64 NATURAL SCIENCE. July. 



known forms. Amphiirettis (PL xv., Fig. 2), for instance, differs from 

 all other cephalopods in that the mantle is firmly united to the siphon, 

 leaving two openings into the branchial cavity, one on either side, 

 immediately below the eyes. Japetella and Eledonella are two curious 

 gelatinous and semi-transparent forms, allied to Bolitcsna. Bathyteuthis 

 abyssicola (PI. xv., Fig. i) is one of the few cephalopods that really does 

 appear adapted for life at great depths : the small fins are in marked 

 contrast to those of pelagic species, while the small suckers and 

 delicate tentacles are equally little fitted for raptorial purposes ; on 

 the other hand, the large circumoral lip seems well-suited for 

 collecting nutritive matters from an oozy bottom. Promachoteuthis 

 has a small, round body with very large fins ; it comes from the 

 N. Pacific. Histiopsis, from the S. Atlantic, is closely related to 

 Histioteiithis, Chiroteuthis, and Calliteuthis. 



As regards their distribution, the Cephalopoda seem divisible into 

 Pelagic, Littoral, and Abyssal ; and all the species of any one genus, 

 usually belong to the same group. The occasional occurrence of a 

 species in two categories is probably due to the want of complete 

 information. Exact localities and conditions should be carefully 

 noted by future collectors. Meanwhile the " Challenger " collection 

 has confirmed the general statement, that, while pelagic animals 

 belong to but few types, each of which has a comparatively wide area 

 of distribution, littoral forms belong to many species, each of which 

 is confined within narrow limits. Deep-sea forms seem to be even 

 more widely distributed than pelagic ones, owing to the uniformity of 

 the conditions of life, especially temperature. The bathymetrical 

 results are unsatisfactory, as there was no means of determining at what 

 depth the animals found in the dredge or trawl were captured. 



W. E. HOYLE. 



Brachiopoda. 

 These animals live chiefly on coral-reefs and shallow rocky 

 bottoms ; the deep-sea species are small in size, and few both in 

 species and individuals ; moreover, they are not easily collected by 

 dredge or trawl. Our knowledge was, therefore, confirmed rather than 

 added to by the " Challenger." As in other groups, abyssal forms are 

 less localised than those that occur in seas of moderate depth. As 

 the three most interesting species brought home by the " Challenger," 

 Davidson who reported on them, quotes the following : — Terebratiilina 

 wyvillei, the largest species of the genus, dredged in 390 fathoms, off 

 Culebra Island, north-west of St. Thomas, in the West Indies. Tere- 

 bratula wyvillei (PL xv.. Fig. 3), which occurs over a wide area, at depths 

 from 1,035 to 2,900 fathoms, the greatest depth whence any living 

 brachiopod has been brought up ; a small species, with a shell, as in 

 all deep-sea brachiopods, smooth, glassy and semi-transparent. Discina 

 atlantica (PL xv., Fig. 4), another of the widely spread abyssal forms ; 

 the cirri proceeding from the edges of the mantle are of great com- 

 parative length, equalling the diameter of the shell. Only a small 



