156 THE VOYAGE OF H.M.S. CHALLENGER. 



a vertically descending phyllocyst, and two lateral, horizontally diverging canals, arising 

 from its apex {Amphiroa, Genus 14). 



The genus Abyla was founded by Quoy and Gaimard (1827, 20) for the Mediterranean 

 Abyla trigona, observed by them in the Strait of Gibraltar. I retain this species as 

 the characteristic type of the genus, sensu strictiori. The majority of later authors have 

 united with this typical species the very different Diphyidae which belong to the two 

 following genera, Bassia and Calpe. But the characteristic form of the nectophores, as 

 well as of the bracts, justifies the separation of these three genera of Abylidse. The large 

 distal or inferior nectophore is trigonal in Abyla, tetragonal in Bassia, and pentagonal 

 in Calpe. The polyhedral form of the hydropbyllia or bracts, too, exhibits characteristic 

 differences in the three genera, and their phyllocysts give off two horizontal lateral 

 canals in Abyla, one odd descending canal in Bassia, and four canals (one ascending, 

 one descending, and two lateral) in Calpe. The free Eudoxia of the first genus is 

 Amphiroa, of the second Sphenoides, and of the third Aglaisma. 



The new species of Abyla, here described as Abyla carina, differs as w T ell from the 

 well-known Mediterranean Abyla trigona, very accurately described by Gegenbaur (10, 

 Taf. i., ii.), as from the species inhabiting the Tropical Pacific which Huxley has described 

 under the same name (9, pi. iii., fig. 1) ; I call this latter Abyla alata. Different from 

 these is Abyla leuckarti of Huxley (9, pi. iii fig. 2), inhabiting the Southern Pacific. 

 I observed myself Abyla carina in 1867 in the Canary Island Lanzerote, and made there 

 the drawings reproduced on Pis. XXXV. and XXXVI. from the living specimen. The 

 same species occurred in a bottle in the Challenger collection, taken at Station 34S. 



Abyla carina, n. sp. (Pis. XXXV., XXXVL). 



Habitat. — Tropical and Subtropical Atlantic; Station 348 ; April 9. 1876. 

 Coast of Sierra Leone, lat. 3° 10' N., long. 14° 51' W. Surface. 

 Canary Islands, Lanzerote, February 1867 (Haeckel). 



Nectophores. — The two nectocalyces united are 35 to 40 mm. long ; they are very 

 different in form and size. The distal or posterior nectophore is 25 to 30 mm. long and 

 12 to 14 mm. broad, about twice as large as the proximal or anterior, the length of which 

 is 10 to 12 mm., the breadth 7 to 8 mm. The ground-form of the smaller is symme- 

 trical, of the larger asymmetrical. 



Apical Nectophore (fig. 3, apical view, from above ; fig. 4, basal view, from below ; 

 fig. 1 and fig. 5, lateral view, from the left side ; fig. 6, ventral view ; fig. 7, dorsal 

 view). — The first nectophore (the proximal, anterior, superior or apical nectocalyx) is a 

 hexagonal prism of a completely symmetrical bilateral ground-form. When the axis of 

 the nectosac stands vertically (as in figs. 5-7), then the .six lateral faces of the prism 



