Beattie. — On the Anatomy of the Bed Cod. 81 



posterior canal being posterior. The ampulhe of the anterior 

 and horizontal canals open into a common branch, probably 

 of the ovoidal vestibule. In this small pouch is a very small 

 calcareous otolith — asteriscus (as.). The ovoidal vestibule 

 uho contains a large calcareous otolith — sagitta (5.). 



It will be noted from my description that this auditory 

 organ of Lotella bacchus differs very markedly from that of 

 Gadiis morrhua as figured by Professor G. B. Howes in 

 Parker's " Zootomy," and as figured by Smith and Norwell in 

 tlu'ir " Illustrations of Zoology." Whereas in Gadus morrhua 

 tl)e small otolith, asteriscus, is contained in a separate pouch 

 at the posterior end, in Lotella bacchus it is placed in a pouch 

 at the anterior end, and a pouch which is in direct communi- 

 cation with the ampullae of the anterior and horizontal 

 semicircular canals. The utricle is not sharply marked off 

 from the saccule. There is no trace of the cochlea of Gadus. 



Relation of Auditory Organ and Air-bladder (fig. 6) : At its 

 posterior end the ovoidal vestibule is somewhat flattened. 

 This flattened part, which is composed of an exceedingly thin 

 membrane, fits exactly and very closely against a thin, bony, 

 and perfectly transparent membrane, /, %\diich almost closes 

 tlie auditory fontanelle. This bony membrane consists of two 

 parts : one has its origin on the left side of the fontanelle, and 

 passes parallel with the transverse axis of the cranium towards 

 the centre of the foramen ; the other has its origin on the 

 rig] it side of the fontanelle, and passes in like manner almost 

 to meet its fellow of the opposite side. Fitting very closely 

 against this bony lamina is the very thick button- or pad-like 

 process of the air-bladder, already referred to. This button- 

 like body, b, actually forms a sort of plug for the foramen. 

 This plug is, in an ordinary-sized fish, about -^o^n- "^ thickness. 

 Behind, this plug comes to cavity of the cornu of the air- 

 l)ladder. 



Parasites. — Large numbers of crustacean parasites were 

 found attached to the gills. Others were attached by their 

 star-like extremity to the mucous membrane of the mouth, and 

 to tlie muscles of the body. 



These parasites have been described by Mr. G. M. Thom- 

 son in the "Transactions of the New Zealand Institute," 

 vol. 22, pp. 3G8 et seqq. The former have been named by 

 Mr. Thomson Chondrocanthus lotella, and the latter Lernea 

 lotella. 



Two tapeworms between Bin. and 9in. long were found in 

 the intestine of one specimen — species of Tceiiia. 



Nematoda : These worms were very numerous, and varied 



from 1-Jin. to 4in, in length. They were found mainly in the 



muscles of the ci-anium. One, however, was found between 



the olfactory lobes, while another was in the brain-case proper. 



6 



