s 



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calcified part has a somewhat irregular triangular form, the base (the margin directed toward: 

 the carinal latus) being hollowed out, the two others margins being convex. The apex is bluntly 

 pointed, the sharply pointed umbo lying at some distance from the apex. 



The rostral latus is trapeziform : the scutal and basal margins are parallel to each 

 other, the latter being much shorter than the former. 



The shape of the calcified portion of the i n f r a - m e d i a n latus is that of a wine-glass 

 Avith a very short foot. The umbo is near the base. 



The carinal latus is quadrangular and has the umbo at the base of the carinal 

 margin, where it slightly projects beyond the line of the carina. The carinal margin is hollowed 

 out and forms with the upper margin a ver>^ sharp angle. The lateral margin is indistinctly 

 hollowed out, the basal margin forms a sharp angle with the carinal margin. 



The peduncle is cylindrical, slightly narrower at its base than at the upper extremitv. 

 The scales on the surface are rather broad and placed at considerable distances from one another. 

 One row is exactly at the carinal side (fig. 6a), then there are three lateral rows on each side 

 of the peduncle, the rostral side being occupied by two rows, the scales of which alternate 

 vertically with one another. There are no more than five or six scales in each vertical row. 



Size. The largest specimen collected by H.M.S. "Siboga" has a total length of 35 mm. 

 the length of the capitulum being 22 mm. 



I have not studied the structure of the animal within the capitulum. I found the dwarf- 

 males lodged in a pouch, formed by a duplicature of the mantle or sac at the margin of the 

 scutum. Each side has a pouch and in the specimen I have investigated each pouch contained 

 two males. I believe I observed them also in the other specimens; but as I did not wish to 

 destroy them I did not investigate very closely with regard to this point. The shape of the 

 male (PI. VII, fig. 7) is oval; it is rather large, the longest diameter being not quite i mm., 

 the breadth about half the length. Its surface is beset with short spine-like hairs; these are 

 more numerous and especially longer at the peduncular than at the capitular pole of the little 

 creature. A small opening at the capitular pole gives entrance to the interior of the sac. There 

 is no trace of real calcareous plates which would represent the valves of the male; but as 

 the surface of the sac is naked and smooth in the immediate neighbourhood of the openincr, 

 these slightly swollen marginal parts may after all stand for rudimentary valves. So far as could 

 be ascertained without cutting sections, the structure of this male corresponds with that of the 

 male of Sc. regiuiii, Sc. velutmum and other deep-sea species. Of the internal organs the male 

 reproductive organs (testicula and receptaculum seminis) are the only ones which are in a 

 relatively good state of development, the abdominal segments with the long spines attached to 

 them being visible but in quite a rudimentary condition. 



This species was collected at : 



Stat. 18. March 18, 1899. Lat. 7°2S'.2S., Long. ii5°24'.6E. Depth 10 18 m. Bottom: fine grey 

 mud. Three .specimens. 



II. Scalpellum curiosum n. sp. PI. VII, Fig. 8, 8« and ^b. 



Valves fourteen, imperfectly calcified, covered by a thin chitinous membrane. Calcified 



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