230 



2 middle figures on PI. 96) are of very considerable size, projecting with their 

 outer, broadly rounded parts far into the marsupial cavities, and they are divided 

 by several irregular folds, so that they might have presented themselves for the 

 above mentioned authors as consisting each of several superposed plates. It is also 

 very probable that the maxillipeds, owing to their anomalous direction, have been 

 taken by them for another pair of incubatory plates. The 2 narrow, juxtaposed 

 folds, which extend behind the oral area, and which, by their posterior lappet, 

 serve for closing the posterior openings of the marsupial cavities, are described by 

 MM. Giard and Bonnier as the 5th pair of incubatory plates. It may be that 

 they answer to the plates so named in Dajus, but between these folds and the 

 above described 1st pair no other plates exist, for a slight lobe found at about 

 the middle of the length of the folds, and extended laterally within the mar- 

 supial cavities, has on dissection turned out to be only a lateral lappet issuing 

 from these folds (see the upper middle figure on PI. 96) — The appearance of 

 the immature females, of which I have examined specimens scarcely exceeding 

 1 mm. in length, is rather perplexing; for. contrary to what is the case in 

 Dajus and probably also in Notophryxus, the body exhibits in such specimens a 

 still more compact form than in fully grown females, and there is scarcely any 

 trace of a caudal division. In such young specimens, the appertinent male is 

 generally found to be still in the Cryptoniscian stage, and is invariably found 

 clinging to a peculiar, more or less contorted fleshy cord hanging down from 

 the posterior hollowed part of the body answering to the caudal part in fully 

 grown specimens. The same peculiar mode of affixion could also be proved to 

 occur in adult specimens, and this cord therefore appears to be an integrant 

 part of the genital apparatus of the female. MM. Giard and Bonnier have also 

 seen a cord of this description in the specimen examined by them; but they have inter- 

 preted its significance in a very different manner, believing it to belong to a parasitic 

 Copepod (Aspidoecia Normani) found by them attached to the same host (a spe- 

 cies of the genus Erythrops) below the body of the Aspidophryxus, and accord- 

 ing to their assumption, at the same time affixing itself by the aid of this cord 

 to the Epicarid. This supposition is evidently quite wrong. For the above-named 

 Copepod, which I have found not infrequently attached to different places of the body 

 in specimens of Erythrops," h&s in reality nothing to do with the Aspidophryxus, 

 and the apparent association of the 2 parasites, as observed by MM. Giard and 

 Bonnier, has certainly been due to a mere accident. 



Occurrence. — I have found this peculiar Epicarid not infrequently along 

 the whole south and west coasts of Norway, and northwards at least to the Lo- 

 foten Islands, especially infesting species of the Mysidian genus Erythrops. Its 



