172 RUNCINA. 



Two very small species are known. They have the general aspect 

 of the Limapontias, but are readily distinguished on superficial ex- 

 amination, by the gill. 



K. CORONATA Quatrefages. PI. 68, figs. 31-41. 



Animal presenting a smooth body covered with vibratile cilia ; 

 mantle quite convex, visibly emarginate in front, extending a little 

 on the sides, incompletely covering the foot, rounded behind ; color 

 black, with minute brown dots, except in front and at the hind end, 

 where it is a more or less light fawn tint. Eyes sunken in the in- 

 tegument, rather large, each surrounded by a pale stripe ; behind 

 the eyes there is usually on each side a curved line of little white 

 spots, forming a sort of continuation of the light colored frontal re- 

 gion. 



Foot yellowish (pale ochre), sometimes marked with black spots 

 or flames ; its forward margin is perceptibly concave ; sides nearly 

 parallel, and towards the head it is slightly wider than the mantle ; 

 tail end extending beyond the mantle about a fourth the length of 

 body. 



The semipinnate gill is composed of 3 or 4 little plates, and pro- 

 jects slightly behind the dorsal integument on the right side (see 

 fig. 39). 



Formula of teeth 1.1.1 ; jaws triangular, wide, formed of little 

 chitinous pieces of more or less polyhedral form, well separated from 

 each other. Gizzard with 4 equal cartilagi no-calcareous pieces (pi. 

 68, figs. 33, 34). 



Length of animal, 4 to 5 mill. 



Brehat Island, off N. Brittany (Quatrefages) ; Torbay, England 

 (Alder & Hancock) ; Belmont Bay, near Weymouth (Thompson) ; 

 Clyde district (Norman) ; Gulf of Marseilles (Vayssiere). 



Pelta eoronata QUATREF., Ann. Sci. Nat. (3), i, 1844, p. 151. 

 VAYSSTERE, Ann. Sci. Nat. (6), xv, 1883, p. 6, pi. 1, f. 1-12 ; pi. 2, f. 

 13-21 ; Rech. Zool., Moll. Opistobr., Tectibr., p. 104, pi. 5, f. 126- 

 129. Pelta ornata QUATREF., t. c., p. 152. Pelta or Limapontia 

 ALDER & HANCOCK, Ann. Mag. Nat. Hist.,xviii, November, 1846, 

 p. 289, pi. 4, f. 1-7. Runcina hancoeki FORBES, Hist. Brit. Moll., iii, 

 p. 612, pi. CCC, f. 2. GRAY, Guide Syst. Dist. Moll. B. M., p. 205, f. 

 114 (dentition). H. & A. Ad., Gen. Rec. Moll.,ii, p. 43, pi. 61, f. 5. 

 JEFFREYS, Brit. Conch., v, p. 15, pi. 1, f. 3. Pelta nigra "Alder & 



