OCT 11 18P7 



THE ADHESIVE TENTACLES OF NAUTILUS. 209 



EXPLANATION OF PLATE 11, 



Illustrating Dr. Willey's note on '' Adhesive Tentacles, 

 Spermatophore, and Pericardium of Nautilus." 



EiG. 1. — Nautilus macromphalus attached to the side of a vessel by 

 its cephalic (pedal) tentacles ; not by their extremities, but by their recurved 

 sides. Lifu, September 9th, 1896. 



Fig. 2. — Nautilus pompilius dissected to show the pericardium by 

 throwing back the ventral integument. June, 1896. p. v. I. Pallio-visceral 

 ligament (Huxley), c. I. Cardiac ligament, o. p. I. Outer or posterior peri- 

 cardial ligament, i.p.l. Inner or anterior pericardial ligament, o.p.g. Peri- 

 cardial follicles of outer or posterior renal organ, o. r. Outer or posterior 

 renal sac. i. p. g. Pericardial follicles of the inner or anterior renal organ. 

 i. r. Inner or anterior renal sac. r. m. Reflected flaps of median ventral 

 integument, m. Mantle. 



A, B, c. " The three apertures of communication between the two divisions 

 of the fifth chamber " of Huxley — that is to say, between the pericardial 

 coelom and the perivisceral coelom (the four other chambers treated of by 

 Huxley being the two pairs of renal sacs). 



H. Systemic heart (ventricle). 



Fig. 3.— Male Nautilus pompilius, to show spermatophore sac in 

 position. Blanche Bay, New Britain, May 24th, 1895. 



CORRIGENDA. 



(To be bound opposite to Plate 11.) 



Tlie following corrections sliould be noted in the lettering of Dg. 2 of tlie 

 plate (Pi. 11) accompanying Dr. Willey's note on "The Adhesive Tentacles 

 of Nautilus, &c. &c.," in Part 2 of Vol. 40 of this Journal : 



1. For "ovarian artery '' read anterior pallial artery. 



2. For "siphonic artery" read posterior pallial artery. 



3. The bristle is passed through the left external viscero-pericardial orifice. 



