138 BULLETIN 84, UNITED STATES NATIONAL MUSEUM. 



The outlines of the mouth pieces are completely hidden by the teguments. 

 Large rounded granules, which form two or even three regular rows, extend along 

 the mouth angles and represent oral papiUse. At the end of the jaws, there is a 

 group of two or three tooth papillae which are more developed than the preceding 

 ones, flattened and lanceolate. 



The arms are somewhat higher than broad; the upper face is strongly convex 

 and the under face is flattened. They are a little narrower at the beginning and 

 then they become slightly wider 2 or 3 centimeters from the base; at the same 

 time, the division into successive rings becomes more apparent. The granules of the 

 radial ribs extend over to the upper face of the arms where there are to be found, as 

 well as on these ribs, fairly large granules separated by other smaller ones, it being so 

 on the first six or eight brachial articles; beyond the granules lie wider apart, and 

 at the same time, their size decreases and becomes uniform. There are then to be 

 seen only loose minute granules which become still fewer and smaller as the distance 

 from the disk increases; finally, the granules completely disappear about 10 centi- 

 meters from the basis of the arms, and their upper face consequently remains 

 completely smooth. 



The granules of the upper face of the arms extend over to the lateral faces with 

 the same characters; they become, however, a little smaller and more uniform 

 toward the under edge of the arms. On the under face of the arms granules are 

 again found which are analogous to those of the upper face of the disk, although 

 much smaller, but these granules rapidly become very small and fewer and thej' 

 finally disappear 3 or 4 centimeters from the disk. 



The first pair of brachial tentacular pores is deprived of scales. On each pore 

 of the three succeeding pairs, one only is to be seen, and the second scale appears 

 on the pores of the fifth pair in the largest specimen. 



These scales always have the shape of almost cylindrical spines, with thin but 

 obtuse ends. The length of the internal spine progressively increases from the 

 pores of the second pair and it finally reaches one and a half articles ; this spine 

 is rather strong, a httle thinned at its tip, and it shows in its terminal part, on about 

 one-third of its length, rather strong successive denticulations. The external spine 

 always remains much weaker; it is conical and more pointed than the internal one, 

 and it hardly exceeds half the length of the latter; it also displays in its terminal 

 part denticulations, which, however, are weaker than on the internal spine. 



In the second specimen, the disk of which is 8 mm. in diameter, the external 

 spine appears generally from the fourth article upward, and in the third specimen, 

 which is smaller, it appears now on the fourth, now on the fifth article. 



After the above description was written, I received an additional specimen 

 from the U. S. National Museum, as follows: 



Albatross station 2152. Apr. 30, 1884. 21 miles NW. of Havana Light; 

 387 fathoms; co., temp. 49° F. One specimen. 



The specimen is incomplete; the arms are all broken oflP near the basis and a few 

 loose fragments only are preserved. 



Tlie sample was labeled Astrochema arenosum, but the determination is evi- 

 dently incorrect, and we have to deal here with A. dongatum, a new species which 

 I have described above from specimens of the U. S. National Museum. I mention 



