Zoarium dendritic or linear, firmly fixed to extraneous objects; zoœcia tubular, not fused together to form a gelatinous mass.
Subfamily B. LOPHOPINÆ.
Zoarium forming a gelatinous mass in which the tubular nature of the zoœcia almost disappears, capable to a limited extent of progression along a smooth surface.
Both these subfamilies are represented in the Indian fauna, the Plumatellinæ by two of the three genera known to exist, and the Lophopinæ by two (or possibly three) of the four that have been described. The following key includes all the known genera, but the names of those that have not been recorded from India are enclosed in square brackets.
Key to the Genera of Plumatellidæ.
| I. | Statoblasts withoutmarginal processes. | |
| A. | Zoœciacylindrical, not embedded in a gelatinous investment(Plumatellinæ). | |
| a. Zoœcia arising directlyfrom one another; no stolon; free statoblast oval | Plumatella, p. [212]. | |
| a'. Zoœcia arising singlyor in groups from an adherent stolon; free statoblasts oval. | Stolella, p. [229]. | |
| B. | Zoœciacylindrical, embedded in a structureless gelatinousinvestment. | |
| Zoœcia arising from a ramifyingstolon; statoblasts circular | [Stephanella.] | |
| C. | Polypides embedded ina hyaline synœcium that conceals the cylindrical form of thezoœcia (Lophopinæ). | |
| c. Polypides upright, their basefar removed from that of the zoarium when they are expanded | Lophopus, p. [231]. | |
| c'. Polypides recumbent for thegreater part of their length at the base of the zoarium | [Australella[[BE]].] | |
| II. | Statoblasts armed(normally) with hooked processes (Lophopinæ). | |
| A. | Processes confined tothe extremities of the statoblast; zoaria remaining separate throughoutlife | Lophopodella, p. [231]. |
| B. | Processes entirelysurrounding the statoblast; many zoaria embedded in a common gelatinousinvestment so as to form large compound colonies | Pectinatella, p. [235]. |
Subfamily A. PLUMATELLINÆ.
Of the two Indian genera of this subfamily, one (Plumatella) is almost universally distributed, while the other (Stolella) has only been found in the valley of the Ganges. The third genus of the subfamily (Stephanella) is only known from Japan.
It should be noted that zoaria of different species and genera of this subfamily are often found in close proximity to one another and to zoaria of Fredericella, and that the branches of the different species are sometimes entangled together in such a way that they appear, unless carefully separated, to belong to the same zoarium.
Genus 1. PLUMATELLA, Lamarck.