-^*^ 



THE OPHIURIDiE. 



131 



make an exception ; but they ought not to be refem^ed to the genus Opliio'mii- 

 siimiy they would better make a separate genus. The other characters of 

 OpMomusiwn^ closely soldered disk-plates, few tentacle porcs^ etc., may also 

 be found in Ophioglypha species. Opliioghjplia Forleu evidently is a typical 

 Opliioglyplia species. 



18. Ophiocten pacificum n. sp. 



Plate III. rigs. 5-7. 



Diameter of disk, 12 mm. ; width of arm close to disk, 2.5 mm. ; length 

 of arms, 5 to 6 times the diameter of the disk. Four short, close set mouth 

 papillae on each side of mouth angle ; the two outer ones are broad, espe- 

 cially the outermost; the two inner ones and that on the apex more acute, 

 though not spiniform. Mouth shield somewhat broader than long, with 

 outer edge a little curved, outer corners rounded, lateral sides straight ; an 

 obtuse an^>*le within. Side mouth shields a little broader within than with- 



O 



out, not always meeting within. 



Ventral plates all widely separated ; the first one four-sided, larger than 

 the following, with outer edge slightly curved, lateral sides almost straight, 

 inner end truncated. The other ventral plates have their outer edge 

 strongly curved and an angle within; this angle or peak becomes afterward 

 less prominent farther out on the arm, and the ventral plates thus have 

 their inner side almost straight, w^ith only a little peak in the median line.* 

 The side arm-plates meet broadly below in the Avhole length of the arm ; 

 the sides are slightly curved. The dorsal plates are four-sided, roof-shaped, 

 broader than long; the outer edge is broader than the inner, both are 

 sli<''htly curved, the outer convex, the inner concave, the lateral sides 

 straight. They cover almost the whole dorsal side of the arm, the side 

 arm-plates thus being very broadly separated above. At the base of the 

 arm the sides are partly naked, and both the dorsal and the side plates are 

 somewhat smaller than farther out. 



Disk covered wdth small, irregular, somewhat swollen scales, among 

 which the primary plates are rather inconspicuous. Kadial shields small, 

 triangular, separated by numerous small scales. Ventral side of the disk 

 covered with numerous small, overlapping, not swollen scales; edge of the 

 disk sharp, as common in O^hioden, Genital scale not distinct. Some 



* ri"-urc 5 gives tlic vcutral plates a little too short, and their outer edge should be a little more curved. 



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