; teeth numerous and well developed in both jaws; thoracic plates small, the ante- rior margin of the mailed region truncate, extending to the gill-openings; fine longitudinal series of ventral plates; anal plate and the plates anterior to it as in L. tefieana; nuchal plates obscurely bicarinate; lateral keels becoming more or less entirely coaleseed on the fifteenth plate. Distance of dorsal fin from tip of snout 33-3} in the length; first dorsal ray higher than length of head; outer- most caudal rays produced; anal fin higher than ventrals or pectorals. Light brown with six broad cross-bands, the first on the nape, the second under origin of dorsal fin; a dark band extending forward from eye, a narrower one down- ward; head and anterior portion of body with black pores; dorsal sightly dusky, obscurely spotted, its base with a few spots; base of caudal and a band parallel to its mar- gin dark brown; anal and ventral fins ight; pectoral sim- ilar to the dorsal. Head 43-5; Lat. 1. 29. 316. Loricaria anus, Loricaria anus Valenciennes, Voy. d’Orb. ix, atlas ii, pl. vi, fig. 1, 1847; Cuvier & Valenciennes, xv, 470, 1840 (Buenos Ayres); Giinther, Catal. v, 258, 1864 (copied); Hensel, Wiegm. Arch. 1870, 77 (locality ?); Eigenm. & EHigenm. Proc. Cal. Acad. 2d Ser. 11, 38, 1889 (Rio Grande do Sul). Habitat: Rio Plata and its tributaries. - Depth 13-13 in the width. Surface of the head and scutes of the body slightly hispid. Head long, pointed, its depth 24-2? in its length; occipital without keels, with a triangular process which is margimed by two nuchal plates, its apex touching a third plate; inter- SOUTH AMERICAN NEMATOGNATHI. Bi) orbital flattish, a shallow groove extending backward from the nares. Margin of snout naked. Orbit with a triangular notch on its posterior rim, which is $ as long as the orbit; diameter of orbit with- out notch, 3? in the snout, 8 in the head, 1? in the interorbital. Lower surface of the head naked except a narrow mar- ginal band. No teeth in the upper jaw; lower jaw with a few mi- nute teeth. Upper lip rather coarsely fringed, lower lip broad, covered with thick papille. Anal plate joined to the plates preceding it, forminga subtriangular buckler. Nuchal plates inconspicuously bicarinate. Lateral keels remaining separate to the caudal but becoming approximated on the 25th lateral scute. Tail with a median depression above and below. Distance of dorsal fin from tip of snout 23 in the length; first dorsal ray highest, 17 in the head. Caudal emarginate, upper lobe a little the longer. Anal rounded, lower than the ventrals. Third ventral ray highest, reaching slightly beyond origin of anal; pectoral reach- ing to base of ventral. Color uniform dark brown. Eieadiaz—3-c2.8> Acv6: Vel, b:.P. I, 6: Two specimens .28-.33 m. Rio Grande do Sul. Dom Pedro II. 317. Loricaria acuta. Loricaria acuta Cuv. & Val. Hist. Nat. Poiss, xv, 472 (? Brazil); Kner, Panzerwelse, 85, 1853 (Barra do Rio Negro); Giinther, v, 258, 1864 (copied); Vaillant, Bull. Soc. Philom. Ser. 7, iv, 159, 1880 (Calderon); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 38, 1889 (Villa Bella; Lake Hyanuary; Cudajas; Manaos, on the Rio Negro; Xingu Cascade; Lago Alexo; Obidos; Coary; Teffeé.) ? Loricaria castanea Castelnau, Anim. Amérique du Sud, 46, plate xwiil, fig. 4, 1855 (Rio de Janeiro.) ? Loricaria maculata Ginther, Catal. vy, 257, 1864 (British Guiana; Surinam). Habitat; _Amazons and northward. 376 CALIFORNIA ACADEMY OF SCIENCES. This species is closely related to Loricaria maculata Bloch and to L. spixii Steindachner, but is readily dis- tinguished by the large, angular, orbital notch, by the broad, black margined lower lp, by the teeth and by the anal plate. Depth about 1$ in the width. Head long, narrow, de- pressed, its depth 13-2 in its width; postorbital region flattish, the occipital with two distinct keels in the young, which become more or less obsolete in the old; the occip- ital ends in an attenuated process which is margined by three nuchal plates; interorbital concave, the superciliary margins being slightly raised. Snout long, pointed; a narrow naked strip at its tip. Orbit with a large, angular, rhomboidal notch, the diameter, including the notch, 4 in the head; diameter of the eye 33 in the snout, 73 in the head, 1 in the space between the orbital notches. Lower surface of the head naked, the lower lip greatly expanded, entirely covering the naked portion. Teeth small, numerous, well devel- oped. A large, elongate anal plate, broadly rounded in front, margined by three large plates, together forming a large ventral buckler. Belly with three series of plates; breast with numerous smaller plates. Nuchal plates bicarinate; lateral keels strong, remaining distinct, approximated on about the nineteenth lateral scute. Surface of the anterior scutes and of the head with longitudinal series of small spines. Distance of dorsal fin from tip of snout 23-3 in the length, first dorsal ray about as high as the length of the head. Caudal emarginate. Anal fin large, its first ray little lower than the dorsal. Ventrals lower than the anal, reaching to or little beyond origin of the anal fin. Pectorals less than the ventrals, about reaching the latter. SOUTH AMERICAN NEMATOGNATHI. Od Head obscurely spotted with dark; body marbled; dor- sal rays spotted with dark, the spots extending upon the membrane in front of each ray; caudal rays spotted, the tips of the lower rays blackish; anal rays spotted; pec- toral and ventral fins dusky, indistinctly spotted, nearly black in the male; breast blackish (in the male); margin of lips black. Head 44-4. Sie AG Vv. Var P ne. 6 Wat lkes Over thirty specimens .06-.26 m. to base of caudal. Villa Bella; Lake Hyanuary; Cudajas; Manaos on the tio Negro; Xingu Cascade; Lago Alexo; Obidos; Coary; Teffé. 318. Loricaria maculata. Loricaria maculata Bloch, Ausl. Fische viii, 73, pl. 375, fig. 1; Lacépéde, Hist. Nat. Poiss. vy, 140, 1803 (South America); Cuv. & Val. xv, 473 (loc. ?); Kner, Panzerwelse, 80, 1853 (Rio Gua- poré; Matogrosso; Surinam); Vaillant, Bull. Soc. Philom. series 7, iv, 157, 1880 (Calderon); Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. ii, 38, 1889 (Coary; Santarem; Ica; Hyavary; Obidos; Teffé; Jutahy). Loricaria cirrhosa var.maculata Bloch & Schneider, Syst. Ichthyol. 125, 1801. Plecostomus maculatus Swainson, Fishes, Reptiles, etc. ii, 304, 1839. Loricariichthys maculatus Bleeker, Silures de Suriname, 16, 1864 (Surinam). Loricaria amazonica Castelnau, Anim. Amérique du Sud. 46, plate Xxiil, fig. 2, 1855 (Amazon). Plecostomus cataphractus Gronow, ‘‘Cat. Fish. 158,” 1854. Habitat: Rio Guaporé; Calderon; Surinam. Depth 14-13 in the width. Head long, depressed, its depth about 2 in its width; occipital with two keels, margined posteriorly by three plates; interorbital con- cave; snout depressed, acute, most so in the young, its margin turned upward slightly and narrowly naked in the adult. Orbital notch rather shallow, parabolic, rarely somewhat angular; diameter of orbit with the notch 43-5 in the length of the head. Eye 23-3? in the snout, 57-7 in the head, 12-14} in the interorbital. 378 CALIFORNIA ACADEMY OF SCIENCES. Lower surface of the head naked except a narrow mar- ginal band. Teeth few, minute in the upper jaw, similar teeth but more numerous in the lower jaw. Margin of upper lip slightly fringed, lower lip rounded. Anal plate pointed in front, margined by 2, rarely 3, anal plates; belly with 3 series of plates; breast with irregular smaller plates. Nuchalplates bicarinate. Lat- eral keels prominent, remaining distinct, becoming ap- proximated on the 16th or 17th scute. Surface of the head and of the anterior scutes with longitudinal series of small spines. Distance of dorsal fin from tip of snout about 3 in the length; first dorsal ray about 14 in length of head. Cau- dal fin emarginate, the uppermost ray slightly produced. Anal about as high as the ventrals; ventrals higher than the pectorals, reaching beyond origin of the anal; pec- torals about to the ventrals. Back with five dark cross bands; dorsal rays spotted, the spots extending upon the membranes in front of each ray, tips dusky; margin of lower caudal lobe black- ish, the rays spotted, base of caudal dusky; anal plain; ventrals sightly dusky; pectorals much darker. Head 4-41; D. 8; A. 6; V.I, 5; P.1,6; Lat. 1. 28-29. Twenty-five specimens .075-.17m. Coary; Santarem; Ica; Hyavary; Obidos; Teffé; Jutahy. 319, Loricaria konopickyi. Loricaria konopickyt Steindachner, Denk. Ak. Wien, xli, 45, pl. vii, 1879 (Amazon); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 39, 1889. Loricaria valenciennesi Vaillant, Bull. Soc. Philom. Ser. 7, iv, 157, 1880 (Calderon). Habitat: Amazon; Calderon. 320. Loricaria lanceolata. Loricaria lanceolata Ginther, Proc. Zool. Soc. Lond. 1868, 235, fig. 3 (Xeberos); Boulenger, Proc. Zool. Soc. Lond. March, 1887, 277 (Canelos); Eigenm. & Eigenm. 1. c. Habitat: Xeberos; Canelos. SOUTH AMERICAN NEMATOGNATHI. S(t, 321. Loricaria teffeana. Loricaria tefeana Steindachner, Denk. Ak. Wien, Ixi, 44, pl. vi, 1879 (Amazon, near Teffé); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 39, 1889 (Cudajas; Tonantins; Teffé; Jutahy; Lago Alexo; Tabatinga). Habitat: Solimoens. Depth 13-12 in the width. Head depressed, its depth 2 in its length to upper angle of gill-opening, its width equal to its length to upper angle of gill-opening. Occi- pital with two parallel ridges in the young, which diverge in the adult. An orbital notch of moderate size. Eye 2-34 in snout, 54-7 in the head, 14-14 in the interorbital. Snout moderately acute, its tip with a narrow naked space. Teeth numerous, well developed; lower lip fringed with rather long cirri. Breast with numerous small plates; five longitudinal series of plates on the belly; a rather large anal plate, bordered anteriorly by 3 plates, these three by 5 others. Nuchal plates bicarinate; lateral keels uniting more or less completely on the 15th lateral scute. Distance of dorsal fin from tip of snout 3{-3? in the length; first dorsal ray higher than length of head. Upper caudal ray produced, about 23 in the length. Height of anal, pectoral and ventral fins about equal, the first ray of each thickened. Pores of the head blackish, a series of six surrounding the eye, one pore near the anterior tip of the occipital plate, other pores above the gill-opening and above the nares. Color very variable: dark brown in young with six blackish cross bands, the first and last narrowest; outer- most caudal rays spotted, the rest of the fin black; tip of dorsal fin black, the rays spotted; anterior rays of the anal, ventral and pectoral spotted; two brownish spots on the upper lip. Specimens .14 m. to base of caudal are 380 CALIFORNIA ACADEMY OF SCIENCES. less black, the caudal is dark brown with one or more light cross bars; anal, ventral and pectoral with faint dusky bars. Specimens .16 m. to base of caudal have indistinct spots on the dorsal surface, the spots being most conspicuous on sides of head; dorsal spotted; base and margin of caudal blackish, the central portion of the fin spotted; a dark oblique cross band on the anal fin; a blackish spot on the plate on either side at base of anal fin; ventrals similar to the anal; pectorals dusky, a darker cross band faintly indicated. Headvo=o5 DOS AL 6y Vl, De O: Taide 202 Twelve specimens .08-.17 m. Cudajas; Tonantins; Teffé; Jutahy; Lago Alexo; Tabatinga. Two specimens, No. 8079 .06 m. to base of caudal from Jutahy have the lateral keels more or less distinct throughout, the dorsal surface everywhere with light re- ticulations. 322. Loricaria leviuscula. Loricaria leviuscula Cuv. & Val. xv, 476, 1840 (loc. ?); Kner, Panzer- welse, 81, pl. 111 & pl. i, 1853 (Barra do Rio Negro; Rio Branco; Marabitanos); Giinther, v, 256, 1864 (River Capin); Vaillant, Bull. Soc. Philom. series 7, iv, 156, 1880 (Calderon); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser, 1i, 37, 1889 (Rio Madeira; Rio Trombetas; Coary; Jutahy; Porto do Moz; Fonteboa; Gurupa; Manaos; Lake José Assu; Silva, Lake Saraca; Xingu; Tonantins; Hyavary). Habitat: Amazon, Solimoens, and tributaries from Para to Tabatinga. This species is very variable but is readily recognized by the large eye, the narrow interorbital, and the spotted appearance. : Depressed, the depth 13 in the width; caudal portion of the body with a median dorsal depression; posterior part of the head depressed. Anterior profile rapidly de- scending; depth of the head 2 in its width; occipital end- ing in a triangular process, margined by two nuchal plates. Head without distinct ridges or keels; 2 obscurely bicarinate nuchal plates; head and all the scutes m1- SOUTH AMERICAN NEMATOGNATHI. 381 nutely granular. Superciliary edges raised, interorbital narrow, the loreal region convex. Orbit with a shallow notch behind. Eye 23-4 in the snout, 5-7 in the head, 3—} in the interorbital. Snout pointed, its margin and tip granular. Lower surface of snout and head naked. Teeth well developed, numerous in both jaws; upper lp with a fringe of long cirri; lower lip closely covered with larger and smaller papille in the female, short in the male, covering the entire under surface of the head. Barbels fringed, the free portion about equal to an orbital diam- eter. Sides of the belly with a series of rather large scutes, a large anal plate, the central portion of the belly en- tirely covered with small scutes in the adult, entirely naked in the young (.065 m.), with two median series of scutes in example .10 metre long. The anal plate in the adult is bordered in front and laterally by a series of small plates which are larger in the 4 than in the ?. Lateral keels scarcely developed, coalescing on about the 25th scute. No pectoral pore. Distance of the dorsal fin from tip of snout 34-3} in the length; dorsal fin about twice as high as long. Caudal emarginate, its outer rays scarcely produced. Anal fin well developed. Ventral fins emarginate, the 3rd and 4th rays higher than the Ist and 2nd, the spine produced, reaching base of anal. Pectorals emarginate, reaching beyond base of ventrals. Head and body with small roundish dark spots, those on the tail arranged in series, one along the median line of back, one between the dorsal and lateral plates, an- other between the lateral keels; the spots more conspicu- ous in the female than in the male; the fins similarly spotted except the anal and sometimes the ventrals; tip epi CALIFORNIA ACADEMY OF SCIENCES. of dorsal sometimes smutty; young with about six dark cross-shades on the back; a jet black spot on base of cau- dal, its tip dusky. Head 4244 -") 8-904. 6; Ville Sy sR 6: hates Forty specimens .06-.30 m. Rio Madeira; Rio Trom- betas; Coary; Jutahy; Porto do Moz; Manaos; Fonteboa; Lake Jose Assu; Gurupa; Silva, Lake Saraca; Xingu; Tonantins; Hyavary. 323. Loricaria variegata. Loricaria variegata Steindachner, Flussfische Siidam. i, 15, pl. ili, 1879 (Mamoni River, near Chepo); Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. ii, 36, 1889. Habitat: Mamoni River. 324, Loricaria macrodon. Loricaria macrodon Kner, Panzerwelse, 79, pl. ii. 1853 (Cujaba); Ginther, Cat. Fish. Brit. Mus. v, 255, 1864 (copied); Hyrtle, Denk. Ak. Wien, xvi, 18, 1859 (Vertebre 1427); E. & E.1.c. Habitat: Cujaba. 325. Loricaria nudiventris, Loricaria nudiventris Cuy. & Val. Hist Nat. Poiss. xv, 469, 1840 (Rio San Francisco); Giinther, Cat. Fish. Brit. Mus. v, 256, 1864 (copied); Eigenm. & Kigenm. |. c. Habitat: Rio San Francisco. 326. Loricaria cataphracta. Loricaria dura Linneus, ‘“‘ Mus. Ad. Fred. 79, pl. 29, figs. land 2;” Bleeker, Silures de Suriname, 18, 1864 (Surinam). Loricaria cataphracta Linneus, Systema Nature, ed. x, 307, 1758; id. 1. c. ed. xii, 508, 1766 (America); Bloch, Ausl. Fische, viii, 76, pl. 75, figs. 3 and 4; Cuv. & Val. xv, 459 (Surinam, Cayenne); Kner, Panzerwelse, 77, 1853 (Cujaba, Guaporé); Giinther, v, 255, 1864 (Surinam); Peters, MB. Ak. Berl. 471, 1877 (Calabozo); Cope, Proc. Am. Philos. Soe. xvii, 681, 1878 (Maranon, Peru); Eigenm. & Eigenm.1. c. (Vigia; Sao Gongallo; Cameta; Man- aos; Para; Rio Negro; Coary; Villa Bella; Gurupa; Rio Preto; Tajapuru; Porto do Moz; Teffé; Maranon; Ucayale; Obidos). Loricaria cirrhosa Bloch & Schneider, ‘‘Syst. Nat. 125, pl. 34,” 1801. Loricaria setifera Lacépéde, Hist. Nat. Poiss. v, 140, 1803 (South America). Loricaria carinata Castelnau, Anim. Amérique du Sud, 46, pl. xxiii, fig. 8, 1855 (Amazon). Plecostomus flagellaris Gronow, ‘‘Cat. Fish. 158, 1854.” Habitat: Rio Preto; Amazons; Guiana. SOUTH AMERICAN NEMATOGNATHI. 