1 82 Transactions of the Royal Canadian Institute 



antero-posteriorly ; this line is shorter and narrower on the inside than 

 the outside and forms a definite cap to the cerata. There is a small white 

 cap to the clavus, a short narrow line on its antero-lateral margin and a 

 wider line on its postero-lateral margin which passes down to the head 

 and unites with its fellow in the middle to form a continuous line. In 

 large specimens the interior of some of the larger cerata has been of a 

 bright brownish colour which however quickly disappears in preserved 

 specimens. MacFarland (p. 519) notes that "In large individuals the 

 body and cerata are occasionally flecked with minute spots of pure 

 A/'hite". I have not observed this in any of the living specimens I have 

 seen. 



Dimensions. — MacFarland (12, p. 519) gives the dimensions as follows 

 "Total length up to 42 mm. height 8 mm. width 7 mm." but I have se- 

 cured several specimens larger than this, the largest being 72 mm, long 

 by 14 mm. broad by 15 mm. high, when measured in the living condition. 



Head. — The head is somewhat squarish and broad passing forward 

 into an undulating veil which is wider than the foot when in locomotion; 

 the wavy margin bears a white line. No labial tentacles are present. 

 The mouth is a longitudinal slit with thick rounded lips and when 

 exerted as it is sometimes in preserved specimens, the powerful jaws are 

 clearly seen. 



Foot. — The foot is elongated and very broad and flat. At the front 

 it is abruptly rounded while behind it tapers to a point and has a median 

 dorsal ridge which bears a white line. The front margin though thickened 

 is npt divided and not notched. 



Rhinophores. — The rhinophores are long, non-retractile, without 

 sheaths, and pass forward and outward. The stalk is sub-cylindrical and 

 about equal in length to the clavus which is deeply perfoliate having 

 from 14-18 leaves. The rhinophores are separated by a distance about 

 equal to the length of one of their stalks, a point that is not obvious in 

 MacFarlan.d's figure (1, c, pi. 30). 



Radula.— The yellow radula when removed and flattened for e?camina- 

 tion is of a characteristic pear shape in outline. It is deeply grooved and 

 bears from 29-31 rows of teeth. The median tooth is small and almost 

 rudimentary being somewhat squarish behind and passing forward to a 

 bluntly rounded point. The first lateral tooth is small with a depressed 

 linear base bearing a spine on its upper en^ ; on the inner end of the base 

 of the spine are from 2-4 small denticles. The second lateral tooth is 

 far bigger, stout and hamate, the base is inserted laterally and slightly 

 curved. It bears a stout well curved smooth spine that points inwards. 



Jaws. — The shell shaped jaws are very large relative to the size of the 

 animal an,d the masticatory edge strongly developed and turned back 



