COUES ON INSECTIVOROUS MAMMALS. 641 



teetb, larjie friuged feet, and long keeled tail, finds its strict representa- 

 tive in the American genus yeosorex, wliicli includes equally aquatic 

 species, with large fimbriate feet, though the tail is scarcely carinate 

 with hairs,, and the teeth are 32 in number.* 



Blarina with its several species is the most characte ristic American 

 genus, and the most prominent of those peculiar to this continent, hav- 

 ing no exact Old World analogue. It is well marked by the structure 

 of the small external ears, in\'isible on ordinary inspection, very short 

 tail, and a special condition of the dentition, although the number of the 

 teeth, 33 or 30, is the same as in Sorex. Like the latter, it is divisible 

 into subgenera, according to the number of the teeth ; Blarina proper 

 (type hrei-icauda) having 32 teeth, while there are but 30 in the section 

 Soriciscus, defined beyond. 



Following are the diagnostic characters of the American genera and 

 subgenera of ISoricidce, with their respective synonyms : — 



I. Genus NEOSOREX, Baird, 1857. 



Sorex, sp., Rich., F. B.-A., i, 1329, 5. {S. palusiris, oi'ig. descr. in Zool. Jonrn., iii, No. 



xii, April, 1828, 517. Teeth miscpuuted 30 instead of 32, the true number.) 

 Neosovex, Baird, M. N. A., 1857, 11. (Type A^. nav'ujator Cooper, sp. n.) 

 Hydrogale, Girx, Bull. U. S. Geol. and Geogr. Surv., 2d ser., No. 2, 1875, 111. (Not of 



Pomel, 1848, -which is a figment, based on a blunder.) 



Chars, gen. — Teeth 32 (f§), as in Sorex proper. Upper nnicuspidst 

 5, the fifth minute, the fourth and third smaller than the second and 

 first, which are equal to each other; third equal to or smaller than 

 fourth. Upper incisors with a posterior hook as large as the succeed- 

 ing tooth, and like it in shape, and with a notched lobe on the inner 

 side, connivent with its fellow. Lower incisors with several (normally 

 three) denticulations on the cutting edge, and reaching back beyond 

 the next tooth, which is thus entirely above them. Teeth all colored- 



* Dr. Gill having recently proposed to supplant the term Xtosorcx Baird, 1857, by 

 Hydrogale Pomel, 1848, it becomes expedient to inquire into the case. Hydrogale was 

 based upon Sorex fimhripes of Bachman — a species which has occasioned much uncer- 

 tainty and confusion. The name suggests an aquatic species ; but this is altogether 

 erroneous. In 1861, Baird examined Bachraan's type preserved in the Philadelphia 

 Academy, and found it to be a species of ordinary 32-toothed Sorex, scarcely or not 

 distinguishable from "cooperi". Bachman miscounted 34 teeth (which number no 

 known American species possesses), and wrongly laid stress on certain characters of 

 the feet, which had no basis except in the accidental condition of the specimen as 

 preserved. Hydrogale is therefore based on a misapprehension, the characters assigned 

 having no existence in nature, and the type of the "genus" being scarcely or not spe- 

 citiculiy separable from a previously known form ; it therefore becomes of course a 

 synonym o{ Sorex proper, as a pure figment — so far is it from being " uudoubledly con- 

 generic with Neoisorcx", as assumed by Dr. Gill witlunit that degree of caution which 

 distinguishes that trained naturalist. 



t By the descriptive term " unicuspids", I intend to cover in these descriptions the 

 anterior series of lateral teeth betweau the bicuspid front incisor aud the pluricuspid 

 molarifurm teeth, purposely avoiding committal to the homologies which would be im- 



