104 



ical* characters of various members of the group have been discussed and 

 illustrated. Among the latest publications relative to members of the 

 group are to be especially cited the Researches on Mammals of Messrs. 

 H. and A. Milne-Edwards.t and a monograph on the genus Hijlomys by 

 Dr. John Anderson )% i^ the former, several peculiar geuera, previously 

 briefly described by M. A. Milne-Edwards, are at greater length descri- 

 bed and illustrated, and in the latter the external and internal char- 

 acteristics of the animal are made known and the osteology figured in 

 detail, and the correctness of the reference to the family Erinaceidcc 

 rather than to the Tupaiidm satisfactorily demonstrated. 



EAIS^GE OF YARIATIOI^. 



The studies undertaken to ascertain the various degrees of relationship 

 of the several forms of the order were based on the skulls or skeletons § 

 of representatives of eacli family and subfamily except Potamogalidce 

 and Ehync1iocyo7iincc, and were much facilitated by the memoirs of Pro- 

 fessor Mivart. Indeed, so thoroughly had that gentleman applied him- 

 self to Ms task that little remained but to verify characters he had 

 discovered ; to intercalate forms unknown to him ; and to express the 

 subordination of the groups and their relations in a more decided 

 manner. In order, however, to test this work, the writer of the present 

 article examined the comparative characters of each part of the skeleton 

 (so far as he had the material) ; collated the results of this examination 

 with those of others ; incorporated what else appeared to be reliable from 

 others ; and tabulated all the characters so found in parallel columns and 

 contrasted terms. 



After thus co-ordinating all the characters of each family, and check- 

 ing the results then gained by renewed examinations, it began to ap- 

 pear that the most natural antithetical distribution of the non-flying 

 forms would be into (1) those with broad (fore and aft) molars provided 

 with two triangles or corresponding tubercles on the one hand, and 

 (2), on the other, those with narrow molars furnished each with a single, 

 well-developed triangular area. Assuming this division as a basis, the 

 other parts of the organization could be best correlated, and the 

 arrangement of the various forms became less involved. The successive 

 contrasts of the remaining forms, led to tlie results exhibited in the 

 classification now submitted, and the elimination from the associations 

 of forms familiar to the American student of (1) the Macroscelididw, 

 and then (2) the EHnaceidce, leaving the Soricidce and Talpidw in 

 closer mutual connection. These last, as now constituted, form a 

 rather heterogeneous group, and it may be that the Talpince and 

 Myogalincc should be divorced, and distinguished as separate fami- 

 lies. Inasmuch, however, as the resemblance in the skull is great, 



* Meckel (J. Fr.) Ueber die osteologischen Differenzen der Igelarten. < Beitr. zur 

 vergl, Anat., I. Heft 1 , 34-56, 1808. 



Sundevall (C.J.) Ofversigt, af sliigtet Erinaceus. <K. Vet. Akad. Haudlgr., Stock- 

 holm, 1841, p. 215-240,— Isis, 1845, pp. 273-280. 



t Edwards (Henri Milne et Alphonse Milne). Recherches pour servir a I'histoire natii- 

 relle des mammiferes. [2 vols.]— Paris : Victor Massenet Ills. . . . 1868-J874. [4to, vol. 

 I, 2 p. 1. 394 pp.; vol. II, viii pp., 105 pi., with 105 1. explanatory.] 



t Anderson (John). On the osteology and dentition of Hylomys. <^Trans. Zool. Soc. 

 London, VIII, art. XIII=pp. 453-467, pi. Ixiv, 1874. 



§ The specimens chiefly studied were in the museum of the Smithsonian collection ; but I 

 have also to record my indebtedness to Professor Marsh, in whose collections I found several 

 skeletons I could not see elsewhere, and among these was at least one of the types (Hemi- 

 centetes madagascariensis) of Professor Mivart's descriptions, obtained from Mr. Gerrard. 



