ECHINOIDEA. II. Q, 



Species from ^i. fitlva, tliat no spatelf6rmige>> spines occur inside tlie fasciole (evidently judgino- from 

 Agassiz' statement in his description of tlie large form tliat within the peripetalous fasciole tlie 

 spines are longer, not clnbsliaped ); this does not hold good, at least in the speciniens before me. 

 De Meijere further finds a difference in the strncture of the spines of the two species, viz. tliat in 

 A. /ulva the widened point of the spines is serrate along the edge, whereas it is smooth in xi.roslrata 

 — founding on the fignre (PI. XIvI. 7 evidently) given by Agassiz. This character will not hold good 

 either; the widened part of the spine is (more or less) serrate at the edge also in .i. rostrata. — The 

 small spines and clavnlæ have an v:ampulla» ' at the point, as fonnd by de Meijere in ^-l. /ulva 

 (PI. XV. Fig. 43). — The sphæridiæ are slender, generally rather elongate; in the anterior ambulacra 

 tliey continue up to the fasciole, in the posterior to the anal area. 



Pedicellariæ. Only rostrate and tridentate pedicellariæ have been found. The rostrate pedi- 

 cellariæ (PI. XV. Figs. i, 13) have alniost straight, flat valves, witli the point rounded, not widened, 

 faintly serrate; neck very short; the stalk mav have a faint tmilled ring below. The head is ca. 0-5'"'" 

 in length; the strong brownish adductor muscles between the valves make these pedicellariæ rather 

 conspicuous. They mav occur very nnmerously over the whole test, or very sjjaringly. The tridentate 

 pedicellariæ (head up to i'""" in length) have simple, leafshaped valves, which join in almost their whole 

 length. In large speciniens the edges are bent somewhat inwardly in the lower part of the blade and 

 very irregularly serrate. The blade may be open down to the apophysis, or the edges may unite to 

 form a coverplate over the lower part; generally there is no meshwork in the blade, but in a speci- 

 men examined in the Museum of Yale College I found the larger tridentate pedicellariæ with a rather 

 richly developed meshwork (PI. XV. Fig. 2). The basal part is rather narrow; the edges may be some- 

 what serrate. The neck is short, the stalk without a <anilled:> ring below. They occur in all sizes from 

 quite small to ca. i""" length of head. (PI. XV. Figs. 8, 21, 29, 52.) Ouite small forms (PI. XV. Fig. 37) 

 may perhaps better be ternied triphyllous. According to a sketch of a living specimen made on board 

 the Ingolf the colour is light yellow, the fasciole alone being of a prominent brown colour. In some 

 speciniens seen in the Museum of Yale College the frontal tube-feet were violet. — 



This species was taken by the Ingolf, at the following stations: 



St. 36 (61° 50' Lat. N. 56" 21' Long. W. 1435 fathoiiis. i°5 C. Bottom tenip.) 3 speciniens. 

 -37 (60° 17' - 54° 05' - 1715 - i°4 - - )5 - 



The geographical distribution, as far as hitherto known, is the Northern Atlantic, at the Ame- 

 rican .side, and the Davis Strait; the bathymetrical distribution is 1240— 1750 fathoms. In the Chal- 

 lenger >-Report the species is stated to occur also in the Bay of Biscay and at the Coast of Portugal, 

 as also in the Arafura .Sea (Chall. St. 191. 800 fathoms). That the specimen from the latter locality is 

 wrongly referred to A. ros fra fa I have shown above. Regarding the locality «Bay of Biscay and Coast 

 of Portugal^ it may be remarked that in Summary of Results of the Challenger >-Expedition I. 

 p. 114 A. rostrata is naraed from St. 2, off the Mouth of the Tågus, 470 fathoms; but since the 

 specimens were without «distinctive» Station number, it seems not to be relied upon that the 



I I name it thus, as it is evidently a structure of the same kiiul as the < aiupulla > in the secondary spines of some 

 Cidarids, described by Hamann and Prouho. 



^ Duncan (Revision, p. 270) from this expression concludes that one specimen was taken in the Bay of Biscay, 

 later on another off the coast of Portugal, which there is nothing else to support. 



