530 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



Genus KEMPOMETRA John 



Kempometra JOHN, Discovery Reports, vol. 18, 1938, p. 161 (diagnosis; only included species K. grisea, 

 n. sp.). 



The details of the genus are given below under the heading of K. grisea, the type 

 and only species. 



KEMPOMETRA GRISEA John* 



Kempometra grisea JOHN, Discovery Reports, vol. 18, 1938, p. 161, pi. 4, fig. 4; text fig. 9, a-e, p. 162 

 (description; South Shetland Islands; 830 meters). 



Diagnosis. A genus of Zenometrinae of which the two known specimens are of 

 small size; PI and P a are absent; the centrodorsal is rounded conical, not higher than 

 broad at the base, its surface showing no differentiation into radial areas; the cirrus 

 sockets are in 15 closely crowded columns; cirri with not more than 16 segments, all of 

 which except the two basal and the penultimate are longer than broad; no dorsal spines; 

 opposing spine absent or vestigial; brachials and pinnulars with everted and spinous 

 distal ends; viviparous, the females with brood pouches distal to and somewhat to the 

 side of the ovaries. 



Geographical range. Known only from the South Shetland Islands. 



Bathymetrical range. Known only from 830 meters. 



History. The genus Kempometra was established by Dr. D. Dilwyn John in 1938 

 for the reception of a new species, Kempometra grisea, that had been dredged by the 

 Discovery Investigations in the South Shetland Islands. 



Description. The centrodorsal is conical, nearly as high as broad, with the ventral 

 border produced interradially into low angles. The cirrus sockets, which are consider- 

 ably longer than broad, are arranged in 15 closely crowded columns of 3 or 4 each, the 

 sockets of one column alternating with those of the columns on either side. 



The cirri are about L, 9-16 (usually 14), up to 9 mm. long. In the longer cirri 

 the first two segments are broader than long, the second longer than the first; the third 

 is about half again as long as broad, and the fourth to sixth are more than twice as long 

 as broad. The segments following decrease gradually in length, though ah 1 but the 

 penultimate, which is about as broad as long, are longer than broad. They are slightly 

 broader than the first six segments, and each is broader distally than proxknally, but 

 there is no trace of a dorsal spine. The whole cirrus is laterally compressed, more 

 strongly in the distal than in the proximal half. The opposing spine is usually absent, 

 but may be represented by a minute terminal tubercle. The terminal claw is small 

 and hyaline. The texture of the cirrus segments, like that of the brachials, is very 

 finely thorny. The apical cirri are considerably smaller than the peripheral; they may 

 be only half as long, with usually 9 to 12 segments. 



The radials are fairly long, broader distally than proximally; their length is less 

 than one-third the maximum width. The IBr t are widely separated from each other 

 for their entire length. They are deeply incised in the median line by the posterior 

 projection of the IBr 2 (axUlaries). Whereas the lateral edges are more than half as 

 long as the greatest width, the median length is only about one-tenth of the width. 

 The IBr 2 are longer than broad and form shoulder-like projections with the IBr^ the 

 two proximal sides are slightly, and the two distal strongly, concave. 



*See also Addenda (p. 837) under 1963. 



