's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 73 



from a depth of 300 M. and an other large specimen met with by 

 Hilgendorf in the vicinity of Hakodate ; the last-named specimen had only 

 18 elytra, but the glochideal spines were provided with 5 to 6 opposite 

 fangs. In my opinion it therefore does not excite astonishment that Miss 

 Buchanan among the Polychaeta, dredged in the deep sea off the West- 

 coast of Ireland (500 M.) met with four specimens, nearly allied to 

 L. producta ; for, as already observed by Ehlers l ) and Fauvel 2 ), several 

 species of Annelida, living in the littoreal regions of the Arctic and Antarctic 

 continents, are also met with in the depths of the Tropical Atlantic, where 

 they find. about the same temperature. The Ireland-specimens, distinguished 

 besides by the absence of eyes, by the presence of a smaller number ol 

 segments (43 to 44) and a great deal of variation with regard to the 

 length of the palps, are afterwards described by Mc Intosh as belonging 

 to the variety brittanica. Though none of both authors mentions the exact 

 number of the elytra, I cannot accept Marenzeller's opinion, that the 

 specimens should belong to the sphere of varieties of L. filicornis. Unfor- 

 tunately there reigns a good deal of controversy among Annelidologists 

 with regard to the species and varieties of this genus; f.i. von Marenzeller 

 rightly reproches Mc Intosh, that he, in describing the rich material of 

 the Challenger-expedition, considers Laetmonice filicornis as a constant, 

 nearly invariable species, whereas L. producta is regarded by him to be 

 very variable. Now examining the descriptions of different authors, we 

 meet with two well characterised species : Laetm. filicornis especially from 

 Northern and Laetm. producta from Southern seas. L. filicornis reaches a 

 length at the most of 36 mm., has no more than 36 segments, usually a 

 dorsal felt, 15 elytra, eye-peduncles without pigment, dorsal spines with 

 3 to 4 alternating fangs and neuropodial bristles with numerous closely 

 packed fine pinnae. L. producta however can reach a length of 100 mm., 

 possesses 45 to 47 segments, 18 to 20 elytra and eye-peduncles provided 

 with eyes, whereas the glochideal spines possess 6 opposite fangs and 

 the neuropodial bristles are provided with few and stiffer pinnae. Consi- 

 dering that both species have a very wide geographical distribution and 

 are found at different dephts, I think it rather probable that there occur 

 also varieties of both species. 



Laetmonice mcdayana n. sp. 



Siboga-expedition, Stat. 52, south off Flores, depth of 959 M.; Stat. 161, 



north off Misool, depth of 798 M. ; Stat. 178, north off Ceram, depth of 835 M.' 



At the above-named stations several specimens were collected of a 



1) Geogr. Verbreitung der Polychaeten. 



2) Annél. polychètes de San Thome; Arch. Zool. Expérim, t. 54, 1914, p. 111. 



