MONOGRAPH OF THE EXISTING CRINOIDS. 



Zenometra columnaris. 



li'. The plates are very narrow and band-like. 

 Psathyrometra borealis. Thautnatocrinus burealis. 



Psathyrotnetra fragiUs. Isometra vivipara. 



d'. Each lappet contains a single rod or spicule, 

 e". The rods or spicnies are straight. 



281 



Cfimatonia cristaia. 

 Himerometra martensi. 

 Mariametra deHcniissiiiKi. 

 Cyllomctra discifoi-mis. 

 Cyllomctra albopurpurea. 

 Decametra taprobanes. 

 Decametra tigrina. 

 Decametra parva. 

 Colohomeira vepretum. 

 Colobomeira discolor. 

 Prometra chadwicki. 

 Cotylometra gracilicirra. 

 Oligometrides adconw. 

 OUgometra carpenteri. 

 OUgomcIrn .lerripiiind. 



c'. The rods or spicules are curved 

 f. The convexity of the curve 

 Catopiomctra hartlaubi. 

 Catoptometra ophiura. 

 Amphimetra papnensi-i. 

 Oxymetra fiinschU. 

 Cyllometra albopurpurea. 

 Prometra chadtoicki. 

 Antedon petasus. 

 Compsotnetra lov^ni. 

 Toxometra paupcra. 

 Iridometra adrcstine. 

 Iridomeira melpon\ene. 

 Andromeira psyche. 

 Coccomctra nigrolinrnln. 



Tropiometra picta. 

 Tropinmririi indicn. 

 Antedon pctasiis. 

 Compsotnetra loveni. 

 Compsotnetra incomttwdn. 

 Erythrometra ruber. 

 Erythrometra avstrnlis. 

 Heliometra maxima. 

 Heliomctra glacialis. 

 Florometra marice. 

 Florotnetra asjyerritnn. 

 Florometra serrati^ssima. 

 Florometra mageUatiica. 

 Psathyrotnetra gracillima. 



or bent, 

 is outward and proximal. 



Coccomctra hagenii. 



\anometra clyinene. 



Florometra tnari^, 



Florometra laodice. 



Florometra asperrima. 



Florottxctra serratissima. 



Cyclometra clio. 



Trichometra cubcn.<iis. 



Th a um<i tncritms borealis. 



Pentametroerinus tubereulntus 



Pcntametrocriniis japonicus. 



Pcniattietrocrin us rarians. 



f. The convexity of the curve Is Inward and distal. 



Comatonia cristaia. Psathyrometra antarctica. 



Diohrometra doderlcltii. Hathrometra prolixa. 



Mariametra delicatissitna. Hathrometra tenelJa. 



Decametra mylittn. Hathrometra .larsii. 



Olignmetra serripinnn. Thauiiintometra tenuis. 

 Hypalnmetra defirtn. 



From the precedinjr analysis it is evident that the rehitionships between the 

 various types of adamlnilacral structures and the systematic position of the species 

 is quite similar to the relationships between the latter and the various types of 

 cirri ; that is to say, only a small minority of the systematic units have character- 

 istic adambulacral plates. It is inteiestin" to note further that the systematic 



