267 



that tins must be in reference to the established habit of each 

 kind, and that it is essential to the wellbeing of the insect that 

 its head, which is always directed to the point of attachment, i.e., 

 the base of the gall, either bear the weight of its body, or be 

 relieved of it ^^'hen lateral, or that the posterior end in pendant 

 galls bear that weight. 



A sectional difference appears to be afforded by the type of the 

 form, i.e., whether regular or symmetrical ; in the former case all 

 longitudinal sections are normally alike, in the latter only one 

 such will produce sinjilar halves — irregularity is always the result 

 of abortion. The above differential characteristics I propose to 

 use as a convenient artificial classification of the galls until 

 further knowledge of the insects themselves may furnish a better 

 one. 



The female insect varies in form from broadly turbinate to 

 elongated fusiform in the genus Brachyscelis. The- head is com- 

 pletely fused with the thoracic segments, and separately undis- 

 tinguishable ; it is, therefore, included in the term " thoracic part 

 of the body," and is usually thick and forms the greater portion of 

 the bulk. There are eleven dorsal segments besides the last, which 

 is very small and bears two subparallel, horny "tail bristles" of 

 varying length. The segments are more or less constricted at their 

 junction, those of the abdomen decreasing rapidly in diameter 

 to the acute apex, and are either quite smooth, armed with short 

 spinelets, or (especially those of the abdomen) more or less clothed 

 with fine, sometimes rather long, hairs. \"entrally six, very 

 short, three-jointed, widely separate legs are placed near the 

 margin; the forelegs near the anterior extremity are the shortest; 

 a little behind, and forming a triangle with them, is placed the 

 minute mouth, or what is considered as stich. Schrader says that 

 " he could not detect the promuscis in his specimens, and was in 

 doubt whether an opening existed," but in a large, fine specimen 

 of my B. ovicoloides the latter appears to be quite distinct under 

 a strong double lens, and Mr. Maskell describes the oral parts 

 very succinctly in his genera. More in front and laterally the 

 very short antennae are placed near shallow, more or less indis- 

 tinct, impressions considered as " eye spots." The former I have 

 not been able to detect in the above specimen. The hindlegs are 

 the largest, the forelegs shortest, and the others intermediai-y ; 

 all consist of three joints, the basal one being very much thicker 

 than the others, the last very minute, bearing a minute simple 

 claw. The colour in Bracliyacelia is usually a paler or darker 

 rusty-yellow or brownish tint, the terminal bristles being dark- 

 brown or black. When alive the whole body is surrounded by a 

 whitish, flaffy substance, exuded from the surface, of a waxy 

 nature apparently, and which almost entirely dissolves in alcohol. 



