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Show 1902.] ON THE YOUNG OF POLYPTERUS. 121 large, whitish, especially at their edges. Arms and legs like sides hands and feet heavily built, their upper surfaces greyish white ; soles naked except under the heels. Tail but little bushy, its hairs broadly ringed with black and pale yellowish, their tips whitish. Skull rather heavier than that of F. cejxtpi. Nasals broad, expanded posteriorly. Interorbital region broad, flat or slightly concave ; postorbital processes well developed, projecting directly outwards instead of backwards. Premolars |-. Molars heavier than in F. cepapi. Dimensions (approximate) of the type, measured in skin :- Head and body 205 mm.; tail 145 ; hind foot s. u. (wet) 41; ear (wet) 19. Skull-henselion to basilar suture 28 ; nasals, length 12*5, least breadth 5, posterior breadth 6; interorbital breadth 12; tip to tip of postorbital processes 19 ; intertemporal breadth 13 ; palate length from henselion 18*5 ; diastema (to front of px) 10'6 ; length of tooth-row (omitting the small p3) 8. Lower jaw, condyle to incisor-tip 27*7. Hab. Muezo, near Lake Mweru. Type. Old male. B.M. No. 2.1.6.8. It is difficult to say to which species F. yulei is really most closely allied. Externally it has a certain resemblance to F. annularis, but that animal has only one upper premolar and differs in many other details. From F. cepapi, found in the same region, it is distinguished by its larger ears, grey instead of fulvous limbs, whitish feet, larger molars, and other points both external and cranial. I have connected with this distinct Squirrel the name of Mr. J. B. Yule, of the official staff of the Protectorate, by whom a large number of the North Nyasa specimens described now and in former papers have been collected. 4. On some Characters distinguishing the Young of various Species of Polypterus. By G. A. B O U L E N G E R , F.R.S. [Received January 28, 1902.] (Plates X. & XL1) The increased interest which has lately been paid to the remarkable African Crossopterygian Polypterus has resulted in a better understanding of the characters by which the species can be distinguished2, and the recent exploration of the Congo has added several forms, fully entitled to specific rank, which were undescribed3. 1 For explanation of the Plates, see p. 125. 2 Of. Boulenger, Ann. & Mag. N. H. (7) ii. 1898, pi 416. 3 Of. Boulenger, Poiss. du Bass, du Congo (1901), and Ann. Mus. Congo, Zool. ii. (1902). |