498 ]\Ir. A. "\V. Waters on a Structure in 



Adeonella (^Laminopora) contorta (Michelin). 

 Laminopora contorta, Michelin, Magaain de Zoologie, 1842, pi. iii. 



I saw several specimens marked Laminopora contorta in 

 tlie Museum cl'Hist. Nat. in Paris and found tiiat it had been 

 described by Michelin. I have since seen it in several 

 museums, from the North Atlantic, mostly from the Cape 

 Verde Islands. However, there are two specimens in tlie 

 British Museum marked the lied Sea. One of these is known 

 to have been bought at a sale, or in some such way, but the 

 other is marked " Mrs. Robinson bequest," so that we must 

 conclude it occurs in the Ked Sea, but it did not come before 

 me when I was at work upon the Red Sea fauna, 'i'here is 

 also in the British Museum a specimen from Cape St. Vincent, 

 Spain, 54. 11. 15. 334-336, and some specimens from "John 

 Adams Bank,'' which, according to Harmer *, is near the 

 Abrolhos Island, Brazil. There is another Abrolhos Island 

 off W. Australia. Tliese specimens had the raanuscrij)t 

 names Eschara and Adeonella dolichostoma^ Busk. 



Calvet records it from the Cape Verde Islands f and in tlie 

 same work describes Gemellipora arbuscida, Calvet, from 

 the same locality |. This has not the numerous short branches 

 at right angles to the main branch, but it is like A. contorta 

 and may be a colony before subsequent lateral growth had 

 forni.ed. Both have large lateral avicularia along the border 

 of the zoarium, with broad triangular mandibles directed 

 distal ly. 



The specimens from which I cut sections were collected 

 by Crossland from Boa Vista, Cape Verde Islands, and will 

 be described with his collection trom Cape Verde Islands. 

 As the opercula are very thick and there is some gritty 

 matter enclosed during growth it has been difficult to get 

 good serial sections. 



In a branch it often happens that the opposite zooecia are 

 of the same kind — that is, zooecia containing an embryo are 

 often opposite, as are zooecia nearly filled with testes, and 

 also zooecia with the bodies described are often opposite. 

 Should it be found advisable to separate A. contorta from 

 Adeonella tlien Laminopora may stand. 



In A. contorta and some fossil Adeonidse there is a tubule 

 over the operculum in some of the older zooecia ; but although 



* " Revision of the Genus Steyanoporelhi," Quart. Journ. Micr. Sci. 

 vol. 43, n. s. p. 254 (1900). 

 t E.xped. 8c. du ' Travailleur ' et du ' Talisman,' p. 4i*0 (U»07). 

 X Loc. cit. p. 4i'0, pi. x.vvii. tigs. 16-19. 



