MOLLUSCA OF PLYMOUTH SOUND. 185 



it was very pale in colour and possessed intermediate branchiae, 

 diiJering in these respects from the other individual. The edges of 

 the tentacular sheaths, I noticed, were capable of undulation, though 

 they formed no fixed wavy outline. Several of the characteristics 

 of this individual are thus seen to afford an approach to Alder's 

 species T. lineata, of which he found two specimens at Scarborough. 

 Indeed, I think the distinctness of this species is open to consider- 

 able doubt. 



i^amt'Zy.— DENDEONOTID^, Alder and Eancocli. 

 12. Dbndronotus, Alder and Hancock. 



20. D. AEBORESCENS, Milller. 



Only one small specimen of this species has been obtained since 

 June, 1888. It was brought up with the dredge from a depth of 

 about twenty-five fathoms south of Penlee Point, in November. It 

 was half an inch in length and had five pairs of branchial appen- 

 dages, the tufts forming the two last pairs being arranged alter- 

 nately, not opposite each other. The markings were of a brown- 

 pink hue, with yellow tubercles and colouration here and there (cf. 

 Alder and Hancock's variety, pulchella). 



A lai'ger specimen, just over seven eighths of an inch in length 

 was dredged in twenty -three fathoms, about three miles south of 

 the breakwater, on February 9th of last year (1888). 



Though so rare here, Herdman (12 and 14) reports this species 

 to be abundant at Hilbre Island during the winter months. It is 

 abundant at Wimereux, and has a protective resemblance to the red- 

 brown much-branched weeds of the genus Callithamnion (Giard, 6.) 



13. LoMANOTUS, Verany. 



21. L. VARIANS, mihi. 



On June 11th of this year three Nudibranchs were included in the 

 results of the day's dredging at about three miles south of the Mew- 

 stone which I found with pleasure to belong to this rare genus 

 Lomanotus {Eumejiis, A. and H.). It was not so easy, however, to 

 assign them to any of the specific divisions which have been founded 

 for the reception of the five hitherto known British examples, and 

 after a careful examination I have come to the conclusion that I 

 must either institute two new species for the specimens which wo 

 have dredged or unite the four previously described British species 

 and the three specimens which we have dredged into a single species. 



