110 Miscellaneous. 



the pleon are more distinctly indicated and there is a well-dovbloped 

 pair of uropoda. As to the thoracic feet, they are of the normal 

 number of seven pairs, of which the first and smallest belong to a 

 narrow segment soldered to the head, which has escaped the notice 

 of G. 0. Sars. The prominent rostrum and the very long outer 

 antennae very closelj' resemble in form the same organs in the 

 Cryptoniscians, The passage from the DajidaB to the Cryptoniscians 

 may bo understood in the following manner : — In the male the 

 development has been arrested in the Cryptoniscians at the second 

 larval form, whilst in the Dajidse there has been a transformation 

 into a degraded male. In the female the anterior part of the incu- 

 batory chamber has been considerably contracted in the Crypto- 

 niscians, whilst a cavity was formed at the expense of the lateral 

 folds and of the posterior part of the body ; but this cavity cannot 

 be in any way confounded, as suggested by Fraisse, with the coelo- 

 raatic cavity. The profound modifications of the incubatory cavity 

 of the Dajiduj and Cryptoniscians will be examined in detail in a 

 memoir with plates. It may be observed, in conclusion, that tho 

 Erythrops microphthalma parasitized by A. Sdrsi was a female 

 destitute of ova, no doubt owing to parasitic castration. — Com2>tes 

 liemlas, May 13, 1889, p. 1020. 



A Parasitic Copepod. By Prof. Leidt. 



The author stated that last summer while at Beach Haven, 

 N. J., there was brought to him from the surf a living specimen of 

 tho singular transpai'out fish Leptocej)liaJus. In examining it he 

 observed attached to the tail-fin a minute Copepod Crustacean, 

 apparently of the genus Chalimus. The parasite was attached by a 

 long filiform rostrum, and resembled in this and other respects more 

 the Chalimus Scombri as represented by Baird in fig. 5, tab. xxxiii. 

 of the ' British Entomostraca,' than it does the original of this 

 species as represented by Burmeister in the Nova Acta Nat. Cur, of 

 Bonn, xvii. tab. xxiii. fig. 13. The species, which may be distin- 

 guished as Chalimus tenuis, is considerably less than half the 

 size of C. Scombri. The cephalothorax, nearly twice as long as 

 broad, is obcordate and proportionately much narrower than in 

 the latter species. The frontal segment is narrow and not promi- 

 nent laterally, and the biarticulato antennae are concealed beneath. 

 The abdomen, half the length of the cephalothorax, exhibits three 

 conspicuous divisions, and the short caudal appendages end in three 

 minute setae. Abdominal feet ending in biramose leaf-like seg- 

 ments fringed with short setae. Rostrum linear and almost as long 

 as the cephalothorax. Whole length 1-125 millim. ; length of 

 cephalothorax 0-5, breadth 0'275 ; length of rostrum 10-5 ; length 

 of abdomen 0-25.— Proc. Acad Nat. Sci. Philacl. April 16, 1889, 

 p. 95. 



