258 QUARTERLY JOURNAL. 



periphery. These are large, occupying full two-thirds of the entire 

 head. They are of a deep black color, and are separated from each 

 other on the top of the head only by a slight and almost impercep- 

 tible cleft, so that when viewed in front they appear like a continu- 

 ous broad black band surrounding the head, and interrupted only 

 below at the mouth, thus resembling a horseshoe in their figure. 

 The/ace is pale yellow. In its centre, and contiguous to each other, 

 are two pale yellow tubercles or spherical eminences, more or less 

 conspicuous, on which the antennae are inserted, and which are by 

 some regarded as forming a joint of these organs, in addition to the 

 number commonly stated. The antenncB are of a deep brown of 

 black color, less intense than the eyes. They are of about the same 

 length as the body, and composed of twelve joints. Each joint 

 (Plate 5, fig. e) is commonly oblong, with a marked contraction in 

 its middle, a shape which is sometimes designated as ' coarctiform,* 

 and is surrounded with a whirl or row of hairs near its base, and I 

 another near its apex.* The joints are ordinarily about thrice asl 

 long as they are broad, their diameter being but little less than that i 

 of the legs. They are connected together by a slender thread inter- 

 vening between each joint, and about a fourth as long as the joints 

 themselves. The two palpi are pale yellow, and clothed with shortish 

 hairs : each is composed of four oval joints ; the terminal one being 

 longer, but of the same diameter with the preceding. 



The THORAX is of a pale yellow color ; its upper side commonly 

 tinged with fulvous brown, which sometimes, though rarely, forms 

 three vittae or longitudinal spots forward of the middle. It is of an 

 ovate form, its greatest breadth being immediately back of the wing 

 sockets. Its vertical diameter much exceeds the transverse, as is 

 common in most species of TipulidcR, the breast jutting down far 

 below the level of the head and abdomen. The poisers are oval, 



* Not unfrcquently, however, singular anomalies occur in these joints. Thus in 

 some the contraction will be so considerable as to cause the segment to appear like 

 two globular joints slightly but distinctly separated from each other ; whilst other seg- 

 ments of the same scries are abbreviated and dilated, the usual contraction thus be- 

 coming obsolete, and the joint taking on a short cylindrical form. It would thus seem 

 as though we, in the female, met with the twenty-four joints of the male antennae in 

 a modified or imperfectly developed condition ; that what appears as a single oblong 

 coarctiform joint, is in reality two joints united. This would give but a single whirl 

 of hairs to each joint, as is common in most of the species of this genus. 



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