1854.] 191 



exclusive of the teeth is the peculiar form of the alar membrane, which on the 

 sides extends only to the middle of the tibia, and in the tail being shorter than 

 the interfemoral membrane and in having its extremity free by passing through 

 it near the middle. 



There are very good representations of this animal in Schreber and in D'Or- 

 bigny. The figure in Seba vol. i. pi. Iv. fig. 1, referred to by authors, has nothing 

 to do with it. 



In order to remove any difficulty which may hereafter occur in the determina- 

 tion of this species I add a detailed description, observins that very little reliance 

 ought 1o be placed on the color. 



Noctilio le-porimis. Linn. Syst. Nat. i. p. 47, Noctilio dorsatus Geoffroy de 

 St. Hilaire and Wagner, N. albiventris Spix, N. affinis D'Orbigny, N. unicolor 

 Wagner. 



Fur short and soft fulvous a little paler beneath, back with a very conspicuous 

 narrow stripe of a paler and yellowish color from the base of the head to the 

 root of the tail. The hair of the back occupies a triangular space the base of 

 which lies between the shoulders and the apex reaches to the tail, leaving the 

 sides naked. Beneath the whole body is covered with hair. Face black: nose 

 broad, flat, emarginate, sulcate on the top ; nostrils somewhat tubular and pro- 

 jecting; upper lip tumid confluent with the nostrils, hanging down and its de- 

 pendant sides so placed as to form a wide excavation below the part which 

 covers the incisors ; it is not however cleft nor resembling a hare lip (unless it be 

 shrunk and contracted upwards by the drying of the parts) lower lip very tumid, 

 three lobed the lateral lobes recurved and crenate on their edge. Chin with a 

 small semicircular appendage and four folds diverging from it. Cheeks with 

 four small warts, each furnished with two bristles. Ears rather long, oval, blunt 

 pointed, outer edge with four or five transverse plica? the lower part with an up- 

 right rounded lobe ; tragus small with a small branch on the inner side and four 

 blunt teeth on the outer. Membrane thin, black, naked, not reaching as in most 

 other bats to the carpus of the hind feet but ending about the middle of the tibia, 

 on the under side it is whitish for a considerable space near the body, around the 

 tail and along the hind legs: at the thumb, on the under side of the membrane on 

 each side of the innermost figure is a small pouch or cavity formed by a narrow 

 appendage or supplementary portion of the membrane which proceeds from the 

 joint and runs down the wing for a short distance. Interfemoral membrane in- 

 cluding the tail, broad rounded at the end with a small tooth on each side about 

 one quarter of the distance from the middle. Tail not half as long as the inter- 

 femoral and projecting from the middle of the membrane for about one fifth of 

 its length. Hind legs stout, feet very long toes with parallel claws very long 

 and very much hooked calcaneum bordering the membrane for the greater part 

 of its length. 



Length of head and body 4 inches, head 1.2, extent 22.7, length of interfemoral 

 2 inches, tail 1.0, naked portion 2.0, foot 1.1, nail 35. 



On TJrnatella gracilis and a new species of Plumatella. 

 By Joseph Leidy, M. D. 



In the Proceedings for November 1851, (page 321), I published the description 

 of what I then suspected to be the coencecium of a new genus and species of 

 fresh water bryozoid polyps, to which I gave the name of JJmatella gracilis. 

 Since then I have examined this body and find my suspicion was correct ; and 

 TJrnatella proves to be the most beautiful of the fresh water polyzoa which has 

 yet been discovered. I have made drawings of the species, and propose hereafter 

 to give a full description of it; and at present will simply give its diagnosis. 



TJrnatella, Leidy. 



Cancecium consisting of a series of segments up to eighteen in number, and 

 forming free, semi-erect, curved stems, attached only by the base of the lowest 

 segment. Segments, excepting the three last ones, simple, urniform ; the ante- 

 penultimate and the penultimate oblong, with simple or compound branches of 



