MacFarlii 11(1 — PrdiiiiiiKiri/ Acconnl of DorhVidge. 51 



1 or 2 coiiipres>;ed pointed tubeirk's; hrliiml the branclii;e tlie 2 lateral 

 ridges unite in a low median crest to tip of tail ; branchiae 8, simply pin- 

 nate, non-retractile, tallest in front, decreasing regularly in size from in 

 front backward; rhinophores stout, without sheaths, perfoliate ; oral ten- 

 tacles very short, loliiform ; toot linear, the anterior angles prominent; 

 general ground-color black, the dorsum and sides with numerous longitu- 

 dinal rows of yellow spots, more or less confluent into continuous lines, the 

 intermediate spaces l)etween the spots of each row greyish, also the l>asal 

 l^ortion of frontal veil and the foot of same color ; mandibles light yellow, 

 verv strong, each divided into a ventro-anterior cutting portion and adorso- 

 latiTal arched wing; radula andjer to dark brown in color, rather deeply 

 grooved ; teeth in !l or 10 rows, the half rows not in a straight transverse 

 line; rhachis naked ; pleurae 2, unequal; the first smaller than the second, 

 alike in form, the shaft stout, flattened slightly, bearing a broad triangular 

 wing directed toward the median line ; the hook broad, large, bent toward 

 median line ; length of first tooth, 8 mm., the second .412 mm.; uncini 3, 

 prismatic, triangular in section decreasing in size from within outward; 

 rarelv a fourth rudimentary unciuus may l)e |)resent. Glans penis closely 

 set with minute hooks arranged in rows. 



Length of animal, up to 23 mm.; width to 6 mm.; greatest height, 7 mm. 



Found on red algse {Gigm-tina) in rocky tide-pools all along the southern 

 coast of Monterey Bay; abundant. 



17. Acanthodoris hudsoni sp. nov. 



Tape from Point Pinos, Calif. No. 181,289, U. S. National Museum. 



Body plump, liighly arched, slightly higher and broailer in front than 

 behind, oval ; dorsum soft villous, the papilU« short, thickly set, bluntly 

 conical; mantle margin broad, thick; general ground-color clear translu- 

 cent yellowish-white or pinkish, the i)apillae and branchiae tipped with 

 lemon-yellow, the mantle edged with the same color; head wide, the oral 

 tentacles broad triangular, a wide median anterior notch between them ; 

 foot broad, rounded abruptly in front, much less so behind ; rhinophores 

 long, tapering, clavus recurved ; ])erfoliate with about 24 leaves, the length 

 of stalk and clavus nearly the same, retractile into low sheath with pa- 

 pillose margin ; branchiae 5, bipinnate, without sheath, widespreading; 

 pharyngeal i-rop large, hemispherical, very thick-walled; labial armature 

 a pavement of minute hooks upon the lowei' and lateral walls of opening ; 

 lowermost portion free from hooks and bearing a Inroad slightly concave 

 cuticular plate, pointed behind, and forked anteriorly into 2 blade-like pro- 

 cesses which project beyond the margin of the oi)ening, its total length 

 Ijeing about ."-'88 mm. 



Radula very narrow, deeply grooved; teeth in 27 rows; rhachis very 

 narrow, naked ; first pleural tooth very large, upright, compressed, its base 

 quadrangular in outline, the i)Osterior border thin and wing-like, over- 

 lajiping the succeeding tooth; anterior lower margin very strongly thickened, 

 rounded ; the ujjper anterior margin of the base prolonged upward into a 

 strong nearly straight hook, the ui)])er inner margin of which l)ears a 