383 Form elongate, little depressed forward, the greatest depth 1} in the width. Caudal peduncle broad, depressed. Head rather high, its depth about equal to the length of the snout; occipital roof-shaped, with two serrate ridges which widen somewhat and become blunt anteriorly, uniting above the posterior nares; humeral plate with a low ridge which extends upward and is continued on 3 of the lateral plates; occipital margined by 3 nuchal plates; 2 large bicarinate nuchal plates between the oc- cipital and dorsal plates. Orbit moderate, with a broad shallow notch; the su- perciliary edge coarsely hispid; orbit without the notch, 24-3? in the snout, 6—% in the head, 1—14 in the inter- orbital. Snout with its margin entirely granular, pointed in young, less so in adult specimens. Mouth small, the lips wholly covered with papille and tentacles, the marginal ones largest, the lower lip emarginate; teeth few, those of the upper jaw much larger than those of the lower. Barbels well developed, longer than the diameter of eye, fringed with tentacles. The lateral line runs close under the upper lateral keel, and is composed of two pores at the posterior margin of each scute. All the seutes in front of the dorsal carinate; the lat- eral keels approximated on the 17th or 18thscute. Breast and central portion of the belly backward to the vent covered with small, irregular plates, the sides of the belly with a series of larger plates; in the young the breast is partially naked. Distance of dorsal fin from tip of snout 38-32 in the length, the dorsal fin much higher than long. Caudal short, emarginate, the upper ray produced, the filament sometimes much longer than the length to its base. 384 CALIFORNIA ACADEMY OF SCIENCES. Anal short, high, little lower than the dorsal fin. Ventrals inserted very slightly behind the dorsal fin, their tips reaching beyond origin of anal fin; pectorals to or little beyond origin of ventral fins. Purplish to olivaceous; dorsal fin closely covered with chocolate dots; caudal dusky, the tip of the upper lobe light; anal transparent or dusky; upper surface of pecto- ral and ventral fins closely covered with dark dots and blotches; upper lip and barbels dotted with chocolate. Mead 4—44 : D8 AWG? Vol ba Pe IG hat. lO eu Forty-eight specimens .14—.27 m. long to base of cau- dal. Vigia; Sao Goncallo; Cameta; Manaos; Para; Rio Ne- ero; Villa Bella; Gurupa; Rio Preto; Tajapuru; Porto do Moz; Teffé; Maranon; Ucayale; Obidos; Coary. Thayer Expedition. 327. Loricaria lata. Loricaria lata Kigenm. & Eigenm.Proc. Cal. Acad. 2d Ser. ii, 36, 1889 (Goyaz). Types: No. 8123; eleven specimens .11-.27 m. to base of caudal. Goyaz. Senhor Honorio. Body elongate, everywhere greatly depressed, the depth about 1? in the width, the width at origin of anal equals snout and orbit in the adult, equal to the snout alone in the young. . Head depressed, its depth consid- erably less than length of snout, its width little longer than its length to upper angle of gill-opening; posterior half of occipital with two inconspicuous keels. Hum- eral plate without keels. A shallow, rounded orbital notch; interorbital very slightly concave. Eye 37-44} in snout, 7-84 in head, 14-13 in the interorbital. Snout pointed, its margin entirely granular. Lips margined with cirri, the lower emarginate, its surface also covered with cirri; teeth few, large, those of the upper jaw longer. Nuchal plates faintly bicarinate; lateral keels rather SOUTH AMERICAN NEMATOGNATHI. 385 prominent, approximated on the 20th scute; breast and belly with numerous small plates, almost wholly naked in specimens .10 m. to base of caudal. Distance of caudal fin from tip of snout 3 in the length. Caudal fin injured. Anal fin as high as the ventrals; outer ventral ray greatly thickened and pro- longed, reaching beyond origin of anal fin. Pectorals higher than the ventrals, reaching beyond base of the latter. Coloration uniform in adult (?); all the fins dusky; young with five dark cross-bars which are most promi- nent on the sides; fins all more or less spotted; upper lip and barbel dotted. 328. Loricaria macromystax. Loricaria macromystax Giinther, Proc. Zool. Soc. Lond. 1869, 426, fig. 5-6 (Upper Amazon); Eigenm. & EKigenm. Proc. Cal. Acad. 2d Ser. ii, 37, 1889. Habitat: Upper Amazon. 329, Loricaria vetula. Loricaria vetula Valenciennes, Voy. d’Orbigny, ix, Atlas ii, pl. vi, fig. 2, 1847; Cuv. & Val. xv, 466, 1840 (Buenos Ayres); Giinther, v, 256, 1864 (copied); Eigenm. & Eigenm. 1. c. Habitat: Buenos Ayres. 330, Loricaria lamina, Loricaria lamina Giinther, Proc. Zool. Soc. Lond. 1868, 239, figs. 6 and 7 (Xeberos); Eigenm. & Eigenm. 1. c. Habitat: Upper Amazon. 331, Loricaria platystoma. Loricaria platystoma Giinther, Proc. Zool. Soc. Lond. 1868, 236, 237, and 238, fig. 4 and 5 (Surinam); Eigenm. & Eigenm. 1. c. Habitat: Surinam. LXIV. Harrrta. Harttia Steindachner, Siisswasserfische siidéstl. Bras. 111, 110, 1876 (loricariformis). Type: Harttia loricariformis Steindachner. Body short, broad, greatly depressed; adipose fin none; 25 386 CALIFORNIA ACADEMY OF SCIENCES. a series of. broad paired plates behind the dorsal fin, lateral plates not keeled. Dorsal inserted a little in front of the ventrals. _ This genus is composed of a single species which is restricted to Southeastern Brazil. 332. Harttia loricariformis. Harttia loricariformis Steindachner, Siisswasserfische Siidostl. Bras. iii, 111, fig. 2a.b. (Rio Parahyba); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 39, 1889 (Rio Parahyba; Itabapuana; Muriahe). Habitat: Southeastern Brazil. Form broad, greatly depressed; depth about 23 in the width which is one orbital diameter less than the length of the head; the least width, immediately in front of the caudal fin, is about equal to one diameter of the eye. Head broad, depressed; occiput flattish, interorbital slightly concave, anterior margin of the snout naked; margin of the head with very fine movable bristles. Orbit 34-4 in the snout, 64-74 in the head, 14-1? in the interorbital; mouth broad, teeth fine, very numer- ous, lips rather narrow, thickly papillose. A series of broad plates on the sides of the belly, a pair of rather large anal plates and sometimes a few small plates in front of them; ventral surface otherwise naked; the azygos plate in front of the anal fin is roundish; jateral plates without keels. Two or three plates bordering the occipital. First dorsal ray thickened and flexible, its outer sur- face with short bristles; dorsal fin higher than long. Caudal short, slightly emarginate, its outer rays thick- ened. Anal fin varying in height, 1-2 in the length of the head. Ventrals reaching at least to origin of anal; pec- torals to the second third of the ventrals. Back marbled; fins spotted. Head: 38—4; D. 8; A. 6; Lat. 1. 28. SOUTH AMERICAN NEMATOGNATHI. 387 Twelve specimens, length .11-.283 m. Rio Parahyba; Itabapuana; Muriahe. LXXV. OxyRopsis. Oxyropsis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. ii, 39, 1889 (wrightiana). Type: Oxyropsis wrightiana Kigenm. & Kigenm. This genus differs from Harttia as Hypoptoma differs from Otocinclus. The head is depressed, the eyes mar- ginal, the orbit infringing slighty on the lower surface of the head. Tail depressed. A lateral keel. Belly cov- ered with granular plates. Adipose fin none. 333. Oxyropsis wrightiana. Oxyropsis wrightiana Kigenm. & Higenm. |. c. (Lake Hyanuary). Type: No. 8055; one specimen .037 m. to base of caudal. Lake Hyanu- ary. L. Agassiz. Depressed elongate; the depth about 2 in the width. Head depressed, the snout rounded; occipital margined by two nuchal plates; interorbital convex; nares above the anterior margin of the orbit; surface of the head and all the scutes with longitudinal series of small spines; no keels on the head. Lower surface of the head as in Hy- poptoma. Hye 23 in the snout, 53 in head, 23 in the in- terorbital. Teeth well developed; lower lip convex, pap- illose. Anal groove bounded laterally and posteriorly by a horse-shoe shaped plate, anteriorly by the large shield- shaped anal plate. Belly with three series of plates which are separated anteriorly; thorax with two pairs of large plates. Four series of plates covering the body, the lateral series with a median keel which is strongest above the tip of the anal. Distance of dorsal fin from tip of snout about 23 in the length, the first dorsal ray equals the distance between base of pectoral and tip of snout. Caudal fin damaged. 388 CALIFORNIA ACADEMY OF SCIENCES. Anal fin as high as the snout and the eye. Ventrals short, not reaching the anal. Pectorals reaching beyond middle of ventrals, little lower than the first dorsal ray, the spine strongly spiny on its outer margin, almost smooth on its inner margin. Back marbled; sides with numerous minute dark dots; dorsal rays spotted with dark; middle caudal rays black- ish; anal and inner surfaces of ventrals and pectorals spotted like the dorsal fin. iD? hy Weak? OVE dk, ope, shat: Iei2ee SuBFAMILY HYPOPTOPOMIN &. LXXVI. HyvproproroMa. Hypoptopoma Giinther, Proc. Zool. Soc. Lond. 1868, 234 (thoracatum). This genus is distinguished by its low, spatulate snout, and by the armature of the belly. The eyes are on the lateral edge of the head. In the shape of the body it ap- proaches Pl. granlosus. The breast is covered by two pairs of granular plates, the dermal ossification of the clavicula and coracoid. Habitat: Amazon from Rio Negro westward; Venezuela. ANALYSIS OF THE SPECIES OF HYPOPTOPOMA. a. Lateral plates not keeled. b. Space between the suborbital shield and the clavicle partially naked; lateral plates with spiny ridges; caudal with dark bars. thoracatum 334. bb. Space between the suborbital shield and the clavicle with an osseus shield; lateral plates smooth; caudal rays brown, margin of the caudal and a vertical line near its base pale; dorsal deep brown at base, dark spots on its middle. gulare 335. aa. Median lateral plates keeled; pectoral spine more strongly serrate on its inner than on its outer margin. carinatum 336. 334, Hypoptopoma thoracatum. Hypoptopoma thoracatum Giinther, Proc. Zool. Soc. Lond. 1868, 234, fig. 2 (Xeberos); Peters, MB. Ak. Berl. 1877, 471 (Cala- bozo); Steindachner, Denk. Ak. Wien, xli, 47, pl. iv, 1879 (Am- SOUTH AMERICAN NEMATOGNATHI. 389 azon, near Rio Negro; Calabozo); Eigenm. & Eigenm. Proce Cal. Acad. 2d Ser. ii, 40, 1889 (Teffé; Obidos; Manacapuru; Ica; Rio Negro). Hypoptopoma bilobatum Cope, Proc. Am. Philos. Soc. xi, 1870, 566, fig. (Pebas, Ecuador); id, 1. c. xvii, 1878, 679 (Peruvian Am- azon); Steindachner, Denk. Ak. Wien, xli, 48, pl. vi, 1879 (Obidos; Lago Alexo; Manacapuru); id. Flusfissche, Siidam. iv, 7, 1882 (Rio Huallaga). Otocinclus joberti Vaillant, Bull. Soc. Philom. 7th Ser. iv, 147, 1880 (Calderon). Habitat: Solimoens, Marafion and northward. We are unable to detect any constant differences be- tween thoracatum and bilobatum. Dr Giinther’s speci- men had a damaged caudal. The figures of bilobatum by Cope and by Steindachner do not agree in coloration, ventral covering, etc. Body subterete, the greatest depth equal to the greatest width. Head greatly depressed forward, its width equal to the length of snout and eye; profile little concave in front, somewhat convex on occiput; interorbital a little convex; occipital ending in a triangular process which is bordered by 3 nuchal plates; prefrontals arrow-shaped. Snout margined by a rhomboidal plate at tip and 4 plates between it and the eye; a series of small plates and sometimes a narrow naked area from the nares for- ward; marginal plates of the snout with hooklets above and larger ones below. Eye 3 in snout, 6 in head, 34-4 in the interorbital. Two small plates below the 2d marginal plate in front of the eye, a much larger plate below the eye and 4 small plates between the gill-openings. Belly covered with 6-7 pairs of plates, a small median one connects the anterior 2-3 pairs, a large shield-shaped plate be- tween the ventrals. In a specimen (No. 7760) .05 m. long to base of cau- dal, there are no plates between the gill-openings, the ventral armature consists of 6 pairs of plates confined to the sides and 5 roundish plates along the middle. 390 CALIFORNIA ACADEMY OF SCIENCES. Lateral plates hispid and with a marginal series of spines. Distance of the dorsal fin from tip of snout little more than 2 in the length; dorsal fin emarginate, its spine as long as the head to the upper angle of gill-opening. Spine of the adipose fin small, its distance from the dorsal fin almost twice the length of the latter. Caudal deeply emarginate, its lobes pointed, equal in length to the dorsal spine. Pectoral spine, in the young, reaching to middle of ventrals, in the old to the origin of the anal, its outer margin with 2 series of spines, largest near the tip. Ventrals short, not reaching beyond the vent. Light brown, anterior dorsal rays spotted with darker; caudal fin barred with brown. Head: 222253 Di Ts tj. d, Os Ves os Peak Ge lates 22-23. Six specimens .06-.09 m. Teffé; Obidos; Manacapuru; Ica; ? Rio Negro. Agassiz, James and Dr. Jeffrys. 335. Hypoptopoma gulare. Hypoptopoma gulare Cope, Proc. Am. Phil. Soc. xvii, 1878, 679 (Mar- anon; Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 40, 1889. Habitat: Marafion. 336. Hypoptopoma carinatus. Hypoptopoma carinatus Steindachner, Denk. Ak. Wien, xli, 49, pl. vi, 1879 (Amazon near Peruvian boundary); E. & E. 1. ¢. Habitat: Solimoens near Peruvian boundary. LXXVII. Hutsonoruvs. Hisonotus Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. 11, 40, 1889 (notatus). Type: Hisonotus notatus E. & E. This genus is distinguished’ by its large ventral plates, superior eyes, unperforated humeral plate, and absence of an adipose fin. Habitat: Southeastern Brazil. SOUTH AMERICAN NEMATOGNATHI. 391 337, Hisonotus notatus. ? Otocinclus maculicauda Steindachner, in part. Hisonotus notatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 42, 1889 (Santa Cruz; Juiz de Fora). od Types: No. 7,764. Ninety-five specimens, the largest .04 m. Santa Cruz. Dom Pedro II. No. 8,177. One specimen, .043 m. Juiz de Fora. Thayer Expedi- tion. Body somewhat depressed anteriorly, wider than deep. Head narrow and comparatively high; occipital end- ing in a triangular process which is bordered by asingle nuchal plate; profile rather steep and slightly convex; all the plates of the head strongly hispid; a series of rather large recurved spines margining the granular por- tion of the snout below. Orbit 35 in the snout, 7 in the head, 3 in the inter- orbital. Outlines of the marginal plate of the snout indistinct. Ventral surface entirely covered with about 3 series of irregular plates. Lateral plates strongly hispid, the marginal spines scarcely enlarged. Distance of dorsal fin from tip of snout little more than 2 in the iength; margin of dorsal fin convex. Caudal emarginate. Pectoral spine not reaching middle of ventrals, its outer marginspiny. Ventral fins reaching little beyond vent. Light brown; caudal with a large median blackish blotch which extends to the margin of the middle caudal rays; outer caudal rays yellow. Fegdes i Ds Tei AL oa oN ee APG ylaaibes OZ oe Dr. Steindachner probably includes minutus with his maculicauda. We here wish to restrict the name macu- licauda to the species figured by Dr. Steindachner. 392 CALIFORNIA ACADEMY OF SCIENCES. LXXVIII. Parotocincuvus. Parotocinclus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 11, 41, 1889 (notatus). Type: Otocinclus maculicauda Steindachner. This genus is distinguished from Hisonotus by pos- sessing an adipose fin. 338. Hisonotus maculicauda. Otocinclus maculicauda Steindachner, Siisswasserfische siidostl. Bras. iv, 6, pl. 1, fig. 2-2b (loc. ?); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 41, 1889 (Santa Cruz). Habitat: Santa Cruz. Caudal with a dusky spot on base of middle caudal rays and a smaller one on the tip of its lower rays; eye larger than in H. notatus; otherwise as in Hisonotus notatus. Three specimens. Santa Cruz. Dom Pedro II. LXXIX. Orocrinc.us. Otocinclus Cope, Proc. Acad. Nat. Sci. Phila. 1871, 283 (vestitus ). Type: Otocinclus vestitus Cope. This genus is distinguished from all other Loricartide by its perforated temporal plate and large ventral plate. These characters seem to us to be of generic value in themselves, and we exclude from Otocinclus all species not possessing them, however closely they may resemble it otherwise. Habitat: Ambyiacu River; Santa Cruz. ANALYSIS OF THE SPECIES OF OTOCINCLUS. a. Lat. 1. 23-24. Eye 5in head. D.I, 7. affinis 339. aq. Lat. 1.21, Kye dain head.) D716. vestitus 340. 339. Otocinclus affinis. Otocinclus afinis Steindachner, Siisswasserfische Siidostl. Bras. iv, pl. ii, figs. 1-1b (Santa Cruz, near Rio Janerio); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 41, 1889 (Santa Cruz). Habitat: Santa Cruz. SOUTH AMERICAN NEMATOGNATHI. 393 Body heavy, compressed, everywhere deeper than wide. Head angular, profile steep and straight; occipi- tal terminating in an elevated triangular process. Sides of the head vertical, eyes lateral. Interorbital slightly convex; a shallow groove extending from nares forward; all the bones of the head hispid, the spines being strong- est on the occipital process. Orbit 2 in the snout, 5 in the head, 2 in the inter- orbital. Snout pointed; lower surface of the head naked except a triangular area below the eye. Surface of clavicle and coracoid hispid, the ventral surface between them and the ventrals closely covered with 3 series of plates; a larger triangular plate between bases of ventral fins; a Y-shaped naked area extending from the vent forward and on either side of the interventral triangular plate. Tail flattened above and below; all the plates hispid. Distance of dorsal fin from tip of snout 2-2} in the length; dorsal spine high, about one diameter less than length of head. Caudal emarginate. Pectoral extending little beyond origin of ventrals, the ventrals not to the anal fin. Light brown; a narrow dusky bar extending from eye to base of caudal. Eeadrs: Deis ALG VAG0R> 16s Lat) 23224 Twenty specimens .03-.045 m. Santa Cruz. Dom Pedro II. 340, Otocinclus vestitus. Otocinclus vestitus Cope, Proc. Acad. Nat. Sci. Philad. 1871, 283, pl. iv, fig. 2 (Ambyiacu River); Eigenm. & Eigenm.1. c. Habitat: Ambyiacu River. 