NOTES ON NUDIBRANCHIATE MOLLUSCS 



229 



The latter have a tendency to develop into epipodial flaps 

 like those of Ancula, and at the same time there appears 

 a tendency to have the normal trace of an epipodial ridge 

 very marked (see Herdman, 

 " Fauna of Liverpool Bay," 

 Report in. p. 133). 



The extent to which these 

 variations may occur can be 

 seen in the following descrip- 

 tion of a specimen dredged 

 in about 20 fathoms near the 

 Farland Pt. during Oct. 1906 

 (see fig.) :— 



Length 18 mm., a rather 

 pale - coloured specimen. 

 Velar processes 3 on right side, 

 followed by a very small one 

 which was hardly more than 

 a tubercle, then 2 long ones, 

 I short one and 5 long ones 

 and a tubercle on the left ; 

 i.e. I o well-developed, slightly 

 contractile, yellow-tipped pro- 

 cesses of normal size, and 

 3 uncoloured small ones (see 

 Garstang, "Journal M.B.A.," 

 vol. i. new series, p. 455). 

 Rhinophores short and thick 

 with a few closely set laminae, 

 yellow tipped. Branchice 7 

 small, tipped with yellow 



among 



which 

 black pigment. 



was a little 

 Cera fa large. 



palmate, consisting of 5 or 6 

 yellow-tipped lobes. Coloured 

 tubercles absent, except the 

 median dorsal row posterior 

 to the branchiae. Eyes very 

 indistinct ; the left anterior 

 angle of the foot coloured 

 yellow, the right being white. 



This specimen, which was healthy and active, lived and 

 spawned in captivity for nearly two months ; the spawn was 

 destroyed by Infusorians. 



Two days later we dredged three more specimens of P. 

 quad7'ilineata in the same locality. The first was quite a normal 



p. QUADRILIXEATA, SHOWING VARIA- 

 TION IN THE CERATA AND VELAR 

 PROCESSES. 



