Gymnohlastic Antkomedusoid and a Scorpcenoid Fish. 211 



On not one of these was the polyp of Minous inermis seen 

 though upon some specimens of a Leucosia crab I have since 

 found, in a condition too bad for accurate determination, 

 colonies of a Hydroid with a conspicuous perisarc continued 

 up to the tentacles, and with pedunculated sporosacs (?), that 

 may be a Bimeria^ or a Garveia, or perhaps Eadendrium 

 vestitum, AUman. 



Minous inermis was found a third time in a small but 

 valuable collection of fishes presented to the Indian Museum 

 by Mr. H. I. Row, a gentleman who has lately been attracted 

 to the still but little appreciated Indian sea-fisheries. In 

 January of this year Mr. Row dredged a single specimen, in 

 about 70 fathoms of water, somewhere between the delta of 

 the Ganges and that of the Mahtlnaddi, and along with it 

 numerous specimens of Minous coccineus, Lophius indicuSj 

 Trigla hemisticta, Schleg., Lepidotrighi spiloptera, Gthr.,and 

 Lobops Guentherij all of which undoubtedly share the habitat 

 of Minous inermis. Now, though no epizoon of any sort can 

 be found upon any of these fishes last named, yet the single 

 specimen of Minous inermis is coated with the same fleshy 

 polyp-colonies as were found upon this flsh on the two 

 previous occasions of its capture. 



It may be stated in anticipation that in the January speci- 

 men the reproductive elements of the colony are particularly 

 well and extensively developed, and that there is now good 

 evidence that the Hydroid is not Podocoryne, as was supposed 

 at first, but a Stylactis of a species that seems to be unde- 

 scribed. In the sequel it is described as Stylactis minoi. 



From the foregoing accounts it will, I think, be admitted 

 that we have proved the existence of a definite symbiosis 

 between the polyp and the fish. Accident will hardly account 

 for the facts, (1) that we never find the Minous without the 

 Stylactis or the Stylactis without the Minous ; (2) that in 

 two instances where two species of the genus occur together 

 the polyp selects Minous inermis ; and (3) that the associa- 

 tion holds good for the northern half of the Bay of Bengal, 

 for the southern half of the Bay of Bengal, and for the 

 Laccadive or Malabar Sea. 



The next question to be decided is, Is the symbiosis para- 

 sitic or commensal ? 



On general principles it is hardly justifiable to infer that 

 an animal is a parasite unless it presents some evidences of 

 degeneration, at any rate of some of the organs of nutrition. 

 Stylactis minoi, however, is fully equipped for self-main- 

 tenance, the nutritive hydranths having a prominent hypo- 



