1914, 



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1915. 



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1917. 



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160 PISTA CRISTATA. 



1912. Pista cristata, Gravier. 2nd Exped. Antarct. Fr., p. 133. 

 Meyer, A. H. Inaug. Dissert. Kiel, p. 36. 

 Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 123. 

 Fauvel. Campag. Scient. Monaco, xlvi, p. 302. 

 Mcintosh. Ann. Nat. Hist., ser. 8, vol. xv, p. 20. 

 Hessle. Zool. Bidr. Uppsala, v, p. 154. 



Habitat. — Dredged in 4 — 5 fathoms in Ardmaddy Bay, Lochmaddy, amongst shelly 

 mud and grey clay (W. C. M.). Dredged in St. Magnus Bay, Shetland, in 80 fathoms; 

 50 miles west of Valentia in 160 fathoms; Outer Haaf, Skerries, Shetland, in 70—80 

 fathoms (J. Gr. J.); usually in deep water; Plymouth (Spence Bate and B. Rowe) ; 

 Berehaven, Ireland, and S.W. Ireland, R. I. Acad. Exped., 1885; Blacksod and other 

 bays on west coast, Ireland (Southern). 



Abroad it occurs off Sweden, Norway and Finmark (Malmgren) ; Canada (dredged 

 by Whiteaves) ; Mediterranean (Grube, Marion, Marenzeller, Lo Bianco) ; North America 

 and Congo var. ? (Grube) ; New England and Atlantic coast, U.S.A. (Verrill) ; Magellan 

 (Ehlers) ; Antarctic Seas (Gravier); amongst Posidonia, Isle of St. Marguerite, Cannes, 

 and at St. Raphael amongst Zostera (De St. Joseph) ; Virginia coast (Webster) ; Siberia 

 and Behring's Sea (Wiren) ; White Sea (Ssolowiew). 



The cephalic plate has a thick dorsal collar and the margin passes externally and 

 ventrally to join the anterior fold, though it does not run evenly into it, a notch or a fold 

 separating it from the raised anterior fold, which sometimes has a median projection with 

 symmetrical lateral curves or in others slight frills. This anterior or supra-oral fold 

 does not project so far forward as in many Terebellids, and it sometimes shows an inner 

 fold over the mouth. The pale orange tentacles seem to be of moderate length and 

 grooved, but are somewhat more slender and tapered than in ordinary Terebellids. 

 Below the mouth is a well-developed tongue-like process which pushes the rim of the 

 first segment backward when it projects, and ventrally it has a narrow rim. 



The body is comparatively short and in the preparations is less dilated anteriorly 

 than in the ordinary Terebellid. It tapers posteriorly to a slender tail with a terminal 

 anus, which has four large rounded papillae, two dorsal and two, slightly more prominent, 

 ventral. Dorsally the body is rounded, ventrally flattened at the shields in front, and 

 then grooved throughout the rest of its extent. Anteriorly behind the dorsal collar the 

 setigerous papillae approach the median line, where a bifid process occurs in front of 

 them, and from the sides of the divisions the branchial stem originates— not always in the 

 same place, for in some the right branchia springs antero-laterally in regard to the right 

 process, whilst the left branchia arises behind and to the left of the left process. The 

 free margin of the first segment forms a continuous fold ventrally which ends dorso- 

 lateral^ in a rounded free flap, and a process is continued dorsally beneath its edge to 

 the representatives of the setigerous process, which lies immediately behind the bifid cone 

 formerly mentioned. The next segment has ventrally a large free lateral flap on each 

 side whilst the median is differentiated into a narrow scute. The following segment has 

 a still larger lateral flap which stretches further outward and upward and almost touches 

 the base of the branchial stalk in the preparation. It thins off toward the narrow scute 

 in the mid- ventral line. Laterally it ensheaths the lamella in front of it. 



