NUDIBRANCHS OF THE VANCOUVER REGION 1 53 



Colour. — When preserved these animals are of an opaque white 

 colour and one had a faint pinkish tinge. Dr. Fraser informs me that 

 when alive the dorsum is of a rose pink colour. 



Dimensions. — The largest specimen measured was considerably larger 

 than that examined by Bergh for it measured 84 mm. long by 51 wide 

 by 30 high as agains 44 mm. long by 17 broad by 15 high so that when 

 alive it was quite a large animal. 



Head. — ^The head is broad and well marked. The mouth is a longi- 

 tudinal slit with thickish lips and the latero-dorsal comers of the head 

 continued out as the grooved tentacles that have already been noted as 

 forming the postero-lateral border of the veil. 



Foot. — The foot is very broad and flat; posteriorly it terminates in a 

 pointed end while anteriorly it is abruptly rounded and bilabiate, both 

 lips being about equally thick. 



Rhinophores. — ^The clavus of the rhinophore is not perfoliate. The 

 stalk of the clavus is cylindrical and bears at its upper end a crown of 

 from 10-12 feather shaped papillae. These alternate as simple and 

 doubly pinnate structures of which the posterior is bi-pinnate much 

 taller than the rest and terminates in a point so that it is quite unlike 

 that of T. hombergii as described by Alder and Hancock. The short 

 sheath is cylindrical and terminates at the upper extremity in a slightly 

 crenulate margin. 



Branchiae. — The small branchial tufts numbered from 16-18 on each 

 side and decreased in size and complexity from before backwards and 

 alternate; the larger ones being directed medially and the smaller later- 

 ally. The stem of each tuft is broad, somewhat flat and soon dividing 

 into two or three main stems which in their turn split into smaller bi- 

 or tripinnate branches. 



Radula. — The radula is large and well developed being slightly 

 longer than broad. It bears from 45-52 rows of teeth. The median teeth 

 are broader than long and tricuspid. The middle cusp is moderately long 

 and pointed while the lateral cusps are not so long and have a point at 

 their inner comer. On each side of the median tooth is a modified lateral 

 tooth somewhat triangular with a bluntly pointed cutting edge at their 

 interior comers. They are followed by a series of lateral teeth varying 

 greatly in numbers reaching a maximum near the middle of from 60-64. 

 Each tooth is fairly thin and claw shaped. 



Jaws. — The yellow jaws too are very well developed and occupy 

 practically the whole anterior end of the wide pharynx. The crista con- 

 nectiva is well developed and the two jaws lightly bound together by 

 tough connective tissue. The cutting border of the mandible, corres- 

 ponding to the processus mascatorius, is quite long, brown in colour 



