NUDIBRANCHS OF THE VANCOUVER REGION 1 83 



over the front margin of the mandible. The inner ventral border of this 

 edge is thickened to form a yellowish brown tooth like prominence close 

 to which a very tough ligament binds the two jaws together. 



The penis is stout, sub-conical and covered with papillae. 



This genus was first recorded by Cockerell and Eliot (4) who examined 

 a closely related form namely D. picta and noted that an allied species 

 had also been found. It had previously been recorded in MS. by MacFar- 

 land and Cockerell and Eliot name it from his MS. The genus is so 

 peculiar that in a full and accurate description of the two species D. picta 

 ajid D. albolineata published subsequently by MacFarland (1913) this 

 author raises the genus to the status of a new family a step which appears 

 quite justifiable. 



Habitat. — MacFarland lists this species as rare. It is not common 

 near Nanaimo but has an interesting distribution. Every year it spawns 

 in a narrow cleft of the rocks on Jesse Island and a dozen individuals 

 were obtained there in the low tides of May and June 191 9. This Dr. 

 Eraser informs me is the case each year. No specimens have been taken 

 at any other place although searched for, save one that was dredged in 

 20 fathoms in Northumberland Channel (Station 5), or at any other 

 time, thus constituting a curious example of limited distribution. 



Family Dendronotidae. 



Limaciform animals with oral veils and dorsal appendages which are 

 usually branched and sometimes arborescent. Rhinophores retractile 

 into projecting sheaths. Radula moderately wide or narrow. Liver 

 djixnded into three portions which commonly but not invariably send 

 branches to the dorsal appendages. 



Genus Dendronotus Alder and Hancock. 



Dendronotus Alder and Hancock, Mon. Brit. Nud. Moll., Pt. I, 1845, 



Fam. 3, pi. 3. Bergh, Proc. Ac. Nat. Sci. Phila., Pt. I, 1872; Die 



Nudibr. des Willem Barent's, 1885, p. 25; Bull. Mus. Comp. Zool., 



Vol. XXV, 1894, P- 137- Eliot, Brit. Nud. Moll., Pt. VIII, 1910, 



p. 161. 



Animals of large or moderate size. The oral veil and rhinophores 



sheaths bear arborescent processes. Rhinophores perfoliate. On either 



side of the back a single row of arborescent cerata. Radula varying from 



about 6, I, 6 to 21, I, 21. Liver consisting of a large posterior mass and 



two smaller anterior portions. The hepatic diverticula extend into the 



cerata in some cases, but not in others. The genitalia are unarmed. The 



hermaphrodite gland is large, and lies above the posterior liver. Prostate 



present. 



