106 OKHAMANDAL MARINE ZOOLOGY REPORT 



Polyonyx ohesulus (White). 

 Polyonyx hendersoni, n. sp. 

 Petrolisthes armatus (Gibbes). 

 Petrolisthes bosci (Andouin). 

 Petrolisthes, sp. 

 Galathea elegans, White. 

 Munida spinulifera, Miers. 



All these species are shallow-water forms, and in most cases were taken in 

 under four fathoms. 



With the exception of Porcellana tuberculosa, and the two new species, 

 all the forms herein described have previously been recorded from the Indian 

 Ocean. Both the new species included in this paper, viz., Polyonyx hendersoni 

 and Porcellana gaehwari were collected by me from the Ceylon Pearl Banks. 



A noticeable feature of the collection from the Gulf of Kutch is the preponderance 

 of Galatheidse over the Paguridse, both in point of species and numbers. This 

 fact is to be correlated with the peculiar nature of the fauna on the ground 

 where the collection was made. The commensal habits of many genera included 

 in this family are well known. Generally, Galatheids and Munidids are to be found 

 crawling over the surface of dead coral, or under rocks, or upon living coral, but 

 the more brightly coloured representatives of the former genera — such as Galathea 

 elegans and Galathea deflexifrons — are more commonly to be found commensal with 

 similarly coloured species of Comatulids. 



On the other hand, the members of the genera Polyonyx find a home in the 

 large exhalant cavities of niany species of sponge, and they are but rarely found 

 elsewhere. The species of Porcellana proper are likewise more or less commensal. 

 Their commonest habitat is amongst the short stumpy branches of diflferent species 

 of Spongodes, many having pink or dark purple tips, and the colour markings of 

 the Porcellanids commensal thereon agree with those of the partner so well that 

 they are often difficult to see. 



The Kutch collection was made on ground rich beyond description in corals, 

 sponges, crinoids, and such alcyonarians as Spongodes, and it is therefore natural 

 to find a predominance of such forms as usually occur in such a habitat. 



The classification of the Galatheidas adopted in this paper is the one adopted 

 in the Eeport on the Challenger Anomura, and the definitions of the genera 

 here given are also those therein given by Henderson. In the group Paguridea, 

 however, the classification adopted and the characters given are those given by 

 Alcock in his Indian Decapod Crustacea. In some instances I have had difficulty 

 in satisfactorily referring some of the Kutch genera to their proper place. Especially 

 was this the case in the family Porcellanidse, and it would appear that, with our 

 extended knowledge of this group, a more suitable and precise method of classification 



