At the end of the description of Sc. longirostrum^ Gruvel in bis "Monographie" (1. c. 

 p. 58) says that the dwarf males also differ. It is true that I named Sc. actdiim as one of the 

 species whose males have 110 peduncle, mouth or stomach (Challenger Cirripedia, Anatomical 

 part, p. 20). However, as I did not observe the male of this species (Ibidem, p. 4), this was 

 a supposition only and the name of the species, therefore, was placed in brackets. I found little 

 males (one on each) on two of the "Siboga" specimens and I figure one of them on PI. VII, 

 in hg. 1. Comparing this figure with that given by Gruvel for the male of Sc. longirostrum, 

 the main difference is the absence of a peduncle in Gruvel' s and its presence in my figure. 

 Had my specimen been without a peduncle then I would admit at once that the little stump 

 had been broken off on isolating the little animal from the female - I dare not say that this 

 happened to Mr. Gruvel's specimen, but I think it is possible 



I consider this species, like Sc. squamuliferwn Weltner and Sc. striatum Aurivillius, as 

 belonging to the group of Proto-Scalpclliims. The carinae of these species are not quite straight 

 but they are only little bowed and (with the exception of that of Sc. squamuliferuni) relatively 

 short. Further, these species have a rostrum and a sub-carina and the valves of the lower whorl 

 triangular with the umbo at the apex; they have (so far as known) males with a capitulum 

 with valves and a peduncle. In all these regards the present species corresponds with the others 

 of this division. 



The "Siboga" collected this species at the following Stations: 



Stat. 122. July 17, 1899. Lat. i°58'.sN., Long. i25°o'.5 E. Depth 1264 — 1165 m. Bottom: 



stone. 2 specimens. 

 Stat. 151. August [2, 1899. Lat. o°i2'.6S., Long. I29°48'E. Depth 845 m. Bottom: fine grey 



mud with coarse particles. 1 specimen. 

 Stat. 211. September 25, 1899. Lat. 5°4o'.7S., Long. i2o°45'.5 E. Depth 1158 m. Bottom: 



coarse grey mud. 2 specimens. 



What I said in my "Challenger" publication on the distribution of this species, viz. that 

 it occurred at places situated very far from one another, has now proved to be true in a still 

 higher degree: whereas the "Challenger" found it in the Atlantic, near the Azores, and in the 

 Pacific, near the Kermadec Islands, it has now been observed in the Malay Archipelago. 



According to Gruvel the only specimen of his Sc. longirostrum he could investigate was 

 taken in the Atlantic Ocean not far from the coast of Portugal at a depth of 1923 m. 



B. Sectio: Eu-Scalpellum 



4. ScalpcUitm rostratum Darwin. PI. V, fig. 13. 



DARWIN, Monograph of the Sub-class Cirripedia. The Lepadidae, 185 1, p. 259, pi. VI, fig. 7. 



I doubt whether this species has ever been observed since Darwin published his 

 description. Yet it is perhaps the commonest of the genus under the tropics — at least in the 

 Malay Archipelago; the "Siboga" collected it there at four different places, 6 specimens in one 

 haul at two of them, and numerous specimens at a third. 



65 



SIBOGA-EXPEDITIE XXXI a. 9 



