Mr. W. Clark on the Animals of the Bullidse. 99 



sometimes fail in his views, from various causes, especially in 

 the investigation of the difficult tribes of the minuter animals ? 

 where is the critic, who, under such circumstances, would so 

 egregiously misapply the phrase, 



" Indignor, quandoque bonus dormitat Homerus " ? 



I propose to show that the B. cylindracea and B. truncata are 

 congeneric with B. hydatis ; if this is so, it may be further ob- 

 served, that on analogical considerations it is extremely probable 

 that M. Loven's B. umbilicata, which is also one of our indigena, 

 is in the same category as to error, and with our B. obtusa and 

 B. mammillata, not yet I believe observed, will tm*n out to be 

 strict Bulla. Until these minute creatures have had fresh ex- 

 aminations, this family cannot be settled ; no conchological con- 

 siderations will suffice. It may be that the unobserved species 

 will affi)rd valid generic distinction ; but I think, from the con- 

 stancy of structure of all the Bulla that have been adequately 

 observed, they will, though the presumption rests on analogical 

 grounds, be found to have the tripartite gizzard and typical foot 

 with its accessory lobe extending from one extremity of the ani- 

 mal to the other, with the sides more or less reflexed, producing 

 the quadrilobated character of the tribe. 



I can say little of the genus Amphisphyra ; the only British 

 species, the B. hyalina, is not found on our southern coasts, and 

 the notices of it are so meagre, that at present it cannot be placed 

 with safety. It has been stated to have neither gizzard nor head- 

 disc ; if so, it cannot belong to the Bullida ; it is possible those 

 parts in so minute a being may have escaped detection, and it 

 may turn out a Bulla. Natm-alists residing in the locality of 

 this species should re-examine these points and communicate 

 their notes. 



The Scaphander of IMontfort is synonymous with Bulla, and 

 the Philine of Ascanius adopted by M.Loven, with Bullaa: though 

 these ancient titles may have priority of date, still, whatever in- 

 justice may be done — and it would appear from the want of sup- 

 port of these genera, it cannot be great — it is impossible at this 

 time of day to dispense with the Bulla of Linnaeus and Lamarck, 

 and Bullaa of the latter, which have been so long in use and 

 universally acknowledged. 



I have given a general and anatomical description of Bulla 

 hydatis from many live individuals, which have enabled me to 

 verify the observations of M. Cuvier, to till up some gaps, and I 

 believe to correct some errors, which, for the reasons I have 

 assigned below, have escaped the attention of that prince of 

 anatomists. 



