132 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



Milne Edwards and Haime proposed Pachyseris valenciennesi for Dana's rugosa, con- 

 sidering it a different species from the one named by Lamarck. Verrill 1 proposed 

 the name monticulosa for the same species. Quelch considered the P. speciosa of 

 Milne Edwards and Haime different from Dana's, and proposed P. haimei 2 for it. 

 Therefore the following species are supposed to be recognizable: P. rugosa (Lam.), 

 P. speciosa (Dana), P. levicollis (Dana), P. valenciennesi M. Edw. and H. { = P. mon- 

 ticulosa Verrill), P. involuta Studer, 3 and P. haimei Quelch, and I am here adding a 

 species, P. torresiana, from Torres Strait. 



Distribution. — East Indies (Dana); Murray Island; Tahiti (Quelch). 



Pachyseris torresiana, new species. 

 Plate 55, figures I, \a. 

 The following is a description of the type specimen of Pachyseris torresiana: 



Basal part of the corallum an undulating plate, with irregularly sinuous margins, 19 cm. 

 in diameter and up to 18 mm. thick. Thickness on the edge 0.75 to 1.5 mm. No area of 

 attachment shows on the type, but it was probably attached on the side now broken. The 

 lower surface shows no perforations, there are fine costae alternating in size, and although in 

 general naked, apparently in places there are a few epithecal threads. 



On the upper surface there are undulating areas on which are long, rather straight or 

 sinuous collines, and tall flabellate crests, on which are collines similar to those on the less- 

 elevated part of the corallum. Two crests may fuse by their edges. Height of the crests 

 up to 95 mm.; width of single crests up to 40 mm.; width of two crests fused into one, 50 

 mm. or more. The maximum width of a crest, when fully developed, is approximately 

 twice that near its base. Thickness of crests just below the edge, about 1.5 mm.; just 

 above the base, about 15 mm. 



Width of valleys, between top of adjacent collines, from 1.75 mm. to 3.5 mm., 2.5 to 3 

 mm. usual. Collines. height 2.5 mm.; profile triangular, with the apex slightly blunted. 



Septa continuous across collines, equal, crowded, 18 to 19 within 5 millimeters, occasion- 

 ally slightly kneed on the colline summit. Sides densely beset with blunt granulations. 



Columella a distinct longitudinal lamella, except near the growing edge. It is formed of 

 septal processes developed along the axis of the valley floor. 



Type: U. S. National Museum. 



Locality. — Torres Strait, Australia. 



This is so strikingly different from any of the other species that critical com- 

 parison is scarcely necessary. None of the others known to me has its high, more 

 or less spatulate crests or its lamelliform columella. 



Genus PAVONA Lamarck. 

 1801. Pavona Lamarck, Syst. Anim. sans. Vert., p. 372. 



Typespecies: Pavona cristata Lamarck = Madrepora cristata Ellis and Solander = 

 Lophoseris knorri Milne Edwards and Haime = Pavona for?nosa Dana = Pavona 

 cactus (Forskal). 



According to Klunzinger, 4 Madrepora cristata Ell. and Sol. = Madrepora cactus 

 Forsk., while he describes the Lophoseris cristata of Milne Edwards and Haime as 

 Pavonia angularis Klz. It therefore seems that the name cristata has been applied 

 to two species which now bear the names P. cactus (Forsk.), and P. danai (M. 

 Edw. and H.). 



I believe P. knorri, evidently based on Knorr's plate AX, figure 1, the same as 

 Dana's P. formosa, which, judging from the figures published by Klunzinger and 



'Dana, Coral and Coral Islands, p. 383, 1872. 



2 Reef corals, Challenger Reports, p. 124. 



3 K6ngl. Akad. Wissensch. Berlin, Monatschr. fur 1877, p. 644, pi. 3, fig. II. 



4 Korall. Roth. Meer., pt. 3, pp. 73, 74, 1879. 



