0(VI,AK AM) CKNITAI. I'l.ATKS. 



117 



Of the first family, the Temnopleuridae, 400 specimens inclmlinn !."> -pcrio li 

 studied as listed in the table, p. 159. The Cretaceous (Ih/phocyphuH rmlinlux h;i- vrry low- 

 genitals and oculars, and the latter are all insert in the x-vm -pecimens seen. Tin 

 Temnopleurus reevesii shows a strong tendency for ocular I to be in.-eri. and tlii- with other 

 cases indicates that this is the first plate to become insert in this family an in the Kchinid.-ie. 

 All the other species have all oculars exsert with rare except ion. Mimici/phut macul" 

 specimens) in one case has oculars I, V insert, the only case seen in the family, and two al>errantx 

 were found, one with ocular IV insert and one with II insert, both very rare occurrence- m 

 Echini as a whole. Mr. Agassiz (1873) and Dr. Mortensen (1904, p. (>.'*) note that one or mon- 

 ocular plates may be insert in species of this family, but in Recent species they are apparently 

 exceptional characters, and, as a whole, the family from present evidence is characterized by 

 oculars all exsert. 



In the family of the Echinidae I have had the opportunity to examine a large number of 



m 



i 



in 



in 



Ma 



TEXT-FIOS. 115-117. Ocular plate arrangement in species of Echinus. 



115 Echinus affinis Mortensen. Off east eoast of rnit.,1 Slat, 1,022-1,106 full......*. 



M 851 X 3. All oculars exuert, extra genital pores, ambulacra! plates compose,! f !.. .-Inn-iitr. 

 primaries next the ocular. Plates of periproct numerous and very small ,-N.T,,I ing t he surana 



' 



116a. Same species and locality. R. T. J. Coll., 891. X 3. Ambulacra! plaU* of two ek-m-n,, 

 down to the mid-zone, below which all have three elements (p. 216). 



115b The same R T. J. Coll., 892. X 3. No ambulacral plnir* with two *M 

 U6.' Echinus esculentusUnut. English Channel. Diam. 103 mm. R. T. J. Coll.. V.':. 



Plymouth, England. Diam. 94 mm. R. T. J. O-U.. 7,,, 



X ,. , Vuh, 1 tat. . 



variant. 



