ANATOMY OF ACLESIA FREERI. 



75 



Fig. 3.— Central tooth, first 

 and second inner 

 laterals, and four 

 outer lateral teeth of 

 the radula of Aelesia 

 freeri sp. nov. 



The radula sac opens by a V-shaped aperture in the middle 

 of the posterior half of the dorsum of the tongue. The posterior 

 wall of the sac is folded into it, so as to lie against the lateral 

 walls. The sac is deep, extending obliquely downward and 

 forward to the base, and almost to the an- 

 terior extremity of the tongue. 



The radula (figs. 27, 28, and 29, Plate IV) 

 consists of two portions; one lying upon the 

 dorsal and anterior surface of the tongue, 

 the other bending sharply at right angles to 

 the first portion, and lying on the posterior 

 face of the tongue and in the radula sac. 

 The central part of the exposed portion of 

 the radula is considerably raised above the 

 margins, and at the anterior end forms a 

 high sharp ridge, where the central teeth 

 are apparently the only ones used. The 

 center of the posterior portion of the radula, on the contrary, 

 is greatly depressed. 



The radular teeth are of the type common to the family, 

 and little different from those of other known species of aclesias. 

 Text figure 3 represents the central tooth, 

 the first two lateral teeth, and the four 

 outermost lateral teeth of a row. A de- 

 tailed description would be superfluous. 



The inner surface of the anterior and 

 ventral part of the pharynx is covered by 

 a fairly heavy, chitinous cuticula which 

 bears numerous spines of the kind shown 

 in text figure 4. They are of two kinds; 

 in the anterior region the spines are short, 

 thick, and sharply pointed; posteriorly, 

 there are patches of long, slender, blunt 

 spines which seem to be totally lacking 

 in rigidity, and are more like cuticula- 

 covered villi than spines. 



The long (35 to 40 millemters), lobu- 

 lated, salivary glands lie parallel to the 

 oesophagus (fig. 12, Plate III) ; their pos- 

 terior ends are loosely attached to the sur- 

 face of the gizzard. The ducts of the salivary glands pass under 

 the posterior edge of the outermost circular muscle layer of the 

 pharynx until they reach the dorsal surface of this organ. They 

 then turn forward for a distance of from 3 to 4 millimeters, 



Fig. 4. — Cuticular spines or 

 thorns upon the inner 

 surface of the pharynx 

 of Aclesla freeri sp. 

 nov. The four spines 

 at the bottom are from 

 the anterior, the ones 

 above from the posterior 

 region of the part of 

 the pharynx thus armed. 



