306 NOTE ON TWO SPECIES OF CUCUMAIUA I'lfOM PLYMOUTH. 



of the Devonshire Ciuuiiiiuiaii, Imt Montagu's actual form is probably 

 the one that is described as Holothuria pcntadcs in the Historif uj 

 Bvitish Animals. 



Fleming's name appears to have dropped into almost complete disuse 

 until revived by Dr. A. M. Norman (5). Norman, however, overlooked 

 the fact that Fleming was not dealing with the same species as 

 Montagu ; and in addition, he has failed to realise that there are 

 two species of Cucuinaria of somewhat similar outward appearance 

 living upon the South Devon coast. Norman's CHCuiiinria Montayui 

 is, in fact, a complex, and it is mainly as the result of this that sub- 

 sequent authors have experienced so much difliculty in reconciling 

 their ideas as to the identity of C. Montagui. 



Before proceeding further, it will, perhaps, be most convenient to 

 say something regarding the characters and habits of the two Cucu- 

 marians in question, and to call attention to the more important points 

 of difference between them. 



During life it is an easy matter to Separate the two forms ; and from 

 quite an early date in the history of the Plymouth Laboratory they 

 have there been recognised as distinct species. At Plymouth, for some 

 years past, these species have been recorded and distributed as " C. 

 pentactes," and " C. Planci,'' the one known by the latter name being 

 the one figured by Montagu. However, neither of these names can be 

 retained. Linnfeus' Holothuria ijentactes is now generally regarded as 

 being an indeterminate* species; and, whether Brandt's name Planci 

 be eligible for the common Mediterranean species or not, it certainly 

 cannot be applied to the very different species from Plymouth. For 

 the moment, it will perhaps simplify matters if we refer to Montagu's 

 " Ilolof/mrui peiitacte.% var.," as CuciDiiaria sp. 1 and to the second 

 Plymouth form as Cucumaria sjj. 2. 



Both of these species of Cucumaria, sjj. 1 and sj). 2, are fairly common 

 in the neighbourhood of Plymouth Sound, being found under stones and 

 in crevices on rocky ground from low-water mark down to a depth 

 of a few fathoms. S/k 2 is perhaps the more frequently met with, and 

 it appears, also, to live in somewhat deeper water. 



There are no very great points of difference in the ouhvard form 

 of the two species, which are also of much the same size ; but sp. 1 

 is rather shorter and of less even calibre than sp. 2, and it has the 

 posterior extremity more tapering. I'he j^dia in sj). 1 are numerous, 

 appearing as though disposed in two })arallel rows in each ambulacrum ; 



* Absolutely no useful purpose is served by guessing as to wbat an author had before 

 liim when founding a species. Unless, in tlie case of an insufficiently described species, 

 the type-specimen is available, it is far better to entirely discard the name in question 

 rather than to accept the interpretation of a subsequent author. The latter course 

 is a fruitful source of error, for it is seldom possible to say delinitely which later writer 

 is the one to be followed. 



