248 NATURAL SCIENCE [April 



Balanocrinus, primarily applied by L. Agassiz to an abnormal stem- 

 fragment of another genus ; but nothing would be gained by contest- 

 ing his action. D is the genus called Metacrinus by P. H. Carpenter, 

 who took the name from a MS. label of Wyville Thomson. 



C and D are the types about which there is confusion. C is 

 called Extracrinus by Carpenter (1884) and De Loriol (1886), while 

 the name Pentacrinus is restricted by them to D. This course has 

 been followed in the Geological Department of the British Museum. 

 I shall now prove that by the rules of nomenclature, by the practice 

 of many early naturalists, and by a literary history of three centuries, 

 the name Pentacrinus is the property of type C. 



First let us remember that living examples of a Pentacrinid have 

 been known to men for less than a hundred and forty years, while 

 the fossils have been well known for centuries. The name Penta- 

 crinus itself is supposed to be due to Georg Bauer, better known as 

 Agricola. This is what he says in his work " De Natura Fossilium " 

 Lib. V. pp. 25 6-8 (1558). First he describes the " trochites," circular 

 bodies with smooth circumference but with upper and lower surfaces 

 covered with striae that radiate from the centre, with a u'littering 

 fracture and regular cleavage like Jew-stones [i.e., fossil spines of 

 sea-urchins], giving off gas when placed in vinegar. The " entrochos " 

 consists of trochites not yet separated from one another. Next, 

 under the name Ceraunia, Agricola describes certain bodies, which 

 appear to be fossil sea-urchins. He then proceeds : " But as the 

 Entrochos when divided represents the effigy of wheels, so the 

 Encrinos does of lilies. For when one angular part is separated 

 from another, each shows a set of five lilies. For the elevations of 

 the one fit into the striae of the other. And any such part has five 

 angles and as many sides, and on each is a quintet of lilies. Whence 

 it may be called pentacrinos in Greek. But just as the entrochos 

 consists of many trochites, so the encrinos consists of many penta- 

 crini. . . . The stone of the pentacrini when broken has the colour, 

 smoothness, and glitter of the Jew-stone." 



It is clear from this that the syllables " crinos " originally re- 

 ferred solely to the leaf-like or petaloid markings on the joint- 

 surfaces of the stem, and not to the lily-like appearance of the 

 whole animal, just as the Japanese call a similar fossil ' the 

 plum-flower stone.' Further, that both Encrinos and Pentacrinos 

 applied to the same fossil under different aspects. This was 

 understood by the successors of Agricola, among whom Lachmund 

 (1669) is conspicuous. It was, however, this writer who intro- 

 duced confusion, for in his chapter " De Encrino et Pentacrino " he 

 says, " To Encrinus I refer a stone, which consists of many other 

 small and angular stones, the elevations of which are inserted into 

 the striae of another, just as the skin, imprimis in the anterior part. 



