Numbers
4 species in our region: cavatus, gertschi, puebla, and tehama.
Identification
These spiders make a characteristic triangular web with four radii connected to a bridge line which the spider holds taut. The web looks something like a 45-degree portion of a typical orb web.
Range
Found throughout the US and Canada.
H. cavatus is found in the eastern US from New England to southern Florida, west to Wisconsin, Missouri, East Texas; north to below the Great Lakes, New York, New Hampshire coast
H. gertschi is found in the western US, entire west coast, California to Alaska, Idaho and Montana, mountains of Utah and Colorado, and all across Canada, probably with some overlap in range with cavatus in the Northeast.
The other two species appear to be poorly studied and more restricted in range -
H. puebla is found in the Southwest, Arizona, New Mexico, southern Utah, west Texas
H. tehama has only been found in portions of Northern California, Tehama and Siskiyou counties, and Wyoming
although this range information may be quite dated.
Internet References
The Spider Family Uloboridae in North America north of Mexico, Muma and Gertsch revision, American Novitates, 1964. This paper has a description of the genus and a key to the four species found in our region, as well as range maps and drawings of the male and female genitalia and habitus.