394 CALIFORNIA ACADEMY OF SCIENCES. SuBFAMILY PLECOSTOMIN &. LXXX. MIcROLEPIDOGASTER. Microlepidogaster Eigenm. & Eigenm. Proc. Cal. Acad. Sei. 2d Ser. 11, 42, 1889 (perforatus). Type: Microlepidogaster perforatus KE. & E. This genus resembles Otocinclus in its perforate tem- poral plate, and differs from it in the ventral covering and position of the dorsal fin. 341, Microlepidogaster perforatus. Microlepidogaster perforatus Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 42, 1889 (Rio Carandahy, Brazil). Type: No. 8182. One specimen .032 m. to base of caudal; Rio Car- andahy, Brazil. Broad and depressed anteriorly, the depth less than the width. Head broad, depressed, its depth little more than 2 in its length to end of temporal plate; its width 14 in its length. Snout narrow, pointed, loreal region concave; eye small, 4 in snout, 8) in head; inter- orbital concave, equal to the postorbital portion of the head. | Temporal plate perforate, a larger foramen posteriorly directly behind the eye. A large foramen above and be- hind the pectoral spine. All the plates hispid, most so on tail, but without keels. Lower surface of the head naked. Teeth well developed in both jaws. Coracoid and clavicula granular. Belly to between the ventrals entirely covered with small gran- ular plates; a rather long, narrow, naked pre-anal region. Origin of dorsal equidistant from tip of snout and base of caudal; origin of ventrals equidistant from tip of snout and tip of anal fin. De Goi Ae to Ge bathe 2a SOUTH AMERICAN NEMATOGNATHI. 395 LXXXI. NEoOPLECOSTOMUS. Neoplecostomus Eigenm. & Eigenm. Proc. Cal. Acad. ad Ser. 1,470, 1715 1888 (microps); id., lc. 11, 42; 1889: Type: Plecostomus microps Steindachner. This genus is very closely related to Plecostomus from which it differs in the general form, the number of the fin rays, the granulation of the ventral surface and the position of the adipose fin. ANALYSIS OF THE SPECIES OF NEOPLECOSTOMUS. (de ING is) granosus 342. aa. A. 6. microps 343. 342. Neoplecostomus granosus. Hypostomus granosus Cuy. & Val. Hist. Nat. Poiss. xv, 502, 1840 (Cayenne). Plecostomus granosus Giinther, v, 237, 1864 (copied). Neoplecostomus granosus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. ii, 42, 1889. Habitat: Cayenne. This species is known only from the types; as far as we are able to judge, it agrees with N. microps in all characters but the number of the anal rays. 343. Neoplecostomus microps. Plecostomus microps Steindachner. Siisswasserf. Siidostl. Bras. iii, 130, pl. xiii (Rio Janeiro); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 170, 171, 1888 (Juiz do Fora, Rio Parahyba; Goyaz). Habitat: Rio Janeiro; Rio Parahyba; Goyaz. Head broad, flat, parabolic in front; interorbital region flat; an indistinct ridge from the eye to the nares, no ridges or crests on the postorbital portion of the head. Occipital bone rounded behind, margined by about three nuchal plates; about five plates between the occipital and the dorsal fin. Plates not keeled. Tail terete. Sides of the head with rather large plates. Tip of snout naked. Twelve teeth on each side of the upper jaw; 16 teeth on each side in the lower. 396 CALIFORNIA ACADEMY OF SCIENCES. Eye 53 in the snout, 93 in the head, 3 in the interor- bital. A large subcircular patch of minute granular scutes on the center of the belly; a triangular patch between the gill-opening and the rictus; ventral surface otherwise naked. Base of the dorsal fin 2 in its distance from the adipose fin; 7 plates between the spine of the adipose and the caudal. Caudal equal lobed, the shorter ray 2 in the head. Light brown marbled with darker; tips of the caudal dusky. hat, 1,28; An 6... Head: 33. One specimen .09 m. Juiz de Fora, Rio Parahyba. Thayer Expedition. Two specimens .085 m. Goyaz. These two specimens collected by Senhor Honorio have large dusky spots on the rays of all the fins. LXXXII. PLEcostomus. Plecostomus Gronow, ‘‘ Mus. i, 24, 1758;” id. Zooph. 127, 1868. (sp). Plecostomus Bleeker, Neder]. Tijdschr. Dierk. i, 77, 1863 (brasiliensis = plecostomus. ) Hypostomus Lacépede, Hist. Nat. Poiss. v, 144, 1803 (guacart = plecostomus. ) Hypostomus Cuy. & Val. xv, 489 (plecostomus). Type: Plecostomus braziliensis Bleeker. Habitat: Cordova and Rio Plata to Guiana region and Rio Magdalena; Amazon to the Ambyiacu; Guaya- quil. ‘ In a foot note, page 127 of his Zoophylacitm, Gronow says: | ‘Species subsequentes 391 and 392 huc proprie non pertinent, ut pag 28 monui; ob labia revoluta huic gen- SOUTH AMERICAN NEMATOGNATHI. 397 erl eas adjunxi.”” This leaves in his genus Plecostomus: Nos. 393, Pl. dorso dipterygio: ore dentata; cirris pluri- mis, etc., = ? and 394, Pl. plecostomus. Bleeker first restricted the name Plecostomus as it stands at present. Hypostomus Lacépede and Hypostomus Cuy. & Val. are identical in so far as they have plecostomus for their type. Hypostomus Lac. is composed of a single species while Cuv. & Val. include in their Hypostomus species of several genera. ANALYSIS OF THE SPECIES OF PLECOSTOMUS.*t a. Head with three distinct ridges, snout pointed, head usually elevated, occipital plate ending in a pointed occipital crest. b. Belly entirely covered with small granular plates. c. Posthumeral ridge becoming strongest on the tail which is flat be- low; outer caudal rays greatly produced; occipital plate margined by several small plates which become codssified with it in the adult. Tip of snout naked or granular. emarginatus 344. cc. Posthumeral ridge strongest in front, lower surface of the tail similar to its upper surface. d. Free margins of the lateral plates covered with long spines; eye 92 in the head; tip of snout granular; back with a median depres- sion. Lat. 1. 32. (Steindachner.) spinosissimus 345. dd. Margin of the lateral plates with short spines or none. e. Tip of snout naked; Lat. 1. 28-30; occipital plate margined by a single large nuchal plate except in carinatus. f. Spots on the caudal as distinct as those on the dorsal. g. Lower surface of the head covered with scutes. h. Spots all small, as many as 20 on one of the anterior lateral scutes; belly plain. commersonii 346. hh. Spots rather large, not more than 4 on one of the an- terior scutes, forming 4 or 5 longitudinal series on the tail; belly with similar spots. commersonii affinis 346a. gg. Lower surface of the head naked except a triangular spot in front of the gill-openings; spots large as in affinis; oc- cipital process shorter than in commersonii. commersonii scabriceps 346d. Jf. Spots on the caudal less distinct than those on the dorsal; all the scutes with high keels; nuchal plates bicarinate. *Doubtful species of this genus are Plecostomus robini Gill, not of Cuv. & Val. Hypostomus commersonii Kner, not of Cuy. & Val. Hypostomus punctatus Kner, not of Cuy. & Val. tNo. 352, Plecostomus virescens Cope, we have not been able to assign to a place in this key. 398 ~ CALIFORNIA ACADEMY OF SCIENCES. i. Lat. 1. 28; eye 44 in the snout, 8 in the head, 3 in the in- terorbital; outer caudal rays little produced; middle caudal rays 11-1} in the head. Base of the dorsal fin equal to its distance from the caudal, or very little less. limosus 347. vi. Lat. 1. 30. Eye 34 in the snout, 6-64 in the head; base of the dorsal equal to its distance from the posterior margin of adipose fin. carinatus 348. ee. Tip of snout granular, occasionally naked in plecostomus. j. Lateral plates all more or less strongly keeled; nuchal plates conspicuously bicarinate; shortest caudal rays 14in the head. Light brown, everywhere spotted with darker. Lat. 1. 26. plecostomus 349. jj. Lateral plates scarcely if at all keeled. Lat. 1. 27-28. k. Head with vermiculating light and dark lines; ventral sur- face with short curved bars; occipital plate margined by three nuchal plates; superciliary edge raised. vaillanti 350. kk. Head with round spots; ventral surface plain; superciliary edge scarcely raised; base of the dorsal less than its dis- tance from the adipose fin. villarsii 351. bb. Belly partially or entirely naked.* o. Belly covered with minute scutes, except a quadrate space between the ventrals. biseriatus 3538. oo. Belly with scutes only on the sides, and sometimes a narrow strip between the ventrals. p. Lat. 1.27. Upper lateral plates with a strong median keel; head with a strong occipital keel and smaller temporal keels; nuchal plates bicarinate; a band between the pectorals, sides of the belly and a narrow band between the ventrals covered with scutes; dor- sal surface, sides and fins spotted with brown; ventral surface plain. seminudus 304. pp. Lat. 1. 30; lateral plates not keeled. anne 355. ooo. Belly entirely naked. pantherinus 356. aa. Head without distinct ridges or keels; snout broad, rounded. q. Belly entirely covered with granular plates. rv. Tip of snout naked. s. Dorsal crossed by six or seven black zig-zag stripes; base of the dorsal less than its distance from the adipose; 17 scutes between the anal and the caudal. Lat.1.30. Brownish black with black dots, largest on belly; rays of the caudal, pectoral and ventral fins crossed by a number of black streaks. cordove 357. ss. Dorsal spotted or uniform dusky; base of the dorsal longer than its distance from the adipose fin. Lat. 1. 26-27; occipital bérdered by a single plate. *352 virescens Cope, should probably be placed here. SOUTH .AMERICAN NEMATOGNATHI. 399 t. Superciliary edge not raised, interorbital highest in the middle, orbit moderate 3 (in specimens .16 m.)-3} (in specimens .30 m.) in the snout, 54-64 in the head, 2 in the‘interorbital; postfron- tals with a long descending process which forms the entire poste- rior margin of theeye; dorsal spots as large as or a little smaller than the eye. Lat. 1. 26. lima 358. t’. Fins all uniform dark brown. lima atropinnis 358a. tt. Superciliary edge greatly raised, interorbital area concave; orbit large, 3 inthe snout, 54 in the head, 1} in the interorbital; postfrontals without a descending process, forming part of the upper margin of the orbit only; dorsal uniform dusky. Lat. 1. 2c macrops 359. rr. Tip of snout granular; eye 64 in the head; more than 2 in the in- terorbital; head 34; base of dorsal larger than its distance from the adipose. Olive brown with one or more orange yellow spots on each lateral scute, similar ones on the head, dorsal and caudal. Srancisci 360. qq. Belly partially or wholly naked; tip of snout naked. u. Each of the large scutes with two or three small, round yellow spots; eye 2 in the interorbital; thorax nearly entirely covered with granulations, sides of the belly naked; anterior dorsal rays much longer than the head; caudal subtruncate; pectoral spine broad reaching 2nd third of the ventrals, its upper surface with slender curved spines; scutes granular, not keeled; head little more than 4 of the length. Lat.1.27. (Giinther.) alatus 361. uu. Sides of the body and the fins with irregular longish yellow spots, sometimes confluent into bands; head with round dark spots; head as wide as long; eye 3} in the snout, 54 in the head, more than 2 in the interorbital; caudal subtruncate; irregular granular patches on the throat, breast and belly, the granules on the middle of the belly smallest; first dorsal ray equals the length of the head. Lat. 1. 27. (Kner.) auroguttatus 362. uuu. Sides of the body usually with round dusky plates; fins with similar spots or plain. Head longer than broad. v. Occipital bordered by two or three nuchal plates*; base of dorsal almost equal to its distance from the caudal; lateral plates striate not keeled. w. Caudal plain, spots on the head and on the dorsal not confiu- ent into lines or bars; ventral surface plain, with very few granules; head 34. liitkeni 363. ww. Caudal with wavy crossbars formed by dusky spots on the rays; spots on the head sometimes confluent into vermiculating ' lines; ventral surface plain, with very few granules. vermicularis 364. > * Not examined in brevicauda. 400 344, CALIFORNIA ACADEMY OF SCIENCES. www. Caudal with two series of spots between each two rays. Eye nearly 4 of the interorbital; first dorsal ray longer than the head; caudal obliquely subtruncate; pectoral spine with long, curved spines; head 3}. (Giinther). brevicauda 365. vv. Occipital bordered by a single nuchal plate. xz. A single series of large round spots between two dorsal rays, similar spots on the caudal; scutes of the belly reduced to a minimum; snout more regularly convex in transverse profile than in wuchereri. Lat. 1. 26. robinii 366. xa. Two series of spots between two dorsal rays, the spots much smaller than the eye; upper caudal lobe little shorter than the lower; space between and behind ventrals naked, or with few granules. Lat. 1. 26. wuchereri 367, xax. Spots on the caudal much smaller than those on the dorsal, which are large and ill-defined; caudal very obliquely truncate, the lower lobe being much the longer; space beeween and be- hind the ventrals mostly granular. Lat. 1. 25. johnii 368. Plecostomus emarginatus. Hypostomus emarginatus Cuvier & Valenciennes, xv, 500, 1840 (Brazil). Hypostomus emarginatus Kner, Hypostomiden, 260, 1853 (Barra do Rio Negro), not Cuy. & Val. Plecostomus emarginatus Giinther, v, 233, 1864 (copied); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 167, 1888 (Cudajas; San- tarem; Manacapuru; Tonantins; Obidos; Fonteboa; Tabatinga; Hyavary; Sao Paolo; Goyaz). Hypostomus horridus Kner, Hypostomiden, 259, pl. i, fig. 1, 1853 (Rio Guaporé). Plecostomus horridus Giinther, Cat. Fish. Brit. Mus. v, 232, 1864 (copied); Peters, MB. Ak. Berl. 1877, 471 (Calabozo). Hypostomus squalinum Schomburgk, Fish. Brit. Guiana, 142, pl. 2, 1841 (Rio Branco, Rio Negro and Rio Essequibo). Plecostomus scopularius Cope, Proc. Acad. Nat. Sci. Philad. 1871, 55 and 286, pl. 16, figs. 1 and 2 (Ambyiacu). Plecostomus tenuicauda Steindachner, Fisch-fauna Magd. Stromes, 24, pl. vii, 1878 (Magdalen River); id. Fisch-fauna des Cauca and Fliisse bei Guayaquil, 11, 1879 (Cauca). Habitat: Amazons and tributaries from Para to Ambyiaca; Guiana region; Rio Magdalena. H. emarginatus C. & V. was based on a dried speci- men .51 m. long. The age and condition of the individ- ual most likely prevented the discovery of the small plates on the side of the occipital process, which therefore SOUTH AMERICAN NEMATOGNATHI. 401 appeared emarginate. Dr. Steindachner has identified horridus with this species. On page 286 Prof. Cope states that scopularius differs from his biseriatus in having the dorsal radii, 11, 12.1. The plate, however, shows the dorsal radii as 1, 7.1, and a comparison of Cope’s and Kner’s plates will convince any one of the identity of the two species. Dr. Steindachner separates his tenuicauda on account of the entire granulation of the snout. We have exam- ined a number of specimens which are undoubtedly identical with emarginatus which have the tip of the snout granular, and the type of emarginatus will most probably be found to have a granular snout. While this is usually a convenient character in separating species, it is not constant in emarginatus and plecostomus. We would include under emarginatus all those indi- viduals in which the tail is broad, flat below, margined on the sides by the posthumeral keel, and which have the peculiar arrangement of plates already described. Of how little value other characters are may be seen from the following comparisons: Two specimens of emarginatus, each .215 m. long, one a 6 from Fonteboa, the other a ? from Hyavary, differ considerably. MALE SPECIMEN. | Occipital ridge or keel prominent. Nuchal plates bicarinate. All the lateral plates keeled. Tail more slender than in@. Snout pointed, entirely granular. Pectoral spine reaching beyond | middle of base of ventrals. Much darker colored than the fe- male. 26 FEMALE SPECIMEN. Occipital keel or ridge almost obso- lete. | Nuchal plates not bicarinate. | Lateral plates on the abdominal portion without a trace of a keel, some of those on caudal portion slightly keeled. Snout more rounded, naked at tip. Pectoral spine not reaching base of ventrals; all the fins lower than intheé. Pectoral spine and out- er caudal rays bristly. 402 CALIFORNIA ACADEMY OF SCIENCES. Two specimens about .57 m. long from Manacapuru, ?,¢, have the tip of the snout granular; the occipital ridge more prominent in the male than in the female; the nuchal plates obtusely bicarinate in both, the lateral plates slightly more carinate in the male; the pectoral spine not reaching the ventrals in either; pectoral spine and outer caudal rays bristly in both, the bristles in the male being about twice as long as in the female. The male is much lighter colored than the female. Elongate, slender; head pointed; occipital with a nar- row keel. Blunt ridges from the anterior nares to the occiput. Superciliary margin raised; occipital mar- gined with several small nuchal plates, which, with age, become united with the occipital, making its posterior edge appear emarginate. Humeral ridge becoming strongest on the caudal por- tion of the body, margining the flat lower surface of the tail; other scutes more weakly or not at all keeled. A conspicuous plate before the anal fin. Tip of snout naked, rarely granular. Eye 4-53 in the snout, 7-93 in the head, 3-34 in the interorbital. Ventral surface, except a small space in front of the ventrals, entirely covered with small scales. Base of the dorsal fin less than its distance from the adipose fin. Outer caudal rays greatly produced, comparatively shorter in the adult and with numerous long bristles. Pectoral spines in the adult with similar but much longer bristles than those on the caudal fin. Straw color or ashy, roundish dark spots on the dorsal surface, smallest on the head, sometimes confluent into vermiculations, especially in the adult; fins all spotted or with irregular cross bars, the markings least distinct on the caudal; ventral surface usually plain. SOUTH AMERICAN NEMATOGNATHI. 403 Head 33-4. Lat. 1. 28-29. Fifty-four specimens. Cudajas; Santarem; Manacapuru; Tonantins; Obidos; Fonteboa; Tabatinga; Hyavary; Sao Paola; Goyaz; Teffé; Para; Ica; Tajapuru. One specimen, No. 7992, .88 m. long, from Gurupa and another specimen, No. 8021, the exact locality of which is not known, differ in having darker, more regu- lar round spots. All the marginal spines of the scutes are greatly exaggerated; the opercle and preopercle with a marginal series of movable but not truly erectile spines. 