NO. 3 HARTMAN : ORBINIIDAE, APISTOBRANCHIDAE, PARAONIDAE 273 



Distribution. — Haploscoloplos robustus is common in littoral sands 

 from New England south to southern Florida and in the Gulf of 

 Mexico. 



Haploscoloplos elongatus (Johnson) 1901 

 Plate 26, figs. 1-11 



Scoloplos elongata Johnson, 1901, pp. 412-413, pi. 10, figs. 105-110; 

 Treadwell, 1914, p. 199; Berkeley, 1927, p. 413; Monro, 1933d, 

 pp. 1045-1046. 

 Aricia sp. Treadwell, 1914, p. 199 (in part). 



Haploscoloplos elongata Hartman, 1944c, p. 257; Hartman, 1948a, p. 

 30;Hartman, 1955, p. 174. 



Collections. — Many individuals, including the type collection, come 

 from Puget Sound, Washington, Alaska, central and southern California 

 in intertidal zones to 293 fathoms, including the following stations of the 

 Velero III and Velero IV (data for stations are published in Fraser, 

 1943, and Hartman, 1955): 886-38 (1); 905-38 (1); 992-39 (1); 

 1201-40 (1); 1441-41 (1); 2026-51 (7); 2107-52 (4); 2114-52 

 (2) ; 2115-52 (2) ; 2116-52 (5) ; 2120-52 (7) ; 2149-52 (6) ; 2168-52 

 (5) ; 2175-52 (4) ; 2176-52 (9) ; 2189-52 (4) ; 2202-53 (4) ; 2217-53 

 (6); 2224-53 (6); 2227-53 (11); 2228-53 (2); 2232-53 (14); 

 2233-53 (12); 2291-53 (6); 2307-53 (6); 2311-53 (34); 2337-53 

 (1) ; 2389-53 (9) ; 2418-53 (1) ; 2506-53 (1) ; 2508-53 (1) ; 2618-54 

 (1); 2646-54 (4); 2725-54 (2+). 



The type collection from Puget Sound, Washington, shore, consists 

 of twelve large individuals 100 to 200 mm long. The prostomium is 

 depressed, conical and has no eyes. Branchiae are first present from seti- 

 gerous segment 14 to 16; the transition from thorax to abdomen varies 

 between segment 19 to 21 and the change is complete thereafter. Thor- 

 acic neuropodia have a low transverse postsetal ridge from which a 

 small papillar lobe projects at midlength. 



In another lot of 5 individuals from Tomales Bay, California, 

 branchiae are first present from setigerous segment 18 and the transition 

 from thorax to abdomen is at 23. Others from off southern California, 

 measuring less than half as long, have branchiae first present from seg- 

 ment 13 to 16 and the transition from thorax to abdomen is at segment 

 16 or not before 21. The first appearance of branchiae thus varies from 

 segment 13 to 18 and the transition of thorax to abdomen from segment 

 15 to 21. 



In mature individuals the prostomium is acutely pointed, a little 

 longer than wide and has no eyes. The dorsum between the bases of the 

 larger branchiae usually has a reticulated brown pigment persisting in 



