Lab rum with a row of about 24 small teeth, standing close together; at each side the 

 5 or six outer ones are sharply pointed, the dozen in the middle being rather blunt. Pal pi small, 

 conical, with about five longer hairs at the tip and a few smaller ones along its inner side. 



According to Darwin the fourth tooth of the mandible is pectinated. 1 found a small 

 tooth on the inner edges of the second and third teeth, one on the outer edo-e of the fourth 

 tooth and also one on the edo-e of the inferior anede. 



The maxi 11 ae were unknown to Darwin. The upper part (PI. X, fig. 2 and 2a) is 

 furnished with three spines : two claw-like and the third rather straight and more delicate ; of 

 the two claw-like spines the first is one and a half times as broad and long as the second. 

 Under the upper part there is a deep notch, on the inferior margin of which two minute hairs 

 are planted. The inferior part of the edge of the maxilla is much producecl and bears about 

 ten unequally stout spines. Of these the one placed about the middle is by far the strono-est. 



The second maxilla (PI. X, fig. 3) has the outline not truncated, but rounded; hairs 

 over the inner surface of unequal length, rather delicate and not very numerous. Near the 

 outer margin the surface shows, moreover, numerous rounded spots of peculiar aspect, which I 

 have not observed in other species, so far as I can remember. 



Cirri of the first pair were lost in Darwin's specimen. They have unequal rami of 

 respectively 6 and 9 segments. These segments are broad, short, quadrangular, bearing at the 

 extremity a transverse row of numerous spines, which are longer than the segments themselves. 



Cirri of the second to sixth pair much as described by Darwin. Concerning those of 

 the 6 th pair the following may be pointed out : they have rather short pedicels and also short 

 rami of 11 and 12 segments. Their lower segments are as long as broad, the more distal grow 

 slightly longer, to about twice as long as broad, being slightly broader at the distal extremity; 

 the terminal segments of both rami are short and narrow. The spines form two groups or tufts 

 near the extremity of each segment (PI. X, fig. 4) : a dorsal and an anterior tuft, all of them 

 arranged in a transverse line. Darwin says that they are arranged in a circle, interrupted 

 widely on the two sides and, of course, it may be expressed in that way. But what is especially 

 characteristic for this species is, that the pairs of spines which as a rule in other Cirripeds are 

 seen at the anterior faces of the segments of the cirri are totally wanting. 



Caudal appendages (PI. X, fig. 5) elongate, slightly broader in the middle, narrow 

 at the extremity, where they bear a tuft of long slender hairs, like a kind of pencil. They 

 reach to about the middle of the second segment of the pedicel of the 6 th cirrus. 



Penis long, pointed at the extremity, where it bears a tuft of delicate hairs. 



General Remark. Aurivillius (1. c. p. 12) points out himself that there is a close 

 affinity between his new species (P. amygdalum) and Darwin's P. fissum. Vet he thinks they 

 are different, and to prove it he lays particular stress on the general form of the capitulum — 

 more oval, with a broader basis in P. fissum, more elliptical with a narrow basis in his P. 

 amygdalum. As I have said already, Darwin used for his description a specimen which had 

 long been kept dry and further, to judge from the material collected by the "Siboga", individual 

 differences occur in this species with regard to the shape of the capitulum. One might consider 

 some of the Ternate specimens as approaching more to Aurivillius' and others more to Darwin's 



9 



SIBOGA-EXl'EDITIE XXXI a. 



