196 THE entomologist's eeoord. 



The Description of a Lepidopterous Ovum. 



By Hy. J. TURNER, F.E.S. 

 It has been suggested to me at various times that a schedule of the 

 chief points to note in the description of a lepidopterous ovum would 

 be very useful to some of our more enthusiastic field workers. Some 

 years ago, simply for my own use, I compiled a rough list of such 

 details as I found mentioned in a large number of descriptions of ova 

 given by different writers. This I have revised and added to, but 

 before publishing it I thought it would be advisable to submit it to 

 Dr. Chapman for his criticism and opinion. His remark in his 

 private note to me was somewhat strong, but probably as a preface to 

 his criticism and advice, herewith included, it will serve its purpose to 

 drive forward a more perfect registration of facts, in opposition to the 

 tendency to mark time for an indefinite period at certain stages of our 

 scientific methods. 



Dr. Chapman says {in litt.) : — " Although it condemns some of my 

 own work as prehistoric, I have written a short introduction that you 

 may use or not as you like." 



He then goes on to say: — "M. Oberthiir contends, and Ave have 

 no higher authority, that no name of a lepidopteron should be valid 

 that is not founded on a good figure, a description alone being the 

 source of many of our difficulties in nomenclature. Our superstitious 

 veneration for a description dates from a time when a good figure was, 

 in, say, ninety-nine cases out of a hundred, an unattainable luxury. 

 Things are different now-a-days. Substituting usefulness for validity, 

 the same auguments and conditions are even more applicable to eggs. 

 The best descriptions of eggs are, perhaps, Scudder's, how few, however, 

 read them, and how evanescent that number would be without his 

 figures to enable them to grasp them. To " describe " an egg you 

 must take a photograph such as Mr. A. E. Tonge has made us familiar 

 with, you must take two others of rather greater magnification, one 

 vertical and one exactly lateral, two others of still larger magnification 

 to show the details of the sculpture, say, laterally, and still another to 

 show the structure and details of the micropylar area," like those of 

 Mr. F. Noad Clark. 



Written descriptions will then be confined largely to points of 

 Life-History rather than description, it will also elucidate points that 

 for any reason the photographs are hazy about, it will deal with 

 colour, and may refer to any points of relation or distinction from 

 other eggs, or the classificatory value that its structure appears to 

 suggest. 



It should, however, if possible, give accurate measurement. Much 

 description may be saved by saying it is a more or less ordinary 

 Pierid, Noctuid, or Geometrid egg, or belongs to those Geometers, 

 whose eggs are becoming upright, or as the case may be. 



We now know broadly the characteristics of most groups of the 

 macro- and of some of the micro-lepidoptera, but there are still many 

 of the latter that we know nothing of, and a good many of which we 

 know something, without being able as yet to group them. 



It may be useful to have a schedule of points to be dealt with in 

 describing an egg, leaving out those that the photographs sufficiently 



* These must all be to a definite standard scale of magnification. — H.J.T. 



