1896. | NEW YORK ACADEMY OF SCIENCES. 245 
Body rings 4. Tail equal to the head, with a strong T-ringed 
axis, and smooth punctate sides, margin distinct.” 
G. Linnarsson’s description of AL eucentrus is the following : 
Equalling the preceding (7. e. M. Scanicus), but the head more 
convex; glabella without any occipital furrow behind, prolonged 
into a spine longer than the head. 
Linnarsson’s species is evidently very near to Salter’s, if not 
identical with it; the Swedish naturalist points to the larger 
number of joints in the pygidium of his species as distinctive of 
it, also to the absence of the crenulate border of the head shield. 
But I think Salter’s “7 rings” to the axis of the pygidium re- 
fers only to the more distinct joints in the main part of the axis ; 
and as for the ornamentation of the front rim of the head shield 
(unless the Welsh are different from the American species) that 
exist only on the interior of the rim, and would not appear on 
the outer surface of the test. 
The young tests of MW. punctatus show almost the same pro- 
gressive changes from the embryonic form as MM. pulchellus ; 
among these are the acquisition and subsequent disappearance 
of a rib on the front of the side lobes of the pygidium; occa- 
sionally two ribs are thus developed, but in the adult these larval 
ribs disappear. 
Sculpture.—The surface both of the head shield and pygidium 
are ornamented with close punctures, differing thus fiom MM. pul- 
chellus in which the surface of the pygidium is covered with 
small tubercles, while the head shield only is punctate.* 
Size.—Length of largest head, exclusive of spine,5 mm., length 
of spine 5 mm. (smaller heads show a spine longer in propor- 
tion); width of head shield, 6 mm. The pygidium is of the same 
size (excluding the occipital spine). 
Horizontal and Locality.—In the fine gray shales of the P. 
Davidis Subzone at Manuel Brook, Conception Bay, Newfound- 
land. Common. 
EXPLANATION OF PLATES. 
PLATE XIV., CIRRIPEDIA, ETC. 
Notation of the horizons, used below : 
Div. 1c!. Horizon of Paradoxides lamellatus. 
Div. 1c?. Horizon of Paradoxides Eteminicus. 
Diy. 1d'. Horison of Paradoxides Abenacus. 
Div. 1d?. Horizon of Paradoxides Davidis. 
Fia. 1. Stenotheca concentrica. Flattened and cracked along the back. 
Mag. ?. From Div. 1d!, St. Martins, N. B. See p. 201. 
* Pygidia occur, however, at Chapel Arm, Trinity Bay, Newfoundland, in the P. 
Dayidis Subzone, haying the surface tuberculate ; the species hasnot been determined. 
