106 Miscellaneous. 



brownish, underlined with reddish brown ; a reddish spot on 

 inner margin near base ; faint traces of a rusty brown inner 

 line and wavy exterior line at five sixths ; a small brown 

 subcostal spot in middle of cell ; two snow-white spots on the 

 angles of the cell, the upper the larger, edged with brown, 

 and lying in a small brown blotch; fringe and nervures 

 towards hind margin faintly tinged with brown. Hind wings 

 with discal spot and sinuous indistinct central line ferruginous ; 

 fringe and hind margin much tinged with brown; face 

 yellow, with a narrow reddish bar at base ; shoulders with a 

 reddish line at sides ; collar, patagia, thorax, and abdomen all 

 gilded yellow ; thorax with a red-brown central spot and the 

 crest red-tinted ; second segment of abdomen with two 

 largish reddish spots ; anal tuft reddish brown ; palpi dark 

 brown, the basal joint white. Underside paler yellow, with 

 very faint markings. 



Expanse of wings 24 millim. 



One male, Queensland. 



[To be continued.] 



MISCELLANEOUS. 



Contributions to the Emhryogeny of Simple Ascidians. 

 By Antoine Pizon. 



Several points in the development of the Simple Ascidians are 

 still disputed or unknown, especially the origin of the peribrauchial 

 cavity, the relations of the sensory vesicle to the neighbouring- parts, 

 and the existence of an epicardium analogous to that which is found 

 in the Compound Ascidians. The species which 1 have had at my 

 disposal for the purpose of studying these different points are 

 Cynthia morns and Ascidia villosa, Giard. 



The earliest phenomena of segmentation are dissimilar in these 

 two species, and this is due to the fact that Cynthia morns possesses 

 an enormous quantity of food-yolk, of which we still find a con- 

 siderable portion in the larva at the moment of hatching. 



I # After the formation of the cavity of the archenteron in Ascidia 



villosa, its walls send out two lateral extroflexions which grow 

 pretty rapidly, while each of them speedily attaches itself to the 

 ectoderm. The latter layer on its part becomes slightly invaginated 

 at the two points of contact and then perforated ; the larva hence- 

 forth exhibits two new apertures, which are added to that of the 

 stomodEeum, and the existence of which was first demonstrated by 

 Krohn and Kovalewsky. The enteric cavity is gradually enveloped 

 by the dilatation of its two diverticula, which become the peri- 

 branchial cavity. The two lateral apertures are thrust more and 

 more into the median line on the dorsal side in consequence of the 

 development of the larva ; finally they unite and form but a single 

 orifice, which will be the cloacal aperture of the adult. 



