DORIS. 229 



This is widely distril)utcd, and very variable in size and color, and 

 also in the numl)er of the Itranehial pinnies; lience the great nnni- 

 ber of names which have been a|)})licd to it. Onr specimens vary so 

 ninch from the fignres given by Alder and Hancock that I shonld 

 hesitate to consider them the same, did not Dr. Stimpson assnrc me 

 that they are identical with specimens dredged by him on the coast 

 of England. 



Doris tenella. 



Plate XX. Figs. 2S9, 290, 293. 



Body ovate, covered with small, pointed tubercles, yellowish-white ; branchial 

 plumes six to seven, simple ; mantle extended anteriorly beyond the foot, head 

 dilated laterally. 



Doris tenella, Agassiz, Proc. Bost. See. iii. 191 (1850), no description. 



Body ovate, broadest in front, of a yellowish-white, transhicent 

 color, covered with very numorons small, pointed, opaque white tu- 

 bercles. Tentacles long and slender, with aljout fourteen oblique 

 lamina) occupying nearly their whole length. Branchial ])lumes sim- 

 ple, short, six or seven in number. Foot ellij)tical, Ijluntly rounded, 

 extending a little lieyond the mantle, lemon-yellow, with a central 

 orange l)lotcli. Head short, rather broader than foot, pointed at 

 angles, and somewhat l)i-lol)cd in front, broadly shielded l»y the 

 mantle. Length, half an inch; breadth, three eighths of an inch. 



Found by Professor Agassiz at Beverly, February, 1848. 



The above characters are drawn from a figure made of a single 

 specimen, without any detailed description. The animal is delicate 

 and almost transparent, and quite remarkalde for the Ijroad expan- 

 sion of the anterior part of the mantle beyond the foot, and for the 

 lateral dilatation of the head itself, and its angular form. Were 

 the means at hand of examining the tongue, spicule, and other con- 

 ditions, it might be found identical with some European species. It 

 seems to approach most nearly to D. inconspicua, Alder and Han- 

 cock, and is not very different from D. pusilla. 



Doris pallida. 



Plate XX. Figs. 284, 287, 288, 291. 



Body elonq'ated, sides parallel, ends equally rounded, covered with large, mnsh- 

 room-like tubercles, cream-colored ; branchial plumes seven to eight, simple, re- 

 tractile. 



