CYCLOPOIDEA. ng± 



mentioned in the course of the preceding remarks. When the ante- 

 rior antennae have the double curvature of the Calani, falling back 

 behind the line of the beak, the inferior eyes are quite small, the 

 right male antennae, though geniculant, is but little different from the 

 others in form and number of joints, and in the posterior antennas the 

 accessory branch is but little the shorter, nearly equi-articulate, and 

 terminates in but three setae, with others along the side of the first 

 joint. From this condition, there is a gradual change to those in 

 which the antennae are oblique forward in position, and all the Pon- 

 tella characters are strongly brought out. 



This genus was instituted by Milne Edwards, in 1828, under the 

 name Fbntia, by whom three species have been described. As this 

 name was given by Fabricius long before to a genus of Lepidoptera, 

 another branch of the Articulata, it becomes necessary to change it, 

 and the word Pontella is therefore substituted. It was first proposed 

 by the author in 1846 (Amer. J. Sci. [2], i. 228). 



The genus Irenceus of H. Goodsir (Jameson's J., xxxv. 337) is iden- 

 tical with Pontia. This author has given detailed figures, and he repre- 

 sents the inferior eyes, observing that the organ is an organ of vision, 

 but not distinguishing, in his description, the superior from the inferior, 

 although the former are figured in the back view given in Plate 6, 

 figure 15. The species Irenceus splendidus is near P. detonsa and P. 

 margaritacea, though evidently different. Anomalocera of Baird (Brit. 

 Entomost., 229) is another name given to the Irenceus splendidus. 



This genus may be conveniently subdivided into three subfamilies : 



1. CalanopiA. — Including the Calanoid Pontellae, in which the 

 anterior antennae are situated as in Calanus, with the tips not ante- 

 rior to the line of the front; the anterior branch of the posterior 

 antennae have but three setae at apex ; the inferior eyes are quite 

 small. This subgenus may include some species referred to Hemi- 

 calanus. 



2. Pontellina. — Antennae of second pair having five setae at the 

 apex of anterior or smaller branch ; head either side unarmed. 



3. Pontella. — Antennae as in the last; head either side armed with 

 a reversed spine. The Pontia atlantica of Edwards is of this kind. 

 In this division, the second of the caudal setae is considerably longer 



