257 



Fio-ure 2. — The same. Dorsal view. The dotted lines indicate portions of the arms 



that had been destroyed. 

 Figure 3. — The same. Side-view of the head and siphon, with the anterior part of 



the mantle, cut open ; e, the eye ; s, siphon ; o, o', o", the three nuchal frills ; 



c, c', c", the smooth facets, where the mantle bears upon the neck ; c, ventral 



facet of mantle ; c', ventral facets at base of siphon ; c", dorsal facet of neck ; 



in, m', cut edge of mantle. 

 Figure 4. — The same. The entire dorsal ' pen ' ; side-view, ^^ natural size. 

 Figure 5. — The same. Yentral view. 

 Figure 6. — The same. A portion from the middle of the ' pen,' less reduced. 



All the figures were made from the fresh specimens by Mr. W. H. Dall. 



Plate XXIV. 



Figure 1. — OnycJioteuihis robusta (Dall). Odontcphore ; side-view, enlarged 3f diame- 

 ters. 



Figure 2. — The same. Part of a row of the teeth from near the anterior bend of the 

 odontophore. x 22 diameters; a. median tooth, front view ; a', side-view of same ; 

 6, first lateral ; V. the same, side-view ; c, second lateral, front view ; (/, outer 

 lateral, front view. 



Figure 3. — The same. One of the inner lateral teeth, side-view, x 54 diameters. 



Figure 4. — The same. Median tooth, side-view, x 54 diameters. 



Figure 5. — The same. Upper mandible, natural size. 



Figure 6. — The same. Lower mandible, natural size. 



Figure 7. — The same. Anterior end of cone of pen. showing portion of posterior end 

 of quill inserted into it, i natural size. 



Figure 8. — The same. Section of a ventral arm, close to the base, natural size; a, 

 one of the suckers, side view ; b, and 6, marginal membranes ; c, crest on mem- 

 brane along outer angle ; e, median vessel near inner surface. 



Figures 1 to 4 are camera-dravrings by the author ; the rest are by J. H. Emerton, 



Plate XXV. 



Figure 1. — Architeuthis Hartingii V. Lower mandible, showing anterior portion 

 only, natural size ; la, section of a sucker of sessile arm of same ; 16, horny ring 

 of same, natural size. After Harting. 



Figure 2. — Architeuthis dux Steenstrup. Lower mandible, natural size. Copied from 

 Harting's figure, after Steenstrup. 



Figure 3. — Architeuthis monachus Steenstrup (t3'pe specimen). Lower mandible, nat- 

 ural size. After Steenstrup. 



Figure 4. — Enoploteuthis Hartingii Verrill. A secrion of one of the claw-bearing 

 suckers, somewhat enlarged ; 4a, the horny claw, isolated ; 46, median and lateral 

 teeth of odontophore. After Harting. 



Figures 5 and 5a. — Architeuthis Harceyi V. (No. 4). The two halves of the lower 

 mandible, natural size. Camera-drawings from the .specimen, by the author. 



The author is greatly indebted to Professor S. F. Baird, U. S. Commissioner of Fish 

 and Fisheries, for the use of a large number of the excellent drawings made by Mr. 

 J. H. Emerton, of Salem, Mass., under the direction of the author, for the Fish Com- 

 mission, many of which are included in these plates. 



