394 BRITISH LEPIDOPTERA. 



Pachythelia, West. (Penthophera pars, Curtis, but not of Germar). — This curious 

 genus is well characterised by its semi-transparent hairy wings of an uniform 

 blackish colour, the deeply bipectinated antennas of the males, the want of a spiral 

 tongue, the small porrected palpi, terminated by an acutely ovate joint, and the 

 robust thorax. The females are entirely wingless, with a large fleshy body, and 

 with very minute rudimental antennas and legs. The arrangement of the veins of 

 the wings agrees with Hypogymna rather than with Spilosoma, but differs from 

 both these groups in having the precostal vein and its branches in the forewings 

 pushed considerably into the disc of the wings, so as greatly to diminish the 

 ordinary size of the discoidal cell, as we have also seen in Psyche, to which the 

 genus is related very closely (and next to which it should be arranged in the system), 

 especially in the transformation of the species, the caterpillars residing in movable 

 cases (Humphrey and Westwood, Brit. Moths, i., pp. 84, 94). 



The genus Pachythelia having been created in 1848 by Westwood 

 for nigricans this species becomes the type. Westwood afterwards 

 strangely enough uses (Proc. Zool. Soc. Lond., 1854, p. 220) Pachythelia 

 as a subgenus of Oiketicus. Heylaerts has adopted the genus (which 

 he writes Pachytelia) for villosella and unicolor (graminella) , but the latter 

 is not congeneric with the former, and is also the type of Canephora, Hb., 

 Tent., p. 2. One suspects that some of the species placed by Heylaerts in 

 Amicta, are closely allied to P. villosella. Thus Chapman notes lutea 

 as essentially congeneric with this species and he further considers 

 that cana, Hampsn., is also closely allied to it. Should cana be 

 congeneric with P. villosella, it would prove interesting, since cana is an 

 Indian species. 



The principal characters of the genus may be diagnosed as follows : 



Ovum. — Oval, exceedingly delicate, surface irregularly reticulated, very shiny. 

 Eggs laid in an agglomerated mass in pupal skin. 



Case. — A strong silken tube, soft in texture, covered with pieces of grass, 

 heather, stick, &c, fastened by one end, sticking out from central tube at about 30°, 

 the free ends pointing back to the posterior end of case ; the silken anterior end 

 (whence larval head is protruded) hood-like, the opposite end with an uncovered 

 silk prolongation. 



Larva. — Head small, rounded, partly retractile, hairy ; thoracic segments 

 covered with corneous plates (with paler, mediodorsal, subdorsal, and lateral lines), 

 spiracle in pro-mesothoracic incision ; abdominal segments increase to 4th, then 

 decrease to 10th, anal segment chitinous, segments 1-7 divided into two sub- 

 segments ; broad longitudinal lateral flange ; prolegs with oval of hooks incomplete 

 on inner edge, centrally depressed ; spiracles large, placed anteriorly ; tubercles 

 with single setas, i outer and ii inner, i, ii, and iii with large chitinous basal plates, 

 extra plates (without setas) on abdominal segments 1-2, the thoracic setas in trans- 

 verse line ; iv and v close together, v the weaker ; vii carries 2 setas. 



Pupa. — i . Stout, short ; abdominal segments free, 3 (dorsally), 4, 5, 6, 7 ; 

 ventro-anal hooks strong and sharp, wings to end of 2nd abdominal, firmly 

 soldered ; no dorsal headpiece ; prothorax frontal, narrow, mesothorax large, meta- 

 thorax narrow widened laterally ; anterior dorsal spines on 3-8, posterior inter- 

 segmental spines well developed ; the antennas nearly to end of forewings, strongly 

 developed ; 3rd pair of legs to wing apices, 2nd pair to tips of antennas, the 1st pair 

 short of antennas ; tubercular setas as in larva ; elements of larval lateral flange 

 distinct; proleg scars conspicuous ; two hairs at base of labrum ; jaws prominent ; 

 labium slightly bilobed at margin ; maxillas outside and as long as labium, broadly 

 triangular, with a palpal elongation. ? . Somewhat cylindrical ; head bent 

 forwards; anal extremity bluntly rounded; spiracles large; proleg scars pro- 

 nounced ; anterior dorsal spines obsolete, posterior intersegmental hooks well 

 developed from segments 2-5 ; the setas on i and iii small, ii large, iv, y, vi, vii 

 (double) also with setas ; on abdominal segments 8-9 some of the setas with recurved 

 tips ; wings and legs represented by. definite folds. 



Imago. — d • Kobust, forewings somewhat elongate ; hindwings ample, with 

 notch at end of nervcre 2 ; hair-scales basally and on inner margin ; other 

 parts with scales rounded or pointed at free end, with few striae; fringes with 

 notched scales; antennas 32 joints (villosella), two pectinations on joints 3-32; 

 clavola scaled dorsally, pectinations unsealed ; anterior tibial spur - 88 ; no posterior 



