1915. ] J. Rircu1g: Hydroids of the Indian Museum. 567 
GENERIC AND SPECIFIC DIAGNOSES OF ANNULELLA 
GEMMATA. 
Annulella,! nov. gen. 
GENERIC CHARACTERS. 
Trophosome.—Ployps solitary and naked, with conical pro- 
boscis, and long, scattered, capitate tentacles bearing nematocyst 
batteries arranged in many rings and furnished with solid multi- 
serial endoderm. During their fixed stage the polyps are attached 
by an adherent base, connected to them by a narrow neck and 
enclosed in perisarc. Multiplication by vegetative reproduction 
is the rule. 
Gonosome.—? Gonophores producing free medusae. 
Annulella gemmatta,* nov. sp. 
SPECIFIC CHARACTERS. 
Minute solitary polyps, 0°15 mm. to I'o mm. in height, bear- 
ing from 4 to 12 scattered capitate tentacles with nematocyst 
rings (nodes) along their whole length, and delicate solid endo- 
derm. Tentacles and polyp-body are furnished with two types 
of nematocysts (macrocnides and microcnides), The polyp is 
alternately fixed and free, escaping from its basal bulb by rupture 
of the connecting neck, and again developing a new basal bulb by 
a modification of its proximal end. 
Reproduction is normally asexual, by means of buds set free 
in a planula-like stage by means of the detached basal bulb, and 
possibly by means of longitudinal fission. The type of sexual 
phase is not known with certainty. 
Locality.—A brackish pond, Port Canning, Lower Bengal, 
India. 
Type Specimens.—In the collections of the Indian Museum. 
LIST OF WORKS REFERRED TO IN TEXT. 
Allman, J. G., 1871-72. A Monograph of the Gymnoblastic or 
Tubularian Hydroids. Ray Society, London. 
Allman, J. G., 1876. ‘‘On the Structure and Development of 
Myriothela.”’ Phil. Trans. Royal Soc. London, vol. 165, p. 
549. 
Ashworth, J. H. and Ritchie, J., 1915. ‘‘ The Morphology and 
Development of the Free-swimming Sporosacs of the Hydroid 
Genus Dicoryne (including Heterocordyle).’’ Trans. Roy. Soc. 
Edinburgh, vol. 51 (in press). 
Bedot, M., rg1z. ‘‘ Notes sur les Hydroides de Roscoff.’’ Arch. 
Zool. exp. et gén., Ser. 5, T. 6, p. 20T. 
! Feminine diminutive from Lat. annulus, a ring, signifying the ringed ten- 
tacles. 
2 Lat. gemmatus ~ budded. 
