HARD WICKE ' S S CIE NCE - G SSIP. 



151 



ampulla, Oliv.), as well as those of the genus Imati- 

 dium, are also merdigerous, producing an assemblage 

 of very long filaments, resembling a filamentous 

 lichen. The late General Hardwicke published an 

 account of the transformations of a beautiful East 

 Indian species of Cassida. . . . The larva closely 

 resembles my figure of that of C. viridis ; but the 

 lateral rays are much longer, and anal feci-fork much 

 shorter." 



Now, so far as the British species of Cassida are 

 concerned, the " fine branching filaments " into which 

 the excrement was supposed to resolve itself, are in 

 all probability simply the exuviae of the branched or 

 setose spines constituting a goodly portion of each 

 section of the fecal canopy, and a much larger pro- 

 portion of the newly added exuvial platform for its 

 continuation or increment ; whilst with respect to the 

 exotic species, as the " lateral rays (spines) are much 

 longer, and the anal feci-fork (anal appendages) much 

 shorter," may it not be passible, nay probable, that 

 the " assemblage of veiy long filaments, resembling a 

 filamentous lichen," is simply the exuviae alone, the 

 superaddition of the faeces being unnecessary and 

 undesirable, since the " anal feci-fork is much shorter," 

 . and is probably less well adapted for carrying a load 

 of faeces that shall entirely extend over the body of the 

 larva, while the exuvial platform will be larger and 

 more extended, and consequently more protective, 

 owing to the much greater length of the lateral rays 

 or spines. 



In the British species of Cassida, a protective 

 fecal dorsal covering being necessary to the well- 

 being of the larva, the reason why it should be 

 elevated above the body, and borne as it is on an 

 organ specially modified for the purpose, rather than 

 the faeces laid directly upon the dorsum (as naturalists 

 inform us is the case with the larva of the Crioceris 

 merdigerd), is obvious enough ; the spiracles of the 

 flattened larva are situated dorsally, and from the 

 nature of the faeces would at an early period in the 

 existence of the creature become clogged up, and 

 ■ asphyxiation would assuredly ensue ; and thus the 

 very means employed by the larva as a protection and 

 self-defence would be converted into a means of self- 

 destruction. This necessity for a self-provided dorsal 

 covering has involved a considerable and remarkable 

 modification in form and direction of the two spines 

 appertaining to the last abdominal segment of the 

 larva, and of the terminal portion of the alimentary 

 canal or intestine, as well as in the direction or 

 pose of the posterior portion of the body ; thus the 

 spines are enlarged, completely changed in direction 

 (being vertical instead of horizontal), and are further- 

 more thrown forwards horizontally over the body 

 by the singular carriage of the hinder portion of the 

 •abdomen , while the anus, instead of terminating 

 horizontally with the body, is projected far beyond it 

 vertically by an extensive telescopic elongation of the 

 •intestine and the erection of the extremity of the body. 



It seems somewhat singular that (from Kirby and 

 Spence downwards) our most distinguished and prac- 

 tical naturalists, our instructors and authorities in 

 entomology, who have been attracted by this most 

 remarkable larva and have written about it, and 

 most, if not all, of whom must have handled it, 

 should have missed the true formation and constitu- 

 tion of its artificial dorsal covering; and should have 

 entirely ignored the wonderful modification in form 

 and function of the terminal portion of the intestine — 

 its exsertion, and its prolongation telescope-tube-like 

 and evagination on the passage of the faeces ; its 

 remarkable mobility which enables it to assume the 

 most varied forms, and thus to be applied over 

 the entire extent, the length and breadth, of the 

 exuvial platform, so as to suitably dispose the faeces 

 in the construction of its singular canopy ; and, lastly, 

 to be used almost, as it were, as an organ of prehen- 

 sion, in aiding in the disposition of the exuvial plat- 

 form, and in the displacement of the canopy at the 

 close of the larval period. Burmeister, when treating 

 of the artificial coverings of the larvae of insects, 

 useful as a protection from their enemies, has, at page 

 506, the following remarks : "We find other cover- 

 ings in the aphidae and tortoise beetles, which envelope 

 themselves with a white woolly or fibrous substance, 

 the origin of which we are not yet acquainted with, 

 but it appears to be produced by a peculiar secretion 

 of the skin."* Thus this author even classes the 

 artificial exuvial and fecal canopy of the larvae of the 

 tortoise beetles with the natural woolly clothing ot 

 the aphidae, which is certainly an outgrowth from the 

 body of these homopterous insects in all their stages. 



Charles Robson, 



Elswick, Nciucastlc-iipon- Tyne. 



LUNDY ISLAND. 

 By Dr. Crespi. 



VISITORS to Instow and Ilfracombe generally 

 sooner or later are fortunate enough to catch a 

 glimpse of a long, low line far away on the western 

 horizon : that is the tiny Island of Lundy. At a distance 

 of twenty-four miles, it seldom looks more than a 

 nebulous line, slightly raised above the water ; but on 

 near approach it is seen to stand up grandly— a vast 

 granite mass, four miles long, three-quarters of a mile 

 wide, and from four hundred to, in one place, over five 

 hundred feet in height. Its configuration is singular ; 

 its long diameter points nearly due north and south, 

 while its eastern slopes, precipitous enough to make 

 them interesting and remarkable, are only one degree 

 less striking than its western sides, where walls of 

 rock rise in perpendicular steps sixty and eighty 

 feet at a time. The western side is particularly 

 imposing; and were Lundy more accessible, it would 

 attract tens of thousands of visitors. But Lundy has 



* Manual of Entomology, transl. by Shuckard : Lond. 1S63. 



