THECACERA PENNIGERA. 



fill up the only gap that would otherwise have remained in our illustrations of generic forms. 

 This " singular and gaudy animal" as Montagu has not inappropriately called it, attracts the 

 observer at first sight by the decided character of its orange and black markings, which give 

 it a harlequin-like appearance. The specific character inserted in our Synopsis, which was 

 printed off before we had seen the animal, will be found to differ in some respects from that 

 given above. The former was taken from Montagu's description and figure, which we had not 

 perfectly understood. The " anterior end " " extending each side into an angular lobe," we 

 had taken to be a bilobed veil ; but this appearance is caused by the extended angles of the 

 foot, which in the figure are represented as forming a part of the head. Montagu has also 

 made a mistake, as Mr. Thompson has pointed out,* in the number of the branchial plumes ; in 

 this respect departing from his usual accuracy. 



Two specimens were obtained by Mr. Thompson at Weymouth, in the summer of 1854, 

 by dredging, in about ten fathoms water. The first, he states, lived with him about six 

 weeks ; the second, which was sent to us, survived a considerable time, though in a sickly 

 state. Mr. R. d. Couch informs us that he found two specimens of Thecacera pennigera several 

 years ago on the Cornish coast. 



The jaws and tongue of this species very closely resemble those of Pohjcera 

 quadrilineata. 



Fig. 1, 2, 3. Thecacera pennigera, different views. 



4. A tentacle with sheath. 



5. Two of the branchial plumes, much enlarged. 



6. A jaw. 



7. A row of lingual spines. 

 8, 9. Spicula. 



* Ann. Nat. Hist., 2d series, v. 14, p. 237. 



