COKELLA LARVJEFORMIS. 31 



The heart lies along the upper margin of the 

 stomach ; and the rest of the anatomy, so far as it 

 could be determined, agrees with that of the type 

 species. 



C. larvdeformis is distinguished at once from the con- 

 generic species by the extraordinary elongation of the 

 atrial tube, and from (.'. parallelogramma likewise by 

 the comparative deficiency of colour, though much 

 reliance cannot be placed on this character, as the 

 specimens had been some time in spirit before they 

 came into our possession. The fewness of the rows of 

 branchial spirals, and the consequent comparative 

 largeness of the spirals themselves, also distinguish 

 this species. 



3. Corella ovata Hancock. 

 (Plate XXII, figs. 10 and 11 ; and fig. 35 in text.) 



Corella ovata HANCOCK in Ann. Nat. Hist, [(4) VI (1870), 

 p. 363] . 



ovate, rather wide above, not much compressed, 

 adhering by the side of the base, where there are a 

 few root-like processes. Apertures very little pro- 

 duced, almost sessile ; the branchial terminal, the atrial 

 placed at a little distance down the ventral margin. 

 Tt'st soft, smooth, delicate, and perfectly transparent, 

 revealing the colours and structure of the enclosed 

 mantle and viscera. Mantle thin, transparent, of a 

 buff flesh-colour, sometimes with a few obscure reddish 

 markings ; tubes very short, having the margins of 

 the apertures of a pale flesh-colour; muscles few and 

 delicate, of a reddish colour. Branclilal XKC with the 

 spirals numerous and composed of only two or three 

 coils ; papillary membranes well developed and having 

 the free margin not much thickened, and scarcely 



t/ 



bearing at all the semblance of tentacular points. 

 Tentiicnliii' filaments numerous, slender, not very long, 

 set rather close together in a single line on a narrow 



