38 Prof. G. Gulliver on Raphides and other Crystals in Plants. 



anticis fere contiguis, subtrigonatis, erectis ; tibiis posticis apice mu- 

 ticis ; unguiculis bifidis. Prosternum angustissimum. 

 Type, Eumcea pulchra, Baly. 



Distinguished from the preceding genus by the slender an- 

 tenna?, the costate elytra, and the different form of the sulcation 

 of the thorax. In Eumcea the depression extends nearly across 

 the surface of the disk, not quite reaching its lateral border, 

 either side being impressed by a large deep fovea. In Nicea the 

 sulcation is broader, extending entirely across the disk to the 

 lateral border, and has its front and hinder edges much less 

 distinctly marked. 



Eumcea pulchra. 



E. elongata, postice paullo ampliata, convexa, lsete fulva, nitida ; 

 oeulis, pedibus elytrisque nigris, his fascia lata fulva ornatis, sin- 

 gulatim infra basin transversim sulcatis, 5-costatis, costis duabus 

 exterioribus valde elevatis, cseteris indistinctis ; antennis fulvo- 

 fuscis, articulis apice piceis. 



Long. 4| lin. 



Hab. New Guinea. 



VI. — Observations on Raphides and other Crystals in Plants. 

 By George Gulliver, F.R.S. 

 [Continued from vol. xiv. p. 252.] 



Ternstrcemiacece. — Many sphseraphides, but no raphides, in 

 the leaves and bark of young twigs of Camellia euryoides and of 

 a garden variety of Camellia. 



Vitacece. — Leaves, and their modifications or appendages, of 

 Vitis odoratissima, V. apiifolia, two species of Ampelopsis, and 

 Cissus discolor : all abounding more or less in raphides and 

 spliEeraphides, as is the case in every plant which I have examined 

 of this order. 



Zygophyllacece. — The crystals in the bark of Guaiacum officinale 

 are large prisms, like those of Quillaja, Iris, &c. The prisms 

 have commonly four equal faces, and two of them are occasion- 

 ally broader than the other two, as in Fourcroya. We have 

 already noticed that some of the prisms are triangular; and 

 this and the flattened square are such forms as might result 

 from a longitudinal cleavage of the equally four-sided shafts, in 

 one case diagonally from angle to angle, and in the other from 

 the centre of each of the two opposite faces. But I have at 

 present seen only imperfect evidence of such cleavage. 



MelastomacecB. — Leaves and twigs of Melastoma, sp. : sphse- 

 raphides plentiful, especially in the liber and niesophlceum ; but 

 no raphides. 



