254 Bulletin American Museum of Natural History. [Vol. XXVII, 



Primitive Inmctivore characters. General eonfiguration of young skull, 

 especially the long tubular snout; o})posite alveolar borders of premaxillaries 

 parallel. I \ enlarged (the extreme enlargement is secondary). Canine 

 bifanged (possibly independently accjuired). Premolars conical, pi absent; 

 fourth upper and lower premolar submolariform. jNIolars with high pointed 

 cusps; enlarged internal cusp of iq^per molars homologous with protocone of 

 Icfops and Dri/oJcstcs, {cf. Fig. 17, no. 3), basal internal cusps derived from the 

 cingulum; lower molars with very small talonid, lacking hypoconid; pro- 

 tocone of u])])er molars received into cingulum fossa or space back of pro- 

 toconid (all as in Jurassic Tritubercidates and presumably primitive). 

 No post orbital process, orbit broadly continuous with temporal fossa. 

 Palate well ossified, fenestrte slight or absent {cf. Ictops, vacuities in Erina- 

 ceus secondary). No ectopterygoid fossae, the pterygoid wings of the pala- 

 tines and alisphenoids forming a single straight ridge on either side; true 

 pterygoids probably represented by cartilages. Tympanic branch of ali- 

 sphenoid joining ])ost-glenoid crest of squamosal; post-tympanic process 

 separated from glenoid fossa. 



Auditory prominence of petrosal ovoid, closely appressed to basioccij)ital, 

 with depression on inferior surface (all as in Ictops). Basioccipital con- 

 tributing largely to the occipital condyles. Mastoid exposure large. Hole 

 between basi- and pre- sphenoids in the mid line probably an apophysis of 

 the vestigial "hypobasal notochord." Foramen rotundum confluent with 

 sphenorbital fissure. Prominent "sinus canal"; suboptic foramen leading 

 to presphenoid sinus. 



Osseous intercentra below posterior dorsals and lumbars. Humerus 

 of young with slight vestige of supratrochlear foramen (entirely lost in adult). 

 Radius and ulna curved longitudinally. Ilium rod shaped. Pelvis with 

 general resemblances to that of Erinaceus (however, Leche's specimens of 

 S. parado.vus has a long symphysis pubis). 



Tibia and fibula with tendency to fuse distally. Digits II, III, IV, of 

 both manus and pes, subequal, digit III being slightly longer especially in 

 the pes; distal metapodial joints transversely cylindrical, keels slight or 

 absent; ungues compressed not fissured at the tips (secondarily fissured in 

 Talpidse) . Astragalus with tibial notch near to internal trochlear crest, the 

 latter prominent; external and internal malleolar facets subvertical, neck 

 somewhat oblique, head transversely flattened, ectal facet triangular, sus- 

 tentacular facet an elongate oval set near the internal posterior border. 

 Calcaneum with short tuber, large sustentaculum, spreading antero- inferior 

 base; a prominent antero-external process. 



Primitive Zcdamhclodovd characters. Upper molars remaining V-shaped, 

 with basal pseudoprotocone and hypocone; para- and metacones reduced. 



