40 jMr. K. Antlcrscn on the Bafs of the 



posterior leaf of practieally the same broaclth as the horse- 

 shoe, its upper border evenly convex, on the front face three 

 vertical ridges, the Lateral ridges often more or less obsolete. 

 Thus, there are only two noteworthy points of difference 

 between the nose-leaves of a H. diadema and those of a 

 H. Commirsoin , viz. the somewhat stronger development of 

 the lateral leaHcts in the latter type of bat (three with, almost 

 invariably, a small fourth, instead of three with rare indi- 

 vidual traces of a fourth in diadema) and the proportionately 

 slightly smaller posterior leaf ; but the shape of the posterior 

 leat, as well as of all the other nose-leaves, is extremely 

 similar in both types. — A frontal sac, opening by a longitu- 

 dinal fissure, is found in both sexes. 



The cais are considerably modified (as compared with 

 diadema) : narrowed and pointed. The tail much shortened : 

 always shorter than the lower leg (in diadema always much 

 longer than the lower leg). The plagiopatagium inserted on, 

 or a short distance above, the ankle, quite as in diadema * . 



They are all bats of very large size, the forearm varying 

 from 79 to 116 mm. Males seem to average larger than 

 females, but practically there is no constant diflference in 

 size bet\\een the sexes f. The frontal sac is markedly 

 shallower in females. 



Their range is confined to the Ethiopian Region, on the 

 eastern side from Madagascar and the Mozambique coast to 

 British East Africa, on the western from Angola to Gambia. 

 I discriminate three species (five forms). 



believe, not difficult to explain. "When the number is given too low 

 (two, three) it may be due to an examination oi skins, in which the true 

 number of leaflets is often veiy difficult to ascertain, owing to shrinkage ; 

 when the number is given too high (four, with the rudiment of a fifth), 

 the reason may be this : external to the fourth leaflet is almost invariably 

 situated a small rounded gland, which by a hasty examination can easily 

 be taken for the trace of a fifth leaflet ; but similar glands are found in 

 many other places of the upper lip. 



* Some details about the insertion of the plagiopatagium on the hind 

 leg (from alcohol specimens only) : — H. Commersoni, in two ( 2 ad.) on 

 the ankle, in one ( S young ad.) 2 mm. above the ankle ; H. fficjas, in one 

 ( $ ad.) on the ankle, in one ( j" ad.) 2o mm., in two {S ad.) 5 mm., in 

 one (c? young ad.) 6 mm. above the ankle. — It has been suggested that 

 the membranes in younger individuals reach the ankle, but " sich 

 allmahlig so zuriickziehen, dass sie bei alten Exemplaren einen Theil des 

 Schienbeins frei lassen" (Peters, MB. Ak. Berlin, 1871, p. 318). The 

 above details are not in favour of that explanation. 



t A few particulars in support of this statement (forearm of full-grown 

 individuals) : — JF. C. marungensis, one male 94 mm., one female 965 mm. ; 

 H. yif/as, three males 108, 110, and 115 mm., one female 108 mm. 



