HOYLE: REPORTS ON THE CEPHALOrODA. 11 



be added the amount lodged in the lateral extensions of the mantle-cavity, 

 which reach completely round the body, meeting behind the visceral sac. In 

 those cephalopods in which the body is elongated antero-posteriorly there is 

 a large space in the mantle-cavity, behind the gills ; this may be fairly assumed 

 to serve the purpose of holding a reserve supply of water which will gradually 

 pass over the gills during expiration. In the present instance, owing to the 

 short, rotund character of the body, space is found for a similar reserve store of 

 water at the outer side of the gills. To the outer side of each gill this cavity 

 is traversed by a ligament wliich contains the pallial nerve, the ganglion stel- 

 latum, and the nerves proceeding from it. The specimen being small as well 

 as unique 1 was able to make but few observations on its internal anatomy. 

 The heart is fusiform, and lies transversely : the ink-sack is small and pyri- 

 form ; the renal appendages of the veins large and floccular in appearance, and 

 there is the usual curved caecum at the bottom of the visceral sac. I was not 

 able to ascertain the sex of the specimen. 



I have recently had an opportunity of comparing this specimen with one 

 belonging to the same genus in the Hamburg Museum, which closely resembles 

 Steenstrup's type. I find the two specimens agree in the following points : 



1. The form and arrangement of the suckers and the umbrella. 



2. The mantle-cavity extending all round the visceral sac. 



3. The presence of a ligament containing the stellate ganglion. 



4. Tlie wide aperture of the mantle-cavity. 



5. The long siphon with intermediate ligaments. 



The principtil differences are that in the present individual the arm.s are pro- 

 portionally larger and the umbrella does not extend so neiir to their ends, and 

 that the siphon is proportionally somewhat longer. 



Notwithstanding the difference in the radula, above alluded to, I am inclined 

 to believe the specimen under discussion to be a young example of Bolitaetux 

 microcotyla. 



Family ARGONAUTID^. 



Argonautidae Cantrame, '40, p. 20.' 



ARGONAUTA. 

 Argonauta Linne, :58, p. 708. 



6. Argonauta hians. 



Argonauta hians Solander, !86, p. 44. 



Argonauta gowJola Adams & Rteve, '48, p. 3, Plate 2, Figs. 2 i, 2 k, 2 1. 



Habitat. — Station 3425, off Las Tres Marias ; April 18, 1891 ; lat. 21° 19' X., 

 long. 10()° 24' \V., G80 fathoms; green mud and sand; temperature, surface 

 76°, bottom 39° ; one specimen, No. 8138. [H. (50.] 



