42 IVAR ARWIDSSON, SYSTEMATIC NOTES ON SOME MALDANIDS. 



Maldaninae. 



In 1919 (34, p. 409) Chamberlin proposed a new sub-family Heteromaldaninae 

 for Heteromaldane aequalis Ehlers 1908. Ehlers' description shows, however, that 

 we have simply to do with a Maldane-species. The original specimen lacked the 

 head and the l st setigerous segment, as is seen in the figure and as verified by rayself 

 in Dec. 1908, when through the kindness of Prof. Ehlers I was able to investigate his 

 material. The posterior end is described as the anterior one and at the same time the 

 animal was turned upside down, i. e. we have before ns the same mistake which Grube 

 made in 1860 in describing Maldane glebifex, the type of the genus. As Heteromaldane 

 now unfortunately has given rise to a new sub-family, I wish to touch on this matter. 

 In any case both the genus Heteromaldane Ehlers and the sub-fam. Heteromaldaninae 

 Chamberlin must be eancelled. 



It is extremely probable that the same holds good also for Chamberlin' s new 

 genus Sonatsa (34, p. 415) with the species meridionalis Chamberlin, described from a 

 single posteriorly incomplete specimen, which was moreover evidently regenerated 

 from the 6 th setigerous segment. The genus Sonatsa is said to differ from Maldane 

 and Asychis (the former of which it was said to resemble, especially with regard to »the 

 head-plate») by having uncini arranged in several rows (3 in the genotype) on the 5 th 

 setigerous segment and in 2 rows on the following segments. These two rows »may be 

 irregular or incomplete». The number of uncini on the 2 nd — 4 th setigerous segments 

 seems to agree rather well with that in large specimens of M. sarsi (ef. 24, p. 255). 

 The number of uncini — över 100 — on the 5 th setigerous segment is unusually great, 

 while those on the following segments, amounting to 45—50, ought to be far more 

 numerous, to juclge from the conditions in Maldane and Asychis. But as the seg- 

 ments in question are regenerated and evidently could not obtain their complete 

 number of uncini, the only real difficulty left is constituted by the uncini of the 5 th 

 setigerous segment. Their large number alone is not, however, sufficient to justify a 

 separation from the genus Maldane, with which Sonatsa meridionalis agrees e n t i r e 1 y, 

 apart from the fact that the uncini are said to be situated in rows on the 5 th and (im- 

 mediately) following segments. The more or less incomplete double rows on the 6 th 

 and following setigerous segments seem to be easily explained by the setae having been 

 somewhat separated, as is of ten the case, and it seems very probable that some of the 

 numerous setae of the 5 th setigerous segment were also thrust to the sides. It is note- 

 worthy that Chamberlin, who assigns such great importance to these rows of uncini 

 that he proposes the new sub-fam. Sonatsinae on behalf of them, does not attempt to 

 explain in detail their relative position. Chamberlin finds an additional support for 

 the genus Sonatsa in the fact that his new species lacks »the dorsal glandular area on 

 the fifth setigerous somite characteristic of Maldane». Here he has followed my work 

 of 1907 (24, p. 250), in which I included this character in the diagnosis of the genus 

 Maldane, but in parenthesis, as the matter seemed uncertain to me. Låter on I also 

 found that this character is not present in the genus Maldane as a whole (ef. 29, p. 



