[31] CEPHALOPODS OF NORTHEASTEPtN COAST OF AMERICA. 241 



cumscribing a more flattened area, on which are grooves and ridges 

 parallel with the notch. Beyond the notch, on the anterior edges of 

 the alte, there is, on each side, a broad, low, obtnse lobe or tooth, be- 

 yond which the edge is even and slightly concave to near the end of 

 the alne. The lamina of the mentum is short and strongly emarginate 

 in the median line. Detailed measurements of the parts are given in 

 the table of measurements on a subsequent page. 



The roof of the mouth, or palate, between the anterior portions of the 

 palatine laminae, is lined with a rather firm, somewhat chitinous or 

 parchment-like membrane, having its surface covered with strong, acute, 

 recurved, yellowish teeth, apparently chitinous in nature, attached by 

 broad, oval, or roundish flattened bases (Plate V, figs. 4, 5). These 

 teeth are mostly curved, and very unequal in size and form, the various 

 sizes being intermingled. They are arranged in irregular quincunx, in 

 many indefinite rows. Many irregular, roundish, rough, white, stony 

 granules are also attached to this membrane, among the teeth. Similar 

 granules (Plate V, fig. 4a) occur in large numbers on the thinner exten- 

 sion of this membrane, which everywhere lines the mouth and pharynx. 



The radula is about 64 mm in total length, with the dentigerous por- 

 tion, where widest, about ll mm in width. The teeth are in seven 

 rows, with an exterior row of small, unarmed, thin, rhomboidal plates 

 on each side, thus conforming to the arrangement in the other ten- armed 

 Cephalopods. The teeth are deep amber-color to dark brown, and not 

 unlike those of Loligo and Ommastrephes in form. Those of the median 

 row have three fangs, the central one longest ; those in the next row, 

 on either side, have two fangs, while those of the two outer lateral rows, 

 on each side, are acute and strongly curved ; the outermost longest and 

 simple, the next to the outer often having a small denticle on the outer 

 side, near the base. (See Plate V, figs. 1, 2, 3.) 



The membrane of the odontophore is broad, firm, and thick; the 

 dentigerous portion occupies only about a third of its width, in the 

 middle or broader portion, where it is bent abruptly back upon itself. 

 The lower or ventral portion measures, from the anterior bend to the 

 end, 20 mn '; it narrows gradually to the broad, obtuse end, the width of 

 the dentigerous portion decreasing from 9 mm to 5 mm , the naked lateral 

 membrane decreasing from 8 mm to a very narrow border. The upper 

 portion, from the bend to the end, measures 42 mm in length (in a straight 

 line). The upper surface is deeply concave and infolded, at first, with 

 the lateral membrane broad and recurved; farther back it becomes 

 more flattened, with the dentigerous portion broader (ll mm ), while the 

 lateral membrane is abruptly narrowed and then extends to the end as 

 a very narrow border. Toward the end the rows of teeth become more 

 separated and the teeth smaller and paler, while the membrane becomes 

 thinner and narrower. 



The internal shell, or pen, was represented by numerous detached 

 pieces, which, after much trouble, I succeeded in locating and match- 

 S, Miss. 59 1G 



