XXXIX 



western Georgia, where several parallel mountain 

 ranges completely enclose the A^alleys of the rivers, 

 almost all the species inhabiting them appear to be 

 confined Avithin their limits. And here, a space of one 

 hundred and fifty miles in length, by fifty in breadth, 

 will include the waters occupied by probably more 

 than a hundred and fifty species of Strepoynatidce. 



The following table, representing the arrangement 

 of the Strepomatidca followed in my "Synonymy" 

 of the species, published in the Proceedings of the 

 Academy of Natural Sciences, 1863-4, will show 

 both the toted number of species, and the absolute 

 and relative strength of the genera. A few species 

 since published have not all been included, as we 

 are not sufficiently well acquainted with them : — 



NUMBER OF SPECIES OF STREPOMATIDJE. 



1. Trypanostomoid Section. 



lO 



smooth 



spiuose 



PLEUROCERA . . . 



tuberculate 7 



sulcate 8 



striate, angulate ... 12 



carinate > 8 



plicate 2 



smooth, angulate ... 15 



smooth, not angulate . . 32 



ANGITREMA . . . 



with a coronal of tubercles 4 

 with two rows of tubercles 1 

 with a central row of tu- 

 bercles 7 



LITHASIA . . 



large, oval, inflated 

 small, compact . . 

 obliquely flattened . 

 subcylindrical . . 



STREPIIOBASIS 



ovate conical . . 

 cylindrical . . . 



84 



12 



17 



2. Goniobasic Section. 



EURYC^ELON 



GONIOBASIS 



spirally ric'ged . 

 tuberculate . . 

 plicate .... 

 angulate . . . 

 bi-multi-angulate 

 carinate . . . 

 smooth, short 

 smooth, elevated 

 striate, elevated 

 compact, ponderous 



SCHIZOSTOMA 



fissure narrow . . 

 fissure wide . . . 



AXCULOSA 



nodulous . . 

 sulcate . . . 

 striate . . . 

 angulate . . 

 subglobose, or 

 campanulate 



274 



1 

 18 

 85 

 16 

 11 



4 

 26 

 43 



8 

 62 



14 



12 



3 



4 



21 



26 



MESESCHIZA ... 1 



Third Section. 



31 



Total in 1st section 120 species,^ 



"2d " 307 " V 404 species in all. 



"3d " 31 " S 



