Rhinolophus affinis Horsf.

Andersen, Knud, 1905, On some Bats of the Genus Rhinolophus, with Remarks on their Mutual Affinities, and Descriptions of Twenty-six new Forms., Proceedings of the Zoological Society of London 2, pp. 75-145 : 101-103

13. Rhinolophus affinis Horsf.

(Plate III. figs. 11-13.)

Diagnosis. Sella pandurate, p2 in the tooth-row. Forearm 50-56 mm.

Details. This species marks an important progress in development as compared with Rh. rouXi . It is the base of the ferrumequinum section.

The chief modifications are four: in the shape of the sella; in the structure of the wings; in the size of the animal; in the shortening of the palatal bridge.

In the borneensis-rouXi type the sella is practically parallel- margined; in affinis it is pandurate, i. e. the lateral margins concave, as in ferrum-equinum , though generally to a slightly less degree. In simpleX and its closest relations the lancet is almost cuneate; in borneensis there is a tendency towards emargination of the lateral margins; in rouXi this tendency is carried to an extreme; in affinis the lancet falls back to the former stage: it is almost cuneate.

Throughout the whole series of forms reviewed above, with the exception of the somewhat aberrant Rh. nereis , stheno , and thomasi , the wings have remained at the same primitive stage. no length ening of the second phalanx of the third finger. In affinis this phalanx has considerably increased in length, being always more

than, and with very rare exceptions considerably more than, U the length of the first phalanx, a peculiarity which is preserved in the subsequent stage of evolution: ferrum-equinum . The aberrant species just alluded to, viz. Rh. nereis , stheno , and thomasi , are, from this point of view, of especial interest, as being Bats of the rouXi type which already show the wing-structure characteristic of the more highly developed affinis .

Rh. affinis is larger than rouXi ; but small affinis have the same length of the forearm as very large rouXi . In such cases, Rh. affinis , provided the specimens examined are fresh or preserved in spirit, can, of course, easily be discriminated by the shape of the sella and the length of III."; if preserved as dried skins (in which the shape of the sella is often difficult to recognise), still the latter character remains unchanged.

Colour. The many forms in which this species is differentiated seem to agree, rather closely, in colour:—

() Darker individuals: ♂ ad., Darjeeling {Rh. a. himalayanus); Oct. 22nd; teeth unworn; skin:—Upper side “ mars-brown ” with a rather strong hue of “ drab ”; no horse-shoe patch; base of hairs “ ecru-drab ”; under side “ broccoli-brown."

Still darker is a ♂ ad. from Lombok {Rh. a. qrrinceps'); teeth somewhat worn; in alcohol; unfaded: —“ Prout’s brown ” above, base of hairs “wood-brown ”; under side almost “tawny-olive. ”

(2) Light-coloured individuals: ♂ ad., Nanking {Rh. a. himalayanus'); July 5th; teeth somewhat worn; skin:—Extremely light. Above light “ clay, ” almost “ ochraceous-buff, ” hinder back somewhat darker; a rather distinct, “ mars-brown ” horseshoe patch; base of hairs “ cream-buff ”; under side very light, almost “ cream-buff.” — A spirit specimen (♂ ad.) from the same locality (June 15th) is quite of the same colour.

Skull. The essential characters as in rouXi , proving that Rh. affinis originated from a Bat of that type, The skull is generally larger, and the gap in front between the maxillary bones wider. Chief character: the exceedingly short palatal bridge, as a rule only | the length of the maxiliar tooth-row, or even less; in rouXi , with very rare exceptions, decidedly more than sometimes almost 5. The teeth, too, are slightly larger.

Dentition. p3 external and extremely small; but, as a rare exception, this premolar may still, in this comparatively highlydeveloped species, show some tendency towards the tooth-row (one skull, out of 19), or be halfway in row (one). p „ and p 4 generally quite, or almost, in contact (14 skulls); in tbe remaining somewhat more distinctly separated, p2 always in the tooth-row, extremely small, and the interspace between the canine and p4 rather narrow. In no less than five skulls there is an exceedingly narrow, in most cases almost hair-fine, interspace between p- and p * (the formel' place of p3).

Distribution. From the N.W. Himalayas to S. China; through Indo-China, the Malay Peninsula, and N. Natunas, to Sumatra, Java, and Lombok.

Technical name. The type of Rh. affinis is in the British Museum. From the original description it would have been quite impossible to identify the species.

Remarks. Of all the races of Rh. affinis , the Himalayan form {Rh. a. himalayanus) is the most ordinary-looking: in the horse-shoe, the ears, the nasal swellings, the brain-case. There can hardly be any doubt that the affinis type originated in the Himalayas, and from there spread eastwards to S. China, southeastwards through Indo-China, as far as Lombok.

Geographical races. There are, at least, seven forms of Rh. affinis , differing in certain cranial characters, in the size of the ears and horse-shoe, in the length of the tail and tibia, in general size, and in geographical habitat. Some of these forms may be called distinct species by other authors.