Within this larger grouping a number of subfamilies have been identified.
"Shoshone-Bannock Subsistence and Society"
Robert F. Murphy Yolanda Murphy
So gradual, however, is the transition that I find it difficult to decide in one instance to which of two genera, typical respectively of the two "subfamilies," a species should be assigned.
"Freshwater Sponges, Hydroids & Polyzoa"
Nelson Annandale
There are two subfamilies-Spalacinae and Bathyerginae.
"Natural History of the Mammalia of India and Ceylon"
Robert A. Sterndale