SYSTEMATIC AND BIOLOGICAL ACCOUNT 79 



at once noticed the homologies in the bracteal canals of Nectopyramis thetis and species of Rosacea. 

 I know of no descriptions or figures showing exactly how the Prayid bract is attached by its muscular 

 lamellae, and my own efforts to elucidate this point in the living specimens of Rosacea cymbiformis 

 failed though I have lately found a canal linking the stem-cavity with the bracteal canal system in 

 young, preserved eudoxids of Rosacea cymbiformis. 



There is a superficial resemblance between the bracteal canals in Prayids and in Abylids, a quadri- 

 partite arrangement in each case. But whereas the paired longitudinal canals of the Prayid bract run 

 athwart the stem, in the Abylid bract they clasp it. The resemblance can hardly be fortuitous. 



It may be well to record a note on the homologies of the early growth stages of bracts of the eudoxid 

 of Nectopyramis thetis, originally figured by Bigelow, and on figures of mature bracts by Leloup and 

 by Bigelow (Text-fig. 35). Only the canals C. lot. (Text-fig. 36B, C) are wanting in the Abylids. 



Bigelow (191 1 a) in his first figure (3) showed three crests or ridges R 1, R2, and R3. I have studied 

 similar bracts still attached to the stem lying in the hydroecial canal. R3, which runs down to the 

 tip of canal C4 (labelled C3 in Bigelow's fig. 4) is what Bigelow later called the anterior side. The other 

 two ridges are the margins of the dorsal facet (Bigelow's posterior side). They start from the promi- 

 nence over the tip of the ascending bracteal canal (C. lat.), run over the tips of the two horizontal canals 

 and down to Bigelow's postero-dorsal margin of the hydroecium. 



In well-preserved bracts these ridges are preserved. In less well-preserved material they become 

 rounded and obscure. In Bigelow's fig. 4 of his original paper (1911a) only one transverse canal can 

 be seen, labelled C7. The other canal, shown nearby under a prominence, is the ascending canal C3. 

 The descending canal C4 is labelled C3. 



N. thetis was not amongst the specimens sent to me taken by Beebe in his many deep hauls off 

 Bermuda in the years 1929, 1930, 1931. There are, so far, thirteen records in 'Discovery' hauls in the 

 Tropical and South Atlantic and in the South Indian Ocean. Altogether, four polygastric and seven- 

 teen eudoxid specimens have been taken, in seven cases in closing hauls, as well as an eudoxid taken 

 in 1951 and another in 1952 by 'Scotia' to the north-west of Ireland. 



Hitherto only three polygastric specimens had been recorded (see Bigelow & Sears, 1937) and eight 

 eudoxids, often in an unsatisfactory condition. They were taken in the Bay of Biscay, Bay of Cadiz 

 and between the Azores and Canaries ; always in open nets towed at considerable depths. 



Now from Indian Ocean Stations I have to record the capture by R.R.S. 'Discovery II' of five 

 polygastric specimens and eleven eudoxids. 



P. = polygastric. 



E. = eudoxid stage. 



x = closing net. 



