I 26 



while the specimens from the Azores are said to beloiig^ to two species, R. griina/dii Jullien, 

 ;iii(l R. niaimbialis Jullien. 



A', iioriiiaiii appears to be characterised by the great length of the peristomes, or free 

 cylindrical parts of the tube. R. compacta is said to have very short, crowded peristomes. 

 R. (^riutaldii has a short peristome, continuing a creeping portion of equal length, which is 

 characterised 1)\ the presence of '"deu.x tubes tres fins, convergeant par leur e.xtremite anterieure", 

 and running longitudinally along its free wall; while the orifice is somewhat expanded. In 

 A", niannbialis the peristome is about twice as long as the attached portion of the zooecium, and 

 its tube-rings seem to be very prominent. The species is not, however, very well characterised, 

 although it is said to differ from R. griuialdii by the colour of the coenoecium (yellowish instead 

 of brown), by the absence of the two "tubes" of that species, and by the fact that the axial cord or 

 pectocaulus extends into the attached part of the zooecium, which is not \\\iicA^<i.\x\ R. grimaldii. 

 The specimen dredged by the "Siboga" is a perfectly tyjjical Rhabdopletira, its coenoe- 



(iuni consisting of a creeping portion attached to 

 llu; stone, and provided with the characteristic, dark 

 l)n>wn i>ectocaulus embedded in its lower wall. 



I iiave been able to examine onl\- two 

 peristomes which appear to be complete. The 

 s])ecimen figured {A) consists of 1 3 rings, the last 

 of which seems to have been somewhat distorted 

 tluring the preparation of the slide. The rings are 

 much more prominent than in A', normani, giving 

 the peristome an annulated appearance. As in that 

 species the substance of the ring is not completely 

 continuous, but is interrupted by a suture (5-.), which 

 is visible, however, only in cases in which it happens 

 to ()ccu|)y a tavourable position. In the creeping 

 ptjrtion of the zooecium (t^), the sutures have the 



I'ig. 2. — A7/a/<//'p/>/cHn7 sp. (Stal. 204). .r/, a complele perislonif. i . • .• • ,• . . i ■ i i i 



. . .. ' . f .u • .• r.i, ■ characteristic zigzag disposition which has been 



originating from part ol the creeping portion of the coe- " , => i 



noecium; /.'. finginent of the creeping portion: 0., orifice; noticed in Other SpecieS of RJiabdopletira . The 



/., pectoc.iulus; j., suture of tiibe-ring; -tf/., septum; ir., . . . •in 



ma«s of detritus (X 80: magnified to the same extent as junctions ot SUCCeSSIVC lamellae HI thlS portion fomi 



the free end of the peristome of R. „orm„„i shewn in rijcres wliich, liowevcr, are iiot SO prominent as 



Pi. II, fig. 19). ■ ^ ' 



those of the peristomes. The cree])ing part is inter- 

 rupted by transver.se septa (-i4, scp^)^ as in other species of the genus, and its lower or attached 

 wall contains the tubular pectocaulus [p?^. The prejiaration shews one zooid, with recognisable 

 tentacles, and indications of several buds '). 



l) The stone on whlcli the KUohilciflcttra was found Wore several tubes which in size and in being composed of a series of 

 distinct rings have a curious resemblance to the peristomes of KluthilopUHia. One or two of these structures were in fact mounted under 

 the impression that they belonged to that genus. Their wall is, however, much thinner than in Khahiloplciira^ the rings are made up 

 of a series of smaller segments, and the tubes arc conical instead of being cylindrical in form. There can be no question that they belong 

 to ^lephaiioscyphiis^ and 1 am unable to distinguish them from .S'. miruhUis described by Allman in 1875 (Trans. I.inn. Soc, (2), Zool., 

 I, p. 61). Professor Cii. Jui,is, to whom I sent a preparation of the organism, informs me that he agrees with this determination. 



