I30 REPORT OF NEW JERSEY STATE MUSEUM. 

 Family CALANID^. 



Cephalosome well defined or coalescent with first pedigerous 

 segment, front carrying below two soft posteriorly curving tenta- 

 cular filaments. Last pedigerous segment not confluent with 

 preceding one, and its lateral corners but slightly produced. 

 Urosome not very slender, in female of four and in male of five 

 segments, caudal rami comparatively short, with normal number 

 of set3S. Eye simple, very small, sub-ventral. Anterior antennas 

 in female long, slender, of twenty-five articulations, supplied 

 anteriorly with comparatively short and uniform bristles. Penul- 

 timate and antepenultimate articulations each have behind an 

 unusually strong and densely plumose seta extending straight 

 backwards. Anterior antennae in male thickened at base, with 

 some of proximal articulations fused together and supplied below 

 with restricted number of comparatively short sensory append- 

 ages. Posterior antennae with rami of about equal length. Oral 

 parts normal, but slightly transformed in male. Legs with both 

 rami triarticulate, terminal joint of outer ramus with only two 

 spines outside. Fifth pair of legs in female of similar structure 

 to preceding pairs, in male more or less transformed, left leg the 

 stronger. 



Two genera in northern seas. 



Genus CALANUS Leach. 



Calanus Leach, Diet. Sci. Nat., XIV, 1819, p. 539. Type Cyclops finmarchicus 



Miiller, monotypic. 

 Cetochilus Vanzeme, Ann. Sci. Nat., (2) I, 1834, p. 2,2i?)- Type Cetochilus 



australis Vanzeme, monotypic. 



Body comparatively slender, with anterior division, oblong 

 subcylindric in form, and more than twice as long as posterior. 

 Cephalosome generally well defined from first pedigerous seg- 

 ment, slightly carinated dorsally in male, frontal part obtuse, 

 and more or less projects between insertions of anterior antennae. 

 Lateral corners of last pedigerous segment generally rounded 

 off. Urosome symmetrical with genital segment in female com- 

 paratively short and but slightly protuberant below. Caudal 



