SYNCORYNE GRAY ATA. 55 



may, Agassiz conjectures, drop from the parent stem, 

 though he has never found them swimming freely like the 

 perfect zooid. At the same time the polypites are often 

 more or less affected. The tentacles are sometimes reduced 

 by absorption to mere papillae ; sometimes they disappear 

 altogether; and in some cases the whole head vanishes, 

 and the stem is surmounted by a single gonozooid, or 

 occasionally by two. 



In the month of May I found a large colony in the 

 latter condition, overspreading the underside of a stone on 

 Filey Brigg. The heads of the polypites had in almost all 

 cases disappeared, and each stalk bore near its extremity 

 one or two ovate medusiform bodies attached by a short 

 peduncle (Plate X. fig. 1 d) . The tentacles were represented 

 by mere projections on the margin of the umbrella, on 

 each of which there was a dark spot. The maimbrium 

 was rose-coloured and not inflated. The zooids were ac- 

 tive in their movements. 



I have no doubt that the C. gravata of Wright is iden- 

 tical with the C. mirabilis of the American coasts ; and his 

 name, as the first published, must take precedence. 



Agassiz has established the identity of the free zooids 

 produced by his Coryne mirabilis with a Sarsia (of authors) 

 which abounds in Boston Harbour during the spring 

 months (March, April, and May) . The ice has scarcely 

 gone from the shores, we are told, when it makes its ap- 

 pearance in numbers, that " swarm near the surface on 

 any sunny day " *. The adult zooid seems to resemble 

 very closely the Oceania (Sarsia} tubulosa of Sars, figured 

 in the ' Beskrivelser/ and may probably be identical with 

 it. It is described as very active and graceful in its move- 

 ments, and very voracious, swallowing quickly " large 

 numbers of small Medusae and, especially, other kinds of 

 * ' North American Acalephae,' by Alexander Agassiz, 176. 



