1044 CRUSTACEA. 



antenna of the second pair ; the form is nearly like that of Corycaeus, 

 although the species is very unlike those of that genus and family in 

 the mouth organs, and in the absence of the spectacle-eyes. It 

 appears, therefore, to be a connecting link between the other Cala- 

 nidae and the Corycaeidae. 



The subfamilies indicated, and the genera they contain are charac- 

 terized as follows : — 



1. Antennae 2dm non prehensiles. 



Subfam. 1. C ALANINE.— Abdomen longitudine mediocre. Oculi 



inferiores nulli. Antennae lmae longae, fere transversim porrectae; 



dextra maris articulatione non geniculars. Antennae 2dae apice 



setigerae. Maxillae latere interiore setigerae. 



G. 1. CalANUS, Leach* D.— Cephalothorax 4-5-articulatus, capite non discrete 



Frons ssepius rotundatus raro triangulatus, rostro infra tenuiter furcato. Oculi 



superiors minuti, conjuncti. Pedes antici maxillipedibus longiores, lateraliter 



porrecti; postici maris et feminoB sive regulariter biremes sive obsolescentes- 



Antennse lmae fere transversim porrectae, setis regularibus antice ornatas. An- 



tennae posticae birameae, ramo anteriore setis tribus confecto. 



a. 2. Rhincalanus, Dana. — Calano affinis. Frons elongate productus, rostro 



breviter et crasse furcato. 

 G. 3. Cetochiltjs, Goodsir, haud R. de Vauzeme.f— Calano affinis. Oculi supe- 

 riors remoti. Cephalothorax 5-7-articulatus, capite plus minusve discreto. 

 Antennae lmae et 2dae et pedes lmi ac in Calano. Pedes postici biremes prece- 

 dentibus similes. 

 G. 4. Euciueta, Philippi.%— Frons triangulatus, acutus, rostro brevi transversim 

 emarginato et non furcato. Oculi superiores minuti, conjuncti. Antenna? lmae 

 maris non geniculantes sed angulo leviter flexae, femince setis paucis longis et 

 aliis brevibus antice ornatae. Pedes antici elongati, maxillipedibus longiores, 

 duplo geniculati et sub corpore projecti, penecillum setarum nudarum reflexum 

 ferentes. Pedes postici maris ambo valde elongati, subulati. 

 G. 5. Undina, Dana.% — Calano affinis. Pedes antici fere ac in Calano; 



* Diet. Sci. Nat., Art. Entomostraca ; Dana, Am. J. Sci. [2], i. 1846, p. 228 ; Ceto- 

 chilus, Roussel de Vanzeme, Ann. Sci. Nat. [2], i. 333; Edwards, Crust., m. 421; 

 Temora, Baird, Brit. Entomostraca, 1850, 227. 



t Cetochilus australis of Roussel de Vauzeme (Ann. Sci. Nat. [2], i. 333), does not 

 differ essentially from Calanus. The 0. seplentrionalis of Goodsir (Jameson's Edinb. 

 New Phil. J., xxxv. 339, pi. 6) has the two superior eyes remote; and unless & female 

 of a Pontia, is a good genus, as all the true Calani have their eyes united on a single 

 minute spot of pigment. 



% Archiv fur Naturg., ix. 55 ; Euchirus, Dana, Amer. J. Sci. [2], i. 228. 



§ Proc. Amer. Acad. Sci., 1849, ii. 22. 



