I 21 



lateral margins are distinctly hollowed out. The umbo is near the base, beneath the centrum 

 of the triangular part which represents the foot of the wine-glass. 



The carinal latus is large and has an irregular quadrilateral shape. The carinal 

 margin is nearly straight, the umbo of the valve is at the angle where the carinal and basal 

 margins meet. The upper and lateral margins meet at a very blunt angle. 



The peduncle is short and shows eight not very distinct, longitudinal rows of scales: 

 three on both sides, one along the carinal and one along the rostral side of the peduncle. 

 The scales are much larger and much more distinct near the upper extremity of the peduncle. 



Size. The only specimen representing this species has a total length of 19 mm. the 

 length of the capitulum being 14,8 mm. It was found attached to a bundle of brownish threads 

 or hairs, the nature of which is unknown to me. It was taken by H. M. S. "Siboga" at: 



Stat. 295. January 24, 1900. Lat. io°35'.6S., Long. i24°ii'.7E. Depth 2050 m. Bottom: fine 

 grey mud. 



Observation. This species is at once recognisable by the form of its scutum and that 

 of its infra-median latus and carinal latus. It belongs to the same group of species as Sc. fissum, 

 Sc. candiduin and Sc. incertum^ but may be very easily distinguished from each of these species. 



Genus Pollicipes Leach 



In the Malay Archipelago this genus is represented by one species only ^ P. mitclla (Lin.). 

 Like the other species, P. mitella lives near the coast in shallow water, attached to rocks, 

 stones or shells. 



Darwin described six species of this genus in 1851 and since his Monograph appeared 

 the number has increased by one species only: P. Darwini Hutton from New Zealand. It is 

 the oldest known fossil genus of Lepadids and it must have been represented by very numerous 

 species in former geological periods: Darwin enumerates 22 fossil species in his Monograph 

 on the fossil Lepadidae of Great Britain. 



The above-named species was collected by H. M. S. "Siboga" on two different occasions. 



I. Pollicipes luifclla Lin. 



This is a very characteristic species and Darwin has given an excellent description of it. 



RuMPHius knew it already as an inhabitant of the Malay Archipelago and also Seba. 

 It occurs as far north as Japan, as far west and south as Madagascar, as far east as Hawaii 

 (autor. Gruvel). 



Concerning the bathymetrical distribution of this species not much is known : it is 

 generally considered to be a shallow-water species or even a littoral form. In my Report on 

 the Cirripedia of the "Challenger" Expedition I said that it was not on record that any one 

 of the species of Pollicipes occurs at a depth of even 10 fathoms, and so far as I know this 

 still holds good. 



> Gruvel, Monographie p. iS, says that /'. elegaiis Lesson occurs at Java, but he does not name the authority who observed 



that species there — I hardly believe he is right 



121 

 SIliOGA-EXPEDlTIE XXXIr/. '^ 



