THE COLEOPTERA. 23 



insect, but it probably does not differ materially from those 

 of its European allies. Although so very different in 

 general appearance to the preceding insects, this beetle 

 will be found on careful examination to agree with them 

 in all important respects, being only what a ground 

 beetle might naturally become if forced to lead an aquatic 

 existence. Breathing is effected in all the water beetles 

 by the spiracles of the abdomen, which alone are developed. 

 The air is taken in between the elytra and the body, 

 and owing to the convexity of the former, a supply can 

 be retained sufficient to last the insect some twenty or 

 thirty minutes. The beetles may be often observed with 

 the extremity of their elytra protruded above the surface, 

 renewing their supplies of air. On very hot days C. rufi- 

 manus may be occasionally seen flying with great rapidity 

 far away from its native ponds. When doing so it makes a 

 loud humming noise, and is a much more conspicuous 

 object than when in the water. 



Group CLAVICORNIA. 



Family NlTlDULID^E. 



Epitrosa zealandica. 



This curious little beetle is found abundantly in the 

 neighbourhood of decaying fungi, throughout the year, 

 being most plentiful in the autumn and early winter. Its 

 larva is a small cylindrical grub, with the head and legs so 

 minute that they are scarcely perceptible, causing it to 

 closely resemble the maggots of many dipterous insects, 

 occurring in similar localities. It is generally found in the 

 large yellow fungi, so abundant in wet situations during 

 the late autumn and winter months. It forms numerous 

 galleries through the plant in all directions, and owing to 

 the large amount of moisture which is usually present, these 

 galleries are often filled with water, so that the insect may 



