KEPORT ON THE ASTEROIDEA. 79 



36° 21' 0" N., long. 23° 31' 0" W. Depth 2025 fathoms. Globigerina ooze. Bottom 

 temperature 35° - 9 Fahr. ; surface temperature 71°'5 Fahr. 



Remarks. — This species, by reason of its comparatively short and tapering rays, has a 

 somewhat different facies from that of the other members of the genus ; and I felt at first 

 some hesitation in placing it along with them. The length and narrowness of the adam- 

 bulacral plates and the character of their armature show, however, an unmistakable 

 alliance with Dytaster. The general characters of the abactinal surface and of the mar- 

 ginal plates also furnish confirmatory support as to this view of its classification. It is 

 for the present undesirable to damage the solitary adult specimen by dissection to ascer- 

 tain what evidence might be derived from its anatomy. The depth at which this species 

 was dredged is worthy of note (2025 fathoms). 



7. Dytaster inermis, n. sp. (PI. X. figs. 5 and 6 ; PI. XIII. figs. 5 and 6). 



Kays five. E = 1 6 mm. ; r = 5 mm. R > 3 r. Breadth of a ray between the second 

 and third supero-marginal plates, 4*25 mm. 



Pays rather short, broad at the base, and tapering continuously to the extremity. 

 Lateral walls low, and rounded at the junction with the actinal and abactinal surfaces, 

 lnterbrachial arcs rather acutely rounded. Abactinal surface plane, sloping slightly from 

 the base to the extremity of the rays. Actinal surface plane. 



The paxillse of the abactinal surface are very small and widely spaced, composed of 

 three to five short, delicate, spinelets of equal length, each with several denticles at the 

 tip. The spinelets radiate very little apart, and form a rather compact paxilla, the base 

 of which is comparatively robust. There is no central spinelet. On the outer part of the 

 rays the paxillae are very small, with seldom more than three or four spinelets. Near the 

 margin, and at the base of the rays, a number of paxillse are modified into a comparatively 

 robust, valvate, pedicellarian apparatus. 



The supero-marginal plates, fifteen in number from the median interradial line to the 

 extremity, form a narrow but distinct border to the disk and rays, slightly rounded 

 marginally when viewed from above. The plates are small, and their length is slightly 

 greater than their breadth throughout. The height of the plates is less than the length, 

 except in three or four of the innermost plates in the interbrachial arc, in which the 

 height is considerably greater. The surface of the plates appears to have been covered 

 with very minute, short, delicate, microscopic spinelets, widely spaced ; but a great number 

 have been abraded, leaving, where this has occurred, a peculiar spongy-looking surface of 

 plate exposed. There are no large spines, nor is any trace of their existence present. The 

 terminal plate is large, slightly swollen laterally at the proximal extremity, and indented 

 for a short distance by the paxillar area in the median radial line. 



The infero-margiual plates correspond exactly to the superior series, and their surface 

 is covered with similar widely spaced microscopic spinelets, which have been much 



