52 Transactions. — Zoology. 



be spared for dissection, the neuration can be made out by denuding a 

 small portion of the under-surface with a camel's-hair brush moistened ; 

 the part requiring denudation is the neighbourhood of the areole, as in 

 general the other veins can be sufficiently discerned on the lower surface 

 under a lens. Of course the student should first make himself acquainted 

 by full dissection with the ordinary position of the veins, and the nature of 

 the more important points to be observed. 



I will repeat here the explanation given in a former paper of the mode 

 of reckoning the veins, with special reference to the Geometrina. These are 

 numbered in order, beginning from that nearest to the inner margin, and 

 ending with that nearest to the costa. The forewings have normally 12 

 veins, of which 1 and 12 rise separately, the rest from the margins of a 

 central cell. Similarly the hindwings have normally 8 veins, of which 1 

 and 8 are separate, the rest rising from a central cell. Sometimes a vein 

 may be obsolete, especially in the hindwings, which thus appear to have 

 only 7. The veins are assumed to rise from the cell independently of one 

 another, unless otherwise stated. Earely there is a small additional free 

 vein vetween 1 and the inner margin ; this is termed la. The veins 

 rising from the upper margin of the cell are in the Geometrina constantly 

 liable to unite for a short distance in the middle of their course, and then 

 separate again ; this I have termed anastomosing. In consequence of it, 

 there is usually formed a small additional cell (termed the areole) upon the 

 margin of the main cell ; this areole may be single, double, or even triple 

 (though not in New Zealand), according to the number of veins anasto- 

 mosing. Vein 12 is also liable to anastomose with 11. This curious 

 structure is highly characteristic of the group. Other organs require little 

 explanation. The length of the ciliations or pectinations of the antennae is 

 given by numbers in brackets, and is expressed in terms of the breadth of 

 the antennal stalk ; where the two series of pectinations are unequal, the 

 inner series is denoted by a, the outer by b prefixed to these numbers. 



GEOMETBINA. 

 Ocelli always absent. Tongue well-developed. No maxillary palpi. 

 Labial palpi well- developed, usually porrected, roughly scaled. Antennaa 

 moderate, filiform, or dentate, simple, ciliated, or pectinated, pectinations 

 diminishing in length towards base and apex. Abdomen and legs without 

 special characters. Forewings with 12 veins (rarely vein 11 obsolete), 

 1 simple, 7, 8, and 9 always on a common stalk, 10 generally anastomosing 

 with 9, 11 generally anastomosing with 10, 12 sometimes anastomosing 

 with 11. Hindwings with 8 veins (often 7 by obsolescence of 5), normal 

 vein 8 free or anastomosing with 7 towards base, always leaving 7 before 

 the transverse vein. 



