8 F. A. BATHEB, CRINOIDEA OF GOTLAND. 



us for the first time to compare this genus, in a rational manner, with other Monocyclica. 

 Under the Calceocriiiidae (p. 54) will be found a revision of the genera based on morphological 

 principles, and a nomenclature of the various skeletal elements that is no longer arbitrary 

 but scientifie. For the first time too is this family comparable with other Crinoids. Many 

 points of minor morphological importance are also dealt with under the head of Calceo- 

 crinus. In the present paper (p. 39) is published for the first time a eorrect and almost a com- 

 plete account of the morphology of that very curious genus Herpetocrinus (— Myelodae- 

 ti/lus); incidentally this leads to some modifications of the rules that have lately been laid 

 down by Messrs Waciismuth and Springer concerning the stem of the Crinoidea (p. 44). The 

 examination of all these remarkable families has suggest ed a somewhat important alteration 

 in the Classification of the Inadunata, namely, the abolition of the Sub-orders Larviformia 

 and Fistulata and the erection of two fresh divisions, Monocyclica and Dicyclica, separated 

 according to the presence or absence of infrabasals. This may seem at first to be a re- 

 trograde step; but I am confident that a perusal of the arguments will convince everyone 

 that, however imperfect, it is at least a more philosophical arrangement than that which 

 has of late held the field. (See p. 20.) 



To turn to the Dicyclica, there will be noticed first a revision of the genus Homo- 

 crinus, rendered necessary by the discovery for the first time of a European species of 

 this genus (p. 101). In treating of Euspirocrinus I have endeavoured to clear ap a 

 little misapprehension that appears to exist concerning the ventral and anal structures 

 of this very interesting genus (p. 108). In describing the tegmina of the various spe- 

 cies of Cyathocrini I have paid special attention to any facts that might throw light on 

 the vexata qusestio of the orals and interradials. Strepiocrhnts (p. 122) is a singularly 

 interesting form: the only specimen is unfortunately in a very poor sta te of preser- 

 vation and this must excuse any deficiencies in my account of it: it is obviously a 

 genus that will have to be reckoned with some day by the ]>hylogenist of the Inadunata. 

 The chief point of interest noted among the Gissocrini is the fact that the position of 

 the small or unfused infrabasal is by no means fixed even in the same species (p. 152): 

 the böld generalisations that have been put forward as to the base of the Crinoids rest 

 on somewhat insecure facts. The determination of the systematic position of Gisso* 

 crinu* incurvätus affords occasion for some remarks on the rather doubtful genus Arac/irw- 

 crin/is (p. 168). 



It is impossible to abstract all these points of interest, and it is a question whether 

 abstracts do not do more harm than good to him who subsists on them. The above sum- 

 raary is a sign-post, but not a short cut. 



There only remains the duty, or rather the pleasurc of thanking those who have 

 helped me in my work. First Professor G. Lindström, who wclcomed me to Sweden in 

 t lic kindest possible manner, and who ga ve me every facility for work that a paheonto- 

 logist could desire; his critical insight was always at my service in the elucidation of 

 those difficult problems set by his predecessor, and to his profound knowledge of the Got- 

 land rocks many corrections of locality and hoi-izon are due. 



Among the important aids in this study should be especially mentioned the original 

 MS. notes and drawings prepared by Prof. Angelin and his artists. These have fortunately 



