no 



active larvae that I found lacked them: and as these larvae were 

 living in cases apparently like those containing the appendaged pre- 

 pupae, were collected from the same stones at the same time, and be- 

 longed to a long-studied fauna from which no Hydroptilidae were 

 known, it was surely but natural that they should be assumed to form 

 a single series of one and the same species. The hypothesis of hyper- 

 metamorphosis was based on this assumption, and was framed to fit 

 the developmental condition of the specimens found. 



But I certainly endeavored to give the facts with sufficient full- 

 ness so that no one need be misled by any attempt at explaining them. 

 And 1 said in that paper in Psyche: "The possibility that my speci- 

 mens did not all belong to the same species, and that these peculiar 

 appendages of the pre-pupa may have belonged to the (undiscovered) 

 larva of the same species, is not to be overlooked entirely, even though 

 it be highly improbable". In the light of the knowledge that the 

 immature larva of Ithytrichia possesses just such appendages, this 

 alternative hypothesis becomes the more probable; and this proba- 

 bility grows with the knowledge of the Hydroptilid fauna of Ithaca. 

 My former assistant, Mr. C. Betten, sent his trap-lantern catch of 

 adult Hydroptilidae from Fall Creek Ithaca to Mr. K. J. Morton of 

 Edinburgh, who has found them to represent eleven species, belonging 

 to five genera, and one of them a new species of Ithytrichia. 



This most singular larva appears to have been independently 

 described five times. Mr. Morton first noticed it in Ent. Monthly 

 Mag. for 1888, p. 171. In 1897 Prof. Klapalek described it again in 

 a Bohemian paper that I have not seen. Then Richters described it 

 in Bericht Senckenberg. Naturf. Ges. for 1892, p. 19—21. This 

 paper also appeared a little in advance of my own. Then Ulm er 

 described it in Stett. ent. Zeit, for 1902, p. 364; and exactly at the 

 same time my own paper in Psyche, pp. 375 — 378, appeared. Perhaps 

 it was my misfortune to find only the transforming larva, and that 

 associated with another younger larva in cases so similar they might 

 be thought one species. But certainly as to their relationships, must 

 wait upon further life-history studies, and is not fostered by gratuitous 

 hypotheses that contradict the known facts. 



Lake Forest, 15 August 1903. 



II. Mitteilungen aus Museen, Instituten usw. 



1. Personalverzeiclinis zoologischer Anstalten. 



12. Freilburg i. Br. 



Zoologisches Institut. 



Direktor: Prof. Aug. Weismann. 

 Assistent: Dr. med. Waldemar Schleip. 



