APPENDIX. No. IV. 419 
Veretzia. To this genus likewise some additional characters may be added. 
The disc is oval and cartilaginous, having an oblique crest on its upper 
side. The disc itself is composed of two thin oval plates joined together by 
several concentric septa. The whole of the cartilaginous part is covered by 
a dense membrane, and its inferior surface is covered by tentacula, which 
surround its stomach; those towards the centre are terminated by suckers, 
those towards the margin are longest, and appear to be simple. The 
stomach is oblong, and the mouth very prominent. The membrane in 
passing from the upper part of the disc, to the lower, is produced beyond its 
margin, and the produced part is consequently composed of two membranes, 
which are united towards the margin of the disc.* 
1. Velella scaphidea. Crest set on the disc from left to right; its apex abruptly 
produced. 
Velella scaphidea. Peron et Le Seuer. Atlas, pl. xxx. 
2. Velella pyramidalis. Crest set on the disc from right to left; its apex 
gradually produced, pyramidal. ca 
Taken in plenty in 26, 34, ON. lat. 18. 28, 0 W. long. 
From the MS. observations made by Mr. Cranch, it is evident that a box 
containing specimens of marine animals, preserved in spirits, and a very large 
portion of the birds, have been lost. I have before remarked, that of the 
birds received, those enumerated, were the only specimens in a state fit for 
examination ; the greater part being totally destroyed by insects. 
* This produced membrane is to be observed in all the species, and therefore cannot 
be taken as a specific character, as has been done by Lamarck, for our European species. 
