,u,l. il appendages ttïangular, uni-articulate, small; a tufl <>!" ;il>< <ui hall a dozen 

 hairs at the extremit) 



Penis, rather short, reaching t" il"- extremity of the fifth segmenl of the last pair 



rri; its basal part broad with only a feu scattered hairs, the terminal part of about the 



same length as th<- basal part, cylindrical, rather narrow, indistinctly ringed. h bears very 



ate hairs, which are irregularly distributed over the su ind a rather dense tufl ol 



.ii th<- extremity. 



The mantle-cavity of the hermaphrodite animal investigated more in detail contained six 



rather large and nearly globular eggs. The greatest diameter of the eggs is 0,34 mm., the 



shortt t8 mm. They contained larvae in the Nauplius-stage, some of the larvae had partly 



I off th<- exuviae 



The male <>t" this species is a truc complemental male. I found two of them in th<- 

 one, one in the other pouch of the hermaphrodite specimen. In fig. 10 the place occupied by 

 this pouch is indicated as a little swelling [ó). The male is figured PI. 5, fig. 11; its size is 

 mm. 0,25 mm. It lias six valves: two scuta, two terga, a carina and a rostrum, the 

 •4rncr.1l shape of which can be seen from the figure. The scutum is the largest, the rostrum 

 is much broader than the carina. The tergum lias an irregular shape and is divided into two 

 parts: a larger somewhat excavated at the apex and a very small one at the place of the 

 primordial valve. Shape and position of the valves resemble the corresponding parts in the male 

 of Sc. Peroni and Sc. villosum as described by Darwix. But the males of the present species 

 no narrow peduncle, the capitulum going over quite insensibly into the short and flattened 

 part to which the prehensile antennae are attached. The membrane connecting the valves is 

 very slightly rough, but it does not bear distinct hairs. Extremely minute hairs seem to be 

 planted on the surface near the peduncular pole only. The musculature of the peduncular part 

 of the sac is strongly developed. 



The structure of the little body within the sac corresponds in general but in reduced 

 condition with that of the hermaphrodite animal as also with that of the males of the nearly 

 related species Sc. villosum and V. Peroni, It lias ver) - large eyes situated in the median line. 

 beneath, or rather in front of the strongly developed adductor muscle. The mouth is slightly 

 bullate; the cirri have but few segments (four in the first, five in the second pair). The penis 

 is short, cylindrical, rounded at the extremity, where it bears a few curled hairs or bristles. 

 This specii-, was collected during the cruise of H. M. S. "Siboga" at: 



Stat. ^74. December 26, 1899. Lat. 5°28'.2S., Long. i34°53'.9E. Dcpth 57111. Bottom: sand 

 and shells, stones. 6 specimens. 



Observations. This is a very curious species. It belongs to the same group as Sc. 



villosum (Leach) and Sc. irispinosum mihi as is shown at once by the shape of the carina. 



It has one pair more latera, however, than one of these two species and the general shape of 



apitulum is more like a normal Scalpellum in consequence. Like Sc . villosum and trispi- 



•n it comes near to Pollicipes, especially /'. sertus and this is particularly the case with 



rd to the shape of the valves of the lower whorl. 



( me of the specimens shows this relation in a still more conspicuous way and 1 have 



62 



