S. I. Smith — Crustaceans of the Atlantic Coast. 
91 
swimming stages, show close affinities with the nauplius-stage of the 
Copepoda, and at once convinced me of the correctness of the conclu- 
sions of Claus based on his earlier observations on Euphausa. In the 
earliest stage observed the animal is about 24- mm long. The com- 
pound eyes are already present but are crowded closely together, ses- 
sile, and wholly covered above by the front of the carapax. The 
antennulae and antennae are highly developed biramus natatory appen- 
dages, the antennae being still in the simplest nauplial form. The 
mandibles, both pairs of maxillae, and the first pair of maxillipeds are 
developed and show considerable resemblance to the adult form of 
these appendages. The remaining cephalothoracic appendages have 
not yet appeared and the corresponding segments of the cephalotho- 
rax are only indicated by a closely crowded series of rather obscure 
annulations. The abdomen, however, is already well-developed and 
composed of the normal number of segments, and the uropods have 
even made their appearance in a rudimentary form. This earliest 
larval stage was unmistakably connected with the adult Thysan- 
opoda by several intermediate stages found in company with the 
younger larvae. 
I should not have alluded to these very imperfect observations in 
connection with this subject, had not C. Spence Bate,* having appar- 
ently overlooked Sars’ observations, recently seemed to question the 
correctness of Claus’ conclusions in regard to the larvae referred by 
him to Euphausa. 
I am able to throw no light whatever upon the question as to the 
manner in which the eggs are discharged or hatched, though it seems 
most probable to me that the eggs are discharged while the embryo 
is still immature and are hatched while floating in the water. 
Thysanopoda inermis Kroyer. 
In Gaimard, Voyages en Scandinavie, en Laponie, au Spitzberg, pi. 7, fig. 2, 1849; 
Forsog til en monogrphisk Fremstilling af Knebsdyrslaegten Sergestes, Kongl. 
Danske Vidensk. Selsk. Skr., V, naturvidensk. mathem. Afh., iv, pi. 5, fig. 24, 
1856 (showing the peculiar sense organs). — Goes, ffifversight af Kongl. Vetens- 
kaps-Akad. Forhandlingar, Stockholm, 1863, p. 174 (14). — Reinhardt, Naturhis- 
toriske Bidrag til en Beskrivelse af Grbnland, p. 30, 1857 (extr. from Rink’s Grou- 
land). — Ltitken, list of the Crustacea of Greenland, in Manual of Instructions for 
the [British] Arctic Kxpedition, 1875, p. 148. 
Mentioned, on my authority, as T. negledat , by Verrill, American Journal of Sci- 
* On the Nauplius Stage of Prawns, Annals and Magazine of Natural History, V, 
ii, p. 79, 1878. 
