1880. J PROCEEDINGS OF UNITED STATES NATIONAL MUSEU^r. 21 



lateral line. In other respects tliey agree with If. venustus, from which 

 si)ecies they may prove to be not distinct 



13. Notropis tivraini Jordan *.V Gilbert. 



Abundant in the outlet of the spring. 



14. Hybopsis aestivalis Girard. 

 Abundant in the current of the river. 



15. Anguilla anguilla rostrata De Kay. 

 Abundant in Barton Spring. 



16. Gambusia patruelis Baird & (iirard (hiimiUs). 



17. Zygoiiectes notatus Eafiuesqne. 



18. Micropterus salmoides Laceptide. 



These specimens agree with i^Torthern ones in form and squamation. 

 The mouth is, however, a little smaller, and the coloration is somewhat 

 different. The lateral band is broken up into numerous irregular dark 

 cross-streaks, which reach the dorsal fin, and below this there are very 

 distinct longitudinal streaks following the rows of scales. The caudal 

 fin has narrow cross-streaks formed of dark spots. 



19. Lepoinis cyanellus Rafinesque. 



20. Lepoinis inegalotis Rafinesque. 

 Coloration very green. 



21. Lepomis pallidus Mitchill. 



With cross-shades of coppery-red on lower part of sides. 



22. Perciua caprodes Rafinesque. 



23. Etheostoma lepidum Baird & Gir.ard. (36587.) 

 Abundant in the outlet to the sjiring. 



24. Aplodinotus grunniens Rafinesque. 



In the river. , 



I. — RIO SAN MAROOS, AT SAN MARCOS, TEXAS. 



The San Marcos Eiver takes its rise in a very large sirring, one of 

 the largest in the United States, in the limestone hills at San Marcos. 

 From the s[)ring flows a strong stream of very clear and somewhat cold 

 water, rather swift, and full of grass and water- weeds. The size of the 

 stream varies little with the change of season. Three or four miles be- 

 low San Marcos the liio Blanco, a long stream, flowing over gravel, and 

 nearly dry in summer, flows into the San Marcos, pur collections w^ere 

 made in the Rio Blanco and in the Kio San IMarcos, just below the 

 mouth of the former. In the Rio Blanco we found little except Notro- 

 pis lutrensis, which swarmed in all the pools. In the Rio San Marcos 

 Darters were very abundant, as was to be expected in such waters. 



