Dr. A. Philippics Zoological Notices. 



97 



is the parallelism between Nauplius and Peltidium, and be- 

 tween Psamathe and Thyone. 



4. Thyone, mihi. (PL IV. fig. 2.) 



Corpus depressum scutiforme, ovatum, segmentis quinque con- 

 stans, segmento primo maximo. Cauda e lamellis duabus for- 

 mata. Oculi duo confluentes. Antenna quatuor ; anteriores 

 multiarticulata? ; inferiores triarticulatse, apice setis uncinatis, 

 basi seta pectinata munitse. Pes masticatorius apice lamellis 

 duabus terminatus. Pedes sex, natatorii, birami ; Pedes spurii 

 duo lamellares, spatium inter segmentum penultimum caudam- 

 que opplentes. 



Three species, the one, Th. viridis, nearly f long, common. 

 The cibarian apparatus exceedingly complicated. — Peltidium 

 differs by the foot-jaws, the tail, and by the first pair of feet 

 being differently constructed ; Sapphirina, Thompson, from 

 the body having nine segments. There are two pairs of pe- 

 culiar fringed lamellae near the cibarian organs (fig. 2 e. and g.), 

 perhaps analogous to those lamellae in Cypris, regarded by 

 Strauss as branchiae. 



5. Peneus siphonoceros, mihi. (PI. IV. fig. 3.) 



P. rostro brevissimo, supra 7-dentato inermi ; flagellis antennarum 

 superiorum sequalibus, omnibus quatuor canalem clausum for- 

 mantibus. 



I have gradually obtained in Naples about half a dozen in- 

 dividuals of this Peneus, so highly remarkable for the curious 

 formation of the flagella of the upper antennae. They are 

 flesh-coloured, the antennae, feet, and the hinder margins of 

 the abdominal segments darker. The length from the apex 

 of the beak to the extremity of the tail amounts to 2£ inches, 

 of which the abdomen is 1 inch 7 lines, and the beak scarcely 

 2± lines. The cephalothorax has no longitudinal furrows. 

 The abdomen is, as usual, very much compressed, the last 

 three joints keeled. The terminal segment has in the centre 

 a broad groove, and terminates with two points. The scale 

 (Schuppe) of the exterior antennae is quite twice as long as 

 the beak, of usual form, with a longitudinal groove ; the stalk 

 does not attain to half the length of the scale ; the flagellum 

 is once and a half as long as the body. The inner antennae 

 have a very thick stalk, as long as the scale of the outer an- 

 tennae, at the base excavated, as usual, for the large black eyes, 

 and with a curved anteriorly directed appendage (process). 

 They have two equally long, and as above stated, very pecu- 

 liarly formed flagella. They form, namely, with those of the 

 other side, an almost closed tube. For this purpose each single 



Ann. $ Mag. Nat. Hist. Oct. 1 840. h 



