28 CATALOGUE OF THE MOLLUSCA 



straw colour, rather small in proportion to tlie shell, and retrac- 

 tile within it. The frontal disc is large, slightly bilobed behind, 

 but not produced into tentacles, and without apparent eyes. The 

 foot is small and a little extended, and folded up at the sides. 

 The epidermis when fresh is of a rusty orange colour. 



4. B. TRUNCATA, Adams. 



Bulla truneata, Mont. Test. Brit. 223, t. 7, f 5. 



Frequent in shell-sand, and occasionally found alive in pools 

 among the rocks. 



The animal has been described by Dr. Johnston. It differs 

 from the last in having the disc, which is short and square, pro- 

 duced posteriorly into longish pointed tentacles, with eyes at the 

 anterior base. It is the type of the genus Cylichna of Loven, in 

 which he also includes the two preceding and the following 

 species. This genus we should gladly have adopted, but that 

 we have doubts whether the species he has referred it to really 

 belong to the same generic group, which an examination of the 

 animals alone can decide. 



5. B. OBTUSA, Mont. 



Bulla obtusa, Mont. Test. Brit. 223, t. 7, f 3. 

 Rather rare. In sand at Cheswick, and Newbiggin. — J. A. 



20. AMPHISPHYRA, Loven. 

 1. A. HYALINA, Tu7't. 



Bulla hyalina, Turt. in Loud. Mag. Nat. Hist. vii. 373. 

 Utriculus pellucidus, Brown, lUust. Rec. Conch. 59, t. 19, 

 f. 10, 11. 

 In shell sand, not rare. We have once or twice found it alive 

 in pools between tide-marks at Cullercoats. 



The specimens from which Dr. Turton described his Bulla 

 hyalina, we found in sand collected at Tynemouth. The Utri- 

 culus 2^dlucidus, U. candidus, and U. ininutus of Capt. Brown 

 appear to us to be this shell in different stages of growth. 



The animal of this species differs so materially from the other 

 Bullidas that we hesitate not to adopt the genus proposed for it 

 by Professor Loven. The absence of the frontal disc and the 

 position of the tentacles (which are short and obtuse) in front 



