| OCR Text |
Show 4 MR. OLDFIELD THOMAS ON THE [May 3, Teeth of the normal insectivorous structure ; the reduction m size of the incisors, two anterior upper and median lower premolars as in Myotis, though the resemblance is clearly quite superficial. Dimensions of the skull Greatest length 16 mm.; upper length in middle line 14'4 ; basal length 13*5 ; zygomatic breadth 11*8 ; intertemporal constriction 4 ; breadth of brain-case 9'6 ; palate, length 5-8, breadth inside m.2 3, outside m.2 6'4; front of upper canine to back of m.3 6'3 ; front of lower canine to back of m.3 6'7. The skeleton as a whole, including the structure of the sternum and pelvis, appears to be remarkably like that of certain "V esper-tilionidse, notably Scotophilus ; but I suppose this to be due to its being of a primitive nature, without any noteworthy specialisations in the way of ankyloses or hypertrophy of parts. Wonderful differences are to be found in these respects in various genera of Chiroptera *, but I have not studied the subject sufficiently to form an opinion as to the systematic value to be attached to these modifications. Fortunately, Mr. Gerrit Miller is now engaged on a general revision of the classification of Bats, and is dealing fully with the skeletons, so that I do not propose to do more than give a short description of that of Myzopoda for incorporation in his work. The vertebral formula is 0. 7, D. 13, L. 5, S. 4, C. 8 ; total 37, plus a cartilaginous rudiment of a ninth caudal vertebra. None of the vertebrae are ankylosed together, except of course those of the sacrum, thus widely differing from the condition in Natalus. Eight of the ribs are connected with the sternum by costal cartilages, the ninth, tenth, and eleventh also having cartilaginous continuations not reaching to the sternum ; the twelfth and thirteenth are practically without such continuations. The sternum is simple and little specialised ; the presternum normal, with a rather elongate manubrial process (fig. 2 a), which is but little expanded terminally ; the broad sterno-costal plate + between the presternum and first rib, so characteristic of Bats, of average dimensions; mesosternum slender, 6 mm. in length, slightly keeled, the costal cartilages of the 3rd to the 7th ribs articulating with its sides at subequal distances, that of the 8th joining it side by side with that of the 7th at its posterior end ; xiphisternum 2-8 mm. long, slender, scarcely broadened terminally. Proportions of scapula as shown in the Plate (figs. 2 & 4), its antero-internal angle produced into a well-marked process projecting downwards and inwards towards the vertebra] column. Coracoid about 3 mm. in length, therefore not long for a Bat of this size, simple, slightly falciform, not expanded terminally. The pelvis is on the whole very similar to that of Scotophilus * The peculiarly ankylosed vertebral column of Natalus and the highly modified sternum of Kerivoula are examples. f The homologies and proper name of this hone are not as yet definitely settled. It is the " 7 " of Winge's figure on p. 44 of his Chiroptera of Lagoa Santa (E Mus'. Lun^ii, 1892), where its relation to the epicoracoid of Parker is discussed. |
