Reports and Proceedings — Linncean Society. 135 



by Frederick Pearcey. These lists are exceedingly interesting in 

 connexion with the recent Foraminiferal fauna of the Mediterranean, 

 Analyses of the different rocks are given, and the probable depth 

 of water in which they were deposited is discussed. Remarks on 

 the economic value of the rocks as building material, and interesting 

 notes of a practical nature in addition to this subject, are supplied 

 by C. H, Colson. The various caves that have yielded vertelDrate 

 remains are catalogued, and the paper closes with a description of 

 the recent marine deposits in process of formation off Malta, and a 

 long discussion as to the origin of the rocks and soils. The j)lates 

 contain representations of four slices of Foraminiferal Limestones 

 from Malta. The map and sections are in every way excellent, and 

 a copy of these has been framed and hung up in the Fossil Mammalian 

 Gallery of the Natural History Museum, close to Admiral Spratt's, 

 and Dr. Leith Adam's Collections of Pigmy Elephant-remains from 

 Malta, and forms one of many such valuable aids to the student in 

 the Palaiontological Department. C. D. S. 



laiBIPOS-TS J^InTZD I^K-OGIEEIDIlsrG-S. 



LiNNiEAN Society. 



Jan. 15, 1891. — Dr. P. H. Carpenter, F.R.S., read a paper on 

 " Some Points in the Morphology of the Cystidea." 



A large number of the Cystidea may be compared with dicyclic 

 Crinoidea more directly than has hitherto been supposed. 



Group I. has a generally six-rayed structure ; Exx. Caryocrinus, 

 Hemicosmites, Juglandocrinus, Cordylocrinus. Here are three circlets 

 of plates, viz. four infrabasals, two of which are double plates, six 

 basals, and six radials, with two or three interradials enclosed within 

 the I'adial circlet. The summit-plates or orals also are comparable 

 with those of Crinoidea, though differing in number ; thus Caryo- 

 crirms has one central plate and five others around it, corresponding 

 to the one central and four surrounding plates of a Crinoid : the 

 central plate in either case represents the posterior oral. Even the 

 number is sometimes the same as in a Crinoid ; thus, though 

 Caryocystis granatum has six rays, C. testitdinarius (v. Buch. nan 

 His. ) has five ; while there are but four in other species. 



Group II. has a five-rayed structure ; Exx. Lepadocrinus, Apio- 

 cystis, Prunocystis, ^chinoencrinus (Forbes no7i v. Meyer). Here are 

 four infrabasals, one of which is double, five basals, five radials 

 and five interradials (?). Sometimes an interradial is missing, e.g. 

 Cystoblastus (1. post.), Pseudocrinus (r. antr.). Some genera (Apio- 

 cystis, Callocystis) have only four ambulacra. The plates in this group 

 may still be designated by the numbers applied to them by Forbes : 

 thus 1-4 are infrabasals, 5-9 basals, 10-14 radials, 15-18 or 19 

 interradials. The homology of Nos. 10-14 with radials is corroborated 

 by Cystoblastus, in which these five plates have a deep fissure for 

 the ambulacra. There is moreover symmetry in the disposition of the 

 pore-rhombs, which generally occur on plates 1 & 5, 14 & 15, 12 & 18. 



Variations from the simple types occur. Sometimes two of the 

 radials sink into the basal circlet, e.g. Callocystis, while in Glyptocystis 



