for the Microscope. 97 



is also a British Holothurian. The plates which accom- 

 pany the anchors are more rounded than in the last, and 

 the margin of the orifices is minutely toothed. (PI. XL, 

 % 38.) 



761. SPICULES OF SEA-URCHIN (Echinus sphara).T&s. 

 C-shaped spicules are not uncommon in Echinoderms, 

 and occur in this British species of Urchin. (PI. XL, 



fig- 39-) 



762. SPICULES OF SEA-URCHIN (Echinus sphccra]. 

 Other similar spicules are found in the same animal, and 

 in a foreign species of Mespilia, which are swollen in 

 the centre. (PI. XL, fig. 40.) 



763. SPICULES O7^^-\]-SL(zni^ (Echinus Drobrachiensis). 

 Curved dumb-bell spicules, with lobed ends, are found 

 in another Sea-Urchin which occurs on our coasts. (PI. 

 XI, fig. 41.) 



764. SPICULES OF ECHINOMETRA.- In an exotic species 

 of Echinometra very singular elongated perforated plates, 

 or spicules, are found, of which modifications may be 

 traced in some species of Cidaris. (PL XI, fig. 42.) 



765. ANCHORS OF BUSK'S SYNAPTA (Synapta Biiskii). 

 Dr. Mclntosh has found a Synapta in the Outer He- 

 brides with singular anchor plates, having a long handle. 



766. PLATES OF THYONE (Thyone flexus). The discoid 

 perforated plates of this British Thyone, found on several 

 parts of our coast, are, when perfect, attractive objects. 



767. VINEGAR EELS (Anguillula acett). Found in the 

 mucilage of common vinegar, which has been exposed to 

 the air. 



768. PASTE EELS (Angillula glutinis). Not uncommon 

 in sour paste. 



769. WHEAT EELS (Anguillula tritici). Sometimes 

 called Vibriones. Found in diseased kernels of wheat. 

 They will revive, and become active in water, after having 

 been kept dry for years. 



770. The TRICHINA (Trichina spiralis). A small 

 Entozoon, unfavourably known of late years as the cause 

 of a peculiar disease in man, in whose muscles it is found 

 encysted, as well as in some of the lower animals. 



7 



