100 PROCEEDINGS OF THE ACADEMY OF [1880. 



buccal crop making nearly half of the whole bulbus, and of the usual 

 form ; the walls very thick ; the compressed and rather small cavity 

 communicating through a long cleft with the anterior half of the 

 small buccal cavity. The lip-disk (fig. 1) of rounded contour, clothed 

 throughout its whole breadth (on each side to about 0.5 mm.) with the 

 light, horn-yellow colored armature ; the lowest part of this, as usual 

 in the Acanthodorides, injured or wanting ; the breadth of the belt 

 decreasing towards the upper end, where it is interrupted in the middle 

 line, also at the lower end. The armature (fig. 2&&, 36, 4} composed 

 of hooks, whose points are directed forwards (towards the opening of 

 the mouth), nearly like, but still differing a little from those in the 

 typical Ac. piloHO, reaching the height of about 0.04 mm., yellowish, 

 with rounded, bifid or irregularly cleft points. The lancet-shaped 

 (fig. la, 2a, 3a) blades at the inferior angle of the mouth as usual. 

 The tongue with nine or ten sei'ies of plates, farther backwards 

 thirteen to fifteen developed and three undeveloped series ; the total 

 number in this way, twenty-five to twenty-eight. The large lateral 

 plates relatively larger than in the Ac. pilosa, and (fig. 5, 6) less 

 thick in the anterior-inferior part of the body, with relatively larger 

 hook ; the denticulation of this last much weaker and much more 

 irregular ; in one specimen generally two to four denticles, sometimes 

 only a few vei'y insignificant ones or none at all (fig. 6) ; and this was 

 the case with the other specimen, in which only some few plates showed 

 two small denticles.* The outer lateral plates as in the typical form, 

 scarcely more than from four to six. 



The salivary glands whitish, rather strong at their short first part, 

 in the rest of their length thin (fig. 7), accompanying the oesophagus 

 to the cardia ; the duct rather short (fig. 7a). 



The oesophagus forming a little crop,^ with thin walls and longitu- 

 dinal folds on the inside; in the rest of its length rather thin. The 

 stomach rather small, with the usual biliary apertures. The intestine 

 (fig. 8a) somewhat inflated in its first part, with many rather strong 

 folds and one particularly thick ; a little over the point, where it 

 appears on the surface of the visceral mass, on the right side, a little, 

 scarcely pedunculated bag (fig. 8&^, of the length of 1.0 to 1.25 mm., 

 with fine, longitudinal folds ; the rest of the intestine (fig. 8c) some- 

 what narrower; the total length of the intestine about 12.0 to 13.0 



^ Although very like the plates of the Atlantic form, they still bore a 

 somewhat peculiar aspect. 

 ■^ Cf, my Gattungen uordischer Doriden, 1. c, Taf. xix, fig. 14. 



