Bryozoa of the Pacific coast of America, p. 714 |
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714 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14
I have not been able to determine the nature of the primary brood-
chambers near the central area, but the secondary chambers near the
border are covered in the usual manner by a calcified porous membrane;
here they lie between the rays, in some cases extending on both sides of
a short secondary ray. They are soon covered by secondary cancelli.
The ooeciostome is hardly distinguishable from the cancelli in height
and size, but the orifice is wide open, rounded and its wall thin.
I must agree with Borg (1944:223) that the L. radiata of Canu and
Bassler (1928:163 and plate 29, figs. 1-2) from north of Cuba, and
those of Osburn (1940:334) from Porto Rico, cannot be identified with
Discoporella radiata of Waters (1879:276) from the Bay of Naples,
nor with the Melobesia radiata of Audouin (1826:235). Waters states:
"In most specimens the cancelli appear open; but in well-preserved ones
a delicate calcareous cover is found covering the aperture: and this is
perforated with about 2-10 holes," which is clearly shown in his plate
24, fig. 11a. The figures of Melobesia radiata Audouin show a round
zoarium with a small round central area; a central brood-chamber covered by a calcareous porous membrane and with lobes extending between
radii; the radii high, elongate and uniserial, the tubes connate to the
tips and ending in sharp points. Apparently there is no other species
recorded from the Mediterranean or Red Seas with which Waters could
have confused his D. radiata, and we must conclude that it is Audouin's
M. radiata and is a Lichenopora in the strict sense.
On the other hand, the L. radiata of Canu and Bassler and of Osburn,
from the West Indies, has an ovate or rounded zoarium with a large
ovate central area; the cancelli thick-walled and without a covering
calcified membrane; the brood-chambers not centrally located; the uniserial connate radii much less elevated. These West Indian specimens
appear to conform in every particular with Disporella ovoidea, as described above, and it is probable that Canu and Bassler's reference to
L. radiata from the Galapagos Islands is also to the same species, since
Dr. Bassler informs me (in litt.) that it has "a large, slightly elongate
central area, with the cancelli and rows of tubules as in the Cuban one."
How many other references to radiata are untenable it is impossible to
say, as it has often been recorded without description or figures, but it
seems safe to state that it has not been found on the Pacific coast of the
Americas.
Our material consists of 4 colonies, 2 from the Galapagos Islands, 1
from Colombia and 1 from southern California, a wide distribution to
be sure, but they all agree in the elongate form of the central area, the
Object Description
Description
| Title | Bryozoa of the Pacific coast of America, p. 714 |
| Type | texts |
| Format (imt) | image/tiff |
| Contributing entity | University of Southern California |
| Filename | AHF-PUB-PE-14-03~104.tiff |
| Full text | 714 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 I have not been able to determine the nature of the primary brood- chambers near the central area, but the secondary chambers near the border are covered in the usual manner by a calcified porous membrane; here they lie between the rays, in some cases extending on both sides of a short secondary ray. They are soon covered by secondary cancelli. The ooeciostome is hardly distinguishable from the cancelli in height and size, but the orifice is wide open, rounded and its wall thin. I must agree with Borg (1944:223) that the L. radiata of Canu and Bassler (1928:163 and plate 29, figs. 1-2) from north of Cuba, and those of Osburn (1940:334) from Porto Rico, cannot be identified with Discoporella radiata of Waters (1879:276) from the Bay of Naples, nor with the Melobesia radiata of Audouin (1826:235). Waters states: "In most specimens the cancelli appear open; but in well-preserved ones a delicate calcareous cover is found covering the aperture: and this is perforated with about 2-10 holes," which is clearly shown in his plate 24, fig. 11a. The figures of Melobesia radiata Audouin show a round zoarium with a small round central area; a central brood-chamber covered by a calcareous porous membrane and with lobes extending between radii; the radii high, elongate and uniserial, the tubes connate to the tips and ending in sharp points. Apparently there is no other species recorded from the Mediterranean or Red Seas with which Waters could have confused his D. radiata, and we must conclude that it is Audouin's M. radiata and is a Lichenopora in the strict sense. On the other hand, the L. radiata of Canu and Bassler and of Osburn, from the West Indies, has an ovate or rounded zoarium with a large ovate central area; the cancelli thick-walled and without a covering calcified membrane; the brood-chambers not centrally located; the uniserial connate radii much less elevated. These West Indian specimens appear to conform in every particular with Disporella ovoidea, as described above, and it is probable that Canu and Bassler's reference to L. radiata from the Galapagos Islands is also to the same species, since Dr. Bassler informs me (in litt.) that it has "a large, slightly elongate central area, with the cancelli and rows of tubules as in the Cuban one." How many other references to radiata are untenable it is impossible to say, as it has often been recorded without description or figures, but it seems safe to state that it has not been found on the Pacific coast of the Americas. Our material consists of 4 colonies, 2 from the Galapagos Islands, 1 from Colombia and 1 from southern California, a wide distribution to be sure, but they all agree in the elongate form of the central area, the |
| Archival file | hancockunpub_Volume21/AHF-PUB-PE-14-03~104.tiff |
