OPHIOLEPIDAE 



309 



is very inconstant, sometimes four or five as shown by Koehler, sometimes only one or 

 two, and examples of both may be found in one and the same specimen in different radii. 

 The granules of the disk may continue between the first dorsal plates. In the larger 

 specimens there may be as many as seven to eight arm spines. The species has separate 

 sexes and appears not to be viviparous. 



This species bears a very close resemblance to Ophiogona laevigata from Kerguelen, 

 described by Studer (Vbersicht ilber die Ophiiiriden S.M.S. 'Gazelle'. Abh. Akad. 



Fig. 34. Ophiogona Doderleini (Koehler). Part of oral side {a) and dorsal side {b). 



X 10. 



Berlin, 1882, p. 6, Taf. i, figs. 2 a-c). From the description and figures given by 



Studer I cannot gather any other difference than that in O. laevigata the radial shields 



are covered by granules, these being naked in the present species, and as this may quite 



probably be a difference due to age, the type of O. laevigata 



being no less than 40 mm. in diameter of disk (thus twice 



the size of the largest known specimens of O. Doderleini), 



this character alone does not justify us in regarding them 



as two distinct species. On application for the loan of the 



type material of O. laevigata, Professor W. Arndt of the 



Berlin Museum very kindly sent me a large specimen, 33 mm. 



in diameter, for comparison with my specimens. The only 



difference I can find is in the papillae of the first tentacle 



pore. As shown in Fig. 35 the papillae on the adradial side 



of the pore join in the radial mid-line, being all of them 



attached to the ventral plate itself; in O. Doderleini the ^'g- 35- Ophiogona laevigata, 



adradial papillae of the first tentacle pore do not join in the ^'"'^''■- ^^" °^ '"°"'^"' '•^°*- 



J . , . J , . , , . , . ing the arrangement of the 



radial mid-hne, the two or three mner ones bemg attached p^piii^e along the first ventral 



to a small supplementary plate (Fig. 34 a). (Sometimes plate. From cotype. 6. 