345. Plecostomus spinosissimus. Plecostomus spinosissimus Steindachner, Fisch-fauna des Cauca and Fliisse bei Guayaquil, 46, pl. v, fig. l-la, 1880 (Rivers near Guayaquil). Habitat: Western slope of Ecuador. 346. Plecostomus commersonii. Hypostomus commersonii Valenciennes, Voy. d’Orbigny ix, Atlas ii, pl. vii, fig. 2, 1847; Cuv. &. Val. xv, 495, 1840 (Rio San Fran- cisco; La Plata). Plecostomus commersonii Giinther, v, 232, 1864 (Rio Grande); Hen- sel, Wiegm. Arch. i, 73, 1870 (Porto Alegre; Guahyba); Stein- dachner, SB. Ak. Wien, Ixxiv, 1876; Siisswasserf. siidéstl. Bras. ili, 124 (La Plata; Rio San Francisco; Rio Jacuhy and Codea; Rio Parahyba; Rio Quenda near §. Cruz; Rio Grande); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 168, 1888 (Rio de Janeiro; Santa Cruz; Macacos; Itabapuana). Hypostomus punctatus Cuvier & Valenciennes, xv, 493, 1840 (Rio Janeiro); ? Schomburgk, Fish. Guiana, part i, 144, 1841 (Rio Branco). Hypostomus subcarinatus Castlenau, Anim. Amér. Sud, 42, pl. xxi, fig. i, 1855 (Rivers of the province of Mines). Plecostomus spiniger Hensel, Wiegm. Arch. 1870, i, 73 (Rio Cadea). Habitat: Southeastern Brazil; Rio Plata and its tributaries. Head pointed; an indistinct keel from the anterior nares to the occiput, a more prominent keel on the occi- pital bone; the occipital terminating in a triangular pro- cess and bordered behind by asingle large plate; nuchal plates bicarinate. Upper lateral scutes more or less 404 CALIFORNIA ACADEMY OF SCIENCES. strongly carinate; humeral keel strong, continued almost to the caudal fin, the keel indistinct on the caudal portion in the young. Tip of the snout naked. Eye 33-54 in the snout, 6-95 in the head, 23-34 in the interorbital. Belly entirely covered with small scales. Base of the dorsal fin little longer than its distance from the adipose fin; first ray of the dorsal much higher than the last ray, about equal to the length of the head. Outer caudal rays little produced, the shortest ray about 14 in the head. Sides, back and all the fins thickly covered with small roundish dark spots; those on the caudal as conspicuous as the spots on the dorsal fin; in one series between every two rays on the caudal, in 2-6 series on the dorsal; ven- tral surface plain in the adult. Lat. 1. 28-80. Head 34-33. Nineteen specimens .11-.87 m. Rio de Janeiro; Santa Cruz; Macacos; Itabapuana; Rio Parahyba. 346a. Plecostomus commersonii affinis. ? Plecostomus punctatus Giinther, v, 233, 1864 (South America); not H. punctatus C. & V. Plecostomus affinis Steindachner, Siisswasserfische Siidostl. Bras. ili, 127 (Rio Mucuri, near Santa Clara; Rio Parahyba; Muriahé; San Antonio, near San Antonio de Ferros). Plecostomus commersonii afinis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 168, 1888 (Mendez; Santa Clara; Minas Geraes; Rio Doce at Linhares; Mucuri, Janeiro; Parahyba; San Antonio). Habitat: Southeastern Brazil. This variety is much more common than commersonit from which it differs by the much larger spots. The keels of the head are almost obsolete in some of the specimens. We have examined over fifty specimens from .13—.26 m. long. Mendez; Santa Clara; Rio Mucuri; Rio de Janeiro; Rio Doce at Linhares; Rio Parahyba; Minas Geraes; San An- tonio River. SOUTH AMERICAN NEMATOGNATHI. 405 346b. Plecostomus commersonii scabriceps. Plecostomus commersonii scabriceps Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 168, 1888 (Sao Matheos). Three specimens .30-.35 m. from Sao Matheos. Large spots, the occipital process shorter than in com- mersonii; the pectoral spine in two specimens with cury- ed bristles near the tip, the lower portion of the head naked except a triangular area immediately in front of the gill-openings. 347. Plecostomus limosus. Plecostomus limosus Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 167 and 168, 1888 (Rio Grande do Sul). Allied to Plecostomus plecostomus Linneeus. All the scutes with a distinct median keel, the humeral keel being continued back. Occipital bone margined by a single large nuchal plate; occipital keel more blunt than in plecostomus. Tip of snout naked, the snout more rounded than in plecostomus. Interorbital 2 in the head to the end of the opercle. Eye 43-5 in the snout, 8-9 in the head, 3-384 in the interorbital. Outer caudal rays little produced, middle caudal rays much longer than in plecostomus, 14-14 in the head. Base of the dorsal fin equals its distance from the caudal, or a very little less. luat. 1. 28: Otherwise similar to Pl. plecostomus Linn. Types No. 7869. Four specimens .25 m. Rio Grande do Sul; from the Emperor’s collection. 348, Plecostomus carinatus. Plecostomus carinatus Steindachner, Flussfische Siidamerika’s, ii, 108, plate iv, fig. 2, 1881 (Jatuarana; Ueranduba and Lake Sa- raca). Habitat: Amazons. One specimen; Jutahy. 406 CALIFORNIA ACADEMY OF SCIENCES. Dr. Steindachner states that the museum at Cambridge has specimens of this species from the localities quoted. We have not been able to find them. The species is ev- idently closely related to Pl. plecostomus; all the speci- mens of Pl. plecostomus examined by us have 26 series of lateral scutes, while this possesses 30. 349, Plecostomus plecostomus, Acipenser plecostomus Linneus, ed. x, 238, 1857. Loricaria plecostomus Linneeus, ed. xii, 508, 1766 (America); Lin- neeus, ed. xili, 1863, 1788; Bloch, Ausland Fische, 8, pl. 374, 1794, ‘‘ Bloch & Schneider, Syst. {chthyol. 124, 1801; Hyrtle, Denk. Ak. Wien, xvi, 18, 1859 (vertebra 1+ 20). Hypostomus plecostomus Cuv. & Val. Hist. Nat. Poiss. xv, 489, 1840 (Maracaibo); Schomburgk, Fish. Guiana, part i, 139, 1841 (Rio Branco); Kner, Hypostomiden, 263 (Ypanema; Matogrosso; Barra do Rio Negro; Surinam). Plecostomus plecostomus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 168, 169, 1888 (Silva, Lake Saraca; Para; Hyavary; Coary; Rio Puty). Hypostomus guacari Lacépeéde, v, 145, 1803 (America). Loricaria flava Shaw, ‘‘ Zool. v, 38, pl. 101, 1805.” Plecostomus flavus Vaillant, Bull. Soc. Philom. series 7, iv, 155, 1880 (Calderon). Hypostomus verres Cuv. & Val. Hist. Nat. Poiss. xv, 365,°1840. Plecostomus bicirrhosus Gronow, ‘‘Cat. Fish. 158, 1854;” Giinther, Cat. Fish. Brit. Mus. vy, 231, 1864 (Guianas; Cayenne; Para); Kner & Steindachner, Abhandl. Bayr. Akad. Wiss. x, 1, 60, 1865; Hensel, Wiegm. Arch. 1870, i, 75 (Rio Cadeo); Steindachder, Flussfische Siidam. ii, 109, 1881. Plecostomus brasiliensis Bleeker, Silures de Suriname, 7, 1864 (Su- rinam). Habitat: Rio Puty; Amazons and northward. Head pointed, a strong keel on either side from nares to occiput; occipital bone with a strong keel; nuchal plates conspicuously bicarinate. Scutes of upper half of body more or less strongly keeled. , Humeral keel strong, extending backward not beyond the 8th scute; the lower two series of scutes without carination. Lower surface of the caudal portion of the body rounded simi- lar to the dorsal surface of the same region. A distinct SOUTH AMERICAN NEMATOGNATHI. 5 407 occipital process, the occipital bordered usually by a single plate behind. Tip of snout usually granular, sometimes with a tri- angular naked area. Eye 33-4; in the snout, 63-8 in the head, 3-33 in the interorbital. Belly entirely covered with minute scales. Base of dorsal fin equal to its distance from the adi- pose fin, or from the caudal; first rays of the dorsal much higher than the posterior, equal to the length of the head; or not much higher than the last rays. Outer caudal rays produced; shortest caudal rays 13 in the head or shorter. Color very light brown to nearly black, everywhere spotted with darker; the spots smallest on the head; spots on the belly sometimes scarcely larger than those on the head, sometimes 4—6 times as large. Head 3=34. , Lat. I. 26. Twenty-seven specimens. Silva, Lake Saraca; Para; Hyavary; Coary; Rio Puty; Surinam. 350. Plecostomus vaillanti. Plecostomus vaillanti Steindachner, Siisswasserfische siidéstl. Bras. iv, 9, 1877 (Rio Preto): Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 169, 1888 (Rio Puty; Rio Preto; San Goneallo.) Habitat: East Central Brazil. Head rounded in front, superciliary edge greatly raised, a prominent ridge from the nares to the eye, a less prominent one from the eye to the occiput; occipital strongly keeled, terminating in a broad, short, process; — margined by three nuchal plates. Upper lateral plates. scarcely keeled; humeral keel indistinctly evident on the caudal portion of the body. Tip of the snout granular. Eye 4—4? in the snout, 7-83 in the head, 2?-3 in the interorbital. Belly entirely covered with scales, except around the ventrals. 408 - CALIFORNIA ACADEMY OF SCIENCES. Base of the dorsal fin longer than its distance from the adipose fin. Caudal very obliquely emarginate, the shortest rays scarcely more than half as long as the head. Head with vermiculating light and dark lines, sides of the body with large spots forming about 5 series on the tail; all the fins with large spots; ventral surface with the spots coalescing. Lat. 1. 27-28. Head 23-3. Four specimens .15-.25m. Rio Puty; Rio Preto; San Goncallo. Several specimens from Goyaz resemble this species but they are so much damaged as to make it impossible to certainly identify them; these examples have the tip of the snout naked. 351. Plecostomus villarsi. Plecostomus villarsi Liitken, Overs. Dan. Selsk. 211, 1874, (Caracas); Steindachner, Fisch-fauna des Magd. Stromes, 26, pl. vii, 1878 (notes on the type). Habitat: Caracas. 352. Plecostomus virescens. Plecostomus virescens Cope, Proc. Acad. Nat. Sci. Philad. 137, 1874 (Upper Amazon); Cope, Proc. Am. Philos. Soc. xvii, 681, 1878 (Peruvian Amazon). Habitat: Maranon. We have been unable to assign this species to a place in the key. Head wide, depressed; body and tail rather elongate; an obtuse occipital and nuchal elevation; post and pre- orbital angles well marked. A few preopercular spines. Head below naked behind the mouth; teeth numerous, acutely incurved. Posterior lip entire, smooth. Eye 4 in head, 2 in interobital. Base of dorsal equals its dis- tance from the adipose plus one scutum. Pectoral spine reaching a little beyond base of ventral. Head4s: #D, 1, 7. A. 5. (Cope) SOUTH AMERICAN NEMATOGNATHI. 409 353. Plecostomus biseriatus. Plecostomus biseriatus Cope, Proc. Acad. Nat. Sci. Philad. 285, pl. 16, 1871 (Amazon). Habitat: Amazon. 354. Plecostomus seminudus. Plecostomus seminudus Higenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 169, 1888 (? Brazil). Habitat: Brazil. 355. Plecostomus anne. Plecostomus anne Steindachner, Flussfische Siidamerika’s ii, 112, pl. lii, fig. 2, 1881 (Para). Habitat: Para. 356. Plecostomus pantherinus. ' Hypostomus pantherinus Kner, Hypostomiden, 267, 1853 (Rio Gua- pore). Plecostomus pantherinus Giinther, Cat. Fish. Brit. Mus. vy, 231, 1864 (copied). Habitat: Rio Guaporé. 357. Plecostomus cordove. Plecostomus cordove Giinther, Ann. Nat. Hist. (5) vi, 11, 1880 (Cor- dova). Habitat: Central portion of the Argentine Republic. This species is known only from the types in the British Museum. 358. Plecostomus lima. Plecostomus dima (Reinhardt MS.) Liitken, Overs. Dan. Selsk. 1873, No. 3, 70 (Rio das Velhas); id. Velhas Flodens Fiske 141, 1875 (Rio das Velhas). Habitat: Rio San Francisco and its tributaries; Rio Grande do Sul. We have examined 5 specimens of this species .16-.40 m. Rio San Francisco; Rio das Velhas and Rio Grande do Sul. Body short and heavy, its depth 12 in its width. Head somewhat longer than broad, its upper surface flattish. None of the plates keeled; posthumeral ridge prominent on the anterior 5 scutes. Tail stout, compressed, flat on upper and lower surfaces. Breast and belly, except a narrow area around the ventrals, covered with large scutes. : 410 CALIFORNIA ACADEMY OF SCIENCES. Base of the dorsal fin much greater than its distance from the spine of the adipose fin, first dorsal ray con- siderably higher than the last, equal to or greater than the length of the head. Head 33. 358a. Plecostomus lima atropinnis var. nov. Type: No. 7871a, one specimen .21m. Goyaz. Sen- hor Honorio. 359, Plecostomus macrops. Plecostomus macrops Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. i, 170, 1888 (Rio das Velhas). This species differs from lima only in the characters in- dicated in the key. Type: No. 7888, one specimen .28m. Rio das Vel- has. Allen & St. John. 360. Plecostomus francisci. Plecostomus francisci Liitken, Overs. Dan. Selsk. No. 3, 30, 1873 (St. Francisco River); id. Velhas Flodens Fiske, 143, 1875 (Rio das Velhas). Habitat: Rio San Francisco and its tributaries. This species is known to us only from descriptions. 361. Plecostomus alatus, Hypostmous alatus Castelnau, Anim. Amérique du Sud. 41, plate xx, fig. 1, 1855 (Araguay). Plecostomus alatus Giinther, v, 234, 1864 (River Cipo); Liitken, Vel- has Flodens Fiske, 144, 1875 (Rio das Velhas). Habitat: Araguay; Rio das Velhas. This species is known to us only from descriptions. 362. Plecostomus auroguttatus. Hypostomus auroguttatus Kner, Hypostomiden, 269, pl. ii, fig. 3, 1853 (Rio Parahyba). Plecostomus auroguttatus Giinther, v, 234, 1864 (copied); Steindach- ner, Flussfische Siidam. iii, 6, 1881 (Rio Janeiro). Hypostomus asperatus Castelnau, Anim. Amér. Sud. 41, pl. 20, fig. 2. Habitat: Coast streams of Southeastern Brazil. This species is known to us only from descriptions. It seems to differ from all other known species in the width of its head. ; SOUTH AMERICAN NEMATOGNATHI. 411 363. Plecostomus liitkeni. Plecostomus lima Steindachner, SB. Ak. Wien, lxxiv, 1876, Siisswas- serfische siidéstlichen Brasiliens, iii, 121 (Rio Parahyba; Rio Mucuri; St. Antonio; Rio Quenda; Rio de Pedra) (not Liitken), Plecostomus liitkenit Steindachner, Siisswasserfische siidéstlichen Brasiliens, iv, 1877, 1 (Rio Parahyba; Rio Mucuri; Rio San An- tonio; Rio Quenda; Rio de Pedra). Habitat: Southeastern Brazil. Body very broad, depressed, the depth 13 in the width. Head flat above; sides of the snout deeply concave; oc- cipital rounded or obtusely pointed behind; superciliary edge not raised. Eye 33-4 in the snout, 53-7 in the head, 2-24 in the interorbital. Posthumeral keel not continued posterior to the origin of the ventrals. Lateral plates without a trace of a keel. Tip of the snout with a broad naked area; a large tri- angular patch of granules between rictus and gill-open- ing; usually a narrow strip between the pectoral spines granular, a few granules on sides of belly, the ventral surface otherwise naked. Last dorsal ray little more than half as long as the first. Upper portion of the head closely covered with brown spots, a few spots on the body; dorsal fin dusky or more often with large dark spots; caudal uniformly plain dusky; ventrals and pectorals spotted with dark; ventral surface plain; upper surface of the body sometimes with obscure light spots. Head 3-33; Lat. 1. 26-28. Twenty-five specimens .12-.30m. San Antonio River; Campos. 364, Plecostomus vermicularis. Plecostomus vermicularis Higenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 170, 171, 1888 (Rio Parahyba; Rio Janeiro; Mendez; Macacos; Goyaz). Habitat: Eastern Brazil. This species is closely related to Pl. litheni Steind. 412 CALIFORNIA ACADEMY OF SCIENCES. The ventral surface in the adult is almost entirely covered with granules, except a large naked area at base of ventrals; the anus is surrounded with granules. In the young, the belly is almost wholly naked, there being only a few granules in front of the anus, on the sides of the belly and on the throat. The spots on the head frequently coalesce into ver- miculations; all the fins are profusely spotted with dark, the spots on the dorsal, pectoral and ventral fins some- times coalescing into cross bars, those on the caudal forming regular transverse series. Dorsal surface of the body with obscure markings, ventral surface plain. Eye 3-4 in the snout, 54-8 in the head, 2-2? in the interorbital. Lat. 1. 26-27. Head 3-33. 365. Plecostomus brevicauda. Plecostomus brevicauda Giinther, v, 235, 1864 (Bahia). Habitat: Bahia. This species is known only from the types in the Brit- ish Museum. 366. Plecostomus robinii. Hypostomus robinii Cuy. & Val. Hist. Nat. Poiss. xv, 501, 1840 (Trinidad; La Plata); ?? Gill, Syn. Fish. Trinidad, W. I. 46, 1858 (Trinidad). Plecostomus robinii Giinther, v, 236, 1864 (Bahia) [not C. & V.]; Steindachner, SB. Ak. Wien, Ixxiv, 1876, Siisswasserfische Siid- dstlichen Brasiliens, iii, 118 (Rio Una near Bahia); Jordan, Proc. U.S. Nat. Mus. 1886, 560 (name only); Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. i, 170, 171, 1888 (Rio Una). Plecostomus une Steindachner, SB. Ak. Wien, 1878, lxxvii, 383. Habitat: La Plata to Trinidad. Head depressed; snout broad, rounded; interorbital slightly convex; no keels on the head. Occipital termin- ating in a short triangular process, bordered by a single large nuchal plate as in punctatus. Scutes not carinate. Humeral keel strong, disappearing between the fourth and sixth plates. Tip of snout naked. Eye 43 in the snout, 74 in the head, 23 in the interor- bital. SOUTH AMERICAN NEMATOGNATHI. 413 Belly mostly naked; sometimes a few minute rough scutes below the pectoral; a triangular patch of similar scutes between the gill-opening and the rictus, which is sometimes reduced to one or two scutes. Base of the dorsal fin longer than its distance from the adipose fin. Caudal fin slightly emarginate, the shortest ray being 12 in the head. Upper surface of the pectoral spine covered with re- curved bristles which are strongest and longest near the tip of the spine. Dorsal surface and sides thickly covered with dark roundish spots, the spots on the head smallest; ventral surface plain. A single series of spots between two dor- sal rays. Lat. 1. 