1911.] NATURAL SCIEXCES OF PHILADELPHIA. 259 



in the figure. Carriers of forceps jaws (I) only slightly united, 

 widest at the middle, their posterior ends separated and 'pointed; 

 forceps stout at base, the ends acute and strongly hooked. Large 

 dentinal plates (II) stout and broad, the right with nine nr^arly equal 

 stout teeth, the left with six teeth, of which the first is enlarged and 

 separated from the others by a considerable gap. Left unpaired 

 plate (Ila) with seven or eight teeth. Anterior pieces (III) with a 

 narrow, curved, toothed ridge and a large flaring basal plate or wing, 

 the left six- or seven-toothed, the right larger, with eight teeth. Small 

 accessory jaws {IV) triangular, each jjearing a single tooth. 



Except for a small brown^spot at the base of each notocirrus and 

 smaller ones on the bases of the tentacles, the specimens are colorless. 



The anterior ten or twelve segments of every specimen are strongly 

 bent upwards so that the head is usuall}' quite reversed. 



Stations 4,352 (Type), off Point Loma Lighthouse, vicinity of 

 San Diego Bay, 549-5S5 fathoms, green mud ; 4,400, Lat. 32° 50' 20" N., 

 Long. 118° 03' 30" W., 503-507 fathoms, green mud; 4,401, Lat. 

 32° 52' 40" N., 118° 13' 40" W., 448-468 fathoms, green mud, black 

 sand; 4,415, off Santa Barbara Island, 302-638 fathoms, green mud. 



Nothria sp. ? PI. XVI, &gs. 38-40. 



The anterior end of a rather small Noihria 1.6 mm. wide, probal)ly 

 representing another undescribed species. It has much of the aspect 

 of A'', geophiliformis and the setse resemble those of that species, from 

 all typical examples of which it differs, however, in the first appearance 

 of the gills on \TI. The cephalic tentacles are peculiar and may be 

 abnormal. The median just equals the anterior or outer paired and 

 its style is about two-fifths that of the posterior paired. The frontal 

 tentacles are shorter than their diameter. All cephalic ceratophores 

 are short and 5- or 6-annulate. No ej'es. Nuchal cirri very short, 

 only one-third or one-fovu'th of the distance separating them. Gills 

 begin abruptly on VII, resemble those of A'', holobranchia and in their 

 full development reach to the opposite side. Jaws not dissected. 



Taken from a simple mud tube from station 4,387, Lat. 32° 32' 40" N., 

 Long. 118° 04' 20" W., 1,059 fathoms, green mud. 



Nothria hiatidentata s^p nov. Pis. XVI, XVII, figs. 41-50. 



A very interesting species ]:)ased on two specimens found in a jar 

 of Hyalinoecia tuhicola, to which species this bears a remarkabl}' close 

 superficial resem])lance. Indeed, in most characters except the 

 presence of nuchal cirri this species resembles Hyaliivrcia more closely 

 than ordinary Nothrue. It is a noteworthy case of associative resem- 

 blance. 



