KUNGL. SV. VET. AKADEMIENS HANDLING AR. BAND 4l. NlO 4. 



17 



divergent, with a furrow on the under side. Body gelatinous, yellow or reddish, 

 with whitish spots. Shell internal, oval, flexible, with the spire over the side ; whorls 

 2, very minute. L. about 30 mm, animal; 15 mm, shell 



P. plumula (Montagu 1803) sideralis Loven 1846. 



Fam. Umbraculidae. 



Tylodina Rafinesque 1819. 



Head with a velum, terminating in tentacular lobes. Radula oo . 1 . oo . 



Shell ovate, depressed-conic, obsoletely angulate-radiate, with two incomplete 

 sinistral nuclear whorls at the recurved apex. Animal oblong, the head without 

 rostrum, deeply slit in front into lanceolate lobes; rhinophores ear-shaped. Colour 

 of the animal and epidermis of the shell purple. L. 10,7 mm, shell. (Pilsbry 1895). 



T. Duebenii Loven 1846. 



The following forms, perhaps young specimens of Philine, may be added to the Tectibranchia. 



Colpodaspis M. Saes 1870. 



Head with a pair of tentacles; foot with expanded anterior lobes. Shell internal, globose-ovate, with the 

 apex twisted, truncated; whorls 3. Radula 2.1.0.1.2. 



L. of the shell. l 2 /s mm. (Sars): L. of the animal 2,ri mm. (Sars) or mm. (Garstant; 1894). 



C. pusilla M. Saks 1870. 



Colobocepliiilus M. Sars 1870. 



Head with tentacle-shaped side-lobes; font dilated in front. Shell external, subauriform, very thin, with 

 or without an indistinct epidermis; spire small; whorls 3; columella sinuous. Radula 2.1.0.1.2. 



Shell with transversal cost-SR. L. 2,7 mm, animal; height of the shell 2 mm, breadth 2" :t mm. 



C. costellatus M. Sars 1870. 



Fam. Tritoniidae. 



Tritonia Cuvier 1802. 



Ventriculus without dentition. 

 I. Velum incised in the middle, with small papilla?; radula with numerous laterals 

 (subg. Tritonia). 



A. Back slightly convex, warty; the bigger appendages (5 — 6 on each side) 

 distinctly pedunculate, flexed inwards, the smaller ones prominent outwards; 

 porus genitalis close by the margin of the back, half way between head 

 and anus. Colour yellowish, brown or purplish; appendages light. Laterals of 

 the radula smooth. L. 70 — 200 mm. 



T. Hombergi Cuvier 1802 = fimbriata (Vahl 1806). 



PI. II fig. 18, PI. Ill tig. 4 



Laterals of the radula with margin-hooks. L. 25 mm. 



var. alba Alder & Hancock 1855. 



K. Sv. Yet. AkiuL Handl. Bd 41. N:o i. 3 



