-56- 



larva" the head is of triangular form with curved sides and rounded 

 angles, broadest across the front. 



In the larva and imago there is no trace of eyes or ocelli, while 

 there are two ocelli on each side in the " ultimate larva." 



No labrum, whatever, exists in the larva, and but a doubtful 

 rudiment in the imago, while the " ultimate larva" has a rather 

 large, well-developed labrum. 



The mandibles of the larva are slender, lancet-like, while none 

 exist in the imago; the " ultimate larva" has a bidentate and normal- 

 looking mandible, according to the description and figure. 



The antennae in the larva are situated at or slightly under the 

 hind angles of the head, in the imago very decidedly in the latter 

 position, but in the " ultimate larva" they become frontal!' 



Although I have not seen Dr. Riley's specimen, I am satisfied 

 (if his larva is a Platypsyllus at all) that figure "c," p. 28, repre- 

 sents the underside of the head and not the front, the antennae 

 slightly within the hind angles by the drying of the specimen, while 

 the somewhat triangular area at the centre of the head is the limit 

 of the buccal cavity, as may be inferred by an examination of pre- 

 viously published figures. I am equally certain that neither the so- 

 called labrum nor mandibles can be demonstrated in the position in 

 which he represents them, in any Platypsyllus larva in any stage. 



It is highly probable that Dr. Riley's descriptions were made 

 from a dried specimen requiring much manipulation for study, and 

 that the real mouth parts, very soft at best, have become shrunken 

 beyond recognition. 



To me it is incomprehensible that an " ultimate larva" should 

 present such radical differences from the larva from which it has 

 deAcloped and from the imago toward which it is developing. 



In conclusion, I will ask a careful comparison of previous fig- 

 ures published by Dr. Riley and myself with that of the "ultimate 

 larva" as given on p. 28. That there has been a grave blunder in one 

 or the other is, I think, indisputable, and I feel very willing to leave 

 the matter to the inference of students of insect morphology. 



The fearless and excellent young Lepidopterist, Mr. Doherty, 

 who has been collecting for me for the past two years in Borneo, 

 Malayan peninsula, Naga hills of Assam and surrounding countries, 

 has added fresh laurels to his fame by constantly making new dis- 

 coveries. Some of the types just described in the Entomological 

 Society of Bengal adorn my collection. Many of his highly inter- 

 esting letters read like the adventures of a Stanley, and I shall pub- 

 lish extracts from them from time to time. B. Neumoegen. 



