Mr. J. S. Baly on new Phytophagous ///sects. 55 



Medusa, conspicuous through the walls of the gonophorc by the 

 fine carmine-coloured bands by which the inner surface of the 

 stomach is marked. 



When the Medusa escapes from the gonophore, it is seen to 

 present a structure which is very peculiar. The umbrella is of 

 a nearly spherical form, with two marginal tentacles continuous 

 with two opposite radiating canals. A small bulbous dilatation 

 is situated at the intersection of each of the other two marginal 

 canals with the circular canal, but no tentacle is here developed. 

 There is a wide velum. The manubrium is well developed, of a 

 nearly cylindrical shape ; and the mouth is not furnished with 

 lobes or tentacles. 



The structure of the two marginal tentacles is very remark- 

 able. Each commences with a wide bulbous dilatation con- 

 taining reddish pigment-granules, and is then, for the remainder 

 of its length, closely set along its external side with pedunculated 

 oval sacs filled with thread-cells. 



Another striking peculiarity in the Medusa consists in a csecal 

 tube which is given off from each of the tentacular bulbs, and 

 then running in the substance of the umbrella, close upon 

 its outer surface and exactly parallel with the corresponding 

 radiating canal, becomes slightly dilated as it proceeds, and 

 terminates, after a short course, in a blind extremity. An 

 exactly similar tube is given off from each of the two interme- 

 diate bulbs. The contents of these caeca are a clear fluid with 

 thread-cells. 



I propose for the Coryne here described the specific name of 

 Briareus. 



VI. — Descriptions of new Genera and Species of Phytophagous 

 Insects. By J. S. Baly, Esq. 



Farm Chrysomelidae. 



Genus Doryphora, Illig. 



Doryphora dilaticollis (Dej.). 



D. oblonga, convexa, nitido-viridi-senea, cseruleo-micans ; thorace 

 utrinque foveolato, subremote punctato, utroque latere in laminam 

 obliquam subacutam producto ; elytris subcrebre punctatis, punc- 

 tis obsolete subseriatim dispositis, interstitiis aciculato-reticulatis. 

 (Foem.) Thoracis lateribus non dilatatis, rotundatis, antice an- 

 gustatis. — Long. 8 lin. 

 Hab. Brazil. 



Doryphora ccerulea. 



D. oblonga, convexa, nitido-cserulea ; thorace remote punctato, ely- 



