280 PROCEEDINGS OF THE ACADEMY OF [^pril,- 



united. Masticatory plates white and hard, slender, ovate, with 

 smooth or slightly wavy margins, borne in a distal depression of the 

 stem which projects beyond the masticatory plate on the lateral side 

 as a blunt tooth. The mandibles of the type are much larger than 

 those of the cotype, though the two worms differ but little in size. 

 Maxillae (fig. 95) pale brown, the teeth and other thickened parts 

 darker. Carriers of forceps-jaws (I) broad, together about four-fifths 

 length, subquadrate, with a short, blunt projection at the postero- 

 lateral angle; the forceps with basal half broad and nearly straight, 

 the distal half slender, tapered and not very strongly hooked. Max- 

 illae II, outer left plate w^ith thirteen large and one or more very small 

 posterior teeth, inner left with twelve teeth, right plate with fourteen 

 or sixteen or even more teeth. Maxillae III, left with seven to nine 

 small teeth, right with about ten teeth. Maxilla IV, delicate, with one 

 small tooth or none. 



Generally pale or colorless, a small, indefinite, median dorsal, purple 

 spot on anterior dorsal part of prostomium, a pair of small ventral 

 spots below outer lateral tentacles, small brown spots at base of 

 notocirri amd a few dark speckles on anterior segments. Cuticle only 

 slightly iridescent. 



A probably incomplete tube is 65 mm. long, slightly curved and 

 tapered, the large end being 2.5 mm., the smaller 2.2 mm. The surface 

 is rougher than that of small tubes of H. tubicola and the annulations 

 are 2 mm. apart and obscure. Although translucent and nearly free 

 of incrustations, it is not possible to determine the character of the 

 valves. 



An empty tube has living within it a small polynoid, not yet removed 

 for examination, and, completely closing the larger orifice so that the 

 annelid could not leave, is a small hermit crab {Eupagurus or Para- 

 pagurus) with very unec[ual chela, the right being much the larger 

 and forming a symmetrical plug beautifully adapted to the form and 

 size of the tube. 



Type and only station 4,431, off Santa Rosa Island, 38-45 fathoms, 

 varied bottom. 



Hyalinoecia tubicola (Mailer) Malmgren, stricta .subsp. nov. PL XV^III, figs. 96, 97. 



Hyalincecia tubicola Malmgren, Of versigt Kongl. Vetens-Akad. Forh., XXIV 

 (1867), ISl, 2, Taf. IX, fig. 49. 



This is a form of large size, as indicated l^y the measurements of the 

 tubes given below, somewhat exceeding H. artifex Verrill. In many 

 respects it resembles H. t. longibranchiata Mcintosh, from the vicinity 

 of New Zealand, but has no eyes. 



