1910.] ' NATURAL SCIENCES OF PHILADELPHIA. 329 



into the bases of the lateral tentacles, but a well-marked articulation 

 cuts off the latter as distinct ceratophoric segments. 



One example has the proboscis protruded. It is large and evidently 

 powerful, 5 mm. long, 2.7 mm. wide, cylindroid, little depressed dls- 

 tally, smooth. There are nine dorsal and nine ventral prominent 

 apertural papilke and behind each series a small rounded median 

 tubercle. Jaws pale brown, with large blunt fangs, the lower biting 

 to the right; lateral cutting plates thin, low, rather extended but 

 weak and directed chiefly laterally. 



Stations 4,310, off Point Loma, vicinity of San Diego, 71-75 fathoms, 

 green mud and fine sand; 4,414, northwest of Santa Catalina Island, 

 156-162 fathoms, fine gray sand and mud; 4,420, northeast of San 

 Nicolas Island, 33 fathoms, fine gray sand; 4,453, off Pohit Pinos 

 Light, Monterey Bay, 56-62 fathoms, green mud, "on Luidia;" 4,457, 

 same locality, 40-46 fathoms, dark green mud, "on Luidia." 



Halosydna insignis Baird. 



Ilalosydnn insignis Baird, Journ. Linn. Soc. London, VIII (Zool.), 18().5, 



p. 188. 

 Poli/noi' brevisetosa (Kinbero;), Johnson, Proc. Cal. Acad. Sci., Ser 3., Zoology, 

 I' (1897), p. 167. Figs. 24, 31, 40 and 46. 



This very remarkable species is well represented in the collection l:)y 

 both the commensal and the free-living phases. Were it not that 

 Johnson's familiarity with the specias in its native surroundings enabled 

 him to demonstrate their identity workers on preserved material 

 alone would almost certainly have separated them as distinct species, 

 though close inspection shows that they agree in their strictly technical 

 characters. 



Though there are no accompanying notes specifying their hosts 

 or associates it is evident that most of the examples were conniiensals, 

 they having the elongated foi-m and other characteristics of this phase. 

 Tne specimens measure from 15 to 45 mm. long, the smallest, while 

 intermediate in proportions, approximating the short stout form ot 

 the free-living rather than the slender, elongated form of the commensal 

 phase. As is the case with the former the elytra are strongly imbricated 

 and cover the middle of the back nearly or cjuite completely. Both 

 phases exhibit color ^•ariati()ns through various shades of gray antl 

 brown or dusky and the elytra, while usually mottled, may be quite 

 plain and uniformly colored. The jiigment nuiy l)e ai-ranged in dis- 

 tinct spots or assume a reticular i)attern around paler areas a.s in 

 //. californica Johnson. 'Most constant is a white spot over the 

 pedicel of attachment and a black f)r deep brown spot mediad of or 

 l)oliind it. Some specimens with elytra otliorwise completely jug- 



