50 NATURAL TSCLE NG: JAN., 
Dall suggested in 1891.3 The following subdivisions of the great 
family Terebratulidze, which we should place in the following order, 
were proposed by Cehlert in 1887 :—Terebratuline, Centronelline, 
Magasine, Muhlfeldtine, Terebratelline and Magellane. The present 
investigations confirm this grouping. The genus Terebratula of the 
first-named and Centronella of the second are the more ancient terebra- 
tuloid types, and were represented in the Silurian seas. 
Messrs. Gehlert and Fischer received the materials for their re- 
search on the Brachiopoda of the Magellanian province too late to 
permit of the publication of their conclusions in the series of memoirs 
relating to the French scientific mission to Cape Horn, during which 
the ‘“‘Romanche”’ dredged often in many localities. Few species 
were obtained, but the number of individual specimens of different 
ages was large, and afforded them much desired opportunities for 
studying the metamorphoses of the loop and gradational development 
of Tevebratella dorsata and Magellania venosa. The knowledge thus 
gained, it is distinctly stated, should tend to the suppression of many 
so-termed species and some assumed generic forms, for ‘‘ the more the 
Brachiopoda are studied the more the number of legitimate species will 
decrease.” It is demonstrated that the same individual in the course 
of its post-embryonic development assumes successive stages which 
are identical with both specific and generic forms of various authors. 
Thus it is fully proven that the genera Waltonia (Davidson) and Magasella 
(Dall) arereally immature 7 evebratella in which the brachial apparatus has 
not completed its development. Gould’s Terebratella pulvinata is shown 
to be merely a stage of Magellania venosa, which is not permanently 
arrested in the terebratelliform grade like its congener Terebratella 
dorsata, but assumes ultimately the characteristics of Magellania venosa. 
This is a fine but variable species with a large number of synonyms 
which have been well worked out by Davidson. Messrs. Géhlert and 
Fischer state that it attains maturity early, and its complete evolution 
was observed by them in specimens 27 mm. long in which all traces 
of the jugal band had disappeared. The largest known specimen 
measures 3 inches 2 lines in length and 2 inches 8 lines in breadth. 
Magasella gouldi becomes Teyvebratella gouldi, but it is not yet known 
whether it stops there or eventually assumes the generic characters of 
some species of Magellania. It is certain, however, that Magasella 
evanst is but a phase of Terebratella cruenta. Magasella patagonica, M. 
Aexuosa, and M. suffusa name different ages of Terebratella dorsata, M. 
levis another stage of Magellania venosa, while M. adamsi tirst becomes 
terebratelliform and eventually passes into Magellania grayii (4). 
In the course of these investigations the important physiological 
facts of accelerated growth were recognised. Owing to favourable 
conditions of the environment, some adolescent individuals were 
3 The name Terebratuline was accidentally printed for Terebratelling on line 19, p. 
603, of my paper ‘‘ Recent Researches on the Brachiopoda,” in NATURAL SCIENCE, 
October, 1892. The error escaped notice. 
