232 Mr. J. O. Westsvood's Description of a 



compared it witli tlie immature Lilfiol/ii, uliose developement I 

 was then investigating, and wliicli, in tlie very early states of their 

 existence, also presented traces of subabdominal appendages 

 similar to those of my new insect, which appendages are subse- 

 quently developed into abdominal legs. 



Want of opportunity to examine the entire insect, not having 

 since found anotI)er individual, joined with other investigations, 

 induced me to lay aside my drawings and notes until a future 

 opportunity occurred of reinvestigating the insect in nature. The 

 elaborate memoir, however, which Mr. Newport has recently 

 published in the Philosophical Transactions, on the development 

 of the Mi/napochi, (and which the Royal Society have done honour 

 both to themselves and to its author by selecting as the Bakerian 

 Lecture,) has recalled my attention to the subject, and has con- 

 vinced me that the insect in question cannot be a myriapodous 

 larvae, because there are no fewer than seven of these minute 

 subabdominal appendages ; and further, because these minute 

 appendages are succeeded by a pair of elongated anal filaments 

 nearly half the length of the body, whereas in the Myricqwda the 

 number of slightly developed feet at any one period is much 

 smaller, and because the anal appendages do not appear until the 

 feet are fully developed. Another reason which induces me to 

 reject the idea of this insect being myriapodous consists in the 

 structure of the mandibles, which, as noticed in the Journal of 

 Proceedings of the meeting in question (p. 14), are sliort, broad, 

 and 4-dentate at the extremity, which is oblique. 



Rejecting, therefore, the idea of its myriapodous nature, we 

 have therefore now to determine to which class and order of 

 annulose animals the insect belongs. To do this it will be proper 

 to detail its structural characters. 



Corpus elongatum parallelum, depressimi, moUiusculum, apterum, 

 13-annulatum. Caput obovatum, distinctum, horizontale. 

 Antennae dute capite duplo longiores, ad partem anticam 

 capitis insertse, multi- (ultra 15-)articulatte, submoniliformes, 

 articulo basali majori obconico, setosa?. Os inferuni man- 

 dibulis minutis planis latis, apice d-denlatis. Partes reliquj^ 

 oris deteritse. Thorax e segmentis tribus proximis constans ; 

 segmento Imo brevi, 2ndo, .'Jtioque multo longioribus et 

 latioribus, singulo pari pedum instructo, pedibus (fere dimidii 

 corporis longitudine) e coxa, trochantcre, femore, tibia et 

 tarso articulato formatis. Abdomen 9-annulatnm, segmentis 

 fere a^qualibus et transversis, segmento basali subtus ad 

 apicem utrinquc appendiculo brevi lato, ovali piano exarticu- 



