of Terebratulina septentrionalis. 425 



sonic sjx'cirs of Ih'sriiKi (tln>ii;:;li, tVoni nbscrvatinns I liavc 

 made on Limjula jn/r(imi(/iit<i, the embryos examined by him 

 are as likely to bclonj; to this <j^enus as to Discitid) several 

 sets of setai which jirojeet from the body and are capable of 

 locomotion. F. A. Sniitt* has noticed in the development of 

 Lepraliti I\'(irliii a cluster of six bristles, bent at their points, 

 that from time to time were drawn in and a^ain thrust out. 



^Vith propriety niay also be sugi^ested a certain parallelism 

 between the leading groups of the Polyzoa and the Brachio- 

 pods. We have forms, like Lepralia^ attached by one region 

 of their shell, this shell being calcareous and exhibiting mi- 

 nute punctures, which have l)een compared to similar mark- 

 ings in certain lirachiopods. So, among the latter group, do 

 we tind forms attached, as in Tlncith'tun and some species of 

 Proiliictus ; and generally the articulate Bracliiopods might be 

 compared to such forms as Leprafut ; while, on the other 

 hand, such genci'a as PeiUcelltna^ with its long, pliant, and 

 muscular stalk, or Ltxosoma, with a stalk highly retractile, 

 may be compared to Lin<juht. The limits or intentions of this 

 paper will not allow any considerations regarding the relations 

 of the Bracliiopods with the other groups of the animal king- 

 dom. I have elsewhere t expressed my belief that they arc 

 tnic Articulates, having nearer affinities with the Vemies ; 

 and, in view of the above relations of the Bracliiopods with 

 the Polyzoa, it is interesting to remark that Leuckart has for 

 a long time placed the Polyzoa with the Vermes ; and in a 

 new edition of the 'Outlines of Comparative Anatomy '|, 

 Prof. Carl (Tcgenbaur removes the Polyzoa from the Mollusca 

 and associates them w^ith the Vermes. 



EXPLANATION OF THE PLATES. 



In the acconipanyiug figures in desi<m<ates the mouth ; e, epistome ; 

 oe, a?3ophagu.s ; s, stomach ; c, cardia ; i, intestine ; f, fajces ; ?•;», ventral 

 mesentery : /, liver : /*, hepatic cells ; ocf, oral groove ; ot, oral tubercle ; 

 (1, divaiicator muscles ; Ih, lateral gastroparietal bands ; ;;, peduncle ; 

 /M, point of attachment of peduncle ; se, sette ; c«/, pallial cjecum ; /■, cim; 

 (/, granules passing to and fro from liver to intestine ; cr, crura ; cl, cal- 

 careous loop ; ex, external shell-layer, of a chitinous nature ; //«, internal 

 shell-layer, of calcareous scales ; hp, hinge-plate ; cp, cardinal pro- 

 cess ; rfs, dental sockets ; /o, foramen ; te, teeth of shell ; c$, calca- 



* " Om Ilafs-Bryozoemas utveckling och fettkroppar," ffifversigt af 

 Kongl. Vetenskaps-Akademiens Forhaudlingar : Stockholm, 1805. 



t "The Brachiopoda a Division of Annelida," American Joui-n. Sc. 

 July 1870; reprinted in Ann. & .Mag. Nat. llist. ser. 4. vol. \\. no. 33. 



X Grundziige der vergleichenden Anatomic. Zweite umgearbeitete 

 Autlage. Leipzig, 1870. 



