86 Proceedings of Societies. [zoe 



gether. It thus becomes apparent that the latter is a higher struc- 

 ture than the former, being composed of a bundle of bristles united 

 into a single spine. Very frequently the female will have the frenu- 

 lum in the form of a bundle when the male has but a single bristle. 

 The reason of this is obvious, for the male is called upon to make 

 greater use of its wings in flying in search of the female, and thus 

 requires a more perfect structure. 



Sometimes the base of the hind wing is extended up in the form of 

 a shoulder binding the two wings together, and thus replacing the 

 frenulum. In the silkworm moth there is a lobe at the base of the 

 wing and a mere rudiment of a frenulum; even in the male this 

 frenulum consists of a bundle of hairs, such as is present in the 

 female of most species. It is an interesting fact that degeneration 

 seems to directly retrace its steps of progress, as indicated by the 

 above example. One moth, Hepialis, which is in some respects 

 rather lowly organized, was found to have neither frenulum nor 

 lobe. In place of these a sort of loop or thumb was found upon 

 the front wing which Prof Comstock has termed the jugum. This 

 jugum occurs also in Micropieryx, in which genus an elaborate ar- 

 rangement exists to receive it. 



The speaker concluded from the above facts that the Lepidoptera 

 had developed along two distinct lines distinguished by the style ot 

 organ used in binding the wings together, and he accordingly pro- 

 poses the division of the order into two suborders, the JiigatcB 

 and the FrenatcB. From all this it may be learned that a true sys- 

 tem of classification must be based upon a study of the uses of parts. 



February 27, i8g2. Dr. Jordan in the chair. 



After the reading of the minutes Dr. H. W. Harkness was called 

 to the chair, while the president addressed the club on The History 

 of the Zoological Explorations of the Pacific Coast. 



The lecturer was chiefly confined to a historical review of the 

 work which has been done on the fishes of the coast. The sub- 

 stance of the talk was as follows: 



The first person associated with the study of the fishes of the 

 coast was the German naturalist Steller, who was sent by the, Rus- 

 sian Government in 1731 to study the animals of Alaska. Notable 

 among his discoveries was the great arctic sea-cow (Rytina stelleri), 

 a skeleton of which is now owned by the Academy of Sciences. 



