1918] A Urn e ntary Ca n at of A It ica La rva 287 



The hypodermal cells through which the attachments are made 

 become fibrillar, and their fibrils interlace with those of the 

 muscles. (See figure 1, A). In some sections of just molted 

 larvae, these tendons are quite long, but usually the cells are not 

 drawn out at all. (See figure 1, B). The basement membrane 

 of the hypodermis or epitheHum appears to be continuous with 

 the sarcolemma of the muscles. 



THE BUCCAL CAVITY. 



As is to be expected, longitudinal sections show clearly that 

 the cuticula of the body wall is directly continuous with the 

 intima of the fore-intestine, the hypodermis with the epithehum, 

 and the basement membrane of one with the basement mem- 

 brane of the other. The primary cuticula is of about the same 

 thickness as the primary intima, but it becomes deeply pig- 

 mented and beset with many cuticular nodules as soon as it is 

 outside of the oral invagination. The secondary cuticula is also 

 of about the same width as the secondary intima, and both 

 stain pink with eosin. The intima of the buccal cavity is armed 

 with small backward directed spines. 



The epithelial cells are considerably larger than those of the 

 hypodermis, but the transition is gradual and there is no 

 abrupt change of type, the cells first becoming higher than the 

 flat hypodermis, and then gradually broadening out into the 

 cuboidal form characteristic of the pharyngeal and oesophageal 

 epithelium. 



THE PHARYNX. 



In this species, the limits of the pharynx can be determined 

 only by the attachment of the muscle fibres which run to the 

 body wall. Dorsally there are two sets of these, one of four 

 fibres running perpendicularly, and the other of three extending 

 at an angle, to the body wall. Ventrally there is a single set 

 which consists of two large fibres running nearly vertically to 

 the body wall. These muscles are all paired. They are attached 

 to the intima in the usual way, and their sarcolemmata appear 

 continuous with the basement membrane. 



The oral invagination is shown in figure 2. The location of 

 the pharyngeal muscles is shown in figure 3. 



The histological features of the pharynx and oesophagus are, 

 identical as regards the type of intima and epithelium, which 



