Belongs within: Soricidae.
Blarina, the short-tailed shrews, is a genus found in eastern North America. Members of this genus secrete a neurotoxic venom from submaxillary glands that can cause pain for several days in humans bitten (Nowak 1999). Morphologically, the species are primarily distinguished by size, with the northern short-tailed shrew Blarina brevicauda on average larger than the southern short-tailed shrew B. carolinensis, with Elliot's short-tailed shrew B. hylophaga being intermediate both in size and geographical range. However, substantial overlap in size ranges can occur, and morphological distinction of the species can be difficult (Reilly et al. 2005).
Characters (from Nowak 1999): Head and body length 75-105 mm, tail length 17-30 mm, weight 15-30 g. Upper parts slate-coloured, underparts slightly paler. Body robust; snout pointed; eyes small; ears hidden by fur. 32 teeth, with five unicuspid teeth in upper jaw: the second and third incisors, the canine, a normal premolar and a minute premolar.
<==Blarina Gray 1838 [incl. Anotus Wagner 1855, Mamblarinaus Herrera 1899, Talposorex Pomel 1848] V67
|--B. brevicauda (Say in James 1823) B75 [=Sorex brevicaudus B75; incl. Galemys micrurus Pomel 1848 G69]
| |--B. b. brevicauda GC72
| |--B. b. churchi GC72
| |--B. b. kirtlandi GC72
| |--B. b. minima B75
| `--B. b. talpoides GC72
|--B. carolinensis (Bachman 1837) RM05, B75 [=Sorex carolinensis B75, B. brevicauda carolinensis RM05]
| |--B. c. carolinensis RM05
| |--B. c. peninsulae RM05
| `--B. c. shermani RM05
|--B. hylophaga [=B. brevicauda hylophaga] RM05
| |--B. h. hylophaga RM05
| `--B. h. plumbea [=B. brevicauda plumbea] RM05
`--B. telmalestes GC72
*Type species of generic name indicated
[B75] Bowles, J. B. 1975. Distribution and biogeography of mammals of Iowa. Special Publications, The Museum, Texas Tech University 9: 1–184.
[GC72] Genoways, H. H. & J. R. Choate. 1972. A multivariate analysis of systematic relationships among populations of the short-tailed shrew (genus Blarina) in Nebraska. Systematic Zoology 21 (1): 106–116.
[G69] Goodwin, G. G. 1969. Mammals from the State of Oaxaca, Mexico, in the American Museum of Natural History. Bulletin of the American Museum of Natural History 141 (1): 1–269, 40 pls.
Nowak, R. M. 1999. Walker's Mammals of the World, 6th ed., vol. 1. John Hopkins University Press.
[RM05] Reilly, S. M., R. W. Manning, C. C. Nice & M. R. J. Forstner. 2005. Systematics of isolated populations of short-tailed shrews (Soricidae: Blarina) in Texas. Journal of Mammalogy 86 (5): 887–894.
[V67] Van Valen, L. 1967. New Paleocene insectivores and insectivore classification. Bulletin of the American Museum of Natural History 135 (5): 217–284.