MONOTOMID.E loi 



angles of the prothorax, it agrees with LeConte's genus. I have 

 at hand a single example of Pycnotomina cavicollis Horn, taken at 

 Tryon, North Carolina. 



Subfamily RHIZOPHAGIISLE 

 Rhizophagus Hbst. 



It is rather surprising that this small group should have been so 

 uniformly separated widely from the Monotomidse in systematic 

 works, for the two are evidently closely allied. In facies they are 

 so similar that many Monotomids have been described as Rhizo- 

 phagids and the reverse, and that this superficial resemblance 

 really imports close affinity, can be seen at once on examining the 

 general structure. The antennae are identical in structure, and the 

 slight impression beneath, at each side of the buccal opening, in 

 which they lie when flexed beneath, is of very little morphological 

 significance. The mouth parts and unbroken frontal part of the head, 

 excepting a very small epistomal piece in Rhizophagus, are virtually 

 the same, the abdomen of similar structure, the pygidium, with its 

 additional segment in the male, and the general form and vestiture 

 of the legs and tarsi are alike in the two groups. The only tarsal 

 difference is the small free joint at the base of the long terminal 

 joint in Rhizophagus, making them 5-jointed instead of 4-jointed, 

 but the hind tarsi lose a joint in the male in exactly similar manner. 

 There remains but one structural feature of note, and this has been 

 given more weight than it deserves; it relates to the anterior coxse, 

 which are oblique and oval, instead of being smaller and rounded 

 as they are in Monotoma. 



The genus Rhizophagus in general has been very skillfully treated 

 recently by Mr. Mequignon, and our own species have been rather 

 superfically reviewed by Mr. Schaeffer (J. N. Y. Ent. Soc., 1913, 

 p. 309) but I fail to understand the motives of the latter author 

 in changing Say's name bipunctatus to sayi; he states that it is 

 because of the previous use of the name bipunctatus by Herbst in 

 the European fauna, but there is no such name recorded in any of 

 the large European catalogues. There is a bipunctulatus Hbst., 

 recorded in the Munich catalogue, which is a synonym of bipus- 

 tulatus Fabr., but this is not the same as bipunctatus. This error 

 was rectified by Mr. Mequignon (L'Abeille, 1914, p. 168), who also 



