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The pars constituting the Eti group have absolute identity in fauna and in 

 physical characteristics. The rock of each par is fairly continuous in its outcrop with 

 much less sand sprinkled over it than in the case of the Tolayiram Par. To some 

 extent as a consequence of this the fauna is richer in the number of species, in the 

 number of individuals, and in luxuriance of growth. 



Sponges are especially abundant. Among the most characteristic are the black- 

 crested Spongionella nigra, one specimen of which was partly mantled with a thin 

 crust of crimson-lake Botrjlloid; purple-red Siphonochalina communis (Carter) bearing 

 frequently a like-tinted Antedon, clinging to its tubular branches ; the massive 

 Suierites inconstant and the oyster-crusting Clathria indica. 



Several of these sponges, notably Siphonoahalina and Suierites, furnish free 

 quarters to quite a host of diverse lodgers — chief among which are a colourless Alpheus, 

 a scarlet Porcellana, a small Cebia and a long armed spiny Ophiuroid (Ophiactis 

 savignii). The last named chiefly affects the large canals of the Sulsrites, more 

 rarely being found within Siphonochalina. Gelia burrows in the smaller canals of the 

 Suierites, while the Alpheus and Porcellana favour Sipho?iochali?ia much more than 

 they do Suierites, probably because their superior activity enjoys greater freedom in 

 the larger and less tortuous cavities of the former sponge. 



Corals and Gorgonoids are scarce, the handsome Juncella juncea being the only 

 conspicuous representative found. 



Specially characteristic are enormous numbers of the branched parchment-like 

 tubes of a fine Eunicid {E. tulifex, Crossland). The empty tubes were made known 

 to science years ago by Professor Mcintosh from material received from Dr. E. 

 Thurston, Superintendent of the Madras Museum, but it is only in the present year 

 (1904) that the animal has been described and named. Quite a host of smaller 

 creatures settle upon the surface of the tubes — hydroid zoophytes, polyzoa, and 

 compound ascidians, together with an occasional Lepas of a species not yet identified. 

 The last named is of interest in that in colour and outline its appearance approximates 

 so closely to a branch of the Eunicid tube that this may be regarded as a striking 

 case of mimicry or protective adaptation to environment. 



Colonial masses of the delicate calcareous tubes of Filograna were met with and 

 numerous species of the usual errant worms. 



Of Echinoderms, Ophiuroids, Antedon spp., and P. linchi were abundant. Many of 

 the Antedon appeared, as already noted, to be commensal (?) upon sponges and upon 

 Gorgonoids, while commensal in turn with Antedon I found Decapods and Ophiuroids — 

 the former consisting of a small striped crab and a striped Galatheid, the latter of a 

 small, short-armed black Ophiuroid upon an Antedon of the same hue. 



Small Cephalopods (Polypus spp.) were numerous ; polyzoa and tunicates were 

 universal. 



Occasional individuals of a large Pinna sp. were found lying prone on the rock 

 and much enveloped with sponge and tunicate growth, barnacles and the like ; some 

 bore pearl oysters of about one year old. 



To the west of the Eti group of pars a large chank-bed is marked. Here we 

 found rock to be practically absent with a corresponding absence of the faunistic 

 elements noted above. In their place were quantities of chanks (Turlinella rapa) and 

 of Pinna shells. The former were mostly small as is to be expected, this being a 

 recognised chank-bed and within easy reach of Tuticorin. Many of the Pinna were 

 dead shells ; these that were alive were, as is usual on sandy ground, embedded deeply 

 in the sand. Both dead and living bore quantities of large barnacles (Balanus sp.). 



The rock is of somewhat variable composition, varying from a compact brown 

 limestone, similar to that of the Tolayiram Par, to rock of a distinctly quartzose 

 nature ; the angular quartz grains were embedded in a brown calcareous matrix — a 

 quartzose limestone. The sand of the chank-bed is similar to the component material 

 of the par, but containing an appreciably greater amount of recognisable shell 

 fragments. 



After completion of the inspection of the Eti Par region, we proceeded south on 

 the afternoon of May 4th in the face of a stiff breeze and heavy sea, anchoring at 

 5 30 p.m. off Pinnaeoil in the shelter afforded by the reef off Kayalpattanam point. 



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