536 FAUNA HAWAIIENSIS 



(i) Ptiliodcs blackbitnii, Matthews. 



Ptiliodcs blackburni Matthews, Cist. Ent. iii. p. 41 ; Trichop. Sup. p. 76, Sharp, 1. c. 



A small form of short, contracted appearance, with antennae rather short, with 

 the prothorax transverse, nearly quadrate, with the hind angles almost right angles. 

 Matthews' figure (Trichop. Sup. pi. xiir. fig. b. 7) of the antenna is not altogether 

 correct : joints 6 — 9 are not really such simple oval structures as there depicted, but 

 more ampulliform : joints 3 — 8 are however slightly narrower than the corresponding 

 ones of the species described below. 



Hab. Oahu. Under bark (Blackburn). 



I have looked all through the British Museum collection of Trichopterygidae, 

 which contains that formed by Matthews, without finding anything which specifically 

 resembles the two following species ; which appear to be undoubtedly new. I am 

 not quite certain to which genus they should be referred ; whether to Ptiliodcs or 

 Nephanes. 



They are chiefly characterised by the form of the prothorax, which is transverse, 

 rather broad, not steeply sloping at the sides, with the sides rounded and curving in 

 posteriorly, so that the hind angles are much rounded off. The antennae are moderately 

 long, I I -jointed, with the joints ampulliform. The maxillae appear to be like those of 

 Ncplianes. The middle coxae are almost contiguous ; the mesosternum slightly elevated, 

 not keeled. The hind coxae are very remote, short (from base to apex), with a narrow- 

 lamina on the external margin in the apical portion only : the metasternal margin 

 between them is straight. The apex of the abdomen is not sharply acuminate. 



Matthews stated (Trichop. Sup. p. 76) that he was inclined to place Ptiliodcs next 

 to Nephanes, Thomson. When the species described below are placed side by side 

 with Ptiliodcs, the structure of their under surface closely resembles that of Ptiliodcs ; 

 more closely than it resembles that of certain Nephanes. The short hind coxae are 

 also characteristic of Ptiliodcs ; but the presence of the marginal lamina only in the 

 apical portion is characteristic oi Nephanes : for Matthews describes and figures the 

 hind coxa of Ptiliodcs blackburni as having^ a broad rounded lamina extending the whole 

 length of the margin. Insufficiency of material prevents me from making a Balsam 

 preparation of the hind coxa of P. blackburni in order to e.xamine it accurately : I 

 cannot discover that Matthews made any such preparation. 



The two following species are placed provisionally in Ptiliodcs. 



(2) Ptiliodcs in sign is, sp. nov. 



Elongato-oblongus, sat depressus, aegre nitidus, tote alutaceus, piceus antennis 

 pedibusque testaceis, pubescentia parca et pallida ; capite permagno, porrecto, anten- 

 narum articulis 3 — 10 ampulliformibus ; pronoto subtilissime nee dense punctulato, 



