26 JOURNAL OF MARINE ZOOLOGY AND MICROSCOPY. 



an examination of the entire animal of Spirilla australis from New 

 Zealand, taken by Mr. Earl, and now in the National Museum. In the 

 Bufflon de Sonnini, Peron's specimen Avas exactly described by 

 Roissy, but afterwards this priceless treasure was lost. On the 

 voyage of the Samarang, a mutilated specimen was obtained by 

 Sir E. Belcher in the Indian Archepelago, and was handed to 

 Sir R. Owen for dissection, forming the subject for a short memoir by 

 the latter®, wherein he establishes a third species, S. reticulata, from 

 the peculiarity of its skin ; this latter came from Tamor. Lastly, a 

 good specimen was dissected by Professor Huxley, but we have yet 

 to await the published description. 



The body of the animal is cylindrical, compressed laterally, with 

 the head about twice as long as broad : at the hinder end, enclosed in 

 the mantle, is the small coiled shell which in all known specimens is 

 visible on the dorsal and ventral portions, where it is covered only by 

 a thin membrane. The head is not constricted externally from the 

 body, and bears two eyes, eight short tentacles, and two long ones, 

 probably expanded into two lobes like in Sepia. The infundibulum 

 or funnel is entire, not, as in the Nautilus, divided down the middle, 

 and bears a terminal valve ; just behind it, lodged in the cartilaginous 

 cranium, are the two capsules containing otoliths, said to function as 

 hearing organs. The branchial chamber has no septum as in the 

 Octopoda, and the gills, two in number, are elongated, narrow- 

 triangular in form, each consisting of about 24 folds, and bearing at 

 the base a branchial heart with an appendage attached. The liver 

 consists of two lobes ; through the interspace thus formed, the 

 oesophagus, aorta, and visceral nerve pass ; the relation of the inkbag 

 and generative organs, in like manner, resemble those of Sepia. 

 Whatever the soft parts may teach us, it is to the shell that we must 

 look if we wish to understand the place of Spirula among other 

 Cephalopoda, the vast majority of which are only known to us by 

 their hard parts. 



Of the shells there are many apparent species, but on examining 

 a large number, these sink into merely varietal significance, and the 

 authorities of the British Museum acknowledge only one species, 

 S. Peronii, Lam. The differences as far as I can make them out 

 are : 1, the thickness of the shell ; 2, the figure of the transverse 

 section, some being circular, others strongly depressed and oval ; 

 3, the amount of evolution, in some the whorls touch, in others they 

 are widely separated ; 4, the presence or absence of a keel on the 

 inner side of the first whorl ; and 5, the size and shape of the first 

 chamber being often spherical, egg-shaped, or drupe-shaped. 



(8). Zoology of the Voyage of E,M.S. Samarang, Mollusca, p. 6, 1850. 



