NO. 3 HARTMAN : ORBINIIDAE, APISTOBRANCHIDAE, PARAONIDAE 277 



Haploscoloplos panamensis (Monro) 1933 

 Plate 28, figs. 1-3 



Haploscoloplos panamensis Monro, 1933d, pp. 1045-1046, fig. 1 A-B. 

 Haploscoloplos alaskensis Hartman, 1948, pp. 30-32, fig. 8 a-c. 



Collection. — Southern Alaska (several). 



The thorax consists of 17 segments. Branchiae are first present from 

 the twelfth setigerous segment and are simple and lanceolate through- 

 out. The notopodial postsetal lobe is small in the first few segments and 

 increases in size to a slender elongate lobe extending distally about half 

 as far as the longest setae. Anterior thoracic neuropodial ridges have a 

 simple postsetal lobe at the midlength. In posterior thoracic segments 

 this lobe is divided so that there are two similar lobes; the lower one 

 resembles a ventral cirrus. There are no interramal cirri. 



Haploscoloplos alaskensis Hartman (1948, pp. 30-32, fig. 8 a-c), 

 from southern Alaska, is here referred to H. panamensis Monro. Both 

 have a unique development of postsetal lobes in posterior thoracic neuro- 

 podia. A second lobe is present at segments 13 or 14 below the subpodial 

 lobe and in the fifteenth or last thoracic segment a third lobe is present 

 which is continued back through the first 8 to 10 abdominal segments. 



Distribution. — Haploscoloplos panamensis is known only from the 

 Pacific side of Panama in 6-12 fathoms and from southeast Alaska at 

 low tide to 25 fathoms. 



Haploscoloplos bifurcatus, new species 



Collections. — Encounter Bay, on limestone reef among Zostera roots, 

 pebbles and sand (2) and Port Vincent, Yorke Peninsula, South Aus- 

 tralia ( 1 ) all collected by S. J. Edmonds ; Camp Cove, Watsons Bay, 

 Port Jackson, New South Wales, dredged in 6-8 fathoms ( 1 ) collected 

 by Barbara Dew. 



The largest individual, from Yorke Peninsula, measures about 65 

 mm long, 4 mm wide in the thorax, and consists of more than 200 

 segments (a posterior end is missing). Two other individuals (from 

 Encounter Bay, chosen as cotypes) include an anterior end of an ovi- 

 gerous individual measuring 35 mm long for 78 segments and 4 mm 

 wide in the thorax; the other one measures about 50 mm long for 134 

 segments and 4 mm wide in the thorax. 



Transition from thorax to abdomen is at setigerous segments 21/22. 

 Branchiae are present from the ninth segment and very small ; they 



