i6 



With reo-ard to the structure of the cirri the main difference between Darwin's 

 description and what I have found is, that I think the unequality of the rami almost unimportant, 

 and further, that the segments of the rami of the 2"<i and 3-^^ cirri are distincdy protuberant. 

 Altoo-ether the cirri are short, the segments of the rami being but httle longer than broad and 

 not very numerous; the last pair has rami of 13 and 14 segments in one of the specimens I 

 investio-ated. These seg-ments have the ordinary 3 or 4 pairs of spines on the anterior face, 

 but as the segments are rather short these pairs stand close together and form groups of spines, 

 a "brush" as Darwin says, with the more or less numerous lateral marginal spines. The dorsal 

 side of each segment bears the ordinary dorsal tuft near the extremity (PI. X, fig. 7). 



The caudal appendages are short, less than half the length of the lower segment 

 of the pedicel of the si.\th cirrus; they are slightly swollen about the middle, the rounded 

 extremity being distinctly narrower. The distal third part is thickly clothed with delicate bristles, 

 standing out in all directions. 



During the cruise of the "Siboga" this species was collected at: 



About Stat. 51: in Street Molo. Depth 54—90 m. i small specimen. 



Stat. 79. June [2, 1899. Lat. 2°43' S., Long. 11 7° 44' E. Depth 41 — 54 m. Bottom: fine coral 

 sand [Borneo Bank]. Attached to the spines of a Cidaris bispinosa Lam. 8 specimens, 

 most of them small, three larger. The greatest diameter of the largest is about 7 mm. 



Stat. 79". June 12, 1S99. Lat. 2° 38.5 S., Long. 11 7° 46' E. Depth 54 m. Bottom: fine coral 

 sand [Borneo Bank: 5 miles X.N.E. from Station 79]. 4 specimens, greatest diameter 

 of largest 7 mm. 



Stat. 80. June 13, 1899. Lat. 2°25'S., Long. II7°43' E. Depth 40— 50 m. Bottom: fine coral- 

 sand. 4 specimens, largest not quite 5 mm. 



General Remark. This species, which was known to Darwin from specimens from 

 New Guinea only, may now be considered to occur at ditierent places in the Malay Archipelago. 

 It lives attached to the spines of Echinus, Cidaris and perhaps other forms of Echinidae and 

 seems to go down to depths of over 50 m. According to Weltner ' the Berlin Museum possesses 

 specimens of this species collected in the Red Sea (by Lepsils?). 



Genus Dichelaspis Darwin 



Darwin (185 i) instituted the genus Dichelaspis for those Lepadidae which have 5 valves, 

 generally appearing like 7 from each scutum being divided into two distinct segments united 

 at the rostral angle; he distinguished five species of the genus. When my report on the 

 "Challenger" Cirripedia was published (1883) the number of known species had increased to 

 nine. Since that time the number has increased considerably; W^eltner, publishing a list in 

 1897- of the then known species of Cirripedia, was able to count 18 species, or even 19, as 

 by a slight omission one of the 8 new species introduced into science by Aurivillius ^ was left 

 out by Weltner. Weltner also mentioned two new species which Stebbing * described in 1894; 



' Weltner, W., Veizeichnis etc. Archiv f. Natuig. 1897, Bd I, H. 3, p. 243. 



2 Weltnkr, W., Ibidem, p. 241. 



' Aurivillius, C. W., Studien etc. 1894, p. 15 — 28. 



* Stebbing, T. R. R., Notes on Crustacea. .\nn. & Mag. Nat. Hist. (6) XV, 1894, p. 18 — 19. 



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