THE CTENOPHORA 



21 



BOLINIDAE. Sagittal lobes of moderate size ; lobular canals simple ; 

 auricles short. Genera Bolina, Mertens ; Bolinopsis, L. Agassiz ; 

 Hapalia, Eschscholtz. FAMILY 3. DEIOPEIDAE. Body much compressed ; 

 lobes of moderate size, with lobular vessels more complicated than in 

 Bolinidae ; auricles short ; costae comprise very few, but very broad 

 combs. Genus Ddopea, Chun. FAMILY 4. EURHAMPHAEIDAE. Two 

 wing-like projections at the aboral pole in which the sub-tentacular costae 

 and meridional vessels are produced. Genus Eurhamphcea, Gegenbauer. 

 FAMILY 5. EUCHARIDAE. Lobes large, with complex lobular canals ; 

 body covered with elongate touch -papillae ; a main tentacular filament 

 present, as well as accessory filaments ; above the tentacle bases are a 

 pair of openings which lead into elongate blind sacs lying in the sagittal 

 plane and ending blindly in the neighbourhood of the infundibulum. 

 Genus Eucharis, Eschscholtz. FAMILY 6. MNEMIIDAE. Lobes large ; 

 the lobes and auricles spring from near the level of the infundibulum ; 

 auricles long and ribbon-like. Genera Mnemia, Eschscholtz ; Alcinoe, 



FIG. IX. 



Cestus veneris, Lesueur. m, mouth ; tsh, tentacle sheath ; c 1 , c*, cf, c8, the four rudimentary 

 sub-transverse costae ; c 2 , c 3 , c6, c 7 , the four large sub-sagittal costae ; sft, <*, st s , sfi, the four 

 sub-transverse, meridional canals which communicate at a; 1 , &, with the sub-sagittal canals. - 



Rang. ; Mnemiopsis, L. Agassiz. FAMILY 7. CALYMMIDAE. Body much 

 compressed ; lobes large, springing from the level of the infundibulum ; 

 costae nearly horizontal. Genus Calymma, Eschscholtz. FAMILY 8. 

 OCYROIDAE. Lobes of great length, with relatively small attachments to 

 the body ; costae horizontal. Genus Ocyroe, Rang. 



ORDER 3. Cestoidea, Lesson. 



Ctenophora so much compressed in the infundibular plane as to be 

 band-like. The sub-sagittal costae extend over the whole length of the 

 aboral surface ; the sub-transverse costae rudimentary. The sub-transverse 

 meridional canals run down the middle of the band-like body and unite 

 with the ends of the long sub-sagittal and stomodseal canals. Tentacle 

 sheath and tentacle basis present, but no main tentacle ; accessory tentacles 

 lie in four tentacular grooves which extend, on the oral surface, from the 

 mouth to the extremities of the band-like body. Gonads developed only 

 in the sub-sagittal canals. FAMILY CESTIDAE. Genera Cestus, Lesueur ; 

 Vexillum, Fol. 



