Species distribution patterns of the aquatic beetle family Dytiscidae were analyzed in the five major watersheds of New Mexico: the San Juan, the Gila, the Rio Grande, the Pecos, and the Canadian drainages. A map is presented showing the drainage divisions as well as the areas with no external drainage. About 8000 speciments from 175 different locality records supplied the material for the comparisons. So far 65 species belonging to 17 genera have been found. The most common genera are Hygrotus, Deronectes, Hydroporus, Laccophilus, Agabus, Rhantus, and Thermonectus. Occurence and relative abundance is given for each species found. It is estimated from the number of collections made per watershed and the number of species taken per watershed that there may be another 10 to 15 species yet to be found. The bidessines, Copelatus, and the large dytiscines were sparsely collected and more refined collecting techniques are necessary to demonstrate their distribution and abundance. Species distribution is not related to drainage basin; other topographic and climatic factors are more important. (Author)