300 Mr. R. McLachlaii on 



HYDROPSYCHID^E. 



Arctopsyche, n. g. (PI. XIV. fig. 1) . 



Antenyice not so long as the wings, stout, distinctly 

 serrate internally, the joints all short and gradually 

 decreasing in thickness. Head broad, vertex hairy and 

 tuberculate. Ocelli absent. Eyes prominent. Maxillary 

 palpi short; first joint very short; second and third 

 longer, nearly equal, broad ; fourth shorter than the 

 third, and thinner ; fifth about the length of the second 

 and third united, very slender and multi-articulate. 

 Labial palpi very small. 



Thorax stout and slightly hairy ; meso-thorax with a 

 broad median longitudinal impressed space. 



Wingshvoa,dL, slightly pubescent and sub-hyaline, some- 

 what acute, fringes very short ; the posterior pair shorter 

 and slightly broader than the anterior, folded. Anterior 

 wings with the costa nearly straight, and the apex longly 

 elliptical; sub-costa and radius running nearly parallel 

 for their whole length, united before their termination 

 by a straight transverse veinlet, each being slightly in- 

 dented at that point ; an oblique (not distinct) transverse 

 veinlet uniting the costa and sub-costa at about the 

 middle; discoidal cell small and triangular, closed by a 

 transverse veinlet, and united to the radius by a veinlet 

 placed almost in a line with that closing the cell ; 

 cellula thyridii longer than the discoidal, extending 

 much beyond it towards the base, and reaching to its 

 middle towards the apex, closed by a straight veinlet ; 

 a very oblique veinlet unites the ramus thyrifer to the 

 ramus discoidalis, placed between those which close the 

 discoidal cell and cellula thyi'idii respectively; a veinlet 

 unites the base of the cellula thyridii with the ramus 

 clavalis ; and there is- yet another below this near the 

 base; apical forks 1, 2, 3, 4, and 5, all present: 1 and 

 2 short ; 3, 4, and 5, long. Posterior ivings with the 

 costal margin slightly excavated ; apical forks 1, 2, 3, 

 and 5 present ; discoidal cell as in the anterior. 



Legs long ; intermediate tibite and tarsi very strongly 

 dilated in the ? ; spurs 2, 4, 4, long, the pairs slightly 

 unequal. 



Abdomen short and robust, appendices of the $ com- 

 plicated ; in the ? the apex is obtuse, and furnished with 

 short valves. 



