NORTH AMERICAN ACROLOPHIDAE — HASBROUCK 635 



Remarks. — This species, the name of which should be spelled 

 morus to agree gi*ammatically with its present genus, is unusual in a 

 number of respects. Of the various acrolophids occurring in America 

 north of Mexico, it is the only valid species originally described en- 

 tirely from the female. In regard to general distribution, it ranges 

 further northward than any other acrolophid and it undoubtedly will 

 be found to occur in southern Canada, especially in that portion of 

 Ontario south of the forty-fifth parallel. Likewise, morus probably 

 has the northernmost type locality of any acrolophid, and it regularly 

 appears in the adult form considerably later in the year than any of its 

 relatives. This species is also unique among the acrolophids found 

 north of Mexico in exhibiting a pronounced sexual dimorphism in 

 coloration. Lastly, the predominance of 99 over cf cT in morus is 

 quite unusual in collections of the various species of this group. 



Some specimens of morus are abnormally small. A dwarf cf with- 

 out data, furnished by Dr. C. E. Mickel of St. Paul, Minn., measures 

 only 18 mm. in wing expanse. A small 9 from Pittsburgh measures 

 less than 24 mm. in expanse. A second 9, received from the Ameri- 

 can Museum of Natural History, bears the following data: "From 

 larva on birch. Imago Oct. 20, 1905. Laid eggs when pinned, loosely 

 like Arctiinae (?). Egg white, long, narrow, strongly ridged." 



Despite its age, fairly broad distribution, reasonable abundance, 

 variation in size, and sexual dimorphism, morus has no synonyms. 

 The material representing this species was received on loan from ten 

 sources. The largest series were furnished by the American Museum 

 of Natural History (6 cf cf , 8 99) and the Carnegie Museum (7 cf cf , 

 5 99). 



A. morus is not closely related to any of the other acrolophids found 

 in America north of Mexico. It may be characterized, as well as 

 distinguished from the other members of the genus, by the following 

 features: labial palpi of intermediate length, naked eyes, laminate 

 antennae, bifid uncus, and paired gnathos. In addition, its general 

 habitus and genital structure are quite distinct from those of its 

 various relatives . The genital structure of morus is consistent through- 

 out my series of this moth. 



Mr. Tarns of the British Museum (Natural History) has sent a photo- 

 graph labeled "mora Grote, type 9," showing the pinned adult in 

 dorsal aspect, which unquestionably confirms the identity of this 

 species, the 9 exhibiting a very distinctive general habitus. 



The taxonomic history of morus is interesting. Grote 's single de- 

 scription represented both his new genus, Eutheca, and the latter's 

 type species, mora (9), also new. The generic name, Eutheca, was 

 subsequently found to be homonymous with Eutheca Kiesenw. (1877, 

 Coleoptera). In 1892, Kirby proposed the new name, Sapinella, to 



