364 p. HERBERT CARPENTER. 



In the Articulate Crinoids (Apiocrinus , Encritms, Penta- 

 crimis and Comatula), which are supposed not to possess the 

 plates that are now generally known as "Parabasals," and also 

 in Actinocrintis , Miller gave the name Costals to the first of 

 the " ray-bearing " plates (figs, i, iv, v, 4, 4), those, namely, 

 which Miiller subsequently termed radials. Even in Rho- 

 doci'inus, in which parabasals are present. Miller spoke of 

 them as intercostals, correctly regarding the radials as costals. 

 In Poteriocrinus again, he termed the parabasals intercostals, 

 but as in Platycrinus, which has no parabasals, he called the 

 radials not costals, but *^ Scapula? " (as in Marsupites), a 

 term which he employed in describing the Articulata to de- 

 signate the radial Axillaries (fig. iv, ax). In these two 

 genera he described no costals at all, but in Cyathocrinus he 

 gave the name of costals to the plates subsequently termed 

 parabasals by Miiller (fig. vi, 3, 3j, the position of which 

 is interradial, while he called the radials, or true costals (fig. 

 VI, 4, 4), Scapulse, as in Poteriocrinus and Platycrinus. 



Fjg. VI. — Calyx of Ci/atJiocrinus. (After Pictet.) 2. Under basals = 

 Pelvis XMiller) = Basis (Loven). 3. Basals = Costals (Miller) = 

 Parabasals (Lovcu). 4. Badials = Scapulae (Miller). a. Anal 

 plate. i. Interradials. 



Lastly, in Marsupites, he again describes the radials or 

 true costals (fig. in, 4, 4) as scapula;, and applies the term 

 costals to the so-called first parabasals (fig. in, 2, 2), which 

 though radial in position are not ray-bearing plates at all, 

 but are separated from the bases of the rays by the ring of 

 "second parabasals" (fig. iii, 3, 3), termed by him intercostals. 



From the radial position of these first parabasals in 3Iar- 

 supites it is obvious that they cannot be homologous with 

 the basals of Comatula (figs, i, v, 3, 3) nor with the genitals 

 of Echinus (fig. ii, 3, 3), as supposed by Loven, and 

 although Miller called them costals, they are not the horao- 

 logues of the costals (t. e. the radials) of Peiitacrinus, En- 



