Ritchie, J. 1915. The Hydroids of the Indian Museum. II. <i>Annulella Gemmata</i>, a New and Remarkable Brackish-Water Hydroid. Records of the Zoological Survey of India. 11, 6 (Nov. 1915), 541–568. DOI:https://doi.org/10.26515/rzsi/v11/i6/1915/163053.