NUDIBRANCHIATA. 275 



Length of specimen (from spirits) 3 lines ; body broadly truncate ante- 

 riorly, tapering to the tail ; tentacula lamellated ; 3 branchial filaments ; 

 eyes two, at the inner side of the posterior base of the tentacula. Colour 

 whitish, with the frontal processes of an orange-yellow ; a few scattered 

 dots of this colour on the mantle. 



Although the four black lines described by MuUer as extending in an 

 interrupted manner along the body of P. quadrilineata are entirely want- 

 ing in my specimens, I cannot, possessing as they do every other character 

 in common with it, regard them as of a different species. They are at 

 the same time quite distinct from the supposed varieties of P. quadrilineata 

 figured in table 138 of the Zoologia Danica. 



Three individuals of this species occurred to us on the same occasion 

 as the Tritonia lactea, when di'edging at the entrance of Strangford Lough ; 

 they were adhering to Laminaria digitata. When placed in a phial of 

 sea-water, they were generally to be seen suspended by their threads from 

 the surface, the body at the same time moving freely about with much 

 grace. This species has hitherto been unnoticed in the British seas. 



P. typica^ mihi. 



P. with 4 frontal appendages, tapering towards the point ; tentacula 

 lamellate ; branchial lobes very large. 



Length 5 lines ; body narrow ; tail tapering ; branchial filaments 

 elongated, in a tuft anterior to the lobes ; disk thin and flexible at the 

 edges. Colour whitish, tentacula and branchial lobes tipped with yellow ; 

 back and sides thinly studded with tubercles (spots ?) of a yellow colour, 

 three of which are in the middle of the back, and six or seven close to the 

 tuft of branchial filaments ; the intestines (seen through the skin) of a 

 dark colour. 



Of this well-marked species, two individuals were dredged in Strangford 

 Lough by Mr. Hyndman and myself, in January, 1835, at the same time 

 with Euplocanius pliimosus. They seemed partial to coming to the surface 

 of the water in which they were for some time kept, and to moving along 

 with the foot upwards. 



P. ocellata, Aid. and Hanc. 



Mr. Alder, by means of the dredge, took this species commonly, and of 

 all sizes, in Dublin Bay, in August last, and subsequently obtained a 

 specimen at Malahide. 



P. citrina. Alder. 



Mr. Alder dr-edged two or three specimens of this species in Dublin 

 Bay, at the same time with the last. 



P. cristata, Alder. 

 Obtained with the preceding two species : common. 



Genus .^girus. 

 jE. 'punctilucens, D'Orbigny. 



Professor Allman obtained this Pohjcera in a pool at Courtmasherry 

 Harbour, County Cork. 



Genus EUPLOCAMUS. 

 E. claviffer, Mull. sp. 

 Body elongated, tapeiing to the tail ; three plumose branchial filaments. 



