3 

 2. Lepas fascicularis Ellis & Solander. 



This species which is rather common in tropical seas was observed once only durino- 

 the cruise of the "Siboga", viz. on Aug. 22, 1S99 (Station 165), anchorage on north-east side 

 of Daram Island (False Pisangs), East Coast of Misool. 



There are medium-sized and small specimens; the larger ones have the capitulum 

 20 mm. long. 



The valves stand at a certain distance from each other and have very distinctly brown- 

 coloured margins. The shape of the carina nearly approaches that of the typical form; the 

 lower part however does not expand in such a broad disc as figured by Darwin. 



.Some of the specimens are attached to fuci associated with young specimens of L. 

 anserifcra ; others form a group which is attached to a small brown ball of vegetable origin. 



Genus Poecilasma Darwin 



When proposing the new genus Poecilasma, Darwin (185 i) knew five species belonging 

 to it; he thought it probable, however, that several more would be discovered later. 



This prediction of Darwin can be said to have been fully realised : I am not quite sure 

 that all descriptions of new forms have become known to me, but certainly eleven new species 

 have come to my notice up to date, viz. : 



HoEK, Cirripedia "Challenger", 1883, 2 species. 



AuRiviLLius, Studien uber Cirripedien, 1894, 4 species. 



Aurivillius, Cirripedes "Princesse-Alice", 1898, . . . i species. 



Gruvel, Lepadides nouveaux British Museum, 1902, i species. 



HoEK, Cirripedia ".Siboga", 1907 3 species. 



Of some of these species it is questionable, whether they are really "good" species: for 

 example, as P. aiiranfiuin Darwin is considered by Gruvel' to be a variety of P. Kaempferi\ 

 I think also, that it is doubtful whether P . atiiygdahim Auriv. and P. Icnticiila Auriv. are really 

 different from one another and from Darwin's P. fissniu. But even then 9 new forms would 

 remain : a not unimportant increase to the number known to D.a.rwin. 



The mutual affinities of the species of Poecilasma are not easil\- understood. P. Kaempferi 

 Darwin (with anrantium Darwin), P. dudiiim n. sp., P. carinatum Hoek and P. gracile Hoek 

 seem to form a natural group of true Poecilasfiias, mainly differing from one another in the 

 shape and size of the carina. The species with the scutum composed of two segments form a 

 second apparently natural group: the)- are P. fissiiin Darwin (with ainygdalum Auriv. and 

 lenticula Auriv.), P. excavatum n. sp., P. mimctiim Gruvel, P. Iridcns Auriv. and P. vagans 

 Aurivillius. Of these species P . excavatum n. sp. and P . minutuin Gruvel may turn out to be 

 much more nearly related than the others. The remaining species: P. crassum Gray (with 

 P. tingtiiculus Auriv.), P. obliquuin n. sp. P. eburneum Hinds might be considered to form a 



1 Gruvel, A., Cirvipedes. Expeditions du Tiavailleui' et du Talisman. Paris, 1902. 



3 



