''Hiltonius'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of cylindrical
millipedes in the family
Spirobolidae comprising 10 species ranging from the southwestern United States to Guatemala, with most species being found in Mexico. The genus was named by
Ralph Vary Chamberlin in 1918, after Professor William A. Hilton of
Pomona College who collected the
type specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
of ''H. pulchrus''.
Description
Species of ''Hiltonius'' range from long and wide, with 40–49 body segments. The eyes are composed of patches of
ocelli, widely spaced, containing 21 to 37 ocelli per patch. The legs are short, usually not reaching the sides of the body when held horizontally. Like many other spirobolids, color ranges from brown to nearly black, and thin bands of red or yellow may occur on the rear margins of each segment.
Species
''Hiltonius'' contains 10 named species. Some have wide distributions while others are known only from the type locality- the place where the
type specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
s were initially discovered.
[ The northernmost species are ''H. pulchrus'' and ''H. carpinus'', ranging into southern California and northern Arizona, respectively. A ]subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
of ''H. carpinus'' occurs in an isolated population in Guatemala
Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by H ...
.[
]
Similar species
''Hiltonius'' co-occurs with some species of ''Tylobolus
''Tylobolus'' is a genus of millipedes in the order Spirobolida with seven known species found in western North America. It is in the family Spirobolidae, and is the type genus of the subfamily Tylobolinae. The genus was named by Orator F. C ...
'' in southern California. ''Tylobolus'' species can be distinguished by larger maximum size (up to 92 mm or 3.6 in long), having more ocelli per eye patch (27–50), a larger hooked process on the coxa of the third leg in males, and in details of the gonopods
Gonopods are specialized appendages of various arthropods used in reproduction or egg-laying. In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of intromittent organ. In crustaceans and milli ...
, male reproductive structures.[
]
References
External links
''Hiltonius''
on BugGuide
{{Taxonbar, from=Q4255897
Spirobolida
Millipedes of North America