26. Head 34-33. Two specimens .21 m. Rio Una. 367, Piecostomus wuchereri. Plecostomus wuchereri Giinther, v, 335, 1864 (Bahia). Habitat: Rio Mucuri to Bahia. This species is very closely related to Pl. robinii C. & V.; it differs in the markings of the fins, and the transverse profile of the head is less regularly convex; the ventral surface more granular. Head 34. Two specimens, .27-.25 m. Rio Pedra. 368. Plecostomus johnii. Plecostomus johnii Steindachner, SB, Ak. Wien, lxxiv, 1876, Siiss- wasserfische siidéstlichen Brasiliens, iii, 133 (Rio Puty; Rio Preto); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 170, 171, 1888 (Rio Preto; Rio Puty). Habitat: Rio Preto; Rio Puty. Head broad, rounded in front, snout not keeled, reg- ularly convex in transverse profile; superciliary edge raised. Eye 4 in the snout, 6} in the head, 2} in the interor- bital. 414 CALIFORNIA ACADEMY OF SCIENCES. Posthumeral keel not extending posterior to the ven- tral fins. Lateral plates not carinate. Last dorsal ray 13 in the first, which is much shorter than the head. Base of the dorsal fin equal to its dis- tance from the caudal fin. Pectoral fins extending little beyond origin of the ven- trals. Tip of snout with a small naked area. Region between the ventrals naked, except sometimes a narrow median bar; in front of this the ventral region is usually covered with granular plates, the granules on the sides of the belly largest. Caudal very obliquely emarginate. Color markings indistinct in the specimens examined, the spots on the caudal fin’sometimes forming vertical bars. Sixteen specimens, .125-.16 m. Rio Preto; Rio Puty. Types. LXXXIII. RHINELEPIS. Rhinelepis Spix, Gen. et Spec. Pisc. Bras. 4, pl. 2, 1829 (aspera ). Type: Rhinelepis aspera Spix. The larger species of this genus resemble the broad, flat-headed species of Plecostomus from which they dif- fer in the absence of the adipose fin. A. carinatus re- sembles more the species of Hisonotus, Otocinclus and Microlepidogaster. Habitat: Parahyba; Rio San Francisco; Rio Car- andahy; Amazons from Manacapuru to Huallaga. ANALYSIS OF THE SPECIES OF RHINELEPIS. a. Ventral surface mostly naked. b. Lateral plates not keeled, head not crested. parahybe 369. bb. Lateral plates all keeled; occipital with three crests. lophophanes 370. SOUTH AMERICAN NEMATOGNATHI. 415 aa. Ventral surface entirely granular. c. Eye 6-64 in the head to end of occipital plate; head arched above; opercle,jand interopercle with spiny margins; lateral plates keeled, sur- faces of all the plates entirely covered with prominent spiniferous ridges; a series of large plates along the lateral surface of the belly. Lat. 1. 22-25. agassizii 371. ec. Eye small, 10 or more in the head; head flattish above; lateral plates not keeled. aspera 372. 369. Rhinelepis parahybe. Rhinelepis parahybe Steindachner, Susswasserfische siidéstl. Bras. iv, 2, pl. 2 (Parahyba); Eigenm. & Higenm. Proc. Cal. Acad. 2d Ser. 11, 42, 1889 (Rio Parahyba, at Barra do Pirahy). Habitat: Rio Parahyba. Elongate, depressed, the depth 13 in the width. Head broad, depressed; its width equals its length to the upper angle of the gill-openings; occipital slightly raised in the middle, terminating in a triangular pro- cess which is bordered by 3 nuchal plates; interorbital concave. Snout broad, depressed, its tip naked. Orbit 4 in the snout, 74-7 in the head, 3-2? in the interorbital. A tew granules between the pectoral spines, an elon- gate patch along sides of belly, a few granules between the posterior margins of the ventrals, others in front of the vent; the ventral surface otherwise naked. Lateral plates not keeled, thickly covered with minute spines. Base of the dorsal fin equal to its distance from the first unpaired plate in front of the caudal fin. Caudal truncate, the outermost rays prolonged. Pectoral spine reaching base of ventral, the ventral to vent. Uniform dark bronze brown, lighter below. Headias Dl iseA G6 Vel. bebe 6: “lat. a2 b—26: Four specimens .29-.30 m. Rio Parahyba at Barra do Pirahy. Hartt & Copeland. Thayer Expedition. 416 CALIFORNIA ACADEMY OF SCIENCES. 370. Rhinelepis lophophanes. Rhinelepis lophophanes Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. li, 42, 1889 (Santa Cruz). Type: No. 8164; one specimen .018 to base of caudal. Santa Cruz. Dom Pedro II. Body short and deep, the greatest depth equal to the greatest width. Head short scarcely wider than high, its depth 1? in its length. Occipital with three strongly spiniferous ridges, the median one highest, short, term- inating suddenly with occipital. The two other crests extending from above the posterior margin of the eye to the margin of the occipital; other crests extending from the orbit back to the edge of the temporal plate. Nasal pits large, margined by spiniferous ridges; two diverging series of spines extending from between the nares to the margin of the snout. Loreal region concave. Lower surface of head naked, the naked portion bordered by a series of strong recurved spines. Eye small, slightly in front of the middle of the head. Coracoid and scapula granular; belly with a small granular plate between the posterior margin of the ven- trals and a larger plate behind the pectorals, otherwise naked; lateral and dorsal plates with a conspicuous me- dian keel. Dorsal inserted slightly behind origin of ventrals, considerably nearer tip of snout than base of caudal; ori- gin of ventrals equidistant from gill-opening and origin of anal. Traces of a dusky lateral band which is continued on the middle caudal rays. Dee | Asdbse slat: a2: 371. Rhinelepis agassizii. Rhinelepis agassizii Steindachner, Siisswasserfische Siiddstl. Bras. iv, 12, 1877 (Lake Manacapuru); id. Flussfische Siidam. iv, 7, 1882 (Rio Huallaga); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 11, 42, 1889. Habitat: Manacapuru; Rio Huallaga. One specimen .12 m. to base of caudal. Manacapuru. SOUTH AMERICAN NEMATOGNATHI. 417 372, Rhinelepis aspera. Rhinelepis aspera Spix, Gen. et Spec. Pisc. Bras. 4, pl. 2, 1829; Cuv. & Val. xv, 483, 1840 (Rio San Francisco); Schomburgk, Fish. Brit. Guiana, part i, 136, 1841; Giinther, v, 253, 1864 (copied); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 11, 42, 1889. ? Rinelepis strigosa Cuy. & Val. xy, 480 (Parana); Schomburgk, Fish. Brit. Guiana, part i, 135, 1841. Habitat: Rio San Francisco; ? Parana; ? Guiana. LXXXIV. HEMIANCISTRUS. Hemiancistrus Bleeker, Tijdschr. Dierk. 1, 78, 1863 (medians). >Pseudacanthicus Bleeker, 1. ¢. 79 (serratus). Chetostomus Kner. 1. ¢. 442 CALIFORNIA ACADEMY OF SCIENCES. —Chetostomus Bleeker, Nederl. Tijdschr. Dierkunde, 1, 1863, 78 (loborhynchus). ) SOUTH AMERICAN NEMATOGNATHI. 463 450. Dianema longibarbis. Dianema longibar bis Cope, |. ¢, 276, pl. vii, fig. 1-1b (Ambyiacu River). Head depressed, abruptly narrowed in front of the na- res; maxillary barbels not reaching the opercular mar- gin. Pectoral spine serrate within, dorsal spine acute, not serrate. Eye 3? in the head; 23 in the interorbital. Yellowish-brown, fins unspotted. Head a2-depthoss (Dati A, (3. Voc; I 6; Tat: APTA 3 < i ‘ > pl. $3; azygous plates 4. (Cope.) C. - BROcHIS. Brochis Cope, Proc. Acad. Nat. Sei. Phila. 1871, 277 (ceruleus). Chenothorax Cope, Proc. Am. Philos. Soc. 1878, 679 (bicarinatus ). Type: Brochis ceruleus Cope. Habitat: Marafion and tributaries. This genus differs from Corydoras in the number of dorsal rays. The degree of development of the coracoid process in this .case cannot be regarded of generic value. The coracoid processes in all the species of this group are exposed; in some (Brochis) they cover the en- tire breast and belly, while in others (Chenothoraxz) they cover them only partially. This character varies with the sex in some species of Corydoras, and varies still more in Hoplosternum thoracatum. ANALYSIS OF THE SPECIES OF BROCHIS. a. A series of plates between the ventrals and anal, another along the sides of the dorsal. Cheeks and snout entirely mailed. Two rictal barbels. D.I, 11. (Castelnau.) (Sub gen. nov. ?) taiosh 451. aa. Lower lateral plates meeting along the median line of the ventral sur- face. b. Two rictal barbels; coracoid processes extending to the ventrals, di- verging behind, leaving anaked area between them. D. I, 11. (CH NOTHORAX.) c. Eye more than 4 in the head, 2 in the snout, 2 in the interorbital. Two azygous bones between the occipital crest and the dorsal 464 CALIFORNIA ACADEMY OF SCIENCES. spine. Coracoid plates projecting downward to form an obtuse keel on each side of the belly. Lower lip with a short barbel on each side. Facial ossification extending one-third the distance to the maxillary. (Cope.) bicarinatus 452. cc. Eye 3} in the head, 12 in the snout and interorbital space. Cora- coid processes wide, with convex inner margins, the surface striate. Inferior lp beaded on margin, which easily separates, forming a loop; no median barbel visible. Preorbital bone and shield single, extending half way from orbit to maxillary. (Cope.) semiscutatus 453. bb. A single rictal barbel; two barbels near the symphysis which pass outward and connect with the maxillary barbels for a short distance. Coracoid process covering the entire breast and belly. D.I, 10 or1l. (BRocHIs.) d. Dorsal I, 10; adipose fin with a membrane; two median barbels on thelower lip. (Cope.) dipterus 454. dd. Dorsal I, 11; adipose fin without a membrane. Short, stout, elevated and compressed; profile convex over the orbits, concave above and belowjthem; maxillary jbarbels extending to below the middle of the eye. Eye 4 in the head, more than 2 in the snout. Head 3; depth about 24; A. 8; V. 6; P. I, 9. (Cope.) ceruleus 455. 451. Brochis taiosh. Callichthys taiosh Castelnau, Anim. de VAmér. du Sud. pl. 19, wee AL Brochis taiosh Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 165, 1888 (name only). This species is known only from a drawing; no type is preserved. 452. Brochis bicarinatus. Chenothorax bicarinatus Cope, Proc. Am. Philos. Soc. 1878, 679 (Peruvian Amazon). Brochis bicarinatus Kigenm. & Eigenm. 1. ¢. (name only). This species is known only from Dr. Cope’s descrip- tion. 453. Brochis semiscutatus. Corydoras semiscutatus Cope, Proc. Acad. Nat. Sci. Philad. 1871, 280, pl. 6, fig. 1 (Ambyiacu River). Brochis semiscutatus Eigenm, & Eigenm. 1. c. (name only). 454, Brochis dipterus. Brochis dipterus Cope, 1. ¢. 1871, 278 (Ambyiacu River). 455. Brochis coeruleus. Brochis cweruleus Cope, 1. ¢. 277, pl. vii, fig. 2, and pl. ix, fig. 3 (Ambyiacu River). eo SOUTH AMERICAN NEMATOGNATHI. 465 CI. CorRryYDORAS. Corydoras Lacépede, Hist. Nat. Poiss. v, 145, 1803 (geoffroy= punctatus). Hoplisoma Swainson, Fishes, Amph. & Reptiles, ii 304, 1839 (punctata). Hoplosoma Gill, Syn. Fish. Trinidad, 42, 1858 (pwne- tata). Gasterodermus Cope, Proc. Am. Philos. Soc. 1878, 681 (type ?). Type: Corydoras geoffroy Lacépede. Dr. Cope proposes the name (asterodermus for those species of the group having the belly covered with skin. As punctatus, the type of Corydoras, has the belly covered with skin the genus G'asterodermus could not be admitted even if the greater or less expansion of the coracoid pro- cess were of generic value. ? ANALYSIS OF THE SPECIES OF CORYDORAS. a. Coracoid processes meeting on the median line of the anterior portion of the belly at least. 6. A dark brown lateral band extending from the occiput backwards on the upper half of the body; ventral surface and a broad vertical band behind the eye light; caudal without bars. eques 456. 6b. Greenish, fins and top of head brown; a dark-brown band on the cau- dal. D.I, 9; Lat. pl. 24. (Castelnau.) splendens 457. aa. Coracoid processes nowhere meeting; breast and belly with a median naked area. c. Caudal fin plain. d. Body with one or more dusky longitudinal bands; dorsal fin usually spotted. e. Coracoid processes moderately expanded, leaving only a narrow, naked area between them; occipital process triangular, pointed at the tip; a dark band extending from the upper caudal lobe forward, one or more longitudinal series of dark spots along the sides. elegans 458. ee. Coracoid process scarcely encroaching on the breast or belly; occipital process truncate, about twice as wide at the base as at the tip; a blackish lateral band extending'from the middle caudal rays forward; no spots on the sides. nattereri 459. 30 466 CALIFORNIA ACADEMY OF SCIENCES. dd. Body without longitudinal bands; dorsal plain. D. I, 7; A. I, 6; 128 1 Wty Wa Bs J. Head and dorsal plates deep bronze; ventral plates yellowish; all the fins immaculate, opercle, humeral and nuchal plates irrides- cent blue; base of the dorsal fin shorter than the distance between the dorsal and adipose; depth less than } of the total length; eye 44 in the head, more than two in the interorbital. (Gill.) eneus 460. Jf. Olive, the nine or ten anterior scutes with vertical series of blackish spots; base of the dorsal fin equal to the space between the dorsal and adipose fins; depth 3} in the total length; eye about 3 in the head; spines of the fins very strong and long, dor- sal spine as high as the body, pectoral spine shorter; 4-5 azygous shields. (Giinther.) armatus 461. ec. Caudal fin with 4-5 dark vertical bars; dorsal with dark markings. g- Dorsal fin with 2 irregular cross bars; sides of the body with series of dark blotches; middle of the lower fins blackish. paleatus 462. gg. A dark vertical bar on the first dorsal rays sometimes extending on to the body below; anal fin barred or spotted; ventrals and pec- torals plain. punctatus 463. ggg. Dorsal with a black spot on ends of rays. h. Anal spotted; dark brown above, 3 series of dark spots along middle of side. trilineatus 464. Ah. Anal plain. i. Lat. pl. 27; azygous plates none; a pale band on side; clavicle and opercle with blue reflections. (Cope.) acutus 465. az. Lat. pl. #4; azygous plates 4; numerous black dots on the side shields, which are wanting on middle line of side; a black spot at the base of the dorsal spine. (Cope.) amphibelus 466. ecc. A hastate black spot at base of caudal fin, margined behind by white; a black lateral band. hastatus 467. 456. Corydoras eques. Corydoras eques Steindachner, Ichthyol. Beitr. v, 92, pl. 12, figs 3-3a, 1876 (Teffé; Cudajas). Habitat: Solimoens. Form heavy forward, decreasing backward; at the dorsal spine high, compressed, the width about 14 in the greatest depth; the caudal peduncle much compressed, its depth less than half the depth at the dorsal spine. Head short and very deep, the width nearly equal to its length, the profile convex and steep, especially steep from above the eyes forward; transverse profile strongly SOUTH AMERICAN NEMATOGNATHI. 467 arched posteriorly. Occipital process acute, somewhat attenuate, meeting the dorsal plate; the apex of the oc- cipital process usually narrowly truncate, its margins deeply concave, leaving a more convex and larger nu- chal plate on either side than in C. elegans. Fontanel a short groove between the frontals and the anterior part of the occipital bone; usually shorter than the orbit in the é, about equal to the orbit in the ? , the bones nearly grown together, leaving a short, very narrow slit. Sub- orbital bone nearly smooth, very broad, exceeding the orbital diameter; head everywhere mailed except at tip of snout. Inner rictal barbels extending backward about to pos- terior rim of orbit; lower lp free, and with a pair of barbels two-thirds as long as the orbit. Hye lateral, circular, 1} in the snout, 33 in the head, 2 in the interorbital. Mouth inferior, very small, the intermaxillaries vesti- giary. Lateral scutes overlapping on the back behind the dor- sal fin, 3-4 azygous plates before the adipose fin. Coracoid processes meeting evenly for their anterior half, diverging backward. Distance of the dorsal spine from the snout 2-24 in the length; the spine not flattened, smooth in front, mi- nutely serrate behind, higher than the rays, 1-1} in the head, the rays decreasing backward to the last, which is 2-23 in the spine. Spine of the adipose fin hispid on its basal ar eae like the dorsal plates which precede it. Caudal forked, about 2? in the length. Anal rounded, higher than long, the first ray flattened spine-like. Ventrals 13-13 in the head, the outer ray stiffened and bristly. 468 CALIFORNIA ACADEMY OF SCIENCES. Pectoral spine smooth on its outer margin and sides, with short blunt teeth onthe center of its inner edge, sometimes obsolete or sometimes fine, pointed teeth to- ward the tip; pectoral spine longer than the dorsal spine, about 3 in the length. Sides dark brown to the humeral process, this color becoming almost black where it meets across the occi- pital process forming an acute angle on the posterior portion of the occipital bone; the dorsal plate and thence a narrow area backward to the caudal fin light brown; a yellow band meets across the fontanel, broadening as it extends downward across the humeral process whence it merges into the light ventral color; interorbital, cheeks and snout punctate with brown, sometimes forming a somewhat darker streak through cheeks and eyes; ven- trals yellow; other fins more or less punctate with brown. The ? differs in having the suborbital bone much nar- rower, less than the orbital diam. leaving a naked area. below, the tip of the snout more pointed, the dorsal and pectoral spines shorter, the coracoid processes meeting evenly throughout most of their length. The color like- wise differs; the dark brown lateral band being much narrower, not extending to the lateral line, leaving the lower series of scutes wholly light colored. Head 33-37; depth 23-3; D.I,8; A.1I,7; V.1,5. Lat. pl tags ~ Fourteen specimens. Cudajas; Thayer & Bourget. 457. Corydoras splendens. Callichthys splendens Castelnau, Anim. del’Amér. du Sud, 39, pl. 18, fig. 3 (Rio Tocantins). Corydoras splendens Eigenm. & EKigenm. Proc. Cal. Acad. 2d Ser. i, 165, 1888 (name only). Habitat: Rio Tocantins. This species is known only from the description and figure of Castelnau. SOUTH AMERICAN NEMATOGNATHI. 