290 BULLnXZE. 



B. CATENA, Montagu et Auct. 



B. catena, Zool. Journ. iii. p. 337. 



Philine catena, Brit. Moll. iii. p. 545, pi. 114. E. f. 6, 7; (animal) 

 pi. U.U. f.4. 



The animal is an elongated oval ; the upper disk, as in the 

 tribe, is essentially an integral plate, though the skin is broken 

 into two apparently well-separated lobes ; the anterior one is 

 the longer and narrower oval, and shows no trace of eyes or 

 tentacula ; the posterior is broader and shorter, and encloses 

 within the skin an elegant, clear, white clypeiform shell, 

 marked with close transverse catenated striae ; the posterior 

 extremity of this lobe is digitated. The pedal disk extends, 

 without a break, the whole length of the animal, the sides 

 being well reflexed on the upper lobe, giving that surface the 

 quadrilobated aspect of the tribe. Between the two disks, 

 just under the upper one, is a slight inflation, the repre- 

 sentative of the head, beneath which is the vertical buccal 

 orifice. 



For the anatomy, I refer to my accounts of the Bulla 

 hydatis and Bullaa aperta -, it is the prototype in miniature 

 of those species, as far as can be judged in so diminutive a 

 creature. I couple the B. hydatis with the B. aperta, as the 

 internal organs of the animals, though of so different an exte- 

 rior, are essentially identical. The gizzard in this animal pre- 

 sents some difference, being an elastic muscular cylinder cased 

 with three similar-shaped white testaceous trapezoid plates, 

 pointed at the axes. The colour of the upper disk is a yellow 

 ground, closely aspersed with light red-brown minute points, 

 mixed with a very few lines and blotches of similar colours, 

 and some specks of sulphur-yellow ; the pedal disk is powdered 

 throughout on a pale yellow ground with rather intense 

 minute yellow points or small streaks. The animal inhabits 

 the littoral zone, at Exmouth, but is rare amongst algse in 

 the sheltered pools ; it is by no means sluggish, and delights 

 in swimming. Longitude -fe, latitude et altitude circa -fa 

 uhcise. 



This is a reproduction, perhaps not a disadvantageous one, 

 of an account of this animal and the Bullcea punctata which 



