324 PALAEONTOLOGY OF 1 LLINO1S. 



It is also due to Mr. WACHSMUTH, that we should state here that he 

 is not a mere collector only, but that he understands what he collects, 

 and knows just what to collect, as well as how to collect. 



Below we give substantially some notes of observations made in 

 his collection, followed by some remarks on other specimens at Spring- 

 field : 



1. Synbathocrinm, Phillips. Some of Mr. WACHSMUTH'S specimens 

 of a species of this genus show that it is provided with a long, slender, 

 pipe-stem like ventral tube or proboscis, apparently equaling the arms 

 in length. Also, that a double row of minute alternating marginal 

 pieces extends up within the ambulacral furrows of the arms, appa- 

 rently all their length. We are not aware that these characters have- 

 been hitherto noticed in any of the publications on this genus. It will 

 be seen, however, farther on, that minute marginal pieces probably oc- 

 cupied the furrows along the inner side of the arms of other types of 

 Oinoidea, as well as this. 



2. GoniasteroidocrinuS) Lyon and Casseday. Some unusually fine 

 specimens of the typical species of this genus ((*. tnln'n>*inn) in Mr. 

 WACHSMUTII'S collection, from Crawfordsville, Indiana, show the slender 

 pendent arms much more distinctly than any we had before seen, and 

 from these it seems evident that these arms are stouter than we had 

 supposed, and that there are not more than five or six of them to each 

 of the ten openings. In the specimen figured by u.s on page 220 of the 

 second volume of the Illinois reports, these arms were only imperfectly 

 seen by working away, with great difficulty, the hard matrix between 

 two of the produced rays of the vault, which we have termed pseudo- 

 brachial appendages, or false arms. In clearing away the matrix of this 

 specimen, we had cut just far enough to expose the edges of the arms 

 on each side of the deep ambulacral furrow, so that each of these edges 

 presents the appearance of being a separate and distinct, very slender 

 arm, composed of a single series of pieces, and without any ambulacral 

 furrow on the outer or ventral side ; whereas there is a well-defined 

 ambulacral furrow, bearing the tentacula along its margins, on the 

 outer side of the arms, and when the matrix is removed from these am- 

 bulacral furrows, the arms can be seen to be composed each of a double 

 series of small alternately-arranged pieces. It is barely possible that 

 in specimens of this species with the arms perfectly preserved, that the 

 ambulacral furrows may be covered on the outer or ventral side by a 

 double series of alternating pieces, and that the teutacula* may connect' 



* We use the term tentacula here in the sense it is generally used by Paleontologists, with refer- 

 ence to the delicate pinuulse along the arms of Crinoids, and of course not as applying to the minute 

 fleshy organs along the ambulacral furrows, usually termed tentacles by those who have investigated 

 the recent Crinoids. 



