SYSTEMATIC AND BIOLOGICAL ACCOUNT 147 



and Bigelow (191 1 b) for A. trigona. Fortunately Quoy & Gaimard's types have been preserved at 

 Paris (Text-fig. 75 D, E) and thanks to the good offices of the authorities there, 1 have been re-examined 

 by both Dr Sears of Woods Hole and myself. At the moment, I have found no reliable criteria for 

 separating the anterior nectophores of species of the trigona-group, though they are associated with 

 several readily distinguishable types of posterior nectophores. As stated before, the distal (oral) end 

 of the left (larger) hydroecial fold of the posterior nectophore of species in this trigona-carina group of 

 species carries two marginal rows of spines. It appears that there is a tendency for the outer margin 

 to overgrow the inner margin, so that a protuberance is formed as figured by Moser (1925) for 

 A. bicarinata. The relative size and shape of this protuberance, together with the number of spines on 

 the margins and the number of large spines or teeth on the infolded flap, ' Leiste ' or ' comb ' of the right 

 hydroecial wing, may well be found to have specific significance. 



As a result of long and tedious work it appears that, in the Indian Ocean, there are six abyline 

 species, Ceratocymba dentata, C. leuckartii, Abyla haeckeli, A. trigona and the two new ones A. schmidti 

 and A. ingeborgae. 



Dr Mary Sears kindly kept me informed in letters of her intention to publish a revision of the 

 Abylinae and gave me some of her views on the subject. I sent Dr Sears copies of some of my figures, 

 and also one or two specimens. Dr Sears also sent me copies of her figures and finally a copy of her 

 text. Her paper (1953) reached me on 15 June when I was awaiting galley-proofs. In it, one of my 

 supposed new species will be found described and named after Dr Johannes Schmidt. 



Abyla schmidti Sears 1953. (Plate VIII). 



Posterior nectophores resembling one taken by ' Gauss ' to the south-east of Madagascar and figured 

 by Moser (1925, pi. xix, figs. 7-9) were taken at several East African ' Discovery II ' Stations between 

 lats. 7 S. and n°32'N. With two detached anterior nectophores Moser named her posterior 

 nectophore A. bicarinata. In one haul only ('Discovery II' Station 1581, 600-0 m.) an anterior 

 nectophore was found still attached to a posterior one of this kind, and this complete specimen 

 (Text-fig. 77 A) I had designated the holotype of a new species, now schmidti Sears. Dr Sears has 

 shown that Moser's figured anterior and posterior nectophores belong to separate species, the pos- 

 terior one is A. schmidti. I now choose the larger of Moser's anterior nectophores as the holotype of 

 A. bicarinata Moser. 



Moser, did not, I think, figure the velar end of the posterior nectophore very critically, unless the 

 specimen was a dead, disintegrating one such as one finds sometimes in the plankton; but her fig. 7 

 shows a characteristic, distal, chin-shaped protuberance of the left hydroecial wing. It extends 

 considerably more distad than in any of the ' Discovery ' specimens, even than in those which have 

 begun to disintegrate and were presumably mature. 



I have not so far found posterior nectophores like those described and figured above (Text-figs. 73, 

 76, 77) as A. schmidti, except in material from the Indian Ocean, and certainly not from the region 

 of the Canaries, where the types of both A. trigona and A. carina were found. Specimens of those 

 two species (probably one and the same) grow to a size much greater than any of the Indian Ocean 

 specimens that I have seen. But specimens of an intermediate type (Text-fig. 74) were found in the 

 Tropical Atlantic. Much Abyla material is now available for some student of the future. 



Eudoxids. No entirely satisfactory figures have been published of the eudoxid (Amphiroa Blainville) 

 of any species of the trigona-group of Abyla to which A. schmidti belongs. The earliest, Blainville's 

 (1834) co Py °f Lesueur's unpublished drawing of a Bahaman specimen named alata by Blainville 

 (1830), omits details of the hydroecial wings and folds or Leisten. Huxley's (1859) figures are more 



1 I have to thank Dr A. Franc for much help in this matter. 



19-2 



