UNIVERSITY 



OF 



KCHINOIDEA. II. 37 



porus. The apical system differs from that of grandiporus in the ocular pores being much smaller than 

 the genital pores as is the case in pusillus. The madreporic plate is generally larger than in grandi- 

 poms, otherwise it is elevated as in that species and thej]genital pores are likewise covered with long 

 genital papillse. Also in this species I have seen one specimen with 5 distinct genital pores. The pe- 

 tals are very slightly developed, even scarcely so much as in grandiporus, as seen by the following 

 table. The genital pores I find developed in the specimen of 4 mm , while in that of 4-2" they have 

 not yet appeared and in the specimen of 4 4 8 min (the one figured) only the anterior pair is developed. 



As regards the arrangement of the actinal pores, the tuberculation, the structure of pedicellariae 

 and spines as well as the internal structure of the test I do not find any reliable differences from grandi- 

 porus. (PI. XII. Figs. 2 and 7 represent an ophicephalous and a triphyllous pedicellaria of this species.) 



The colour of the living animal is, according to the sketch made on board the Valdivia, 

 green; there are ten darker radiating bands, answering to the bands of tube-feet, the intermediate 

 spaces having a slight yellowish tint; around the peristome there is a darker pentagon, radiating a 



little into the ambulacra. 



Number of pairs of pores in Echino- 



To this species belongs the specimen referred to Echinocya- cyamus macrostomus. 



HI us piisi/li/s from the German Deep-Sea Expedition, St. 37, 1694 m. S i 2e A pai r llrSS f nM 



Petals Petals 



(off Cape Verde. Doderlein op. cit. p. 234), and the two specimens _. , nm 2 t _ 2 ,_ 4 



from the Travailleur 2100111., which I received from the Paris- 7 '4 2 ~ 3 3 



7'2 - I 2 I 2 1 2 



Museum. Further, among the specimens sent me by Professor i_ 2 12 23 



Koehler two specimens from 37 54' Lat. N. 27 3' Long. W. 2178 m. 



O I I 2 2 ^ 



(off the Azores), three specimens (the Azores, 1360 m.), one living speci- 5 i 12 2 



men and some dead tests from 32 Lat. N. 16 Long.W. 2286 m., and one g 



specimen from 39 Lat. N. 32 Long.W. 1600 in. belong to this species. - 4 - 2 - o i i 



4 - o i o i i 2 



The species is then evidently a more abyssal species than grandiporus. 



I have been in considerable doubt as to whether this form ought to be established as a sepa- 

 rate species or not. It is beyond doubt that it is very closely related to Ech. grandiporus, from which 

 species it is distinguished only by the small size of the ocular pores and the large size of the peri- 

 stome, other small differences being too inconstant to be relied upon as specific characters. The 

 two features pointed out are, however, so conspicuous and so far as my experience goes constant, 

 that it seems quite necessary to keep this form separate, as the bathymetrical distribution seems also 

 to indicate its specific difference from grandiporus. Otherwise it is evidently of no great importance 

 whether it is regarded as a variety only of the latter species or as a separate species ; the main thing 

 is that it should not be merely confounded with the typical grandiporus -- not to mention pusillus 

 with which it was hitherto confounded, but to which it is not so nearly related. 



Perhaps yet another species of Echitwcyamus will prove to occur in the Atlantic. Among the 

 specimens from the Josephina> and among those from the Azores sent me by Professor Koehler 

 there are a few small specimens, which look rather different from the other species. They agree with 

 pusillus in the shape of the test, the small size of the ocular pores and in the petals. But the pri- 

 mary tubercles are larger than is generally the case in pusillus. and the scrobicular area is more 

 deepened. Further, it may be noticed that the tubercle is placed excentrically at the anterior side of 



