S. I. Smith — Crustaceans of the Atlantic Coast. 01 



swiniiniiig stages, show close affinities with the iiauplius-stage of the 

 Copepoda, and at once convinced me of the correctness of the conclu- 

 sions of Clans based on his earlier observations on Eup}tai(sa. In the 

 earliest stage observed the animal is about 2|""" long. The com- 

 ])ound eyes are already present but are crowded closely together, ses- 

 sile, and wholly covered above by the front of the carapax. The 

 antennulie and antennae are highly developed biramus natatory appen- 

 dages, the antennae being still in the simplest nauplial form. The 

 mandibles, both pairs of maxillje, 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, i*ecently seemed to question the 

 correctness of Claus' conclusions in regard to the larvjB referred by 

 him to Exiphausa. 



I am able to throw no light w^hatever 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 monogrpliisk Fremstilling af Kraebsdyrslaegten Sergestes, Kongl. 

 Danske Vidensk. Selsk. Ski'., 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 Gronland, p. 30, 185*7 (extr. from Rink's Gron- 

 land). — Liitken, list of the Crustacea of Greenland, in Manual of Instructions for 

 the [British] Arctic Expedition, 1875, p. 148. 



Mentioned, on my authority, as T. negledaf, by Verrill, American Journal of Sci- 



* On the Nauplius Stage of Prawns, Annals and Magazine of Natural History, V, 

 ii, p. 79, 1878. 



