110 
Mr. A W. Waters on the 
35. Eucratea Lafontii , And. 
Eucratea Lafontii , Aud. in Savigny, Egypte, pi. xiii. fig. 2. 
Alysidium Lafontii, Busk, Mar. Polyz. p. 14, pi. xiv. figs. 1-4. 
As Eucratea chelata and E. Cordieri have so close a resem¬ 
blance, I cannot bring my mind to place them in two genera 
merely because the latter has a horny connexion. The Aly- 
sidium parositicum, Busk, being also closely allied to E. Cor¬ 
dieri , Aud., the genus Alysidium seems a superfluity, and the 
definition of Eucratea should be changed to admit A lysidium. 
Hob. Spain, Adriatic, 25-55 fathoms; Naples on seaweed 
from but slight depths. 
3G. Eucratea Cordieri , Aud. (PL XV. figs. 9, 10, 11.) 
Eucratea Cordieri, Aud. in Savigny, Egypte, p. 74, pi. 13. fig. 3. 
Several branches of cells curving inwards, growing on a 
jointed stalk, rising from creeping anastomosing stolons; 
zooecia nearly straight in front, curved behind, narrowing to 
the proximal end ; zooecia growing from the end of the cell, 
connected by short corneous tubes. Zooecium in front coffin- 
shaped with an opening below the oral aperture. 
This is clearly the form figured by Savigny, and differs 
from Eucratea chelata in having no raised border, which is 
very apparent in the British species, as far as my opportunities 
of examination extend. This, however, seems to be some¬ 
what variable, as Prof. Smitt says this border seems to be 
more common in his southern stations, and in his northern 
ones is not so distinct as in the English figures. It also differs 
from E. chelata in not having rigid junctions ; and according 
to Mr. Busk’s definition of Scrap aria, should not be considered 
of this genus ; but with the mode of growth and the shape of 
the cells so similar, it would hardly be justifiable to make two 
genera out of them at present. This, however, would unite 
Alysidium parasiticum, Busk, under the same genus; and in 
many points it has much in common with the present form. 
From one piece of seaweed there are about fifteen colonies, 
all connected together by one creeping and anastomosing root. 
The stem rises up from this radicle, from a round disk which 
corresponds with the rosette-plates. This stalk consists of 
6-10 joints (figs. 9, 10) with, usually, long calcareous tubes 
and short horny tubes, though occasionally the corneous tube 
is about as long as the calcareous one. At the top of the 
stem the joint bifurcates ; and from these and other bifurcations 
branches are given off with about 6-8 zooecia, curling over 
and mostly opening in the same direction. The figure 9 only 
