■ 2 PORIFERA. II. 



however, to a quite imperceptible degree. The tapering may be somewhat varying, but the point 

 itself is always rather short. The length is 0-32— 0-40"™, and the thickness in the middle is 0-005— o-oo8' n "'. 

 As has been mentioned, these styli, as far as I have been able to decide, occur near the skin. b. M/'cro- 

 sclera are of two forms, chelae and sigmata. 1. The chelae are of a quite peculiar structure, but must 

 be characterized as anisochelae palmatse. They are of a wry form; the shaft is somewhat curved, and 

 besides being bent from behind to before it is also bent a little to the side. The tooth of one end is 

 larger than that of the other, and otherwise the teeth are differently constructed. To facilitate the 

 understanding of the description I call the end with the smaller tooth the upper end. When the chela 

 is placed on the back with the upper end turned upward, and the upper tooth directly towards the 

 beholder, and in such a way, that the upper part of the axis is turned directly upward, then the lower 

 part of the axis is bent a little to the left. The frontside of the upper tooth is then turned directly upward; 

 it reaches to a little more than half the length of the chela, is of a somewhat wry form, and has only a 

 plate-shaped extension to the right; at the upper end a small, triangular tuberculum is found, and there is a 

 small falx. On the upper part of the shaft an ala is only found on the right side; this ala is of a similar 

 form and size as the tooth. When the chela is seen in the mentioned position, tooth and ake are 

 accordingly about opposite to each other. In this position the tooth of the lower end is seen on the 

 left side of the chela, and is seen from the edge, as the front of it is turned out towards the side; it 

 reaches to about the middle of the upper tooth, being therefore most frequently somewhat larger than 

 the latter. If now the chela is turned a fourth part of a turning to the right, so that the upper tooth 

 is seen from the side, the lower tooth will be seen as a warped plate somewhat expanded towards 

 the end, reaching up and bending in towards the shaft; at the base there is a roundish tuberculum. 

 On the left side of the lower part of the shaft an ala is found reaching somewhat farther than the 

 lower end of the ala of the right side, but it is rather narrow and bent forward, and is thus rather 

 inconspicuous. Also on the right side of the lower part a small and short ala is found. When the 

 chela is in the position first mentioned, it is seen, that it is especially the lower part of the shaft which 

 is twisted in such a way, that the lower tooth is turned round on the side. In a few of the fragments 

 in hand the chelae are a little larger than in the others, and in these chelae the plate-shaped end of 

 the lower tooth is often marked off by an incision, and this part is finely dentate in the edge. As men- 

 tioned the chelae van- somewhat in size, and seem especially to be varying in different individuals. 

 The length is between o-024 mm and o-052 mm , when the chelae are regarded collectively, but the variation 

 is not so great in the single individual. In one specimen the length was 0-024 — °'°35 mm > m another 

 0-034 — o-052'" m . 



Schmidt has not quite understood the structure of these chelae; especially his figures a and 

 b are quite misleading; figure c, however, showing the chela from the front, is somewhat better. Carter 

 1. c, on the other hand, has quite misunderstood them, and it might be doubted whether he has had 

 the same species before him, if he did not mention that he has had a preparation of the type specimen 

 of Schmidt. Carter figures and mentions the chela as an isochela, and he figures uniform alae on 

 both sides of the shaft and uniform teeth, the only deviation from the normal form thus being that the 

 chela is somewhat twisted. This, as will have been seen, is a quite wrong representation, and when 

 Carter thinks that this chela with regard to its structure recalls the diancistra in Hamacantha, and 



