120 
Mr. A. W. Waters on the 
48. Diachoris patellar ia, Moll. (PI. X. figs. 6, 7, 8, 9.) 
Eschar a patellana, Moll, Die Seerinde, p. 75, pi. iv. Kg. 20. 
Diachoris simplex, Heller, Dry. Adr. Meeres, p. 94, pi. i. Kg. 4. 
Mollia patellaria, Smitt, Floridan Bry. p. 12, pi. ii. Kg. 72. 
The ovicells are situated on the distal end of the zooecia, 
and are sometimes seen to coalesce with the cell above. The 
smaller openings (fig. 6), I presume, show an incompleted stage 
of growth; but if this is the explanation it would seem as if 
the growth of the ovicells influenced the growth of neighbour¬ 
ing cells, as in my specimen some of the cells near the ovicells 
have only this small subcentral opening, while all the neigh¬ 
bouring cells have the usual aperture. 
The lower two thirds of the front is covered with a granu¬ 
lated calcareous wall, the rest is covered with a thin mem¬ 
brane ; the small lid of the oral aperture is near the distal end ; 
border much raised and granulated. 
The attachment of this species is very strange, as from the 
base (figs. 8, 9) there are thrown out a number of radicular 
fibres, by which the colony is fastened to stones, sponges, &c. 
49. Diachoris patellaria, Moll, var. multijuncta. 
(PI. XIII. fig. 4.) 
?Eschara deprcssa, Moll, Die Seerinde, p. 70, Kg. 21. 
This differs from D.patellaria in having from eight to twelve 
or more tubular processes, and in the cells being longer and 
somewhat irregular in shape. The length of the tubular pro¬ 
cesses is also very variable; and the cells, in consequence of 
shorter tubes, are often close together. In such cases I am 
unable to see wherein it differs from Membranipora circum- 
cincta of Heller (Bry. des Adriat. Meeres, p. 96, pi. vi. fig. 5). 
Professor Heller, to whom I sent this drawing, does not, how¬ 
ever, think it is the same; so I suppose there must be some dif¬ 
ference. 
The definition of Diachoris would require altering to 
admit this form ; but the variations indicate that the tubular 
processes are not safe generic guides; and this we see in 
Lepralia Brongniartii with short tubes, L. discreta with longer 
ones, and a form much like discreta , if not the same, which 
Hutton has called Diachoris Buskiana. The genus Diachoris 
can only be looked upon as a provisional one, without any 
scientific basis as at present constituted. 
50. Diachoris magellanica , Busk. (PI. XII. fig. 1.) 
Diachoris magellanica, Busk, Mar. Poly. p. 54, pi. lxvii. Kgs. 1, 2, 3. 
Diachoris Baskei, Heller, Die Bry. des Adriat. p. 93. 
The figure given by Busk is evidently from a dried speci- 
