THE SESSILE BARNACLES. 285 



the infolded median parts of the parietes. These props also sup- 

 port the low dome of the Avail, which without them would easily be 

 stove in by the impacts incident to its station on turtle shells. In 

 other embedded barnacles the base is smaller relative to the sixe of 

 the body-chamber. In some species the outer layer of the parietes 

 is permeated with minute pores, as in many other Coronulince. 



Ouly P. ht'.riistylos is known, from eastern American waters. The 

 other species described are: 



Plaiylepas dccorata Darwin, 1 Galapagos Islands, etc. 



Plat ylf pas ophiophilus Lanchester, 2 Malay Peninsula, on the sea- 

 snake Enhydris curtus. 



riatylcpas kriiyeri, new name for Cryptolepas opfiiopMliis Kriiger. 3 

 Bangkok, Siam, on the sea-snake D-istira; Gwadar, Beluchistan, on 

 the tail of Hydro phis. 



Though rather incompletely described, this species seems to be quite 

 distinct from P. opJiiophilus Lanchester and P. dccorata Darwin. 

 It certainly is not a Cryptolepas. 



PLATYLEPAS HEXASTYLOS (O. Fabricius). 



Plate G7, figs. 1-lc, 3. 



1708. Lepas hcxastylos O. FABRICIUS, Skrivter af Naturhistorie-Selskabet, 



vol. 4, Heft 2, p. 35, pi. 10, figs. 1, 2. 

 1S24. Coronula bisexlobata DE BLAINVXLLE, Dictionaire des Sciences Na- 



tmvlles, vol. 32, p. 379, pi. 117, fig. 1 (republished in Manuel de Mala- 



cologie, p. 600, pi. SO, fig. 1). 

 1825. Platylepas pulclira GRAY, Annals of Philosophy, new ser., vol. 10, p. 



ID.") (Corsica). 

 1825. "C. bisexloba Ranz," GRAY (not of Ranzani), Annals of Philosophy, 



new SIT., vol. 10, p. 105. 

 . Coronula califomiensis CHENU, Illustrations Conchyliologiques, pi. 1, 



fig. 4 (sur les Cetaces, Calif ornie). 

 1854. Platylepas lissexlobata DARWIN, Monograph, p. 42S, pi. 17, figs, la-ltf. 



( Mediterranean, on turtles ; River Gambia and Honduras, on manatee ; 



Moreton Bay, Australia, " apparently attached to the dugong of that 



coast"). 

 1884. JUatylcpas Ussexloltata Blainville, P. FISCHER, Bull. Soc. Zool. de 



France, vol. 9, p. 359 (New Caledonia, on Halicorc dugong). 

 1903. Plati/h'pas bissexlobata Blainville, GRUVEL, Nouv. Ann du Museum, 



ser. 4, vol. 5, p. 151, pi. 3, fig. 13 (Sicily; type of Coronula concent rica 



Valenciennes MS.). 

 1912. Plniylcpas bissexlobata (de Blainville) KRUGER, Abhandl. K. Bayer. 



Akad. Wissensch., Suppl.-Bd. 2, 8 Abhandl., p. 13 (Timor Sea, on 



Chclone im bricata ) . 

 Type. Probabty lost ; from the Mediterranean. 



1 1854, Monograph, p. 429. 



2 Troc. Zool. Soc., London, 1902, pt. 2, p. 371 ; pi. 35, figs. 5-56. 



3 1912, Abhandlungen der math.-phys. Klasse der K. Bayer, Akademie der Wisseu- 

 schafti-u, Suppl.-Bd. 2, 8 Abhandl., p. 12, figs. 6-10 ; pi. 3, figs. 7, 8. 



