550 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



localities. In this there appears "Uca, Solomon Islands," which is an error for Uea, 

 Loyalty Islands, confused with Ughi in the Solomons. The last locality, Philippine 

 Islands, refers to a preceding one, Sulu Sea. In a paper describing a number of new 

 species contained in the Siboga collection which was published in 1912 there is included 

 Comanthus crassicirra. This new form was said to be related to Comanthus japonica, 

 and to be the first member of the small group to which C. japonica belongs to be 

 brought to light south of Japan. 



In 1912 Dr. August Reichensperger mentioned that the chambered organ of this 

 species contains numerous spherules, which are found in all the chambers. He had 

 2 specimens of this form which came from among a number collected by Professor 

 Strubell at Amboina in 1890 which were turned over to him by Prof. Hubert Ludwig. 



In 1913 I published notes upon the 5 specimens in the British Museum. One 

 of these, from Lelti Island, had not previously been recorded. 



In 1918 I recorded 3 specimens from as many Siboga stations, and included the 

 Comanthus crassicirra which I had described in 1912 in the synonymy of bennetti. 



COMANTHUS PLECTROPHORUM H. L. Clark 



Plate 23, Figure 62; Plate 69, Figures 190, 191 



Comanthus plectra phorum H. L. CLARK, Biol. Results Fishing Exper. F. I. S. Endeavour, 1909-1914, 

 vol. 4, pt. 1, June 2, 1916, p. 15 (description; east of Flinders I., Bass Strait; 100-300 fathoms); 

 pl. 4, fig. 1. 



Diagnostic features. The proximal and middle pinnules have the segments in 

 their basal portion produced dorsally into conspicuous dorsal processes which on the 

 lower segments may be as high as the width of the segments themselves. The centro- 

 dorsal is large and discoidal, 10 mm. in diameter. The cirri are very numerous, 

 LV-LX, long, with 29-37 segments of which the distal are carinate with slightly 

 produced distal edges. 



Description. The centrodorsal is about 10 mm. in diameter and more than 2 

 mm. high, with the bare dorsal pole very rough, slightly concave, and about 6 mm. 

 across. The cirrus sockets are arranged in 3 crowded and irregular rows. 



The cirri are LV-LX, 29-37, usually about 32. Some of the proximal segments, for 

 instance the fourth-ninth, are longer than broad; the fifth is particularly long. 

 Beyond the tenth (which from the figure appears to be a transition segment) the 

 distal dorsal margin projects slightly, the segments become laterally compressed, and 

 a marked dorsal keel is formed which is most fully developed on the 4 or 5 segments 

 preceding the penultimate. When seen from the dorsal side this is more of a tubercle 

 than a keel, but the lateral aspect is very keel-like. 



The radials are entirely concealed. The IBr, are short and broad, in lateral 

 contact for about three-fourths of their length. The IB 2 (axillaries) are very short 

 and broad, at least three times as broad as long, and are not at all in contact with 

 each other. Of the IIBr series 9 are 4 (3 + 4) and 1 is 2. Externally they are well 

 separated from each other; internally the IIBri are more or less in lateral contact. 

 The IIIBr series are 4 (3 + 4), in 2 instances 2. The IVBr series, when present, are 4 

 (3 + 4). One of the 2 specimens has no IVBr series, but there are 4 in the other. In 

 1 specimen (that without IVBr series) the distal edges of the elements of the IIBr 



