82 
I have not seen any trace of; budding ; at the same time, it must be 
fairly common to form the large masses constituting this coral. 
Locality. — Banks of Yass River, Portions 53, 126, and 161 (shale 
below limestone), Parish Yass, County King (It. Etheridge — Australian 
Museum) : Hat-ton’s Corner, Yass River, near Yass (shales below limestone), 
County Murray (C. A. Sussmilch — Technical College, Sydney). 
Tryplasma delicatula, sp. nor. 
(Plate XX1T, Fig. 9 ; PI. XXIH, Figs. G and 7.) 
Specific Characters. — Corallum loosely fasciculate, of unknown dimen- 
sions, but probably large. Corallites long, cylindrical, straight or slightly 
flexuous, from one and a half to three millimetres in diameter, united laterally 
by their walls, or by fistulte. Eistulae short, of less diameter than the 
corallites, horizontal, and placed at different levels. Septal lamelke of two 
orders, primary and secondary, about thirty in a cycle ; septal spines tooth- 
like, without lateral denticles, the secondary spines very short. Tabulae 
complete and incomplete, the former at irregular distances apart, horizontal, 
concave, oblique or rolling, sometimes with a central depression, and at times 
provided with longitudinal spines; incomplete are vesicular, the vesicles 
triangular (in section), and marginal. Gemmation unknown. 
Observations. — I do not feel justified in uniting this with T. Lonsdalei, 
although clearly of the same type, particularly of the var. minor. We have 
here a form not only with corallites of considerably less diameter and a 
much smaller habit, but also uniformly possessing thirty septal lamellae, as 
against a considerable augmentation in T. Lonsdalei and its varieties. I 
was, further, always able to at once distinguish this species in the field, when 
in situ and in close contiguity to the former. 
T. delicatula possesses the least number of septal lamellae, in common 
with T. vermiformis, of any of our Tryplasmce. I am not acquainted with 
anything like a perfect corallum, but judging from appearances, and its 
general resemblance to T. Lonsdalei, it must have grown to some size. The 
listukc are well developed for so fragile a form, and the septal spines arc 
non-denticulate, but, as in T. columnaris, the tabulae bear longitudinal spines. 
Eistuloe have not been observed in T. vermiformis, nor vesicular 
tabulae or tabular sjhnes, the cut edges and ends of which are seen in thin 
transverse sections of T. delicatula, and notwithstanding the similarity in the 
same number of septal lamellae, I believe the tw o corals to be distinct. 
