from the Island of Marajo, Brazil. 297 
pectoral spines shorter than the head, the body less elongate, 
the length of the head barely four times in the total, and the 
supraoccipital bone broader than long. Dr. and Mrs. Higen- 
mann have already drawn attention to the great variation in 
the length of the spines in this species, and observed them to 
be shorter in specimens from Para. 
35. Cetopsis cecutiens, Licht. 
36. Doras costatus, L. S§. 
The single specimen, 220 millim. long, has a very 
puzzling appearance, owing to the absence of the caudal 
peduncie. ‘he posterior end of the tail must have been 
accidentally amputated, and the shape of the well-developed 
caudal fin points to neogenesis. The posterior scutes being 
missing, withthe caudal peduncle, the lateral line numbers 
only 23. 
37. Doras Weddelli, Cast. 
38. Doras dorsalis, C. & V. 
39. Callichthys Uittoralis, Hancock. P. 
40. Plecostomus bicirrhosus, Gron. M., P. 
41. Liposarcus pardalis, Cast. 8. 
42. Chetostomus spinosus, Cast. 
43. Chetostomus cirrhosus, Val. 
44. Aspredo cotylophorus, Bl. M., P. 
Characinide. 
45. Macrodon trahira, Bl. Schn.  P. 
46. Macrodon intermedius, Gthr. P. 
47. Erythrinus uniteniatus, Spix. P., 8. 
48. Hemiodus microcephalus, Gthr. 
49. Anostomus fasciatus, Ag. 8. 
50. Leporinus affinis, Gthr. 
51. Tetragonopterus maculatus, L. 
52. Brycon brevicauda, Gthr. 
53. Piabuca argentina, L. 
54. Anacyrtus Myersii, Gill. 
55. Serrasalmo serrulatus,C. & V. 8. 
56. Serrasalmo piraya, Cuv. P. 
Ann. & Mag. N. Hist. Ser. 6. Vol. xx. 21 
