THE GENUS ACRONYCTA AND ITS ALLIES. 3 



I may note that I describe the head as segment one, as is, 

 I think, now universal ; but I mention the matter, as I find 

 descriptions of Acronycta stating the eleventh segment to be 

 large, tuberculated, etc., these count the segments, omitting 

 the head, and refer to the large twelfth segment. 



The pupa is less characteristic ; it serves rather to divide 

 the genus into the three characteristic groups I have referred 

 to than to define the group as a whole. The pupa of the 

 ruinicis group is very characteristic and rather bombyciform 

 in its aspect. The others are more of an ordinary Noctua 

 pattern, but present features that separate them from other 

 families. This is perhaps a somewhat rash statement to make, 

 since I must confess my knowledge of Noctua pupae is of a 

 rather superficial character. 



Of the imago I find my superficial knowledge of other groups 

 compels me to speak with much diffidence. Still I think the 

 dagger mark at the anal angle has some distinctive features. 

 Below the median vein there follows another, usually, I think, 

 called the first sub-median ; but in the long space between 

 these, extending from the base to the hind margin, there is 

 sometimes another, or "intermediate" vein. This is very 

 distinct in Liparis nwnacha, the arched black marks in which 

 show the spaces on each side of this intermediate vein, between 

 it and the median on the one hand and the sub-median on the 

 other, to be of equal value with the other spaces between the 

 veins. 



In Acronycta this intermediate vein is represented by a trace 

 only, towards the hind margin, and the spaces above and 

 below it are reduced to less than two spaces, but are still 

 rather more than one, the vein is marked by the line of the 

 " dagger" (take/^"/ as an example) and the fringe presents two 

 black marks, one for each inter-space, placed closely together, 

 and not regularly spread as in the rest of the wing. In what I 

 take to be a typical Noctua, this intermediate vein is entirely 

 wanting, but there are several groups in which it may be found, 

 not so distinctly as in Acronycta, but in which, nevertheless, it 

 might be described in almost the terms I have used in regard 

 to that genus. The Orthosid.e and the genus Xylina occur 

 to me as such instances. 



Acronycta certainly has some affinity to the Bombyces, 

 probably most to Liparis, and the genus Cymatophora appears 

 also to have relationship with other groups regarded as true 

 Bombyces, and for these reasons the genera Acronycta and 



