234 NUDIBRANCHIATA COLLECTED IN THE NORTH SEA 



CORYPHELLA RUFIBRANOHIALIS (Johnst). 



Voyage XCIII. Station 21. W. of Brucey's Garden. 40 fathoms. 2 



specimens. 

 Voyage XCIII. Station 23. Whitby Outer Eoiigli. 36 fathoms. 5 specimens. 



,j ,, ,, 30. Off Hartlepool. 30 fathoms. Common. 



,, XCV. ,, 24. S. edge of the Coal Pit. 13 fathoms. 1 specimen. 



With the exception of that from XCV — 24, all the specimens obtained 

 from the above, and a number of other stations off the coasts of 

 Durham and Northumberland and to the N. of the Dogger Bank, etc., 

 were referred when captured to the C. pcllucida of Alder and Hancock. 

 In size and external features almost all exactly agreed with the plate 

 and description of those authors, but upon examining the radulte it 

 became evident that they must all be referred to the present species. 



Some 16 specimens were examined from XCIII — 21, 23, and 30. 

 Unfortunately specimens from the other stations had not been pre- 

 served, so I can only conjecture that they were also referable to this 

 species. 



All the radulse examined agreed very closely, and many were 

 identical with the figures and description of Alder and Hancock. 

 Generally of a yellowish white, the central plate with usually 15 

 denticles, the central cusp strong ; the laterals, as described by Alder 

 and Hancock, " of an acute triangular form with the apex turned out- 

 wards ; " the denticles on their inner margins, however, very irregular 

 in size and number, in some cases 12 to 14 and of fair size, in others 

 the same number but much smaller, in otliers again only 7 or 8 might 

 be present upon the upper portion of the tooth. 



It is possible that specimens occur without any denticles on the 

 laterals, and although the radula, figured by Alder and Hancock for 

 C. iKllueida, is of a different shape to any I examined, still the evidence, 

 I think, supports the opinions of Bergh and Vayssiere, who unite 

 these species. 



One specimen from XCIII — 30 had a faint white bifurcating line 

 on the head as in C. lineata, and in another from the same station tlie 

 head region was coloured as in C. landshurgii (A. & H.). Oral tentacles 

 and rhinophores amethystine, and tipped with yellowish white ; length, 

 half an inch. Both these cases also support the views of Bergh and 

 Vayssiere in uniting these species also with C. rujibranchialis. 



Tuhularia indivisa and T. larn.y.'c were in every case the habitat of 

 the species, and when crawling along the stems among the colonies 

 the animals very closely resembled their surroundings. Some of the 

 specimens were 4 cm. and many 3 and 3i cm. in lengtli. 



