4 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 5, 



5. Michelinia favosa, Goldf. Petref. Germ., 1826, vol. i. p. 4, pi. 1. 



fig. 11. 



A single specimen discovered by Dr. Fleming is identical in all its 

 characters with those of this species from the neighbourhood of 

 Tournay. The only and insignificant difference that it presents 

 consists in the rather greater extent and the rather more regular 

 disposition of the vesicular cells. The diameter of the calyces is 

 between 4 and 10 millimetres. 



6. Alveolites septosa ?, Fleming. PI. II. fig. 1. Brit. Anim. 1828, 



p. 529.) 



This specimen appears to me to possess all the characters of the 

 species to which I have referred it ; but as I have not had the advan- 

 tage of being able to compare it with the English examples, there 

 remains in my mind a slight doubt as to their specific identity. 



7. PhilocrijSttjs cometa, De Kon. PI. II. fig. 5. 



While describing this species, I shall indicate the characters of the 

 new genus which I am obliged to create for its reception. These 

 characters consist chiefly in the existence of five basal plates of a 

 quadrangular form, alternating with five rows of radial plates, to the 

 number of two for each ray. The second plate is cuneate, and sup- 

 ports two series of brachial plates, also two in number ; each of 

 these, finally, giving support to two series composed of a great 

 number of brachial plates, thus producing about twenty free arms. 

 All the other plates are soldered one to the other, and form the 

 calyx. 



In the species which I am describing, the calyx is a little gaping, 

 the external surface is perfectly smooth, and the arms are composed 

 of at least fifty articulations. The surfaces of these joints or plates 

 not being parallel to each other, it results that the dorsal or external 

 portion of the rays appears to be ornamented by a zigzag sculpture. 

 I could find no trace of fingers. 



Philocrinus has but two radial plates, and is thus distinguished from 

 the genera Encrinus and Millericrinus, which have three. The dimen- 

 sions of the Philocrinus cometa are as follows : — length of the calyx 

 25 millimetres ; diameter 24 millimetres ; length of the arms 6-8 

 centimetres. 



8. CiDAFvis Forbesiana., De Kon. PI. IV. figs. 1 & 2. 



I am acquainted with but seven spines of this species, which have 

 much analogy with those of 0. Braunii, Desor, from St. Cassian ; they 

 are tolerably large, fusiform, terminated by a rather sharp point, de- 

 pressed on one side, and furnished with from sixteen to eighteen longi- 

 tudinal series of small spiniform tubercles. They are rather less 

 marked on the flattened side than on the remainder of the surface. 

 The tubercles are often connected together by their bases, and 

 seem then to be derived from parallel keels or longitudinal ribs. 

 The neck of the spine is large and smooth, the milled ring or annula- 

 tion does not project much, the head is short and narrow, and the 



