ortmann: south American naiades. 



469 



forming attachment to fishes, but we liave not the shj2;litest direct evidence of this, 

 and Von Ihering directly questions it (l. c, p. 47). Morphologically this organ has 

 been independently developed. It is analogous to the Anodonlinc hook, but not 

 homologous. 



Fig. 4. Glochidia of Hyriince, enlarged fiftj' times (drawn from photographs). 

 a. Diplodon hascmani Ortmann (Rio Guapore), from specimen No. 6. Cat. No. 61.58.57. 

 6. D. imitator Ortmann (Santa Maria), from specimen No. 22. Cat. No. 61.9248. 



c. D. similliwus Ortmann (Morretes), from specimen No. 2. Cat. No. 61.9250. 



d. D. vicariiis Ortmann (Aqua Quente), from specimen No. 9. Cat. No. 61.9251 (.shell of this specimen 



figured on Plate XXXVI, fig. 2). 



e. D. decipiens Ortmann (Serrinha), from specimen No. 10. Cat. No. 61.9253. 



/. D. paiilista (Von Ihering) (Mogy Mirim), from specimen No. 10. Cat. No. 61.9256. 

 g. D. charninnus (D'Orbigny) (Santa Isabel), from specimen No. 5. Cat. No. 61.5861. 

 h. D. piceus (Lea) (Uruguayana), from specimen No. J. Cat. No. 61.5862. 

 i. D. hildw Ortmann (Cachoeira), from specimen No. c. Cat. No. 61.5864. 

 k. D. mogymirim Ortmann (Mogy Mirim), from specimen No. 48. Cat. No. 61.9260. 

 /. Castali/ia iiehringi Von Ihering (Salto das Cruzes), from specimen No. 1. Cat. No. 61.5119. 

 rn. Caslalia acuticusta Ilupe (Rio Guapor^), from specimen No. 1. Cat. No. 61.5112. 



I haye said that onlj' some Hyriinm have this hook. I found it in the case of 

 several species of Diplodon, in Castalina nehringi, and Castalia acuticosta, and it 



