3<d Ihc Irish Naturalist. [February, 



enrich the literature of the subject are omitted, as they are 

 familiar to every one. 



A list of references will be found at the end of each paper, 

 to which the Roman numerals apply. 



Introduction. 



The Order of Chiroptera, belonging to the class Mammalia 

 is divided into two sub-orders, Megachiroptera and Micro- 

 chiroptera (Dobson iv.) 



The Megachiroptera are tropical or sub-tropical Bats, 

 exclusively confined to the eastern hemisphere, feeding on 

 fruit, and with teeth and digestive system modified accordingly. 

 As a rule they are of considerable size. As none of the Irish 

 bats belong to this sub-order, this account will here suffice. 



The Microchiroptera are usually much smaller, and 

 generally insectivorous. Their teeth commonly have acutely 

 pointed cusps, and their stomachs are simple or have a cardiac 

 pouch. Special sense organs are found in many genera, with 

 other modifications of the cutaneous system. Members of the 

 sub-order are distributed throughout the world. 



The seven species at present recognised as occurring in 

 Ireland represent two families of the Microchiroptera, 

 Rhinolophidce and Vespertilionidcc. Rhinolophus hipposideros, 

 Blasius, the Cesser Horseshoe Bat, is the only member of the 

 former family, while the remaining genera Plccotus, Vespemgo, 

 and Vespcrtilio 1 , comprising the rest of the species, belong to 

 the latter. 



The anatomy of the bats presents many interesting 

 features which can only be briefly touched on here. The 

 most noticeable of these is the modification of the fore- 

 limbs to form wings. This is effected, not by any new 

 structures being added, but by the alteration of those already 

 present, and on examining the wing closely, the same bones 

 may be identified that we are familiar with in ourselves. The 

 humerus, though proportionately larger, does not differ much 

 from the human type, but in the fore-arm w T e note that one 

 bone, the radius, is very much elongated and strengthened, 

 while the other, the ulna, is quite rudimentary. The wrist 

 bones are few and short, and the metacarpal bones and those 



1 On the subject of nomenclature see Miller (xiv.), and Thomas (xvi.) 



