A MONOGRAPH OF THE EXISTING CRINOIDS 231 



northeastern Ceylon (in reality off the southern coast of Ceylon), in 34 fathoms; off 

 Puri, in 10 fathoms; 1 mile east of the Terribles, in 13 fathoms; 2% miles southeast of 

 Santapillay lighthouse, in 7-8 fathoms; off the Ganjam coast, in 15-25 and also 8-16 

 fathoms; the Arrakan coast; and from Snod Island, Mergui Archipelago. I listed all 

 the localities from which the species was previously known, including the Tonga 

 Islands the specimens from which should have been referred to 0. caledoniae. I 

 wrote that when I was studying the crinoid collections belonging to the Zoological 

 Museum at Copenhagen I had been unable to identify a pretty little species of Oli- 

 gometra from Singapore which was abundantly represented therein with any species 

 previously known, and I therefore described it as new under the name Oligometra 

 pulchella, believing that the strongly rounded laterally flattened production of the 

 distal dorsal ends of the segments of the more or less styliform lower pinnules amply 

 served to distinguish it from 0. serripinna, in which the production of the distal ends 

 of the pinnule segments is sharp. I noted that the collections of the Indian Museum 

 contained 30 specimens resembling my 0. pulchella from Singapore, except that the 

 production of the pinnule segments is sharp. Accordingly I described the supposed 

 new form in manuscript as Oligometra concinna. 



Upon reviewing the subject more carefully I found that this was at best only an 

 average difference and that no definite line between 0. pulchella and 0. concinna 

 could be drawn; furthermore, neither of them appeared to be separable from 0. serri- 

 pinna as redescribed by Hartlaub in 1891. Hartlaub's description of 0. serripinna, 

 it should be noted, was based on specimens of 0. caledoniae from the Tonga Islands. 

 I said that it seemed advisable to relegate both Oligometra pulchella and 0. concinna 

 to the synonymy of 0. serripinna. Believing that a detailed description of typical 

 Indian specimens might be of interest for comparison with the form from Singapore 

 that I had called pulchella, I published my manuscript description of Oligometra 

 concinna, which was based mainly upon an example from Puri but was comprehensive 

 enough to include all the Indian specimens except that from the Pedro shoal, which 

 has slightly more numerous cirrus segments. I remarked that the specimen from the 

 Red Sea collected by the Electra in 20 fathoms which I had examined at the British 

 Museum represents an apparently well-marked variety that I had called electrae, 

 characterized by being exceptionally ornate, with extravagantly developed processes 

 on the proximal pinnules. In the synonymy of Oligometra serripinna I included 

 Antedon cupulifera (Liitken, MS.), which in reality refers to 0. caledoniae, Oligometra 

 pulchella, and Antedon carinata of Bell, 1894, under which name I had found a speci- 

 men from the Macclesfield Bank in the British Museum. In an appendix I recorded 

 and gave notes upon additional specimens from off Gopalpore in 25-28 and 30-38 

 fathoms. 



On August 8, 1913, I recorded a small specimen of Oligometra serripinna that 

 had been collected in San Bernardino Strait by Captain Suensson. Later in 1913 

 Dr. August Reichensperger recorded and gave notes on 5 specimens of Oligometra 

 serripinna from Nuhu Tawun, on the northern coast of Little Kei Island. 



In 1915 Dr. Hubert Lyman Clark listed Oligometra serripinna as one of the echino- 

 derms of Ceylon, referring as his authority to the author's memoir on the crinoids of 

 the Indian Ocean published in 1912. In the same year I discussed the range of this 

 species and its significance. 



