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NOTES ON A REMARKABLE NUDIBRANCH FROM 

 NORTH-WEST AMERICA. 



By Sir Charles Eliot, K.C.M.G., C.B., etc. 



Read 9th November, 1900. 



The British Museum collection of Nudibranchs contains a remarkable 

 specimen, preserved in alcohol, and labelled " Massett, Queen Charlotte's 

 Island, British Columbia, Rev. J. Keen, 91 : 7 : 10. 23-4." It has 

 been examined by Dr. Willey and myself. 



The length of the animal (Fig. I) is 7*6 centimetres, the breadth 3-5, 

 and the height 2*4. The colour is a uniform brownish yellow, and the 

 general shape Boris-like, both the head and tail being rounded, but 

 the mantle is not continued round the head, and the anus («.) is lateral, 

 as in Tritonia. There are two large rhinophores {rh.) retracted into 

 pits, but not provided with any external sheaths. They show no 

 traces of lamellation, and have no plumes or other appendages. 

 They are somewhat wide apart, the distance between them being 

 1*3 cm. The mantle edge (m.f.) stops on each side of the body under 

 the rhinophores, but is distinct all the way behind. It is narrow 

 and not provided with any appendages, or with lamellae underneath. 

 The whole surface of the animal presents no traces of cerata, or other 

 processes, or of injuries where such pi'ocesses might have been detached. 



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The head parts bear a superficial resemblance to the cephalic shield of 

 Scaphander or Philine. There are no oral tentacles, but a projecting 

 rim without appendages seems to represent the trace of a frontal veil. 

 The mouth {in.) is a simple aperture without lips, and ventrally placed ; 

 above it is a crescent-shaped sinus («.), and below it the faint indication 

 of a transverse line (/.), which does not, however, amount to a distinction 

 between the pedal surface and the mouth parts. Hence the foot may 