469 458. Corydoras elegans. Corydoras elegans Steindachner, SB. Ak. Wien, lxxiv, 1876, Ichthyol. Beitrage, v, 93 (Cudajas; Teffé). Habitat: Cudajas to Teffé. Snout compressed; head as deep as long, its width 1} in its length; profile steep, little arched except at the snout; fontanel long, linear, extending some distance into the occipital bone; occipital process broad at the base, tapering to a point, its margins straight. Top of the head with numerous mucous pores. Hye large, 13 in the snout, 3} in the head, 2 in the interorbital. Snout acute; mouth small, premaxillaries expanded, covering the mouth when closed. Inner rictal barbel reaching about to the gill-openings; lower lip broad, free, terminating in two barbels. Two or three azygous plates before the adipose fin. First plate of the lower series expanded below, with the coracoid process encroaching upon the breast and belly, leaving a rather narrow naked interspace. Distance of the dorsal spine from the snout 2 in the length; the spine shorter than the head, roughened on its outer margin, and near the tip on its inner margin, dorsal rays higher than the spine, when depressed al- most reaching the adipose fin. Caudal deeply forked, 23 in the length. Pectoral spine longer than the dorsal spine, reaching to or past base of ventrals, its inner margin serrate, its outer margin bristly. Light brown; median line of the back darker brown, sometimes wanting, a broader band of dark extends from the upper caudal lobe forward, broadening anteriorly; two or three series of dark spots form lines near the lat- eral line; these series sometimes more or less indistinct; caudal and lower fins plain yellowish; dorsal fin very variable, sometimes plain light, sometimes with its base A70 CALIFORNIA ACADEMY OF SCIENCES. dark and a large dark spot anteriorly, again with four dark brown cross-bars alternating with transparent. Head 34-4; depth 2?; D. I, 7-8; A.1,7; V. 6; P. I, 6-7. Lat. pl. $2. Five hundred and thirty-four specimens. Cudajas. 459. Corydoras natterer1. Corydoras nattereri Steindachner, Ichthyol. Beitrige, yv, 95. pl, xi, figs. 1-lb (Rio Janeiro); Kigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 165, 1888 (Rios Doce and Parahyba). Habitat: Rio Janeiro to the Rio Doce. Short and deep, rapidly tapering to the caudal pedun- cle. Head as deep as long, its width little less than its length; profile evenly arched; fontanel’ small, between the occipital and frontal bones; opercles and suborbitals exposed; width of the occipital 1} in its length to tip of occipital process; occipital process about twice as wide at base as at tip. Eye 13 in the snout, 4 in the head, 2 in the inter- orbital. Snout rather blunt; rictal barbels scarcely reaching the gill-openings. Lower lip broad, free, terminating in a pair of rather long barbels. Coracoid processes scarcely encroaching on breast and belly. Three or four azygous plates before the adipose fin. Distance of the dorsal spine from the snout 2 in the length; the spine 14 in the head, smooth in front, slightly roughened behind; first ray higher than the spine. Caudal deeply forked, 23 in the length. Pectoral spine similar to the dorsal spine, somewhat longer, its inner margin strongly serrate. Light brown, a blackish lateral band; a dusky spot at base of dorsal spine; anterior dorsal ray dusky; other fins plain. SOUTH AMERICAN NEMATOGNATHI. 471 ; depth 24-22; D. I, 7-8; A. 7; V.6; P.1j8. 3 Head 33 Lat. pl. 32 Three specimens .05 m. Rio Doce; Rio Parahyba. Thayer Expedition. 460. Corydoras eneus. Hoplosoma eneum Gill, Syn. Fish. Trinidad, 43, 1858 (Trinidad, Wice le) i Callichthys eneus Giinther, v, 230, 1864 (copied). Corydoras eneus Jordan, Proc. U. 8. Nat. Mus. 1886, 560 (name only). Habitat: Trinidad. This species is known only from the types. 461. Corydoras armatus. Callichthys armatus Giinther, Proc. Zool. Soc. Lond. 1868, 230, fig. 1 (Xeberos and Huallaga). Gasterodermus armatus Cope, Proc. Amer. Philos. Soc. xvii, 681, 1878 (Nauta). Corydoras armatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 166, 1888 (name only). Habitat: Maranon and its tributaries. 462. Corydoras paleatus. Callichtys punctatus (not of Bloch), Valenciennes, Voy. d’Orbigny, ix, Atlas ii, pl. v, fig.1, 1847; Cuv. & Val. xv, 318, 1840 (? Suri- nam ; Monte Video). Callichthys paleatus Jenyns, Voy. Beagle, iv, 113, 1842 (loc. ?); Giinther, v, 230, 1864 (copied); Hensel, Wiegm. Arch. 1870, i, 71 (Porto Alegre). Corydoras paleatus Higenm. & Eigenm. 1. c. (Uraguay). Corydoras marmoratus Steindachner, Denk. Ak. Wien, 1879, 26, pl. v, fig. 1 (La Plata). Habitat: La Plata and tributaries. As the description of paleatus exactly describes Stein- dachner’s plate of marmoratus and our specimens, we have identified marmoratus with paleatus. Body short, chubby; ventral outline almost straight; profile steep, evenly arched; occipital tapering into a pen-shaped occipital process; fontanel elongate. Hye 13 in the snout, 33 in the head, 13 in the interor- bital. Snout acute. Rictal barbels not extending be- 472 CALIFORNIA ACADEMY OF SCIENCES. yond the eye; lower lp ending in two small barbels. Breast and belly entirely covered with skin. Dorsal fin when depressed reaching the adipose fin. A rather broad naked area between the dorsal and adi- pose fins. Brown; a series of large dark spots along the sides, with a corresponding series of smaller spots on the back and below; center of the lower fins blackish; caudal and dorsal fins marbled with dark. Head 3; depth 25; D: 1, 7; A..7; hat: pl: 42. Three specimens .02 m. Uraguay. Professor Wyman. 463. Corydoras punctatus. Cataphractus punctatus Bloch, pl. 377, fig. 2; Bloch & Schneider, “Syst. Ichthyol. 108,” 1801; Lacépéde, Hist. Nat. Poiss. v, 125, 1803 (Surinam). Hoplisoma punctata Swainson, Nat. Hist. Fish. ete. ii, 304, 1839 (name only). Callichthys punctatus Giinther, Cat. Fish. Brit. Mus. v, 329, 1864 (Essequibo). Corydas punctatus EKigenm. & EHigenm. Proc. Cal. Acad. 2d Ser. i, 166, 1888 (José Fernandez). Corydoras geoffroy Lacépede, Hist. Nat. Poiss. vy, 147, 1803 (loc. ?). Corydoras ambiacus Cope, Proc. Acad. Nat. Sci. Philad. 1871, 280 (Ambyiacu River). Gasterodermus ambiacus Cope, Proc. Am. Philos. Soe. xvii, 1878, 681 (Nauta). Habitat: Guiana; Solimoens and Maranon. Corydoras ambiacus Cope, is probably the male of punc- tatus. The description of that species agrees with the de- scription given by Gunther and with our specimens. Short and deep; head as deep as long; profile very steep, rounded above and in front of the eyes; fontanel elongate, extending into the occipital bone; the width of the occipital equals its length to the tip of the process, its margins regularly concave. A conspicuous mucous canal extends from the anterior nares back and down behind the eye. Kye large, 1} in the snout, 33 in the head, 13 in the SOUTH AMERICAN NEMATOGNATHI. 473 interorbital. Snout compressed, pointed; preorbitals very narrow, rictal barbels extending about to the gill-open- ing, the outer one brown, the inner white; lower lip broad, free, terminating in two barbels; upper surface of the maxillary bones with fine bristles. Coracoid process scarcly encroaching on the breast or belly. Two or three azygous plates in front of the adipose fin. Distance of the dorsal spine from the snout 2 in the length; dorsal spine little if any shorter than the head, its anterior margin smooth, its posterior margin finely serrate; first two dorsal rays higher than the spine. Caudal deeply forked, 2} in the length. Pectoral spine similar to and little longer than the dor- sal spine. Light brown, sides and back with blackish-brown spots; a dark vertical bar below the eyes; occiput blackish; a dark brown vertical bar on the first two dorsal rays, sometimes continued on the sides, the remainder of the fin plain or spotted with dark brown; caudal with 4-5 dark brown cross-bars; anal barred or spotted with brown; other fins plain; opercle and humeral process with silvery reflections. Head: 32; depth: 22-3) Ds Dl, 8 UA. 83° Ve GP. 1 29: lat. pl. $5°33. Six specimens .045-.05 m. José Fernandez. Maj. Coutinho. 464, Corydoras trilineatus. Corydoras trilineatus Cope, Proc. Acad. Nat. Sci. Phila. 1871, 281, pl. 6, fig. 2 (Ambyiacu). Corydoras agassizii Steindachner, Ichthyol. Beitr. v, 90 and 186, pl. 12, figs. 2-20 (Tabatinga). Habitat: Maranon and its tributaries. Dr. Cope’s figure represents an individual .049 m. long; it has the snout blunt and eye large. Dr. Stein- dachner figured an individual .07 m. long, which has a longer snout and smaller eye, but on page 186, |. c., Dr. 474 CALIFORNIA ACADEMY OF SCIENCES. Steindachner states that in younger individuals the snout is strongly curved and steep. These two figures un- doubtedly refer to the same species. 465. Corydoras acutus. Corydoras acutus Cope, l. c. (Ambyiacu River). Habitat: Ambyiacu River. 466. Corydoras amphibelus. Corydoras amphibelus Cope, Proc. Acad. Nat. Sci. Phila. 1871, 282 (Ambyiacu River). Habitat: Ambyiacu River. 467. Corydoras hastatus. Corydoras hastatus Kigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. i, 166, 1888 (Villa Bella). Habitat: Villa Bella. Compressed, comparatively slender. Head as deep as long, its width 13 in its length; profile straight, steep; occipital process triangular; fontanel elongate, extending into the occipital bone; preorbital small. Eye large, 1} in the snout, 3} in the head, 2 in the interorbital. Snout little decurved; rictal barbels not extending beyond the eye; lower lip terminating in two barbels. Coracoid processes striate, forming a ridge on the sides of the belly. Distance of the dorsal spine from the snout 2 in the length; the dorsal spine little shorter than the head. Caudal deeply forked, 2? in the length. Pectoral spine little longer than the dorsal spine, weakly serrate along both margins. Light brown; a jet black lateral band terminating at the base of the caudal in a large arrow-shaped spot which is bordered posteriorly with white, which itself is nar- rowly margined with blackish, the caudal dusky beyond; a jet black line extends on either side from a short dis- tance behind the ventrals to behind the anal fin; body and fins everywhere covered with minute black points. Head 33; depth 2?; D. I, 7-8; A. 7-8; Lat. pl. $3. Two specimens .022 m. Villa Bella. Prof. L. Agassiz. LIST OF CENTRAL AMERICAN AND MEXICAN NEMATOGNATHI. AmiuRus Rafinesque. Amiurus dugesi Bean—Rio Turbio; Guanajuato, Mexico, west of the Sierra Madre. Proc. U.S. Nat. Mus. 1879, 304. IcraLuRuS Rafinesque. Ictalurus meridionalis (Giinther)—Rio Usumacinta, Guatemala. Cat. Fish. Brit. Mus. vy, 102, 1864. RHAMDELLA EK. & E. Rhamdella parryi E. & E.—Rio Zanaleneo near Tonala, Chiapas, Mex- ico. Proc. Cal. Acad. Sci. 2d Ser. i, 130. Rhamdella petenensis (Ginther)—Lake Peten; Chiapas, Mexico. 1. c. 1265 Rhamdella brachyptera (Cope)—Mexico. Trans. Am. Philos. Soe. xiii, 404. Rhamdella baronis miilleri (Troscbel )—Pacifie coast of Mexico. Mil- ler, Wierbelth. Mex. 102, 1865. tf Rhamdella guatemalensis (Giuther) —Huamuchal; Guatemala; Nicara. gua. l.c. 122. Rhamdella salvini (Giinther)—Rio San Geronimo, Guatemala. 1. c. 130. Rhamdella polycaulus (Giinther)—Rio San Geronimo. 1. c. 131. Rhamdella managuensis (Ginther)—Lake Managua. Fish. Central America, 393 and 476, 1866. Rhamdella hypselurus (Giinther)—Mexico. Cat. Fish. Brit. Mus. v, 126. Rhamdella motaguensis (Giinther)—Rio Motagua. 1. ¢. 127. Rhamdella laticauda (Heckel)—Mexico. Giinther, 1. c. 127. Rhamdella nicaraguensis (Giinther)—Lake Nicaragua. 1. c. 125, Rhamdella micropterus (Giiather)—Rio San Geronimo. 1. ¢. 124. Rhamdella godmanni (Giinther)—Lower Vera Paz; Rio Motagua; Mex- ico. 1 ec. 124. * The difference between Rhamdia and Rhamdella lies in the fontanels. In Rhamdia there is a frontal fontanel only, in Rhamdelia both frontal and occipital fontanels are present. Only the above two species of those inhabiting this region have been examined in this respect. It is doubtful therefore whether the following ones should be placed in one genus or the other. } We have not seen this paper and know nothing of this fish. 476 CALIFORNIA ACADEMY OF SCIENCES. BIBLIOGRAPHY OF SOUTH AMERICAN FRESH-WATER FISHES. The following list of papers was not compiled till after we had removed from the vicinity of all large libraries. For this reason and because some papers we have never seen, the titles of several works are not as complete as they should be. It is hoped, however, that this catalogue of works will serve the purpose for which it was intended. AGassiZ, L., ’29, Selecta Genera et Species Piscium, qua in itinere per Brasiliam collegit J. B. de Spix. 1829. AGASSIZ, PROFESSOR AND Mrs. Louis. A Journey in Brazil. Boston, 1868. Tichnor & Fields. ArRTEDI, P., ’38. Bibliotheca Ichthyologica; Philosophia Ichthyologica; Genera Piscium; Synonymia Piscium; Descriptiones Specierum Piscium. 1738. Barrp & GIRARD, 754, in Proc. Acad. Nat. Sci. Philadelphia, 1854. Bason, 1777, Mem. pour servir a Vhist. de Cayenne. BENN, ’30, in Proc. Comm. Zool. Soe. i. Biscuorr, “40, Lepidosiren paradoxa, Ann. Sc. Nat. xiv, 1840, pp. 116-159. BLEEKER, P., 58. Ichthyologiw Archipel. Indici Prodromus i, Siluroidei. 1858. 62. Descriptions de quelques espéces nouvelles de Silures. Versl. en Mededeel. Akad. Wet. Amsterdam, xiv. 1862. 63. Conspectus Generum Doradinorum. Nederlandsch Tijdsch- rift voor de Dierkunde. Amsterdam, vol. i, 1863. 63a. Systema Silurorum Revisum. l.c. 64. Description des espéces de Silures de Suriname conseryées aux Musées de Leide et d’Amsterdam. 1864. 66. Description d’une espéce inédite de Stolephorus de Surinam. Nederl. Tijdschr. Dierk. iii. 1866. Biocu, M. E., Auslandische Fische. Berlin, 1785-95. 1801. Systema Ichthyologiw, ed. Schneider. Bocourt, 68. Note sur les Poissons de Genre Tetragonopterus, Mexi- que et Guatemala. Ann. Sci. Nat. ix, 1868. BoNNATERRE, 1788. Tableau Encyclopédique et Méthodique des Trois Régnes de la Nature. Ichthyologie. Bou.encer, G. A., °87. Description of new South American Characinoid Fishes. Ann. and Mag. Nat. Hist. xix, 1887, pp. 172-174. 87a. An account of the Fishes collected by Mr. C. Buckley in East Ecuador. Proc. Zoél. Soc. London, 1887, pp. 274-283. 89. Description of a new Snake and two new Fishes obtained by Dr. H. von Ihering in Brazil. Annals & Mag. Nat. Hist. Oct. 1889. BRADLEY, 738. In Charlesworth’s Mag. Nat. Hist. ii, 1838. Bryant, 1786. In Trans. Am. Philos. Soc. BuRMEISTER, 68. In Anal. Mus. Buenos Ayres, pt.5. 1868. CANESTRINI, ’64,in Arch. Zool. Anat. e Fisiol. ii, 1864. BIBLIOGRAPHY. AT7 CASTELNAU, FRANCOIS DE, 55. Animaux nouveaux ou rares, recueillis pen- dant l’expédition dans les parties centrales de Amérique du Sud. Poissons. 1855. Corr, E. D., 67, in Trans. Am. Philos. Soc., xiii, 404, 1867. 70. Contribution to the Ichthyology of the Marafion. Proc. Amer. Philos. Soc., 1870, pp, 559-570. ‘71. Observations on theSystematic Relations of the Fishes. Proc. American Association Ady. Science, xx, 1871. 72. On the Fishes of the Ambyiacu River. Proc. Acad. Nat. Sci. Philad., 1871, pp. 249-294; issued January and February, 1872. 74. On some Batrachia and Nematognathi Brought from the Up- per Amazon by Prof. Orton. Proc. Acad. Nat. Sci. Philad., 1874, pp. 182-137. 77. Synopsis of the Cold-blooded Vertebrata procured by Prof. James Orton during his Exploration of Peru in 1876-77. Proc. Amer. Philos. Soc., 1877, pp. 33-49. 78. Synopsis of the Fishes of the Peruvian Amazon obtained by Professor Orton during his Expeditions of 1873 and 1877. 1. ¢. 1878, pp. 673-701. CHIAJE, DELLA, 747, in Nuov. Ann. Sc. Nat. Bologn. viii, 1847. Cuvier, Le Cuer, 17. Le Régne Animal distribue d’aprés son Organisa- tion. Paris, 1817. In Mem. Mus. v. CUVIER ET VALENCIENNES, M. Histoire Naturelle des Poissons. 739. | Voloxay, 1839: 40. Vol. xv, 1840. 46. Vol. xviii, 1846. 46a. Vol. xix, 1846. 48. Vol. xxi, 1848. 48a. Vol. xxii, 1848. DumeErRiIL, A. 7°52. Monogr. de la tribu des Torpediniens. Paris, 1852. _ Histoire Naturelle des Poissons, Tomei et ii. Paris, 1865-70. DuMERIL, Marie Const., 06. Zoologie Analytique ou Methode Natu- relle de Classification des Animaux. Paris, 1806. 06. Ichthyologie analytique ou essai d’une Classification Naturelle des Poissons a l’aide de tableaux synoptiques. Paris, 1856. EIGENMANN, C. H., 90. The Evolution of the Catfish. Zoe, i, pp. 10-15, 1890. Bee also Jordan & Eigenmann. EIGENMANN, C. H. anv R.S., 88. A List of the American Species of Go- biidw and Callionymide, with Notes on the specimens contained in the Museum of Comparative Zoédlogy at Cambridge, Mass. Proc. Cal. Acad. Sci., 2d Ser., i, pp. 51-78. 1888. 88a. Preliminary Notes on South American Neméatognathi, ewlunce, pp. 119-172. July 18, 1888. °88b. American Nematognathi American Naturalist, July, 1888. A78 CALIFORNIA ACADEMY OF SCIENCES. 89. Preliminary Notes on South American Nematognathi, ii. Proc. Cal. Acad. Sci., 2d Ser., ii, pp. 18-56. Aug. 18, 1889. 89a. A Revision of the Erythrinine, 1. ¢c., ii, pp. 100-116, pl. i, Nov. 8, 1889. ’89b. A Revision of the Edentulous Genera of the Curimatinea. Annals N. Y. Acad. Sci., iv, No. 12, Nov. 1889. *89c. Descriptions of New Nematognathoid Fishes from Brazil. West-American Scientist, No. 42. 1889. ‘90. A Revision of the South American Nematognathi. Occasional Papers, California Academy of Sciences, i, June, 1890. Eypoux AND SOULEYET, °36. Zoologie du voyage autour du monde, exéc. p. Vaillant s. la corvette ‘‘La Bonite.” Paris, 1836 and 1837. FAHLBERG, 701. In Velensk Ak. ny Handl. 1801. FARADAY, ’39, in Philos. Trans., 1839. Fiuippl, 53. In Guer. Meney. Rev. Mag. Zool., 1853. FirzincEr, 737. Lepidosiren paradoxa, Isis, 1837, p. 379. Fiaae, 1786, in Trans. Am. Philos. Soe. GARDEN, 1775, in Philos Trans., lxy. GARMAN, §., 775. Fishes and Reptiles, in Agassiz and Garman, Explora“ tion of Lake Titicaca. Bull. Mus. Comp. Zodl., iii, No. 11, 1875. 