Malloch — The Generic Status of Chrysanthrax Osten Sacken. 65 



structure. All three species of the latter genus that I have 

 seen are internal primary parasites in lepidopterous or cole- 

 opterous larvae which do not spin tough cocoons, and all of 

 them have the cephalic armature very similar, consisting of a 

 pair of stout upper processes — which are contiguous at base 

 and have the apices somewhat flattened but not thorn-like — a 

 small lateral tubercle, and a similar small one on the central 

 line near the lower margin. On the other hand, Chrysanthrax 

 fulvohirta is parasitic upon a hymenopteron that spins a very 

 tough cocoon, and in order that the imago of the fly may 

 emerge therefrom it has the cephalic armature adapted to the 

 purpose of cutting its way out. The upper pair of processes 

 are widely separated at base and are thorn-like, their apices 

 being sharp and slightly downwardly directed ; the lateral thorn 

 is about as large as either of the upper pair and of similar 

 structure ; the pair on the central line near the lower margin 

 are similar to those of Hyalanthrax. It will be seen from the 

 foregoing that the differences in the pupae are quite as great as 

 are those between other genera in this family and even more 

 distinct than the differences between some of the genera in 

 Asilidee. 



I give herewith a synopsis of the difference between the pupae 

 of the genera of Bombyliidse known to me, and descriptions of 

 those which I have not previously dealt with. The great ma- 

 jority of the pupae of this family may be distinguished at a 

 glance from those of Asilidee, which they most nearly resemble, 

 by the armature of the body. The Asilidse known to me have 

 invariably the transverse abdominal armature in the form of 

 stout spines which are usually alternately large and small in 

 each series. In all the pupae of Bombyliidse which I have 

 seen this armature consists of very short, flattened thorns which 

 are occasionally reflexed at bases and apices, and usually ap- 

 pear to be attached to, rather than a part of, the segment upon 

 which they are located. Another character that at present 

 seems to be of great value in separating the families is found 

 in the structure of the lateral cephalic thorn (antennal sheath). 

 In Asilida^ this consists of three to five thorns on a common 

 base; in Bombyliidse, either of a single thorn, which may be 

 very small, or of two distinctly separated thorns. 



