294 GASTEROPODES. 



PLATE XLII. 



FIG. 1. Doris verrucosa : back. 



2. Belly. 



3. Branchial teeth. 



PLATE XLIIL 



FIG. 1. Spawn of the Doris verrucosa, or Doris argo, in a spiral form. 



2. Another deposit, in great quantity. 



3. A deposit still more ample. 



4. Spawn refining, in its progress to maturity. 



5. The ova, or capsules, in a portion of spawn, enlarged. 



6. Capsules containing more than one Nautiline. 



7. Portions of Fig. 2, shewing the Nautilines within capsules, enlarged 



near maturity. 



2. DORIS ARGO. Plate XLII. Figs. 4, 5, 6, 7. 



Formerly, when a more limited view was taken of the lower animals, 

 authors were disposed to assume this species as the type of the genus 

 Doris ; and they may have been induced to do so, either from the facility 

 of obtaining it, or from its dimensions, that of the Scotish seas being of 

 size inferior only to the Doris or Tritonia Hombcrgii. Plate XXXVIII. 

 figs. 1, 2. 



Length towards five inches ; breadth towards two inches. Figure of 

 the animal in quiescence oval. A verrucose or warty cloak forms the up- 

 per surface, and covers the whole body, which is-quite smooth. The head 

 and sole are distinctly separated ; the former small, not exceeding nine 

 lines in breadth, fleshy, with the mouth in the centre of the face ; and 

 each corner a very short obtuse cone. Two horns rise from the anterior 

 of the upper surface, conical and obliquely indented like a cross cut file, 

 issuing from low sockets, with a tuberculated margin. The branchial 

 apparatus is situate on the back near the posterior extremity. It gene- 

 rally consists of seven or eight foliaceous organs, finely fringed, resem- 

 bling feathers, originating from a short pillar, with the vent in the centre. 

 A prominent smooth rib, with five or six subordinate ribs, also smooth, 



