248 BULLETIN OF THE 



Of Ophiothrix rubra Ljn., there exists only a single specimen, from near 

 Lisbon, at Stockholm. The disk is 7 mm. in diameter, and is crisp, with 

 thorny stumps on it, as well as on the radial shields. Arm-spines stout and 

 thick. Without more material to judge from, I am not satisfied that this 

 differs from 0. lusitanica. Dr. Ljungman thinks it may be 0. ecJiinata. 



There are at Stockholm two specimens of Ophiothrix maculata Ljn., from 

 120 fathoms on the Josephine bank, near the coast of Portugal. They have 

 disks of 12 mm. diameter and somewhat resemble 0. penlaphyllum, but have 

 only seven arm-spines, and bear a reddish spot on each upper arm-plate. 

 The fewness of arm-spines is important, though I have seen an 0. quinque- 

 maculata with a disk of mm. that had no more. The red spots are not of 

 so much consequence, since 0. pentaphyllum is variously mottled in alcohol, 

 0. alopecurus has sometimes banded anus or spots on its radial shields, and 

 O. echinata occasionally carries a large live-sided patch on the back of the 

 disk. Dr. Ljungman considers it a well-defined species, and it should at least 

 be provisionally admitted on such excellent authority. 



Ophiothrix Liitkeni is a deep-sea form, dredged by Wyville Thomson in 374: 

 fathoms S.W. of Ireland. I examined the original at Copenhagen. It differs 

 from others of which 0. fragiiis is the type by having high rounded arms, 

 short, thin arm-spines, and minute spines on the upper arm-plates. The indi- 

 vidual was large, and, in its dried state, was light-colored with red mottlings. 



This completes the list; and it remains to consider its proper divisions. 

 Dr. Liitken* admits (1) a northern species, Asterias fragiiis Abgd., of 

 which he has specimens from Iceland, North Norway, Denmark, North Sea, 

 Spithead, and British Channel. With this he includes, as a variety, 0. penla- 

 phyllum ; and as a variety of the young, O. echinata Mull. & Trosch. from 

 Naples. (2) Ophiothrix quinquemaculata, also from Naples, the same which 

 has just been noticed. (3) Ophiothrix alopecurus (echinata Ltk.), from 

 Trieste, also noticed and illustrated above. (4) Ophiothrix Liitkeni, dredged 

 by Professor Thomson in 374 fathoms, off Ireland. On 0. lusitanica, maculata, 

 and rubra Dr. Liitken has no opinion to offer. In support of his view that 

 all the northern forms are one species, he says pertinently. '"That the animals 

 living in the North Sea should afford such differences — that one form should 

 belong to Scandinavia, the other to Britannica — is hardly credible. That 

 would be in opposition to all analogy from all other inhabitants of that sea, 

 which are of course the same on both sides." 



I have but one objection to this division: it is not possible to include 

 0. echinata as a variety of 0. fragiiis. An examination of the upper arm- 

 plates in two specimens of equal size will satisfy the observer that 0. echinata 

 is an adult, while an O. fragiiis of the same diameter is not even half grown. 



Dr Ljungman, who is naturally more inclined to see specific differences, 



* In a letter, December, 1S72. 



