Physa (fisa)

[NL., der: see Physalis.] 1. The typical genus of Physaliidæ. These oceanic hydrozoans, known as Portuguese men - of - war, are remarkable for their size, brilliancy, and power of urticating. There is a large oblong crested float which buoys the animal up, from which hang many proce es, some of which attain a length of 12 feet or more in ind i viduals whose float is only a few inches long. P. atlantic a or pelagic a is an example. by the fall of a leaf.