LOWER CARBONIFEROUS BRYOZOA 
Fig. 93 Sulcoretepora parallela (Phillips, 1836). Line drawing of 
external features of BMNH PD9678; scale bar = 1 mm. 
} were developed. Mature branches are usually of constant width 
along their length, but a small amount of thinning distally can occur. 
_ The ratio of branch thickness (BW2) to branch width (BW1) ranges 
from 1:4 to 1:2. 
_ Autozooecia are arranged in 4 to 6 longitudinal rows on the lateral 
sides of branches. The number of longitudinal rows remains con- 
stant along the length of a branch. Autozooecial apertures are of 
medium to large size and circular to oval in shape. A thin proximal 
lunarium is present around each autozooecial aperture. Apertures 
lare spaced two and a half to three diameters apart. This spacing 
increases slightly in the rows adjacent to the median ridge. Here 
three autozooecial apertures generally occur in a 2mm line, while 
| four occur in the same length in rows away from the median ridge. 
Between adjacent rows of autozooecial apertures a strong narrow 
jlongitudinal ridge is developed. A smaller, fainter ridge is often 
found either side of the main ridge. This second ridge is found 
between the distal and proximal ends of two autozooecial apertures 
in the same row. The interapertural areas are smooth except for the 
_ longitudinal ridges. 
| Branches are internally divided by a thin plicated median wall, 
from either side of which are budded autozooecia. The median wall 
_is composed of pale laminated skeletal material. 
| Autozooecial chambers are elongate, narrow, and bend distally in 
_ the endozone region. The exozone is extremely thin, being about one 
sixth the thickness of the branch. Autozooecial chamber walls are 
; thin and straight. In shallow tangential section chambers are tear- 
Shaped and narrower proximally. Deeper sectioning shows the 
| chambers to have a rectangular shape. In cross-section chambers are 
hexagonal to pentagonal in outline. 
_ Small vesicles, 0.03 mm in diameter, are commonly found be- 
Ween autozooecial chambers and the branch margin. They are most 
_ frequently developed in the outer endozone and inner exozone. They 
"are thin-walled, circular to irregular in shape, and may be infilled 
with stereom in the exozone. 
_ Table 29 Measurements of Sulcoretepora parallela (in mm). N=21. 
NM x Mn Mx CVw CVb 
3W1 2, 1.02 0.68 1.43 4.39 5.34 
~3W2 38 0.49 0.31 0.75 7.92 3.14 
14 63 ~ 6 8 8.46 19.38 
2) 170 - 3 4 11.57 23.28 
ADI 200 0.19 0.11 0.29 9.90 6.70 
*AD2 201 0.12 0.08 0.20 11.49 6.64 
PAS 201 0.56 0.38 0.82 10.72 lili 
EEE eee 
DISCUSSION. Sulcoretepora parallela is unmistakable in appear- 
_ jce due to its strap-like branches with a regular arrangement of 
159 
autozooecial apertures which are divided by longitudinal ridges. 
This bryozoan displays very little variation either within or between 
colonies in a population. Computed coefficients of variation for 
branch width (BW1), branch thickness (BW2), and autozooecial 
apertural diameter (AD1 and AD2) are all very low. The values for 
the other parameters, those that are a measure of autozooecial 
spacing (Z1, Z2, and AS), are higher, but are still regarded as low 
when compared with other bryozoan taxa. 
Sulcoretepora parallela has a wide distribution in the Carbonifer- 
ous of the British Isles. It is common in the Carrick Lough/Sillees 
River assemblage. 
Three other species of Sulcoretepora have been described from 
the Carboniferous of the British Isles: S$. ramosa Owen 1973, S. 
raricosta (M‘Coy, 1844), and S. robertsoni (Young & Young, 1877). 
S. ramosa is nota sulcoreteporid but is a hyphasmoporid cryptostome. 
Branches are circular and not bifoliate, it lacks a median wall and 
lunaria, and acanthostyles are common. It occurs in County Ferman- 
agh and is redescribed herein as Clausotrypa ramosa (Owen, 1973). 
The other species of Sulcoretepora differ from S. parallela in a 
number of respects. S. raricosta has autozooecia of similar dimen- 
sions to those in S. parallela but has more autozooecia developed on 
one side of the branch than the other. Branches of S. robertsoni are 
nearly circular in cross-section, autozooecial apertures are larger, 
and interapertural areas are pitted and more ornate (Young & Young 
1877). 
STRATIGRAPHICAL RANGE. Carboniferous (Holkerian—Pendleian). 
DISTRIBUTION. British Isles. 
Family GONIOCLADIIDAE Waagen & Pichl, 1885 
Genus GONIOCLADIA Etheridge, 1876 
TYPE SPECIES. Carinella cellulifera Etheridge, 1873, by original 
designation from the Lower Carboniferous of Carluke, Scotland. 
Goniocladia cellulifera (Etheridge, 1873) 
Figs 84c, 94-102 
1873a_ Carinella cellulifera Etheridge: 433. 
1873b Carinella cellulifera Etheridge; Etheridge: 101. 
1876  Goniocladia cellulifera (Etheridge); Etheridge: 522. 
1880b Goniocladia cellulifera (Etheridge); Vine: 81. 
1880c Goniocladia cellulifera (Etheridge); Vine: 507. 
1885. Goniocladia cellulifera (Etheridge); Waagen & Pichl: 804. 
1887 Goniocladia cellulifera (Etheridge); Young: 463. 
1888  Goniocladia cellulifera (Etheridge); Vine: 77. 
1888  Goniocladia cellulifera (Etheridge) var. robusta Vine: 78. 
1953. Goniocladia cellulifera (Etheridge); Bassler: 89, fig. 54. 
1983 Goniocladia cellulifera (Etheridge); Utgaard: 434, figs 
213, la-h. 
1986a Goniocladia cellulifera (Etheridge); Bancroft: 23. 
1987  Goniocladia cellulifera (Etheridge); Bancroft: 196. 
MATERIAL. BMNH PD9563, 9701, 9703-9721; TCD.34112- 
34120, 34135, 34146-34147, 34150-34154, 34157, 42589, 42600a, 
42602b, 42604a, 42606c; BELUM K2162-5, K12003, Upper part of 
the Glencar Limestone (Viséan, Asbian), Carrick Lough, County 
Fermanagh. TCD.42512, Upper part of the Glencar Limestone 
(Viséan, Asbian), Sillees River, County Fermanagh. 
EMENDED DIAGNOSIS. Goniocladia with large reticulate or occa- 
sionally adnate zoaria composed of bifoliate straight to gently 
curved branches. Branches anastomose at regular intervals to form 
