672 RKPOUT — 1881. 



pletely retained tlirougli life, has confirmed and extended this view. In these recent 

 forms the oral plates separate from one another, as they do in the later stages of 

 the pentacrinoid larva of the feather-star, and the peristome is laid open to the 

 exterior. But in many Palseocrinoids the peristome was covered in throughout 

 life either hy a pyramid of oral plates, or by a ' vault ' of greater or less com- 

 plexity. . . 1 , . . . 



De Loriol has recently described a small Jurassic Ormoid — Thiolbericnnus — in 

 which the top stem joint enlarges and bears cirrhi, just as in Comc.tida ; but it 

 retains its connection with the stem below it, instead of becoming free, and_ the 

 basals do not entirely disappear from tlie exterior of the calyx. Thiollicricrinus, 

 therefore, is permanently in the condition of a tolerably advanced pentacrinoid 

 larva of the feather-star. 



Among the Comatulce dredged by the Challe^iger and by the United States 

 Coast SuiTey are three species of a new genus which the author proposes to call 

 Atcleerinus. Two species were obtained in the Caribbean Sea, and the third in 

 the South Pacific. The distinctive characters of the genus are (1) the persistence 

 of the embryonic basals, which do not undergo metamorphosis into a rosette, but 

 remain as a closed circlet, entirely separating the radials fromthe centro-dorsal ; 

 (2) the absence of pinnules from about the first eleven arm-joints. With the 

 e.xception of the doubtful genus Comaster, no recent Comatida yet known retains 

 its embryonic basals on the exterior of the calyx, after the latter part of its exist- 

 ence as a ' Pentacrinoid ; ' while there is no Comatida hitherto lmo\^Ti, eitlier 

 recent or fossil, in which the basal circlet is complete, as it is in some Pentacrinus 

 species, and in the earlier stages of the Pentacrinoid. As regards the characters 

 of its calyx, therefore, Atelecrinm may be considered as a permanent larval form. 

 Tiie absence of pimiules from the basal portions of the arms pomts to the same 

 conclusion. The author has met with five Co?««<M/rt-species which agree with 

 AnL rosacea in not developing pinnules upon the lower arm-joints until after the 

 appearance of cirrhi upon the centro-dorsal and its liberation from the rest of the 

 lar^■al stem ; but Atelecrinus appears to be permanently in this condition. It ex- 

 hibits no traces, however, of persistent oral plates. 



3. Note on the British Comatute. By P. Herbert Carpenter, M.A. 



Some vears a^o Barrett dredged a Comatula on the coast of Skye, to which he 

 wave the specific name celtica. His specimens were lost for a time, and though 

 others were obtained from the same locality by H.M.S. Forcupine, there has been 

 a little uncertainty, especially among Continental zoologists, as to the true cha- 

 racters of the species. Pvecently, however, one of Barrett's original specimens has 

 }ieen discovered at the British Museum, and it turns out to be identical, as do the 

 Porcupine specimens, with the rare Antedon phalangium of the Mediterranean. 

 This species, however, is not known to occur at any intermediate localities betwei'U 

 Skye and tlie Mediterranean. Neither lias it been obtained further north than 

 the Faroe Channel. The Antedon celtica, described by Von Marenzeller and 

 Sladen from the Arctic Ocean, is an entirely ditterent species, and is the one to 

 which this name will have to be applied in future; Miiller's name, ;;//r/to?r/ /«/;;, 

 havino- a priority of several years OAer celtica, Barrett. Besides Ant. phahnif/ium 

 and Ant. Sarsii, which has been obtained in the Shetlands, there are, perhaps, 

 two other Comatulce which are known on our coasts. One is the common Ant. 

 rosacea which is universally distributed, and • the other la Ant. Midleri, vih\c\\ is 

 distinguished fnmi Ant. rosacea, according to Sir Wyvilh Thomson, by the greater 

 leno-th of the ovaries, and a ditferencc' in the relative proportions of tlie lower 

 pinnules. This type has been obtained at Arran, Oban, Belfast, and elsewhere, 

 and it is the one which seems to be the most common in the Jlediterranean. 

 Whetlier, however, it is really distinct from Ant. rosacea is a point for further 

 investigation. 



