On Heterocera from Costa Rica. 231 



is much longer and thicker and generally of a brighter 

 yellow. 



The song is also difterent from that of the smaller northera 

 form^ and will be described elsewhere. 



Type of Ammomanes deserti my a : c? , no. 200. Oued 

 Mya, 7. iv. 1912. In the Tring Museum. 



XXIX. — New Species of Heterocera from Costa Rica. — XVII. 

 By W. SCHAUS, F.Z.S. 



GeometridaB. 



Subfani. BoAMMiiNM, 

 Semiothisa lydia^ sp. n. 



? . Body brownish grey, with some darker irrorations on 

 abdomen. Wings greyish wliite, almost obscured by grej^ 

 strijB, and some scattered black irrorations ; lines grey- 

 brown ; medial line coarse, waviiy dentate ; postmedial fine, 

 lunular dentate, closely followed by a broad didl shade of the 

 same colour, reaching termen, but slightly mottled with 

 ground-colour on termen at middle of outer margins. Fore 

 wings; a fine antemedial line angled on subcostal; a dark 

 streak on di.scocellular ; some wliite mottlings at apex. 

 Hind wings : a black discal point. Wings below whiter^ 

 mottled with grey-biowu strise ; the veins yellow-brown ; 

 the lines daik brown ; the postmedial lunular and the shade 

 following it narrower ; on fore wings the white grounds 

 colour is partly shaded with yellowish. Outer margin of 

 fore wing sinuous, of hind wing bluntly angled, 



Expanse ^^ mm. 



Hah. Tuis, Sixola, 



Semiothisa delta, sp. n. 



$ . Very similar to S. lydia, Sclis. ; the outer margin of 

 fore wing more deeply sinuous, of hind wing more sharply 

 angled ; ground-colour whiter, the markings all dark brownish 

 slate-colour ; the hind wings with medial line much broader, 

 suffusing with strise to near base. Underneath the same 

 difference in colour is noticeable^ and the veins are dark 

 brown, not yellow-brown. 



Expanse 28 mm. 



Hub, Juan Vinas, Sitio, 



JO* 