77. On the Pelvis and External Sexual Organs of Selachians, etc. Proc. Boston Soc. Nat. Hist., xix, 1877, p. 210. Gay, 48. Historia fisica y politica de Chile, 1i, 1848. GIEBEL, 71. Zeitschrift fiir die gesammten Naturwissenschaften, ili 1871. GILL, THEODORE, 58. Synopsis of the Fresh-water Fishes of the Western Portion of the Island of Trinidad, W, I. Annals Lyc. Nat. Hist. New York, vi, 1858. 59. Description of a new generic form of Gobinaw from the Ama- zon River. 1. c¢. 1859. 59a. Description of a New South American Type of Siluroids, allied to Callophysus. Proc. Acad. Nat. Sci. Philad., 1859, 196. 61. Description of a New Species of the Genus Anableps of Gronoyius. Proc. Acad. Nat. Sci. Philad., 1861, p. 3. 63. Descriptive Enumeration of a Collection of Fishes from the West Coast of Central America, presented to the Smithsonian In- stitution by Capt. John M. Dow. Proc. Acad. Nat. Sci. Philad., 1863, pp. 162-174. 70. Fishes from the Marafion and Napo Rivers. Proc. Acad. Nat. Sci. Philad., 1870, pp. 92-96. 72. Arrangement of the Families of Fishes or Classes Pisces, Marsipobranchii and Leptocardii; prepared for the Smithsonian Institution. Smithsonian Miscellaneous Collections, 247. 1872. "76. Notés on Fishes from the Isthmus of Panama, collected by Dr. J. F. Bransford, U. S. N. Proc. Acad. Nat. Sci. Philad., 1876 (338). ’ BIBLIOGRAPHY. 479 78. Elopomorphus jordani. Forest and Stream, 1878, May 2\|st. ‘78a. Hlopomorphus jordani. Ann. and Mag. Nat. Hist., Ser. y, ii, 1878. GILL AND BRANSFORD. 777. Synopsis of the Fishes of Lake Nicaragua. Proc. Acad. Nat. Sci., Philad. 1877, pp. 175-191. GIRARD, CHARLES, 754. Proc. Acad. Nat. Sci. Philad., 1854, 198. 55. The U. S. Naval Astronomical Expedition to the Southern Hemisphere during the years 1849-52. Vol, ii, Fishes, pp. 230- 253, 1855. 59. Report on U.S.and Mexican Boundary Survey. Fishes. 1859. GMELIN, J. T., 1788. Linnzi Systema Naturex, ed. 13. 1788. GRay, ’51 in Proc. Zoél. Soc. Lond., 1851, p. 239. GRAY AND GERRARD 751. List of Chondropterygii in the British Museum London, 1851. GRIFFITH, ’34. The Animal Kingdom, vol. x. Class Pisces. Lond., 1834. Gronow, L. TuH., 1754-56. Museum Ichthyologicum. 1763, 1764, 1781. Zoophylacium. 54. Systema Ichthyologicum; Catalogue of Fish, collected and described by L. Th. Gronow. London, 1854. Ed. Gray. GuIcHENOT, *45. Poissons in Ramon de la Sagra, Histoire Naturelle de Cuba. Paris, 1845. 60. in Rev. et Mag. Hist. Nat., xii., 1860. GUISAN, 1797 in Bull. Sc. Soc. Philom. 19. Comment de Gymnoto electrico. Tubingen, 1819. GUENTHER, A., 59 in Proc. Zoél. Soc. Lond., 1859 (418). 59a. Catalogue of the Acanthopterygian Fishes in the collection of the British Museum, i, 1859. 60. Catalogue of the Acanthopterygian Fishes, ete., ii, 1860. 60a. Third List of Cold-blooded Vertebrata from Ecuador, in Proc. Zoél. Soc. Lond., 1860. ’60b. On new Reptiles and Fishes from Mexico. Proc. Zodl. Soc. Lond., June, 1860. 61. Catalogue of the Acanthopterygian Fishes, etc., 111, 1861. 62. Catalogue of the Fishes, etc., iv., 1862. 63. New species of Fish from Essequibo. Ann. and Mag. Nat. Hist., 1863, December. 64. Catalogue of the Fishes, etc., v, 1864. 64a. Onsome new species of Central American Fishes. Proc. Zodl. Soc. Lond., 1864. '64b. Report of a Collection of Fishes from Guatemala. Proc. Zo6él. Soc. Lond., 1864. 65. Description of New Species of Characinidw from the Upper Amazon. Ann. and Mag. Nat. Hist., xviii, 1865. 66. Catalogue of the Fishes, etc., vi, 1866. 66a. Fishes of Central America. 1866. 480 CALIFORNIA ACADEMY OF SCIENCES. 68. Catalogue of the Fishes, etc., vii, 1868. 68a. Description of Fresh-water Fishes from Surinam and Brazil. Proc. Zool. Soc. Lond., 1868, pp. 229-247. *68b. Fishes of Central America, London, 1868. ‘69a. Description of Fishes from the Peruvian Amazon. Proc. Zool. Soc. Lond., 1869. ‘70. Catalogue of the Fishes, etc., vili, 1870. 72. Ona New Genus of Characinoid Fishes from Demarara. Proc. Zoodl. Soc. Lond., 1872. 77. Report on Collections of Fishes in the British Museum. Proc. Zo6él. Soe. Lond., 1877. °80. Contribution to the knowledge of the Fish-fauna of the Rio de la Plata. Ann. and Mag. Nat. Hist., 1880. 80a. Report on the Shore Fishes, Voy. H. M. S. Challenger, 1880. *80b. The Study of Fishes. Edinburgh, 1880. 83. In Ann. and Mag. Nat. Hist., Feb. 1883. Hancock, 28. In Zodlogical Journal, iv, 1828. Hecke, 40. Brasilianische Fluss-Fische. Annalen des Wiener Museums, ii, 1840. "45. In Miiller’s Arch. Anat., p. 534, 1845. HENLE, Narcin. HENSEL, 68. Fische. Wiegm. Arch., 1868. 70. Beitr. Wierbelthiere Siidbrasiliens. Wiegm. Arch., 1870. Hunter, 1775. In Philos. Trans., lxv. Humeo.pt, 06. Versuche iiber die electrischen Fische, 1806. Recueil d’Observations Zoologiques, vols. i and ii, Paris, 1811 and 1833. Hyrte, 45. Monogr. d. Lepidosiren paradoxa, Abhandl. Bohm. Ges- ellsch. iii, 1845, pp. 605-668. *59. Denkschr. Ak. Wiss. Wien, xvi, 1859. JreNnyNS, L., “42. The Zodlogy of the Voyage of H. M. 8. Beagle—Fishes. London, 1812. JoRDAN, D.5., 84. Note on Mlurichthys eydouxii and Porichthys poros- issimus. Proc.8U.8. Nat. Mus., vii., 1884, pp. 40-41. °85. A List of the Fishes known from the Pacific Coast of Tropical America, from the Tropic of Cancer to Panama. Proc. U.S. Nat. Mus., viii, 1885, pp. 361-394. 86. A Preliminary List of the Fishes of the West Indies. Proc. U. S. Nat. Mus., ix, 1886, pp. 554-608. °87. Note on Achirus lorentzi. Proc. Acad. Nat. Sci. Philad., 1887, pp. 389-391. JORDAN AND EIGENMANN, C. H., °89. A Review of the Sciwnide of Amer- ica and Europe. Ann. Rept. Comm. Fish and Fisheries, 1886, pp. 1-104. ‘90. A Review of the Serranide, 1. c., 1890. 5 BIBLIOGRAPHY. 481 JORDAN AND GILBERT, C. H., ’82. A Review of the Siluroid Fishes found on the Pacific Coast of Tropical America, with Descriptions of Three New Species. Bull. U. 8. Fish. Comm. ii, 1882, pp. 34-54. 82a. List of Fishes now in the Museum of Yale College, collected by Prof. Frank. H. Bradley at Panama, with Descriptions of Three New Species. Proc. U.S. Nat. Mus., v, 1882, pp. 620-632. °83. Synopsis of the Fishes of North America. Bull. U.S. Nat. Mus., xvi, 1882. JORDAN AND Goss, D. K., 89. A Review of Flounders and Soles (Pleuro- nectida) of America and Europe. Ann. Rept. Comm. Fish and Fisheries, 1886, pp. 1-112. Kaup, 56. Catalogue of Apodal Fish in the British Museum. Lond., 1856-8. 60. In Wiegm. Arch., 1860. Kner, R., 53. Die Panzerwelse des K. K. Hof-Naturalien-Cabinets zu Wien. Denkschr. K. K. Ak. Wiss. Wien, vi, 1853. 58a. Die Hypostomiden Zweite Hauptgruppe der Familie der Pan- zerfische. 1. c., vil, 1853. 55. Ichthyologische Beitriige. Sitzb. K. K. Ak. Wiss. Wien, xvii, pp. 92-162, 1855. 57. Ichthyologische Beitrige, ii.Abtheilung, 1. ¢., xxvi, pp. 373- 448. 1857. 58. Kritische Bemerkungen tiber Castelnau’s Siluroiden. Wiegm. Arch. 1859. 59. Zur Familie der Characinen, iii. Folge der Ichthyologischen Beitrige. Denk. K. K. Akad. Wiss. Wien. xvii, 1859. 60. In Denkschr. Akad. Wiss. Wien, xviii, 1860. 64. Specielles Verzeichniss der wihrend der Reise der Novara ges- ammelten Fische. Sitzb. Akad. Wiss. Wien, xlix, 1864. KNER UND STEINDACHNER, F., 64. Neue Gattungen und Arten von Fischen aus Central-Amerika. Abhandl. K. Bayer. Akad. Wiss., ii. Cl., vol. x, part i. Knox, ’24, in Edinb. Journal Science, 1824. KoELREUTER, 61. Novi. Comment, Petrop., viii, 1761. LaAcrepPEDE, 1798-1804. Histoire Naturelle des Poissons. 5 vols., Paris. In Mem. Instit. Nat.Sc. Math. Phys., i. LEYBOLD, in Annales de la Universidad de Chile. LICHTENSTEIN, '29, in Wiedem. Zool. Mag., i, part 3. Linnavs, C., 1754. Museum Adolphi Frederici. Stockholm, 1754. 1758. Systema Nature, ed. x. 1766. Systema Nature, ed. xii. LuETKEN, 74. Ichthyographiske Bidrag. I. Nogle nye eller mindre fuldstaendigt Kjendte Pandsermaller, isaer fra det nordlige Sydamerika. Videnskabelige Meddelelser fra den naturhistoriske Forening 1 Kjébenhayn, 1874. ol 482 CALIFORNIA ACADEMY OF SCIENCES. II. Nye eller mindre vel Kjente malleformer fra forskjellige Ver- densdele. 1. c¢. III. Nogle nyeeller mindre fuldstendigt Kjente mellem-eller syd- amerikanska Karpeplax. 1. c. 75. Velhas-Flodens Fiske. Et Bitrag til Brasiliens Ichthyologi. Vidensk. Selsk. Skr. 5 Raekke xii, 2, 1875, pp. 123-253—xxi. Marceravius, G., 1648. Historizs Rerum Naturalium Brazilie, iy. MeckEL, ’18, in Deutsch Arch. Physiol, iv, 1818. MeryYEN, °35. Reise in Peru, 1835. Mriranpna, 45. Esperimenti istituti sul Gimnoto elettrico. Napoli, 1845. MueELter, J., 42. Beobachtungen tiber die Schwimblase der Fische mit Bezug auf einige neue Fish Gattungen. Miiller Archiv, 1842, pp. 307-329. Mvuetier & Hente, J., “41. Syst. Beschreib. d. Plagiastomen. Berlin, 1841. Mvuetier & TROSCHEL, 44, in Monatsber. Akad. Wiss. Berlin, 1844. 45. Hore Ichthyologice, i and ii, 1845. 48. Schomburgk, Reisen in Britisch-Guiana in den Jahren 1840-44. Fische, ii, pp. 618-644. 1848. 49. Hore Ichthyolgice, iii, 1849. NatTerer, ’39. Lepidosiren paradoxa. Ann. Wien, Mus., 1839, 11, p. 165. OGILVIE-GRANT, W. R. ’84. A Revision of the Fishes of the Genera Sicydium and Lentipes, with Descriptions of Five New Species. Proc. Zoél. Soc. Lond., March, 1884. OLFERS, 31. Die Gattung Torpedo. Berlin, 1831. Owen, R, 46. Lectures on the Comparative Anatomy and Physiology of the Vertebrate Animals. Part i, Fishes. London, 1846. Pactnt, ’52. Sulla struttura del organo. elettrico del Gimnoto e di altri pesci elettrici, sulle condizione elettromotrici di questi organi e loro comparazione a diverse pile elettriche. Firenze, 1852. Paas, 1769. Spicilegia Zoologica Petrop., 1769-79, Peters, M., 68. Ueber einige neue oder weniger bekannte Amphibien und Fische. Monatsb. Ak. Wiss. Berlin, 1868, pp. 445-460. 77. Ueber die von Herrn Dr. C. Sachs in Venezuela gesammelten Fische. Monatsb. Ak. Wiss. Berlin, 1877, July 26. Puiippi, R. A., 57. Ueber einige chilenische Fische und Vogel. Wiegm. Arch., 1857. PuitiPPl, 63. In Wiegman’s Archives, 1863. 65. In Ann. and Mag. Nat. Hist., xvi, 1865. 66. In Monatsb. Ak. Wiss. Berlin, 1866. Putnam, F. W., 71. Note on the Pimelodus cyclopum of Humboldt. In American Naturalist, 1871, p. 694. Quoy ET GAIMARD, 24. Voyage autour du Monde sur les corvettes de S. M.1'Uranie et la Physicienne, sous le commandement de Frey- cinet. Zoologie. Poissons, 1824. BIBLIOGRAPHY. 483 34. Voyage de l’Astrolabe sous le commandement de M. J. Du- mont d’Urville. Zoologie. Tome iii, Poissons, 1834. Ranzant, As. Cam., “40. De novis speciebus Piscium. Dissert i. Novy. Comm. Acad. Scient. Inst. Bonon, iy. 1840. 41. De nonnullis novis speciebus Piscium. Nuovi Annali Sci. Natur, Bologna, 1841, pp. 60-66; 367-370; 443-444. REINHARDT, 49. Nye sydamerikanske Ferskvandsfiske. Videnskabelige Meddelelser fra den Naturhistoriske Forening i Kjébenhavn, 1849, Nos. 3-5. °52. Om Svémmeblaeren hos Familien Gymnotini. 1. c., 1852. 54. Notits om slaegten Pachyurus og de derlil hérende Arter. 1. c., 1849. 58. Stegophilus insidiosus en ny Mallefisk fra Brasilien og dens Levemaade. 1. c., 1858. 66. Om trende formentlig ubeskreyne Fisk af Chareciners eller Karpelaxenes Familie. Oversigt Dansk. Vid. Selsk. Forh., 1866, pp. 49-68. RicHarpson, Voy. Erebus & Terror. Fishes. Rozier, 1776, in Journal de Physique. SauvaGsE, M. H. E., ’80. Description des Gobioides nouveaux ou peu connus de la collection du Museum d’histoire naturelle. Bull. Soc. Philom. Paris. 1880. ScHaw, 703. General Zoology. London. 1803. ScHILLING, ’70, in Neue Abhandl. Akad. Berlin. 1870. SCHOENBEIN, “41. Beobachtungen iiber die electrischen Wirkungen des Zitteraales. Basel. 1841. ScHOMBURGK, RICHARD, Reisen in British Guiana. See Miiller & Troschel. ScHompurck, R. H., 41. The Natural History of the Fishes of Guiana, Part i. Naturalists’ Library; Ichthyology, 11, 1841. 43. Partai kes wo L843" Scuuttze, 58. Zur Kenntniss der electrischen Organe der Fische. Halle. 1858. Sepa, A., 1758. Locupletisssimi Rerum Naturalium Thesauri Accurata Descriptio, vol. iii. SmitH, J. P.G., 50. Proc. Zodl. Soc. Lond. 1850. SpPrx, ‘29. See Acassiz, ’29. STEINDACHNER, FR., 63. Beitrige zur Kenntniss der Scizenoiden‘Brasil- iens u.d. Cyprinodonten Mejicos. Sitz>, K. K. Akad. Wiss. Wien, 1863. 64. Ichthyologische Notizen. 1.c., xlix, 1864. 64a. Chromiden Mejicos und Central-Amerikas. 1. ¢., Denkschr., 1864. 66. Ichthyologische Notizen, iii. 1. c., lili, 1866. 67. Ichthyologische Notizen, vi. 1. ¢., lvi, 1867. 68. Ichthyologische Notizen, vii. 1. c¢., lvii, 1868. 484 CALIFORNIA ACADEMY OF SCIENCES. 68a. Gymnotide d. Naturaliencabinets zu Wien. 1. c., 1868. 69. Ichthyologische Notizen, ix. 1. c., lx, 1869. ‘74. Die Siisswasserfische des Stidostlichen Brasiliens. 1. ¢., lxix, 1874. 75. Beitrage zur Kenntniss der Charicinen des Amazonen Stromes. chan b-o:0 bam koa) ‘75a. Ueber einige neue brasilienische Siluroiden aus der Gruppe der Doradien. 1. c., lxxi, 1875. 75b. Die Siisswasserfische des Siidéstlichen Brasiliens. 1. ¢., lxxi, 1875. *75c. Ichthyologische Beitrige, iv. 1. ¢., Ixxii, 1875. 75d. Beitrige zur Chromiden des Amazonen Stromes. 1. c., lxxi, 1875. 76. Ichthyologische Beitrige, v. 1. c., lxxiv, 1876. 76a. Die Siisswasserfische des Siidéstlichen Brasiliens, iii. 1. ¢., Ixxiv, 1876. 78. Fischfauna des Magdalenen Stromes. 1.c., Denkschr., xxxix, 1878. 78a. Ichthyologische Beitrige, vi. 1. c¢., Sitzb., lxxvii, 1878. 79. Beitriige zur Kenntniss der Flusstische Siidamerikas. 1. ¢., Denkschr., xli, 1879. 79a. Ueber einige neue und seltene Fisch-Arten aus den K. K. Zoologischen Museen zu Wien, Stuttgart, und Warschau. 1.c., Denkschr, xli, 1879. 79b. Ichthyologische Beitrige, viii. 1. ¢., Sitzb., Ixxx, 1879. 80. Zur Fisch-Fauna des Cauca and Fliisse bei Guayaquil. 1.c., Denkschr., xlii, 1880. Sl and ’8la. Beitrige zur Kenntniss der’Flussfische Siidamerikas, jliand ii. 1. c., xliii and xliv, 1881. ’8lb. Ichthyologische Beitriige x. 1. c., Sitzb., Ixxxiii, 1881. 82. Beitrige zur Kenntniss der Flussfische Siidamerikas, iy. 1. ¢. Denkschr., xlvi, 1882. 82a. Ichthyologische Beitrige, xii. l.c., Sitzb., lxxxiv, 1882. 88. Ichthyologische Beitriige, xiv. 1. ¢., xevi, pp. 56-68, pl. 1-4. 1888. See also Kner & Steindachner. Swaltn, J., 82. A Review of Swainson’s Genera of Fishes. Proc. Acad. Nat. Sci. Philad., 1882, pp. 272-284. Swainson, W., 39. On the Natural History and Classification of Fishes, Amphibians, and Reptiles. The Cabinet Cyclopzdia, conducted by the Rey. Dionysius Lardner. 1839. THomInNoT, Alex., 82. Sur un Saccodon d’espéce nouvelle de l’Equateur. Bull. Soc. Philom., 7, vi, 1882. 86. Sur quelques Poissons nouveaux appartenant ala collection du Muséum d’Histoire Naturelle. 1.c., 7, x, 1886. > BIBLIOGRAPHY. 485 TRAIL, 732. In Mem. Wern. Soc., vi, 1832. Tscuupt, 45. In Fauna Peruana, 1845. VAILLANT. ’80. Synopsis des espéces de Siluridae recueillies par M. le Dr. Jobert, 4 Caldéron (Haute Amazone). Bull. Soc. Philom., 7, x, 1880. VALENCIENNES, A. In Humboldt Recuel d’Observations Zoologiques. ‘47. D’Orbigny, Voyage dans l’Amérique Méridionale. Poissons. 1847. VALENTIN, 42. In Neue Denkschrift Allgem. Schweitz. Gesellsch, 1842. VAN DER HoEVEN, 738. In Tijds. Naturl. Geschied, iv, 1838. VAN DER Lort, 1762. In Verhandl. Maatsch. Haarlem. WEYENBERG, H., °77. Algunos Nuevos Pescados del Museo Nacional y Algunos Noticias Ictiologicas. Actas de la Academia Nacional de Ciencias Exactas. Tomo iii, Entrega i, Buenos Aires, 1877. WIEGMANN, in Wiegmann’s Archives, 1835, ii, 269, redescribes Meyen’s Pygidium fuscum. WILLIAMSON, 1775, in Philos. Trans. Ixv. WiLiLuGHBY, 1686. De Historia Piscium. Oxon. Wricut R. Ramsay, 85. On the Skull and Auditory Organ of the Silu- roid Hypophthalmus. Trans. Roy. Soc. Canada, Section iv, 1885, pp. 105-118, plates vili-x. WYMAN, JEFFRIES, 54. Observations on the Development of Anableps Gronovii. Boston Journ. Nat. Hist., 1854, pp. 482-443. GEOGRAPHICAL INDEX. The following index was compiled in order to present a concise list of the species of Nematognathi of each locality where collections have been made. The numbers refer to the serial number of the species as given in this paper. The figures in parentheses refer to the pages of Professor and Mrs. Agassiz’s ‘“‘A Journey in Brazil,” where the given locality is dis- cussed. The map has been compiled with especial reference to the localities where collections have been made. Abrolhos, 61. (p. 540). Acapulco, 42. West Coast of Mexico. Alexo, Lago, 124b, 151, 172, 206, 208, 317, 321, 334, 400. Near Manaos. (p. 294). Altata, 18, 20, 24, 28, 39, 41, 42. West Coast of Mexico. Amable Maria, 288, 291, 416. Peru. Amazons, 32, 67, 70, 67.1, 124e, 145, 147, 151, 152, 153, 156, 161, 183, 185, 232, 236, 244, 318, 319, 326, 334 (near Rio Negro), 353, 375, 393. Ambyiacu, 114, 116, 124, 160, 177, 256, 286, 340, 344, 402, 421, 422, 425, 426, 439, 448, 450, 453, 454, 455, 463, 464, 465, 466. Tributary to Marae non near Nauta. Antilles, 30. Apuré, 67, 75. Apurimac, 434 (at an altitude of 2,000 metres), 442. Araguay, 22, 46, 124, 137, 138, 143, 265, 286, 361, 391. Arary, 12, 108, 124a, 143, 163, 224, 390, 446. Avary. This should read Arary in the text. Azangaro, Rio, 260. 222, 304, 326, 334, 344, 395, 402. Calderon, 67, 108, 114, 124, 131, 138, 143, 151, 153, 155, 156, 172, 177,. 