KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:() 2. 53 



Herpetocrinus scolopendra, n. sp. 

 (Plate ir, tigs. 78—82.) 

 Diasnosis. 



Cirri two to each ossiele, in regions 4, 5 and 6; cirri short; cirrals as wide as long, 

 sometimes constricted in the middle, circular in section. No sutures seen. Coil open, 

 helicoid. 



This species is fonnded on two specimens, — (a) two coiled stems and the distal 

 portion of a third, all rising from the same point and arranged like the Prince of Wales' 

 feathers; there is perhaps a trace of a fourth: (b) a single coiled stem, broken in two, 

 lying in matrix. 



Deseription. 



These stems very elosely resémble the arms of a erinoid, with cirri coming off as 

 pinnules; with this important difference, that each ossiele bears two cirri. 



The columnals in region 5 are 2 mm. high, and 2.5 mm. wide. They have 

 rounded backs. 



The cirri are short, and taper rapidly at the distal end. They are set on a curved 

 facct at the side of the stem-ossicle. The cirrals are round, in many cases constricted in 

 the middle. Their width and height are about 0.9 mm. (tig. 80). 



The stem appears to expand distally into a base; and, in the ease of specimen a, 

 three or more individnals seem to have grown from the same base (tig. 78). The spe- 

 cimen is, however, too broken at this end to prove the point completely; it would seern 

 to be very unlike other Herpetocrini in this respect; bi it no other explanation of the 

 peculiar disposition of the three stems presents itself. 



This species does not appeaf to be at all hollowed on the inner side of the stem, 

 or even obviously flattened; and correlated with this is no donbt the fact that the involu- 

 tion does not lie in the same plane, bnt forms an ascending coil, the inner whorls l)eing 

 eovered only in part by the cirri of the onter ones. This is most probably a primitive 

 character (tigs. 77, 78). 



No longitndinal sutures can be seen. 



Beyond the arrangenient of the cirri, there is not rnuch in the present species to 

 canse one to refer it to Herpetocrinus. Mr. Waciismutii has, in a letter, called my 

 attention to the fact that a double row of cirri has been found in other erinoid stems. 

 Still the species bears some resemblance to H. brachiatus, and may well be placed in this 

 genus provisionally. 



There are in the Riksmuseum several massive coiled fragments of stems, which 

 have hitherto been assoeiated with the specimens of Herpetocrinus. They are the root 

 ends of some unknown stem, and do somewhat resémble Herpetocrinus in their loose 

 coiling and in a certain bilateral arrangement of cirrus-like processes. These processes 

 are often nothing more than extensions of the sides of the ossicles, often coalescing into 



