704 MR FRANK J. COLE 



along the middle line and pinning the halves out laterally, the tendon is seen to lose 

 its identity very quickly. The lateral portion fans out considerably, and fuses with 

 the ventro-lateral mucous membrane at the aperture of the mouth. This portion of 

 the tendon gives off, according to J. Muller and P. Furbringer, a small lateral 

 bundle for the cartilage of the fourth tentacle. I have found this bundle (c. g. s".), and 

 have traced it into the fascia at the base of and behind the fourth tentacle, but could 

 not satisfy myself that any of its fibres were continuously connected with the cartilage 

 of the tentacle itself. The more median portion of the tendon is apparently quickly 

 lost on the mucous membrane of the floor of the mouth. J. Muller, however, states 

 that it is attached to the anterior margin of the " tongue " cartilage ; and P. Furbringer 

 asserts that it splits into two portions, which are inserted one on each side at the 

 anterior lateral region of the dental plate, i.e. lateral to the insertion of the tendon of 

 the copulo-glossus profundus. Dissections certainly favour the statements of both 

 these writers as regards the insertion into the dental plate. 



Now with regard to the sections. In transverse sections the forward course of 

 the tendon from the muscle belly to the ventral margin of the mouth confirms what 

 has already been stated from dissections. As, however, the tendon bends round the 

 anterior edge of the basal plate two stout longitudinal sheets [i.e. one on each side) 

 are given off at the boundary of the lateral and median portions of the tendon, and 

 these pass almost vertically upwards, but at first somewhat medially, and are inserted 

 into the tough fibrous submucosa of the lateral wall of the median ventral longitudinal 

 diverticulum of the mouth. The median portion of the tendon, after it has rounded 

 the basal plate, is at once inserted into the same tissue of the ventral wall of the 

 diverticulum. The tendon fibres can be traced back on the ventral wall of the 

 diverticulum for some little distance, but they are undoubtedly lost before the tongue 

 skeleton is reached. As, however, the connective tissues of the teeth and dental plate 

 fuse in places at the region of the anterior border of the latter, any pull on the mucous 

 membrane is necessarily transmitted to the dental plate. Nevertheless it is quite 

 clear that the tendon of the copulo-glossus superficialis is not inserted into the dental 

 plate. The lateral slips, supposed to pass to the fourth tentacle, were traced forwards a 

 short distance in front of the bend, but were lost in the submucosa and spongy tissue of 

 the postero- ventro-lateral wall of the mouth without reaching the tentacle in question. 



In the longitudinal sections those passing through the median plane show the 

 median portion of the tendon curving round the basal plate anterior and external to 

 the tendon of the copulo-glossus profundus, and at once fusing with the ventral 

 diverticulum of the mouth as above described. Any connection with the dental plate 

 is here out of the question. Further, the complete course of the vertical longitudinal 

 sheets mentioned above is now visible, and we see that the fibres constituting them 

 continue their dorsal course at the sides of the ventral diverticulum of the mouth, 

 curving upwards and finally backwards to fuse with the fibrous tissue and the mucosa 

 immediately anterior to the rows of teeth. As these fibres form a great, if not the 