185, 190, 199, 206, 222, 232, 248, 285, 301, 304, 317, 318, 319, 322, 334, 349, 402, 438, 441, 446. (‘‘ Haute Amazone” not of map.) Callacate, 427. Peru. Callao, 24, 42, 267, 267a, 269. Camapuam River, 127. Cameta, 67, 70, 124b 129, 226, 242 326. Campos, 46, 88, 111, 220, 306, 313. (p. 5: Canelos, 7, 76, 93, 116, 209, 250, 266, 279, 292, 297, 308, 320, 430, 431, 438. Cannavierias, 35, 88, 114. (p. 540). Capin, Rio, 83, 108, 121, 152, 193, 226, 232, 245, 322, 385, 440. Caracas, 242, 300, 101.2, 351, 384, 424. Carandahy, Rio. 341. Near headwaters of the Rio Grande (p. 534). ‘Cauca, 77, 83, 125, 152, 155, 164, 214, 240, 242, 308, 344, 396, 398, 447. «Cayenne, 12, 14, 19, 25, 26, 31, 32; 33, 36, 37b, 55, 55a, 59, 61, 63, 77, 83, 124, 145, 161, 204, 222, 232, 248, 326, 342, 349, 441, 444, 446, 447. “Chagres, 92, 112, 118, 311, 486. Panama. ‘Chepo, 92, 323, 419, 428. On Mamoni river, a tributary to the Bayano, which empties into the Gulf of Panama. Chile, 16, 255, 256.2, 256.3, 256.6, 258, 259, 272, 433. Chilloa, 78.2. On the Magdalena River. Chiquitos, 177, 447. ‘Chota, 291. Peru. Cipo, Rio, 132, 154, 361. A tributary of the Rio das Velhas. Coary, 108, 124b, 138, 151, 152, 174, 185, 189, 225, 233, 236, 315, 317, 322, 326, 349, 380, 400, 489. (p. 197). Colima, 50. Mexico. Colombia, 268, 293, 311, 409. Compucila Lake, 260. Near Cuzco. Cordoba, Sierra de, 256.4 (near Cruz de Eje). Argentine Republic. Cordova, 357. Coroico, 260. On Rio Pontezualo. Corrientes, 71, 110, 154. Costa da Serra, 440. In Province Rio Grande do Sul. Costa Rica, west coast of, 20. Cotopaxi, 289, 292. Crixas, 124, 138. A tributary of the Tocantins, 135 miles north of Goyaz. Cudajas, 5, 7, 83, 96, 109, 124b, 210, 273, 317, 321, 344, 400, 401, 402, 438, 447, 449, 456, 458. (pp. 197 and 294). Cujaba, 77, 83a, 88, 110, 121, 163, 186, 238, 245, 304, 310, 324, 326, 394. GEOGRAPHICAL INDEX. 489 Cumbaca, 266. Cupai, 138, 168, 170, 181, 249, 251, 295, 400, 447. Tributary of the Ama- zon, eight hundred miles from the sea. Curico, 255. One hundred and sixteen miles south of Santiago. Curuca, 15, 19, 33, 159. On Rio Muria. Curupira, 447. (p. 294). Cuzco, 260. Demerara, 4, 14, 19, 33, 83, 129, 143, 163, 168, 212, 223, 309, 404, 446. Doce, Rio, 46, 56, 83, 88, 114, 149, 220, 346a (at Linhares), 459. (pp. 535, 539). Ecuador, 107, 431 (western). Esmeraldas, 86, 112, 113. Essequibo, 67,75, 83,89, 108, 109, 124, 152, 173, 199, 210, 215, 222, 247, 344, 438, 439, 463. Facutu, Rio, 89. Fonteboa,: 120, 124b, 155, 177, 322, 344. (p. 204). Gequitiba, 124a, 130. On Rio San Francisco. (p. 534). Gonegallo, Rio, 124b. In province Rio Grande do Norte (7). Gorgona, 92. Central America. Goyaz, 46, 77, 83, 95, 110, 121, 124a, 152b, 270, 280, 337, 343, 344, 358a, 364, 391, 395, 437. Grande, Rio, 346, 444. ~ Tributary to the Parana. (pp. 382, 535). ° Grande do Sul, Rio, 22, 43, 46, 58, 88, 90, 99, 103, 124, 124a, 313, 316, 347, 358. Guahyba, 22, 46, 90, 346. Guaire, 424. Guatemala, 42, 49, 50, 51. Guaporé, 75, 110, 136, 155, 169, 176, 181, 191, 192, 203, 210, 218, 225, § 301, 318, 326, 344, 356, 405, 438. Guasacona, 260. On Rio Azangaro. Guatanai, Rio, 260. Near Cuzco. Guayaquil, 19, 34, 86, 253, 345. Guiana, 125 19> 29) 30; 33; 365 37, 67, 84, 108, 120, 124, 138, 185; 222) 230 (British, Dutch and French), 244, 349. Guiana, ‘British, 125 15; 19; 33; 36) 57, Gl, 67, 70; 78.3) 83, 84, 120) 124: (Waina Barima), 138, 168, 230, 317, 372, 386, 432, 438, 446, 447 (Cur- assarraka). i Guiana, French, 13, 19, 230. Gurupa, 78, 83, 168, 185, 206, 220, 251, 296, 322, 326, 344, 400, 438a, 441, 446, 447. (pp. 165, 194, 375.) Huallaga, Rio, 5, 75, 108, 124, 155, 158, 169, 196, 248, 249, 312, 334, 371, 402, 438, 439, 446, 461. Huambo, Rio de, 87, 271, 288, 290, 420, 427, 431. Hyanuary, Lake, 120, 138, 152, 162, 285, 317, 333, 380, 400, 441, 446, 447. (pp. 253 and 294). 490 CALIFORNIA ACADEMY OF SCIENCES. Hyavary, 7, 108, 123, 151, 152, 155, 156, 195, 206, 225, 231, 284, 301, 312, 318, 322, 344, 349, 380. (p. 208). Ica, 114, 124d, 155, 208, 249, 275, 283, 305, 318, 334, 344, 441. (p. 201). Imbaburu, 292. Iquitos, 152. Trisanga, 130, 252. Itabapuana, 220, 232, 346. (p. 538). Jacuhy, 124, 346. Janeiro, Rio de, 21, 22, 35, 46, 61, 75, 83, 88, 100, 101, 102, 114, 211, 317, 343, 346, 346a, 362, 364, 438, 444, 445, 459. Januaria, 73. On Rio San Francisco. (p. 536). Japura, Rio, 152. Jatuarana, 208, 348, 400. Jequetepeque, 269. Jequitinhonha, 88, 114, 117, 148, 205. (pp. 535, 540). Jose Assu, 67, 322. Above Villa Bella. (pp. 171, 194). Jose Fernandez, 120, 463. Near Manaos. (p. 294). Juiz de Fora, or Parahybuna, 88, 148, 150, 270, 337, 343, 444. (pp. 63, 75, 78, 101). Jutahy, or Hyutahy. 2, 5, 78, 83a, 108, 120, 124d, 141, 152, 153, 155, 181, 182, 189, 200, 208, 249, 287, 296, 318, 321, 322, 400, 402, 439, 441. (pp. 201,-241). Lagoa Santa, 261. (pp. 534, 536). Libertad, 20, 42. Northwéstern Peru. Lima, 267a. Linhares, 220, 346a. (p. 539). Macacos, 88, 102, 116, 211, 270, 306, 346, 364, 444. Connecting Rio Para with the Amazon. Madeira, Rio, 109, 144, 226, 322, 441. Magdalena Bay, 18, 42. Magdalena River, 51, 78.1, 78.2, 124, 152, 155, 164, 178, 214, 216, 242, 307, 308, 344, 398. Mahn River, 108. British Guiana. Maldonado, 101, 103, 106. Mamore, 298. “ Mamoni, 92, 124, 304, 323, 419, 428. Mana R., 13, 19, 33, 36, 75, 406, 447. Manacapuru, 67, 124b, 138, 151, 155, 156, 185, 195, 206, 281, 283, 301, 304, 334, 344, 371. (p. 294). Manaos, or Barra do Rio Negro, 4, 75, 130, 135, 151, 153, 154, 173, 181, 190, 195, 198, 317, 322, 326, 377, 378, 380, 441. (pp. 185, 219, 276, 322, 340). Manimo Lago, 155. Mapocho, 258, 259. Chile. Marabitanos, 79, 83a, 88, 202, 208, 222, 302, 322, 447. Maracaibo, 19, 124, 349. GEOGRAPHICAL INDEX. 491 Marajo, 109. (pp. 154, 158, 385). Maranhao, or Maranham, 37, 37a, 37b, 55a, 60. (pp. 134, 537, 538). Maraiion, 77, 81, 85, 94, 108, 123, 124, 138, 140, 151, 152, 155, 156, 171, 184, 206, 207, 212, 231, 232, 245, 248, 249, 254, 277, 304, 326, 328, 334, 335, 336, 352, 382, 417, 452, 461. Martinique, 447. Matto Grosso, 75, 110, 192, 218, 301, 318, 349. A province of Brazil. Maues, or Maahes River (connects the Amazons with the Madeira), 226. (pp. 181, 295, 303, 312). Maximo Lago, 184, 400. Near Villa Bella. (pp. 194, 354). Maypu, Rio, 255. Chile. Mazatlan, 28, 42, 47, 48, 50. Mexico. Mendez, 88, 114, 261, 313, 346a, 364, 444. Minas Geraes, 117, 346a. A province of Brazil. (p. 539). Moho, 260. On Titicaca. Montalegre, 67, 124b, 151, 283. (pp. 167, 194, 361). Monterico, 87, 416. Montevideo, 46, 90, 91, 124, 462. Motagua, 60. Guatamala. Mucuri, Rio, 88, 108, 114, 220, 229, 346a, 363, 367, 410. (p. 539). Muria, Rio, 15. Muriahe, 114, 313, 332, 346a. (p. 538). Nauta, 6, 9, 184, 185, 248, 400, 403, 444, 447, 461, 463. Nazareth, 35. Near Bahia. , Neoro;, Rio; 67, 121/124, 138, 1389, 143, 151, 152d, 155, 156; 173; 182; 192, 195, 197, 198, 218, 248, 302, 326, 334, 344, 349, 400, 402. (pp. 295, 324). Obidos, 67, 114, 120, 124b, 138, 151, 152, 152c, 153, 155, 168, 185, 195, 204, 206, 296, 317, 326, 334, 344, 390, 400, 402, 438, 447. (pp. 169, 357). Obispo, Rio, 92, 118, 318. Tributary of Chagres. Orinoco, 21, 78.4, 110, 124, 395. Oroya, 264. Peru. Padaniri, 205.1. Palace, Rio, 294. Tributary of the Cauca, near Popayan. Panama, 18, 20, 23, 24, 28, 34, 39, 40, 41, 42, 44, 45, 47, 48, 53, 54, 60, 62, 64, 65, 66, 92, 301.3, 303, 306, 308. Paral Os. 19s dando) a0, 05 Ol O55 69) 4607 Sos elOSs OO MIDIS 2124. 124b, 124d, 129, 131, 185, 143, 145, 152, 155, 159, 161, 206, 208, 226, 229, 230, 232, 241, 242, 245, 248, 326, 349, 355, 402, 414, 440, 444, 446, 447. (pp. 139, 144, 158, 377, 387). Paraguay, 77, 169. Parahyba, 46, 74, 88, 114, 115, 116, 119, 150, 211, 220, 261, 306, 313, 332, 346, 346a, 362, 363, 364, 369, 411, 412, 413, 459. (pp. 57, 74, 534). Parahybuna. See Juiz de Fora. Parana, 71, 72, 110, 154, 372. (p. 535). Pasawiri, Rio, 179. British Guiana. 492 CALIFORNIA ACADEMY OF SCIENCES. Pastasa, 297. Paz, Andes de la, 260. Pebas, 8, 119.1, 124, 180, 334. Pedra, Rio, 363, 367. In Province of Bahia (?). Pernambuco, 19, 21, 30, 222, 444, 447. (p. 131.) Peru, 234, 256.1, 256.7 (western slopes of southern), 262 (western slopes of), 263 (western slopes), 267 (eastern slopes at 14,000 feet), 271, 289, 427 (Callacate), 442. Pirahy, 369. Tributary of the Parahyba. Plata, mia, 22. 71, 72) 77, 90) 103.1225 124") 1968 127, 1633 187, 2a 278346: 366, 379, 462. (p. 534). Pochachara, 264. On Oroya. Pontezualo, 260. Popayan, 294. Porto Alegre (Minas Geraes) 22, 35, 88, 91, 124, 229. Porto Alegre (Rio Grande do Sul) 114, 346, 375, 462. Porto do Moz, 124b, 143, 177, 181, 204, 204a, 222, 326, 390, 391, 400, 446, 447, 449. (pp. 165, 194, 374). Porto Rico, 30, 388. Porto Seguro, 22, 35, 133, 444. (p. 540). Preto, Rio, 168, 169, 306, 312, 326, 350, 368, 405. (p. 537). Primero, 256.5. Near Cordoba. Principe, Forte do, 136. Puerto Cabello, 419, 435. Puno, 260. Punta Arenas, 20, 28, 42. Costa Rica. Puty, or Poty, Rio, 109, 124b, 124d, 143, 151, 152, 152c, 155, 168, 169; 201, 222, 238, 312, 349, 350, 368, 405. (p. 537). Quenda, Rio, 306, 313, 346 near Santa Cruz, 363. Quito, 292. Remac, Rio, 267a. Reto, Rio, 124b. Rupununi, 301.1. British Guiana. Sabara, Rio, 77. St. Joaquin, 98. Paraguay. St. Martha, 83. Salto Theotonio, 144, 145. On Araguay. Sambaia, 313. San Antonio, 346a, 363. San Fernando de Apuré, 447. San Francisco, 91, 117, 124, 124b, 130, 132, 146, 154, 175, 185, 222, 228, 325, 346, 358, 360, 372, 399. San Goncallo, 108, 124d, 168, 222, 326, 350, 405. On Paranahyba. (pp. 534, 536). San Jose, 42. GEOGRAPHICAL INDEX. 493 San Pablo Lake, 292. At base of Caraguairazo. Santa Anna, 288. Eighty miles northwest of Cuzco. Santa Catharina, 272. \njetals ateluiecsisiehet= 41, 42,49 Bisel oa odoaoondngaeoodooDeOr 223, 234 armatus (Ageneiosus).......... 299, 300, 305 (Calhich th ys) ce ccrcrictepicitsicieictonee 471 (Comy Gora) retest stelafelsiere 466, 471 (Gasterodermus) joc. <<< ....-262, 294, 295 PUY ON TIETEI mequats elogecod sadenoou 267, 270 aurantiacus (Chetostomus)............. 424 (Hypostomus).......... 422, 424 (Parancistrus)......... 423, 424 auroguttatus (Hypostomus), ..-......... 410 (Plecostomus)........399, 410 Eralibiakbcoge poo cooodncpopbsoaaeo c 301, 311 bagre (4lurichthys)....... ...cc..s.se0s 33 (Ailurichthtys)sese-esseeceeseies $1.33 (Bimvelodits) eerie creialeleieiolol-leleleteteiels ves 33 (SiS) eer, eysieiotersistetersieie wieie relieve 33, 36 IBALTOPSIS ter iseyraee ieee eles eriaeiainls 99, 185 CALIFORNIA ‘ACADEMY OF SCIENCES. Bagrus..... pvecefetatercieverstele|eiatetotegatateteiaTstetaistatals 41 bahianus! se ectewios) cee eee Oa eamreet erat 127 bahiensis...... gals cutie. diate ste Sts, omnis eubye, states orale 36 PAM AN CHO meatal \eliciete slate clclete/ Netetal-taleteiats 104 ibarbatanccemeecicclacstaiem reminisce 366 letba orn le noo Soguouobaucouu coe on at 331 La he oH HUIEK(MEE FEAR aeogondaaca voossans000 76 (Callichthiys) Wer cr\ en otereleteyeraia reine 451 (Hypostomus)..... --..... 434, 435 (BICCOSEORITIS) tens etaran eestetststere tls 435 (PReudancistrus) ce <\cs ote meee 435 (Scleromystax)........-......: 451 barbs (Galeiehthiys) fe ac-n - apiclalel=\eleleletel= 76 (Pimelogdus) eee ierw ein cieteienie sleloj=te 76 (LaCHISUMUBS) reyes eraracefelelacetaler= 47, 76 joengoveyie semua og Soahactas sono boo jc oOnD 475 bathyurus (Pimelodus). -.....0..j...2.- 122 (Ethan da) etre ater orsisrare 118, 122 Batrachoglanis.........+.-+-ssssee 108, 109 batrachus (Aspredo).............c..see- 23 (Asterophysus)..... Bie teretieinisters 262 bicarinatus (Brochis) 26. 6.2... eeu 464 (Chenothorax)......--..+..- 464 DICITTNOSUS=ne. ..<0..-.202, 258 coecutiens (Cetopsis).....-......- 318, 320 (Hypoptopoma).......... 388, 390 (Si Tiatris)) Eyerelaletsteleleiaeleieter= 318, 320 (Oxy dOras)riecticcieriewctet terior 258 COLA TTS Serco eeertercleremieisisteer aoe siti eaecers ote 452 (Blecostomius) oe. pes! «sare 398, 405 COSlestinuUs i). te eases ate Shane wt) (Silurus) Feige serie cas bgdncic peoocetite) ccerulescens (Arius)............. miegeeete sexe 81 - CarOlINGHBIS. sesckyacr ers Selene elsisreye ats 33 (Galeichthys) heck menesesiat 81 CHI OM Geno o ap ad OBno: fo -oAoedoc moo vdnn 375 (Lachigunus) sees tees 48, 81 498 (Coan AAS Sano oe Gone n CaO Ce ose OUuaa fo 464 collettii (Acentronichthys)......... 145, 146 (Heptapterus)). cmc sstcisieinesiers 146 OMY ADIN OUEN totsietates sis iaysintcveial erate rare iiraleietatass 295 commersonil (ATIUS)) ...- oc nWeacicle siete < 76 (Bagrus))! 5 sccrestentos ne eres 76 (Hypostomus)...... 397, 403 (Pimelodtus)e. see). -) es 76 (Plecostomus)........ 397, 403 conircostris (Conorhynchos)........... 185 (Conorhynchus)............ 185 (Gonostome) =... cace= dem a 185 (Lesko OCD) oGac an soudoddeas 185 GomorhyChostcecic 2 e-laee «tes 99, 184, 185 Conorh yenuserrce cccincicvsetstiees ences 184 ConORtomMe yet: co. Ase ecis ewe ese sibs cinenients 184 @oracordeusiaciacetsetalem een sreters (sista eisrare 20 Cols Oia nhoocogpaoesoboD osadao -...- 398, 409 COLGUVANSIS netic eee cnc aesieraiseoaerat 326 GCODIACCUB Na ccaparcccyteie me citeters cieic elem aiste nee 264 coruscans (Paradiplomystax)............ 30 (Paradiplomystes)!s-.. sec ce 30 (Bimelodus) acu eee 30 (Vlatystoma) oe... .. > oe 211 (Pseudoplatystoma)..... 208, 211 Cory orasiertenslereietstererclecclsies seth (Pterygoplichthys)....... 428 Duopalatinus coe. .csscat ..- 100, 200 Che RES AReee nar oe anoaoe nado Goocosod 382 MOU Rea poee ene Abo sco D.s.cq0c.c00 Sibn 20 edentatus (Corydoras).....-..-.......5- 247 (Hypophthalmus)............ 313 ole HE, See ea. 4 Gaecoaan shoviiniet +c 418 (MoriGaria Gactentcteiete Sedereistesreanes 418 (Rinelepis) ja esceces oars eos 418 holom elas tac scctateaaneiscrces SAnooosdodoos 124 EVO PLIS OMIT ete cteemiaeleteteres a saisaretefeaere (Mette 455 hoplogenys (Ancistrus)............ 445, 448 (Chetostomus)..'........... 448 HL OMLOB OMA es eteltsieme ieee EGO OCHO 5 465 Ho plostern iis ree errs) eie ae rsiele eiaieate = 450, 455 horridus (Hypostomus)...............-. 400 (Plecostonins) iaa-sacee eure 400 Mn OLAS setetaraloweione lefeterstaye sie erate ois sete 247 humboldtii (Cyclopium)............... 350 (Stygogenes) Wis2-)-ccce-- 350 (VAriNE NON ingonsan Gooaopados 112 humeralis (Corydoras).................- 257 (OLAS) Fe iareseralereteloietatetatefetet-felee=tara 257 (Hemidoras)........ 252, 257, 258 (OXVGOraS)\emeniesicsiesistoni eee 257 humilis) (PimelOAUS) eck. a eal wlatle === 126 (Rhamdia)............ 119, 126, 127 Hy MENOLHINUSS seas ee eee Os Hypophthalmid® - 2.2... 2... =. .s-- 10, 311 Hypophthalmus..............-. 299, 311, 313 hypophthalmus (Arius).............-.-- 92 (Galeichthys).. 7. cscs 92 (Tachisurus)>...... - 50, 92 Hypoptopoma...... cesses see e cee 353, 388 Hypoptopomine............ «> 12, 353, 388 Hypostomatina...........-.+ ssee-.-ee- 351 Hypostomus........... 396, 417, 422, 434, 441 hypostomus .........eee eee ee eee eee ees 425 hhypselurus..........0. esd sees eee ees . 475 hypsiurus (Bunocephalichthys)...... 13, 14 (Bunocephalus)........... 13, 14 INDEX. 501 LW EL ig be hoE On Otee HoseU RO Cemon Aap oueonde 440 levigatus..... Sleletsttvelsiep-/0N Gr -aye lene) Soancepacocoseenoodaes 257 (Panaque) hin. a e.cece 425, 426 HAOWOIN C5854 bdo yeaodausoo cepa obocanopoon 169 WTS rOM A CUA as sp tetelaieis ete eere tol al 327, 336 MMBC tbemonaE geaonoe6dodde ao ooe 475 nigromaculatus..... Jobc Asta DSeVCUnNCb OO 336 mucosa..... eiaye nfaicialahe te ci Yenatersterets (eleieseisiapata'< 196 niveatus (Chztostomus) .... .......... 423 MINTO Te sas cyers sate sis isla ere eter-raievevevene noone led (Hypostomus) <<. 22--ieye 423 MULerA a TatUSe (CATIUS)/S (ie, cic wrererele he -92 MNOGosus (ATIUS) cere tes areca an Sondogon 290 (Hypostomus)..... Serres 433 (Auchenipterus) ccc cas cer eis 290 (Liposarcus).............433 (Felichthys) .......... 286, 290, 291 (Notoglanis) p<. s0-71- 130 (Pseudauchenipterus)......... 290 (Pimelodus)...........-.130 (Silurus) Ri antecectesticttneee 290 (Pterygoplichthys) ..428, 483 | Notarius..............-.s0.sseeeee 29, 42, 45 (Rhamdia)........-. 120, 130 notata, (Rhamd ella ice aemaeececiemeee 138, 139 (Tachisurus) .........50, 92 (Rhamdiia)cssace ieee 139 ORC AoromodeauoU doSaOUL fe raierarVateeisecele 229 notatus! (HIsonOtuUs)).-cstce masta ce 390, 391 WWUPICUS|. = <0) e “aun eoarbeossenno oecese 229 (Pimelodus)/feagacoe seen ase 139 MNT IOWINS Sooo sanoeaaesoobS SSO SRODIaSES 124 Notoglanis) 2s. =)< 1811415 354, 414 Rhinodoras:,...5..-.. eel prateretedahete talelfareratere 246 misslshti\scos ones noospacaccne Selerctelapeiom ramen one Rinelionicaniairrcc ici scletelsss cies 360, 362 506 MU CUTT LL UULTED tatels lata iaie.ieisis) stetoinisiaeieietaisinie te 327, 330 TL VASES ccs. isiois 2b soy Sieve Sie Kiomibia Wiatave 326, 330 robinii (Hypostomus) .................412 (PlecostoOmuUs)) eee cise aiaclaceis 400, 412 robustus (Auchenipterus) ............. 281 (Trachycorystes).......... 274, 281 HOME A Sang aoneoos aodddanSda Gor 362, 366 TOUSSCAUXIL (BAGTUS)| pen) nee ele cece snes 198 (Brachyplatystoma) .. .195 198 MUPISPINIS A CATIU) Wares ele laraioter ners chanel ote iate 83 (Galeichthys) ix... sles-i-\ donoconooadcepac 26 | ((SIEREXSE)) goon acncoccoines “ae 55 tenia (Pygidium).............. 327, 333, 334 | truncatum .......... aleisitels’enihateisirrets - 209 (Lrichomycterus)¥ 5... s--- 6 -e os 333 (NNER) oases be sadandocs -ouundoceN ous 238 teniatus (Trachelyopterichthys)....... 263. | typus (Loricaria)......... OOOSP On 363, 373 (Trachelyopterus) ....... 262, 263 (Parahemiodon) .......0...0--+-- 373 Tachisuring ...... SooRS vob’ Sonnet hy Ze) (Piniram pus) jececcces seatace esc 104 Mi PeCHAS UUM cyeretelsielcisiers i arciere neice 29, 41, 43, 49 (Bininandpus))ycrasey-istl-tteeesiae 104 taczanowskii (Chetostomus)..... neco 2 LEB, (Trachycorystes)............ 272, 276 (Byeidium) eens 8285338, ||| tucayalensis')2. 2/2 use. 0s eciselmeinis 300, 306 (Trichomycterus)....... S8Biw Prana ce cee ae eee Sm rolelevere eters 412 tAiOSHA(BrOCHIS)) veccssciocisci ee seee! «2005 404 undecimalis (Chetostomus)............ 428 (Callichithiys))seri-jerseeta serie seeerske 464 (Pterygoplichthys)....... 428 WOGHIROSELIG syavaiatto/elatsiststetcte!sinicteiniela\sle's pie’ 16 442 | upsulonophorus..... Sep udCsboosusedat 47,7 HIGHIGETEY sacqadue cabocsocosacouDoS sen 364, 379 uracantha..... Gang Bones saodon coOd eau) LOMEANIMSE eleer ic stsie 35 =e somata: