12S 



OBSKHVArU^NS ON THE FomiATlON ANI> En l^VlUiKMKN I" OK THE 



Turks OF THF. Maiunk. Annki.id. [Cluutoptcni^ 

 ]\ii iopc(hitu.<). 



lUnvAun K. Km>krs, 



Vliacioptcnift rariopcdatti^ is a widely disti'ilmtoii txibioiilous annelid 

 of rhe family Chae.opterida. 'I'he individnals of eaoh ivnntry and of wide- 

 l>- distributed aivas in Enro^H^ were olassitied as distinct si>ei'ies till .loy- 

 eux-Lattuie showtxl «.\niolusively. iu lSiX\ that they are really a single 

 species. He alt^o sn!;5;ested that a close stmlv of the species in foreign 

 seas would probably result in referring them to a single species. A care- 

 ful (.H.nnparisou of the spi\imens found at Beaufort, North Caivlina. with 

 Joyeux-I.alTuie's detailed description of Clioctinitcnii< niriopidiitus. leads 

 me to regard the American reprcs^mtative. which Verrill and K. B. Wilson 

 nameil Chactoptcrum pvriiaincntavcHS. as identical with the single Knro 

 ixwu forni. 



This pcvuliar species of sedcntai'y annelid is found in several localities 

 in the harbor of Beaufort. North Carolina, where the conditions for its 

 e.\isten^>e an^ afforde^i by the extensive sand-tiats. either twereil with a 

 thick growth of diatoms or (.vntinually exposetl to curivnts of water 

 heavily ehargeii with these plants. It is here found living within its 

 broadly l-shajxHi parchment tubes in nearly every iK>rtion of the harbor 

 whenner the s;\ud-ilats are formeii iu tJie quieter waters. 



The presence of Ohaetopterus may hi^ recognized by the extremities 

 of the l'-shai>ed tubes that usually protrude several ixMitimeters above the 

 level of the shoal (.Fig. oK The extivmicies of some tnl!e.< are «.iuuH?aletl 

 by ascidiaus, (.x^lonies of bryozoans or of hydroids. attacheil to them so that 

 it may l>e ditti<'ult to dettvt the circular whitish openings within the cluster 

 of attached animals. 



The animal ivmains within its tube during its whole life but. as the 

 auimal grt^ws in size, it increases both the length and the diameter of its 

 tul>e. The horizontal iH>rtiou of the r is of greater diameter than the 

 conical vertical arms that protrude a few centimetei-s above the sub- 



