64 

 Sub-carina triangular, the umbo pointing outwards; laterally it slightly overlaps the 



carinal latera. 



Rostrum strong and rather large, having the shape of a pyramidal wedge, with the 

 apex very prominent beyond the occludent margin of the scutum. Lateral margin nearly straight. 



Latera of the lower whorl two pairs, small, corresponding probably with the rostral 

 and carinal latera of other species of Scalpelluni. The inferior angle of the pentagonal u p p e r 

 latus also meets where they nearly touch one another. 



Peduncle wide at the summit, conical, short. Surface with very numerous narrow, 

 chitinous scales, placed rather far from each other, arranged in regular rows. 



Length of the capitulum 8 mm., of the peduncle about 2 mm. 



The "Siboga" collected this interesting form at: 



Stat. 204. September 20, 1899. Lat. 4° 20' S., Long. i22°58'E. Depth 75—94 m. Bottom: 

 sand with dead shells, i specimen. (A few specimens of Sc. rostratuin Darwin 

 were found at the same Station.) 



General Remark. This curious form belongs to the same group of species as Scal- 

 pelhim villosum Leach, Sc. trispinosuin mihi, Sc. sexcornutum Pilsbry and some of the species 

 provisionally described by Aurivillius and which are all characterised by straight or nearlj- 

 straight carinae. In Sc. arics the carina may really be said to be straight; it can be distinguished 

 easily from the other species by the number (13) of its valves and by the very characteristic 

 shape of its rostrum. 



3. Scalpellnm acntnm Hoek. PI. VII, fig. i. 



HOEK, Cirripedia collected by H.M.S. "Challenger". 18S3, p. 80, pi. Ill, fig. 19, pi. VIII, fig. 12. 



This interestino- deep-sea species was collected by H. M. S. "Siboga" at three different 

 Stations. They are very small animals: I measured two, in one the total length was 7,6 mm., 

 the length of the capitulum 5,6 mm., in the other respectively 6,5 and 4,7 mm. 



I think there can be no doubt, that the specimens are identical with those collected by 

 the "Challeno-er". Gruvel ^ has described as a new species (Sc. lo7igirostriim) a form oi Scal- 

 pelhiin much resembling my Sc. acntuiii, the main difference being that the carina of the new 

 species is somewhat broader. My figure ("Challenger" Cirripedia PI. Ill, fig. 19) represents the 

 little animal with the rostral side slightly turned up, so that the carina in the figure looks 

 narrower than it really is. And my description : " Carina short, simply bowed ; sides almost 

 wantincr, only slightly developed in the .superior part" has been misleading in so far that I 

 should have added : a little more so towards the inferior extremity. Of the other differences 

 Gruvel points out, the height of the sub-carina, which he says nearly equals that of the rostrum 

 ("presque aussi elevee que le rostre") and which is much smaller in the "Challenger" specimens 

 as also in those collected by the "Siboga", is by far the most important. But altogether these 

 differences are only slight: in comparing the specimens with one another they may perhaps 

 prove after all to be identical. 



I Gruvei., a., Cirrhipedes du "Tiavailleui"' et du "Talisman". 1902, p. 70. 



64 



