176 DISCOVERY REPORTS 



Specific characters. The larger specimen measures ii mm. by 1-5 mm. I believe 

 these examples to be conspecific with those New Zealand specimens attributed with a 

 query by Augener to Grube's species. They seem to agree fairly closely with Hessle's 

 account. The paleae are short, scarcely longer than the dorsal bristles, stout and end in 

 hair-like tips longer than that shown in Hessle's figure. There are 17 pairs of thoracic 

 notopods and 15 of abdominal neuropodial pinnules. The dorsal cirri in both regions of 

 the body are only slightly developed and the abdominal neuropodial cirri are 

 prominent. 



The bristles are bordered capillaries and the hooks have a single row of five to six 

 teeth. In the present specimens five is the maximum number that I have seen. The 

 most characteristic feature is the shortness of the rather stout paleae, but this should be 

 treated with caution as the paleae appear to be capable to a large extent of retraction 

 within the body-wall. Moreover, the hinder neuropodial cirri are relatively very much 

 longer than they are for example in A. giinneri. 



Amphicteis gunneri (Sars), var. antarctica, Hessle. 

 Hessle, 1917, p. 116. 



Occurrence. St. 167 (3); 368 (numerous); 652 (i). 



Specific characters. Paleae very much longer than the dorsal bristles. They end in 

 long, finely drawn out tips. There are 17 pairs of chaetigerous notopods and 15 uncini- 

 gerous abdominal segments. Gills arranged in two groups of four, clearly separated by 

 a fold of integument. In the thoracic region the uncini begin at the 4th chaetiger. The 

 bristles are bordered capillaries and the hooks have five to seven teeth in a single row. 

 Dorsal cirri of rudimentary notopods in abdominal region prominent. There is also a 

 small dorsal cirrus at the top of the uncinigerous pinnules in the hinder region. 

 Separated from the stem-form on the ground that the terminal plume of the paleae is 

 more sharply pinched off from the body of the bristles, and that the dorsal cirri of the 

 rudimentary notopods in the abdominal region are longer and more prominent. 



The animal builds a thick tube of mud on a membranous lining. 



The grounds of separation of the variety from the stem-form are very slender. 



Family TEREBELLIDAE 



1. Bristles and hooks absent HauchieUa 



Bristles and hooks present 



2. Thoracic and abdominal uncini of two distinct types 



Thoracic and abdominal uncini of one type ... 



3. Uncini in two rows over a number of thoracic segments 

 Uncini in single rows throughout the body 



4. Uncini of first few segments with long chitinous prolongations 

 Anterior uncini without chitinous prolongations 



5. Uncini pectiniform, set back to back ... 

 Uncini avicular ... 



6. No branchiae 

 Branchiae present 



2 



Octobranchus 

 ... 3 



4 



10 



Pista 



5 



Loimia 



6 



Leaena 



7 



