92 



MEMOIRS OF THE CARNEGIE MUSEUM 



13. Pristella riddlei. 



14. Pristella aubynei. 



15. Hemigrammus unilineatus. 



16. Hemigrammus rodwayi. 



17. Hyphessobrycon minimus. 



18. Ctenobrycon spilurus. 



19. Chalcinus elongatus. 



20. Pygocentrus bimaculatus. 



Clupeid^e. 

 21.*Rhinosardinia serrata. 



Stolephorid^e. 

 22.*Stolephorus guianensis. 



Pceciliid^:. 

 23.*Poecilia vivipara. 

 24. Acanthophacelus melanzonus. 

 25.*Acanthophacelus reticulatus. 

 26. Tomeurus gracilis. 



Doryrhamphid.e. 

 27.*Dorj - rhamphus lineatus. 



CICHLID.E. 



28. Nannocara anomala. 



29. Mquidens moroni. 



Gobiid^e. 

 30.*Eleotris amblyopsis. 

 31.*Evorthodus breviceps. 



A few of these species, like Ageneiosus brevifilis, are not limited to this area, 

 but as no specimens were captured in the interior they are included in this list. 



List of Species not taken at Rockstone, Wismar, or lower down 

 in the essequibo and demerara rlvers. 



While the downward limit of many of these species has not been determined 

 it seems certain that they are excluded from the coastal regions. Sixteen species 

 marked with an * extend as far down as Crab Falls. The large number (eighty-two 

 species) not found at Rockstone shows that the fauna of the upper courses of the 

 river is much richer in exclusives than the coastal region with its thirty-one peculiar 

 forms. 



SlLURIDjE. 



1. Megalonema megacephalum. 



2. Microglanis poecilus. 



3. Pseudopimelodus albomarginatus. 



4. Braehyglanis frenata. 



5. Braehyglanis phalacra. 

 6.*Leptoglanis essequibensis. 



7. Myoglanis potaroensis. 



8. Chasmocranus longior. 



9. Chasmocranus brevior. 



10. Rhamdia quelen. 



11. Rhamdella foina. 

 12.*Pimelodclla megalops. 



13. Pimelodus heteropleurus. 



14. Oxydoras niger. 

 15.*Hemidoras notospilus. 



16. Hemidoras leporhinus. 



17. Auchenipterus brevior. 

 18.*Tympanopleura piperata. 



Pygidiuxe. 



19. Hemicetopsis macilentus. 



20. Hemicetopsis minutus. 



21. Pygidium guianense. 



22. Pygidium conradi. 



23. Pygidium gracilior. 



24. Ochmacanthus flabelliferus. 



Loricariid^e. 



25. Lithogenes villosus. 



26. Corymbophanes andersoni. 



27. Hemiancistrus megacephalus. 



28. Pseudancistrus nigrescens. 



