374 FUNAFUTI ATOLL. 



simple tubular tendril, which entwines itself around other stems 

 or foreign objects, and thus affords the colony an additional means 

 of attachment. 



The corbula is of the closed kind, and consists of a modified 

 branch bearing an alternating series of short stumpy branchlets, 

 each of which carries a hydrotheca differing from those on the 

 ordinary pinnules in being longer, more cylindrical, and in having 

 nine instead of seven marginal teeth. 



The distal branches of the corbulse exhibit the mode of origin 

 of the costse and costal appendages from the mesial nematophore of 

 the hydrotheca. The specimens at my command are very few, 

 and their extreme transparency renders the outlines of the costal 

 membranes difficult to trace. Three stages, however, can be dis- 

 tinctly discerned. In the earliest stage the mesial nematophore 

 is seen projecting from the front and arising from the base of the 

 hydrotheca, it assumes a fan-shaped outline, and consists of a 

 wide membrane with an incipient micro-nematophore at its inner 

 distal angle ; in the next phase the membrane is larger and there 

 is one fully formed micro-nematophore and another incomplete 

 one at the inner extremity ; on the next older costa there are 

 three fully formed micro-nematophores, and the membranous part 

 is proportionately enlarged. 



Prof. All man, in his report on the Hydroida of the Gulf 

 Stream,* describes two species A. distans and A. bispinosa in 

 which there are modified hydrotheca at the base of each costa ; 

 both, however, are of the open corbulse type, and the hydrothecse 

 appear to be more modified than in the species under notice. 



CLASS HYDROZOA. 



Sub-Order HYDROCORALLIN^. 

 FAMILY MILLEPORID^. 



MlLLEPORA SQUARBOSA, Lam. 



Millepora squarrosa, Lain., var. incrassata, Dana, U.S. Explor. 

 Exped., Zoophytes, pi. liii., fig. 1; Synop. Rep. Zooph., 1859, 

 p. 105. 



A single example of this species is in the collection. 

 The specimen consists of a subtriangular plate 12*5 cm. in height, 

 18 cm. in width, from 1 to 1*5 cm. in thickness near the base, and 

 from T5 to 2*3 cm. at the summit. The upper semi-circular margin 

 is much thickened, lobate and roundly truncate ; at one extremity 

 there are two toe-like lobes 5 cm. high, 3-3 cm. broad, 1-3 cm. 



* Mem. Mus. Comp. Zool., v., 2, pp. 44-46. 



