96 MR. J. A. STEWART ON ASTERONYX LOVENI. [Mar. 12, 



this view, subscribe to Prof. Huxley's opinion, that they arehomolo- 

 gically identical with the thread-cells of the liydroid polyps *. • 



In the first of my serial papers on Entozoa, communicated to the 

 Lianean Society (Dec. 3rd, 1857), I proposed the term " sclerous par- 

 ticle " as preferable to that of "calcareous corpuscle," for reasons 

 which are sufficiently obnous ; but I cannot even now pretend to offer 

 a satisfactory solution of the problem concerning the true nature of 

 these bodies. Whatever physiological or morphological signification 

 they possess, I cannot but regard ths oviform sacs in which they occur 

 as specialized structures formed for their secretion and development. 



I also abstain from hazarding any opinion as to the species of 

 Cestode to which the above-described Scolex-forms or Cysticerci are 

 referable ; yet that the latter are merely larval conditions of Tsenise, 

 is an inductive truth which no entozoologist would now for a moment 

 dispute. 



EXPLANATION OF PLATE XVIL 



Fig. 1. Head (a), neck (i), body (e),and part of the circular caudal vesicle (rf) of 

 Ci/stieercus ex Phacochcero (elhiopico. Natural size. 



Fig. 2. Enlarged view of the head of the same. 



Fig. 3. Section of Cysiicercus ex Potamochoero peniciltato, showing the neck 

 (i), body (c), caudal vesicle (rf), coils of granular parenchyma (e), and 

 filament (/) of the same character. 



Fig. 4. Upper part of the neck unfolded and magnified 60 times, to show the in- 

 verted head in situ : it also exhibits the four suckers, the double crown 

 of hooks, and the so-called calcareous corpuscles. 



Fig. 5. Isolated calcareous corpuscles, to show their forms and the changes un- 

 dergone by the addition of an alkahne reagent, x 220 diameters. 



4. Description of Asteronyx loveni, Mull, et Trosch., 

 A New British Starfish. By John A. Stewart, New 

 College, Edinburgh. 



This fine Starfish belongs to the Euryalece. It is the second spe- 

 cies of this division of the OpMuridce which has been noticed in the 

 British seas ; and it is the more interesting as it is a form interme- 

 diate between the already known species {Astrophyton scutatum, 

 Link) and the simple-rayed Ophiurce, having the prehensile scaleless 

 arms, and the radiating body-ribs of the other Euryalea, joined with 

 the undivided arms of the OphiurcB. As in Astrophyton, it wants 

 the mouth-plates between the origin of the rays, but has instead a 

 strong calcareous bar uniting the bases of the two neighbouring arms. 

 The two genera have also the madreporiform tubercle on the under 

 surface in one of the in':erbrachial angles nearest the mouth. The 

 genus Tfichaster is generally placed between Astrophyton and Aster- 

 onyx, but it has the interbrachial mouth-plates, and wants the ma- 

 dreporiform tubercle ; indeed it seems scarcely separable from Ophio- 

 scolex, except in possessing prehensile divided arms, and would per- 



* See his elaborate Memoir on Echinococcus, in the Society's Proceedings for 

 Dec. 14th, 1852. 



