198 THE entomologist's record. 



developed at base of the short obsolete secondary hairs ; the primary 

 warts also nearly absent. The whole group of Saturnians is rather 

 uniform, and without a wide range in the larval characters. 



III. The larv.e of the Microlepidoptera or Tineids. — The 

 larvae of the Tineids have tubercles iv and v in line longitudinally 

 or united. In the lowest forms these tubercles are remote ; the setae 

 are single and snnple, and the subprimary ones are present. This is 

 seen in the Plutellidte. There are two different lines of specialisation. 

 The original Tineid larva was probably an internal feeder, and one 

 line follows out this habit. The larvie have become leaf miners, and 

 the setfB are remarl^ably reduced. So little material has been 

 examined, that I am unable to say whether any of the subprimary 

 sette have actually disappeared, and this point is a good subject for 

 future investigation. The other line of evolution is easier to trace, 

 though it is more complicated. The first step is the consolidation of 

 tubercles iv and v, as seen in some Plutellidfc and Gelechiida^, and in 

 all Cossidae, Pyralidae, Psychidie and Sesiidse. Next, tubercles i and 

 ii consolidate {ci/., Butalis basilaris), and after this the change of the 

 tubercles to many haired warts occurs. As examples of this stage 

 are Pterophoridae, Zygaenidae, Pyromorphidae. In a few instances 

 there are secondary hairs, only in the Pterophoridae, so far as I know. 

 The final stage consists of a reduction in the subventral warts 

 following a change in the mechanism of locomotion, whereby sucking 

 discs are gradually substituted for abdominal feet. There is also a 

 strong tendency for the conversion of the hairs into stinging spines. 

 The beginnings of all these tendencies are seen in the Megalopygidae. 

 In the Limacodidae they are completed, but also greatly modified 

 in the several species. The Megalopygidae possess, besides the ordinary 

 abdominal feet on segments iii to vi and x, a series of paired sucking 

 discs on segments ii to viii. The warts of the Limacodidae have 

 diverged into three types of change from the original Megalopygid 

 structure. In the Palaearctic group the warts have degenerated and 

 nearly disappeared, leaving a hairless granular skin, as in tlctenKjenea 

 and Ajioda. In the American group, represented by Phohctron, the 

 warts are elongated, often unequally, fleshy, and with short hairs of 

 various structure. The third group retains the unequal Heshy horn- 

 like warts, but the seta; are converted into stinging spines. This 

 group is well represented in America and India, but seems to 

 culminate, curiously enough, in Australia, where part of the horn- 

 like warts have become retractile, the others spineless (as in Doratifcra 

 rulncrans, li'iri)ii and casta), and in other species even the whole 

 structure remodelled into the smooth type by the loss of part 

 {Mdci/tha sciiiicana) or all the warts {M. iiifrcijuois'). 



The development of the wing, wing=scales and their pigments 

 in Butterflies and Moths. 



By J. W. TUTT, F.E.S. 



f CoiKiidled I'niiii p. lG2y. 



As to the chemical nature of the pigments in the scales, we know 

 but very little. Hopkins has shown that the white pigments in the 



