Benham. — Oligochaeta from Kermadec Islands. 179 



of the spermathecal duet, the distribution of the chylus cells, relative .size 

 of ante- and post-septal portions of nephridium, and so forth. 



Tlie species without diverticula to the spermathecal ampulla are : 

 F alba Moore, F. bulbosa Rosa, F. striata Levinsen, F. harrimani Eisen, 

 F. joknsoni Eisen, F. fuehsi Eisen, and F. sonorae Eisen. All these have 

 more than 2 chaetae in each bundle. F. alba has, moreover, the first 

 dorsal pore on segment vi, instead of in the usual segment vii ; F. bulbosa 

 has generally 4 chaetae per bundle, though this number is reduced to 2 in 

 the posterior segments. 



Hence the present worm does not fall into any of the above species ; hut 

 how far the number of chaetae may be relied on as diagnostic when certain 

 other structures agree in two species I do not attempt to decide (see below) ; 

 there may be a certain range of variation, and it is also to be noted that in 

 F. bulbosa glands may (according to Ude and Moore) or may not (fide 

 Rosa) be present at the exit of the spermatheca. 



The species in which the number of chaetae is limited to 2 per bundle 

 are : F. bisetosa Levinsen, F. leydigi Veydovsky, F. oligosetosa Nusbaum, 

 F. monopera de Martiis, F. diachaeta Bretscher, and F. clitellaris Bretscher ; 

 but each of these differs from the species under discussion in various other 

 anatomical features. 



As to the extent of the chylus cells, it is only by Eisen that this is used 

 as one of the specific characters. 



The majority of the species of Enchytraeids has, it seems, only been 

 studied in the fresh state on the entire or dissected specimens, hence such 

 a matter has been overlooked ; moreover, it is only of recent years that 

 these chylus cells have been investigated outside one or two common 

 European species. Certain features can only be properly and accurately 

 noted in fresh specimens which can be teased out : such things as the 

 relative lengths of the spermathecal duct, the funnel of the sperm-duct, 

 the exact form of the nephridium — these cannot be well noted in sectionized 

 worms. It thus comes about that when one is limited to preserved material 

 it is difficult to compare one's observations with those recorded by other 

 observers who had fresh and perhaps an abundant supply of such worms ; 

 and it is therefore with some hesitation that I bestow a new name on this 

 worm, for I feel that it is by no means unlikely that it is already known, 

 for Michaelsen (9, p. 19) writes of a species found at St. Paul and New 

 Amsterdam in the Subantarctic region : " Whether this Fredericia is 

 F. bisetosa or some other species doubtless it has been introduced into these 

 islands of the Southern Hemisphere. The ' home ' of Fredericia is the 

 north temperate region. The species of Fredericia of the Southern Hemi- 

 sphere are, so far as can be decided, all wanderers." 



The only species of the genus that has been recorded from New Zealand 

 is a widely distributed form — F. galba (or F. antarctica of Beddard), from 

 which the present one differs in several respects. 



Fredericia bollonsi var. oliveri. 



A collection of five specimens of this variety was forwarded to me by 

 Mr. W. R. B. Oliver with the other material. They were found " under 

 nikau-palm leaves, on damp ground, on the terraces, Sunday Island, 

 July, 1908." 



They measure from 10 mm. to 15 mm. in length, and have from 48 to 50 

 segments. From a study of entire specimens I supposed that this was a 

 different species from the above, but after examination of sections, both 



