170 RUNCINID^E. 



Conch., iv, p. 75, pi. 8, f. 3 ; pi. 12, f. 2Q.L.pictus MARTENS & 

 LANGKAVEL, Donum Bism., p. 54, pi. 3, f. 5. 



When disturbed they cast off all their lobes, which retain their 

 vitality for several hours. (Pse.). 



Pease's dealings with this species have been far from straightfor- 

 ward. He first described it in 1861 without a specific name ; then 

 in 1863 he bestowed the name L viridis ; and finally, in 1868, he 

 repeated the substance of his first description and renamed the 

 animal L. picta. 



III. TECTIBRANCHIATA NOTASPIDEA. 



Tectibranchs in which the dorsal surface is protected by a large 

 shield (" notceum ") or mantle, with or without an external or buried 

 shell ; no head-shield nor pleuropodial lobes. 



Synopsis of Families. 



I. Radula with the formula 1.1.1 ; rhinophores wanting ; stomach 



armed with four large, denticulate plates ; shell very small or 



wanting ; small animals, JRuncinidce. 



II. Radula with very many longitudinal and transverse rows of 



teeth ; rhinophores developed, of the usual slit form. 



a. Shell either wanting or thin, auricular or haliotiform, 



with terminal spiral nucleus, and in part or wholly 



concealed, Pleurobranchidce. 



aa. Shell well-developed, external, patella-like, with the apex 



near the middle, Umbraculidce. 



Family RUNCIN1DJS Gray. 



Euncinadce GRAY, Guide to Syst. Dist. Moll. B. M., p. 204. Pel- 

 tidae VAYSSIERE, Recherches Zool. et Anat. Moll. Opistobr., p. 104. 



Shell small and posterior, or obsolete. 



Body limaciform. convex above, the mantle or dorsal shield cov- 

 ering the upper surface except the end of foot ; separated from foot 

 by a deep groove. Eyes sessile, anterior ; tentacles or rhinophores 

 wanting or subobsolete. Foot about as wide as body. Gills pos- 

 terior on the right side, pinnate with few laminse. Anus behind the 

 gill. Orifice of female reproductive organs in front of gill ; penis 



