204 Transactions of the Royal Canadian Institute 



Alaska and San Diego and San Pedro in California so that it probably 

 extends along the north west coast of America. Its eggs were obtained 

 in May and June. 



Family Dotonidae. 



Small animals agreeing with the Aeolididae in most points except that 

 the rhinophores are protected by projecting sheaths. The cerata are 

 stout and tuberculate. 



Genus Doto (Oken). 



Doto Bergh, Mal^-cozool. Blatter, VI, 1879, pp. 24-30; IX, 1888, pp. 695- 

 698. Vayssiere, Recherches zool. et anatom. sur les Moll, opisthobr. 

 du golfe de Marseille. Ann. Musee d'Hist. Nat, de Marseille Troi- 

 sieme partie, lb.. Vol. VI, 1901, pp. 99.106. Eliot, Notes on some 

 British Nudibranchs Jour. Mar. Biol. Assoc, Vol. VI, 1901, pp. 334- 

 382; Brit. Nud. Moll., Pt. VIII, 1910, p. 166. 



Rhinophores smooth (except in D. crassicornis) with large cup-like 

 sheaths. Cerata arranged in a single row on either side of the back; 

 Clavate and studded with papillae or knobs. An oral veil over the mouth 

 with short tentacular prolongations. Jaws smooth. Radula a long row 

 of small horse-shoe shaped teeth bearing a few denticles or ridges. In 

 Doto the radula is uniseriate, but in the allied Dotilla there are four to five 

 minute lateral teeth. Genitalia not armed. 



Doto colimbiana sp, nov. 



Body. — ^The body is elongated and limaciform. The back is curved 

 and smooth save for a row of clavate cerata on each side and it is not 

 sharply marked off from the sides of the body nor are these from the foot. 

 The end of the body finishes off as a distinct tail clear of the cerata, A 

 narrow oral veil is present over the head and it bears a few short papillae. 

 The cerata number five pairs diminishing in size as they pass backwards 

 and falling off readily during or after preservation. There are no small 

 intermediate cerata as figured for D. coronata by Alder and Hancock, 

 each is swollen and globose, attached to the back by a slender stalk and 

 bearing 18-22 raised areas in the form of short truncated cones. 



Colour. — The colour is greyish white or pale greyish yellow all over 

 the body and foot alike. On the back and along the sides are scattered 

 black pencillings and an edging of the same black melanphores surround 

 the raised areas on the cerata. This black is visible some months after 

 preservation and in formalin the whole animal often turns a dark grey. 



