NO. 3 HARTMAN : ORBINIIDAE, APISTOBRANCHIDAE, PARAONIDAE 271 



pointed farther back, especially in posterior thoracic segments. The 

 postsetal lamella of neuropodia diminishes in size posteriorly and in 

 abdominal segments it is a low transverse ridge extending mainly below 

 the acicular lobe. Transition from thorax to abdomen coincides more or 

 less closely with the origin of the first branchiae and varies accordingly. 

 The individual branchial filaments are cylindrical, increase in size 

 posteriorly and are divided in some abdominal segments. In mature 

 individuals, segments 26 to 65 have gonopores. 



Distribution- — H. cylindrifer is known from southern shores and 

 islands of Australia and New Zealand in littoral zones. 



Haploscoloplos fragilis (Verrill) 1873 

 Plate 25, figs. 1-3 



Anthostoma fragile Verrill, 1873, pp. 598-599; Verrill, 1874, p. 370; 



Webster, 1879, p. 258; Webster, 1879b, p. 121 ; Webster, 1886, 



p. 151. 

 Scoloplos fragilis Verrill, 1881, p. 301, 317, 322; Webster and Benedict, 



1884, p. 724; Hartman, 1942a, pp. 60-61, figs. 113-115. 

 Haploscoloplos tortugaensis Monro, 1933c, p. 261, fig. 10. 

 Haploscoloplos fragilis Hartman, 1944a, p. 340, pi. 46, fig. 5, pi. 50, 



fig. 6; Hartman, 1945, p. 30, pi. 6, fig. 5; Hartman, 1951, pp. 



76-78, pi. 21, figs. 1-3. 

 Collections. — Many individuals come from Massachusetts, North 

 Carolina, western Florida and Louisiana in intertidal zones from sandy 

 beaches. 



The body is long and appears ragged in its posterior parts due to 

 the presence of long parapodial and branchial processes. The prostomium 

 is long, triangular and acutely pointed in front. Branchiae are first 

 present from segment 17 or not before 21 to 30. The parapodial change 

 from thorax to abdomen is abrupt at segment 17 or not until 23. An 

 interramal cirrus is first present from the first branchial segment or the 

 one following; its occurrence is continued back through about 90 to 

 100 segments; at maximum development it is long and cirriform (fig. 

 2). Thoracic parapodia have postsetal lobes that are broadly foliaceous 

 in both dorsal and ventral rami. A subpodial lobe is first present from 

 the first branchial segment ; it gradually enlarges through anterior ab- 

 dominal segments and becomes well separated from a similarly shaped 

 lobe resembling a ventral cirrus. 



The synonymy indicated above has been established (Hartman, 

 1951). 



