No, 4.— Studies from the Newport Marine Zodlogical Laboratory. 
Communicated by ALEXANDER AGASSIZ. 
AVIE 
Preliminary Observations on the Development of Ophiopholis and Echin- 
arachnius. By J. Water FEwKEs. 
Tue following paper considers the development of our common Ophi- 
uran, Ophiopholis aculeata, Gray, and of the Clypeastroid, Echinarachnius 
parma, Gray. All the observations were made last summer, those on 
the former at Eastport, Maine, those on the latter at the Newport Labora- 
tory, Newport, R. I. 
OPHIOPHOLIS ACULHATA, Gray. 
Few observations have been published on the metamorphosis of our 
common Ophiopholis. The eggs of O. aculeata (bellis, Lym.), according 
to A. Agassiz,* are laid in bunches, and the young develop without pass- 
ing through a free plutean stage. He gives two figures of the young 
Ophiopholis made by L. Agassiz in 1848. 
In “‘Sea-Side Studies” the young Ophiopholis is said to be carried in 
a pouch, in which the first stages of development occur.f A figure, one 
of the two mentioned above, is doubtfully identified as a drawing of the 
young Ophiopholis in the second number of the Embryological Mono- 
graphs.{ Packard § states that in Ophiopholis the development is direct 
and without metamorphosis. 
* Embryology of the Echinoderms. Mem. Amer. Acad., Vol. IX., pp. 18 and 22. 
The pluteus referred to Amphiura squamata in the “ Embryology of the Echino- 
derms,” and doubtfully to Amphiura in “‘Embryological Monographs,” may be a 
pluteus of Ophiopholis. Amphiura squamata, Sars, is viviparous, and has no free 
pluteus. 
Tt Sea-Side Studies in Natural History. Marine Animals of Massachusetts Bay, 
p. 137. 
$ Mem. Mus. Comp. Zobl., Vol. IX. No. 2, Pl. III. Fig. 20. 
§ Zodlogy for Students and General Readers, p. 110. As nothing is said of 
direct observation, it is probable that this statement is a compilation probably 
from those already quoted. 
VOL. XII. — NO. 4. 
