ECHINOIDEA. I. III 



varicgahis (Leske). I have had occasion to examine all these species, with the exception of T. macu- 

 latns\ of T. elegans Prof. Doderlein has most kindly sent me a specimen, T. st-fnitubcradatus I have 

 seeu in British Museum, the other species are found in the museum in Copenhagen. I shall therefore 

 make a few supplementary remarks to the existing descriptions of these species. Information is espe- 

 ciall)- wanting with regard to pedicellariæ and spicules. 



Toxopnetistes pilcolus (Lamk.). Some specimeus fouud in our museum have by Liitken been 

 Jetermined as T. »laailahis^ but this determination, no doubt, is incorrect. They agree exactly with 

 the description of 7! pilcolus, having especially the characteristic coloration so often mentioned; on 

 the other hånd they do not at all agree with Lamarck's diagnosis of E. manilatus. Therefore I do 

 not hesitate to refer them to pilcolus. — Only every other ambulacral plate has a primary tubercle; 

 two ocular piates reach to the periproct. The buccal membrane contains numerous fenestrated piates 

 as well inside as outside of the buccal piates; not a few of them are thick and carry pedicellariæ. 

 Besides the fenestrated piates the buccal membrane contains numerous bihamate spicules; also in the 

 gills bihamate spicules are found in great numbers together with the common irregular fenestrated 

 piates. No spines on the buccal piates. The globiferous pedicellariæ without lateral teeth and with 

 tubular blade as in Splia-rcchinus, but they are remarkable by the extraordinary length of the blade 

 and the end-tooth (PL XXI. Fig. 13); in the apophj-sis there is a long, narrow slit; no neck; small 

 glands are found on the stalk. The tridentate pedicellariæ are very large, the head up to a length of 

 ^min. j-hg neck very short. The outer part of the blade where the valves join, is coarsely and irre- 

 gularh' indented in the edge, in the lower part the edge is sniooth, or has a few larger thorns. In 

 the bottom of the blade a strong and very complicate net of meshes is found hiding the usual regular 

 arrangement of the holes, even at the point of the blade (PI. XXI. Fig. 41). In smaller pedicellariæ 

 this net of meshes, no doubt, will be much less developed, but such pedicellariæ I have not found in 

 the specimens in hånd. For a long way the valves are apart, but not much, so that only a narrow 

 slit is found between them. Ophicephalous and triphyllous pedicellariæ without particular peculiarities. 

 The stalk of the pedicellariæ compact. The spicules (PI. XXI. Fig. 21. a) in the pedicellariæ are of the 

 typical dumb-bell shape; in the smaller globiferous pedicellariæ on the abactinal side they form a tliick 

 white border all round the head, the valves being united almost through their whole length by a fine 

 skin. These pedicellariæ are almost always open, and give the animal a very characteristic appear- 

 ance — which, no doubt, also holds good with regard to T. clcgaus. When they are shut the border 

 of spicules is slackened to as to make a kind of fringe round the point; the large globiferous pedicel- 

 lariæ of the actinal side do not seem to have such a border. In the tube feet a few dumb-bell-shaped 

 spicules are found together with more numerous bihamate spicules; most of the latter, especially those 

 nearest to the sucking disk, have some small branches on the outside at the points (Fig. 21. b); the 

 spicules of the buccal membrane are much finer (Fig. 21. c); also liere a few dumb-bell-shaped .spicules 

 are found. 



As a synon\m of 7". pilcolus Agassiz in Rev. of Ech. mentions the species Bolet ia rosca before 

 established by himself. To judge from the authentic specimens before me of B. rosca (from Mus. Comp. 

 Zool.) I think it, however, somewhat doubtful that they are really only one species. Besides the 

 difference with regard to colour (the spines uuiformly brown, the test only with a slight reddish tint. 



