THE CANADIAN ENTOMOLOGIST. ' 81 



ON THE STRUCTURAL AFFINITIES OF THE GENUS DEMAS. 



BY J. W. TUTT, F. E. S., LONDON, ENGLAND. 



In tlie Journal of the New York Entomological Society, Vol. III., pp. 

 130-131, Mr. Harrison 0. Dyar writes as follows: " Prof. E. B. Poulton 

 has shown that dorsal eversible glands are of general occurrence throughout 

 the Lymantriidce (Trans. Ent. Soc, Lond., 1887, p. 300) on the tenth 

 and eleventh joints (segments), or rarely only on the eleventh joint (Das- 

 ycJiira pudibiinda). Probably these structures are characteristic of the 

 family, but Prof Poulton did not find them in Deinas. This genus has 

 been considered to belong to the JSioctiiidce, but English authors assume 

 it to be a Lymantriid. Mr. J. W. Tutt remarks, in speaking of Prof. J. B. 

 Smith's recent 'Catalogue of the Noctuidfe ' (Ent. Record, VI., p. 70) : — 

 '•The obsolete position of Demas among the Nodiiidce is retained." 

 Now, is this position ' obsolete ? ' The absence of the retractile tubercles 

 certainly throws doubt on the matter. Now, I have shown a character- 

 istic difference in the arrangement of the thoracic tubercles between the 

 Lymantriidce and the Noduidce (Trans. New York Acad. Sci., XIV., 

 p. 57), and Demas shows the Noctuid structure. Therefore, on all 

 essential larval characters Demas is a Noctuid. It might, indeed, be an 

 Arctian, as far as the larva goes, but not a Lymantriid. As concerning 

 the structure of the imago, Demas seems to have greater affinity with the 

 Noduidce than any other family ; in fact, it appears to me that the placing 

 of Demas among the Lymantriidce may properly be characterized as 

 premature." Further, Mr. Dyar writes as follows : — " Pupa, shining 

 dark brown with a large wrinkled cremaster and three movable incisures. 

 Of the usual Noctuid appearance (quite unlike Orgyia) and passing the 

 winter." This statement regarding the pupa must be read carefully in 

 connection with the remarks of Dr. Chapman quoted below. 



Now, I would call Mr. Dyar's attention to the following statements 

 made by Dr. Chapman some two or three years ago. He writes : — "We 

 now come to the two species, Demas coryli and Diloba caeruleocephala, 

 that are certainly not very much related to each other, and though they 

 have some indications of affinity vvith Acronyda, are not near enough to be 

 placed in the same family. D. coryli, I should certainly restore to its old 

 place in the Liparidce, to which it is far closer than to the Acronyctas. 

 . . . . But neither of them seemed to me to be nearer to Acronyda 



