134 ON THE ANATOMY OF GONATUS FABRICII. [Mar. 5, 
this. The presence of a phragmocone, the absence of the nuchal 
muscle, the form of the median tooth of the radula, and the presence 
of nidamental glands are all points of considerable importance, 
whilst the size of the anterior salivary glands is merely a matter of 
degree, and the form of the anal appendages in the adult Gonatus is 
unknown. The fusion of the median retractors in one is, so to 
speak, balanced by their separation from the lateral retractors in the 
other. The other remaining point, namely the opening of the 
oviducts into special cavities in Onychoteuthis, does not seem suffi- 
cient in itself to contravene the resemblances on the other side. 
Summary. 
In addition to the general sketch of the anatomy of an interesting 
form, the preceding pages record the existence of several tracts of 
cartilage hitherto unobserved in the Cephalopoda, and give details 
regarding the structure of the pen-sac and the development of the 
pen, as well as new facts regarding the structure of the funnel-organ. 
The genus Gonatus is regarded as being somewhat more nearly related 
to Onychoteuthis than to Enoploteuthis, but as much further removed 
from both than they are from each other. The creation of the sub- 
family Gonatide is held to be justified. 
In conclusion, I have to fulfil the pleasant duty of thanking Mr. 
Robert Gray for some of my materials, Professor Huxley for his 
kindness in allowing me the use of his workroom, and Professor 
G. B. Howes for the friendly interest he has taken in my work and 
for numerous acts of kindness during its performance. 
EXPLANATION OF THE PLATHS. 
These letters have'the same signification throughout. 
a, Anus. op'. Their stem cut short. 
a.ao. Anterior aorta. osp. Foramen for the nerve to the 
br. Gills. osphradium. 
br.a, Branchial artery. o.v. Vein probably from the ovary. 
br.h. Branchial heart. p. Pen. 
br h'., bri’. Branchial hearts. pall.v. Pallial vein. 
b.g. Buccal ganglia. pan. “ Pancreas.” 
br.g. Branchial ganglia. p.ao. Posterior aorta. 
br.v. Branchial vein. p.gl. Pericardial gland. 
ce. Cxecum. p.m. Pallial nerve. 
ce. Cerebral ganglia. p.v. Pedo-visceral ganglia, 
co.', co". Inner and outer limbs of the p.v.c. Posterior vena cava. 
collaris muscle. yr. Rectum. 
cp. Plug of cartilage in the hinder re. Renal sacculi on the veins. 
extremity of the pen-sac. | vi. Ridge for pallio-siphonal ar- 
dg. Digestive gland. ticulation. 
c',e". Epithelium of the pen-sac. | s. Stomach. 
em. Epithelium of the mantle. | sep. Rudimentary septum of the 
g. Articular groove on the | phragmocone. 
siphon. s.g. Stellate ganglia. 
i.s. Ink-sae. s.nu. Supra-nuchal cartilage. 
num. Retractores infundibuli. su.g. Supra-gladial cartilages. 
nu. Nuchal cartilage. v. Ventricle. 
od, Oviduet. v.c. Vena cava. 
@. Cisophagus. |v.f”., v.f". Venous foramina in the 
op. Optic ganglia. cephalic cartilage. 
