"31 December 1999."

Thalamoporella are widespread in tropical and warm temperate waters of the eastern and western Pacific Ocean, Indian Ocean, Pesian Gulf, Red Sea, Mediterranean and eastern and western Athlantic Ocean. Twenty four species of Thalamoporella having acute or subacute avicularium mandible tips are discussed, nine of which are new: T. winstonae, T. vavauensis, T. lanceolata, T. lingulata, T. rasmuhammadi, T. afrogothica, T. minigothica, T. harmelini, and T. molokaiensis. Of these, three species have avicularia with strongly curved or angled rostra; four species have lanceolate acute or subacute avicularium mandibles; three species have isosceles triangle-shaped mandibles and 12 species have atraight avicularia with gothic arch-shaped mandibles, as in T. gothica, but differ in other characters. The ratio of the mean zooid length to the mean avicularium length in 15 of the species ranges from 1:0.80 to more than 1:1.00, while seven range between 1:0.62 and 1:0.72, and two vahe ratios below 1:0.45, one with a very low ratio of 1:0.36. This is consistent with the trend in avicularium size over time that we postulated previously..